IMPERIAL INSTITUTE APHS ON. MINERAL RESOURCES L REFERENCE TO THE BRITISH EMPIRE LED UNDER THE DIRECTION OF THE MINERAL RESOURCES COMMITTEE OF THE IMPERIAL INSTITUTE, WITH THE ASSISTANCE OF THE SCIENTIFIC AND TECHNICAL STAFF MANGANESE ORES A. H. CURTIS, B.A. (LOND.), F.G.S. Assoc.M.lNsT.C.E., M.Ixsr.M.M. (Specially attached during the War to the Staff of the Imperial Institute) LONDON JOHN MURRAY; ALBEMARLE STREET, w 1919 ^mmm^*m^mmm**m*m*mm*m^v^N*mm*t Price 3s. *6d. net IMPERIAL INSTITUTE MONOGRAPHS ON MINERAL RESOURCES WITH SPECIAL REFERENCE TO THE BRITISH EMPIRE IMPERIAL INSTITUTE MONOGRAPHS ON MINERAL RESOURCES WITH SPECIAL REFERENCE TO THE BRITISH EMPIRE Prepared under the direction of the Mineral Resources Committee of the Imperial Institute MANGANESE ORES. By A. H. CURTIS, B. A. (Lond.), M.I.M.M., Assoc.M.Inst.C.E., F.G.S. Demy 8vo. 3s. 6d. net. TIN ORES. By G. M. DA VIES, M.Sc. (Lond.), F.G.S., Scientific and Technical Department, Imperial Institute. Demy 8vo. 3s. 6d. net. TUNGSTEN ORES. By R. H. RASTALL, M.A., F.G.S., and W. H. WILCOCKSON, M.A., F.G.S. Demy 8vo. 3s. 6d. net. IP IMPERIAL INSTITUTE MONOGRAPHS ON MINERAL RESOURCES WITH SPECIAL REFERENCE TO THE BRITISH EMPIRE PREPARED UNDER THE DIRECTION OF THE MINERAL RESOURCES COMMITTEE OF THE IMPERIAL INSTITUTE, WITH THE ASSISTANCE OF THE SCIENTIFIC 'AND TECHNICAL STAFF MANGANESE ORES BY A. H. CURTIS, B.A. (LOND.), F.G.S. Assoc.M.lNST.C.E., M. INST. M.M. (Specially attached during the War to the Staff of the Imperial Institute) LONDON JOHN MURRAY, ALBEMARLE STREET, W. 1919 . ALL RIGHTS RESERVED IMPERIAL INSTITUTE Director : Professor WYNDHAM DUNSTAN, C.M.G., LL.D., F.R.S. Scientific and Technical Research Department and Technical Information Bureau Superintendents: T. A. HENRY, D.Sc. (Lond.), F.C.S. ; H. BROWN ; E. GOULDING, D.Sc. (Lond.), F.I.C. Assistant Superintendents : T. CROOK, A.R.C.Sc., F.G.S. ; R. G. PELLY, F.I.C. Principal Assistant: S. J. JOHNSTONS, B.Sc. (Lond.), A.I.C. Public Exhibition Galleries. Colonial and Indian Collections Senior Technical Superintendent : S. E. CHANDLER, D.Sc. (Lond.), A.R.C.Sc., F.L.S. Other Members of the Scientific and Technical Staff of the Institute A. E. ANDREWS, F.C.S. Miss H. BENNETT, B.Sc. (Lond.). L. L. BLACKNELL. F. BOULTON. G. T. BRAY, A-.I.C. W. S. DAVEY. G. M. DAVIES, M.Sc. (Lond.), F.G.S. F. L. ELLIOTT. A. T. FAIRCLOTH. F. FERRABOSCHI, M.A. (Cantab.), A.I.C. , F.C.S. J. R. FURLONG, Ph.D. (Wiirz- burg),A.I.C. Miss R. C. GROVES, M.Sc. (Birm.), A.I.C. A. B. JACKSON, A.L.S. H. J. JEFFERY, A.R.C.Sc., F.L.S. B. E. LONG, B.A. (Cantab.). A. D. LUMB, A.R.S.M., F.G.S. T. MCLACHLAN, A.I.C. F. MAJOR, B.Sc. (Lond.). G. L. MATTHEWS, B.Sc. (Lond.), A.I.C. E. C. MOORE. Miss A. C. S. PALMER. O. D. ROBERTS, F.I.C. S. J. ROGERS, B.Sc. (Lond.), A.I.C. F. W. ROLFE. W. G. RUMBOLD. H. SPOONER. J.D.F. WEST, A.I.C. B. W. WHITFEILD. W. O. R. WYNN, A.I.C. r *>^ fry 448394 IMPERIAL INSTITUTE Advisory Committee on Mineral Resources 1919 The Right Hon. the VISCOUNT HARCOURT, D.C.L. (Chairman). *Admiral SIR EDMOND SLADE, K.C.V.O., K.C.I. E. (nominated by the Admiralty), Vice-Chairman. EDMUND DAVIS, Esq. *Professor WYNDHAM DUNSTAN, C.M.G., LL.D., F.R.S., Director of the Imperial Institute. W. J. GLENNY, Esq., Department of Overseas Trade (nominated by the Board of Trade). *Professor J. W. GREGORY, F.R.S., Professor of Geology in the University of Glasgow, formerly Director of the Geological Survey of Victoria, Australia. Sir ROBERT HADFIELD, Bart., lately President of the Iron and Steel Institute. *Dr. F. H. HATCH, Consulting Mining Engineer, formerly President of the Institution of Mining and Metallurgy. Major VAUGHAN MORGAN, Intelligence Department, War Office (nominated by the War Office). W. W. MOYERS, Esq. Dr. T. A. HENRY, Secretary. Major A. D. LUMB, A.R.S.M., F.G.S, Acting Secretary. * Members of the Editorial Sub-Committee. PREFACE THE Mineral Resources Committee of the Imperial Institute has arranged to issue this series of Monographs on Mineral Resources in amplification and extension of those which have appeared in the Bulletin of the Imperial Institute during the past fifteen years. The Monographs are prepared either by members of the Scientific and Technical Staff of the Imperial Institute, or by external contributors, to whom have been available the statistics and other special information relating to mineral resources collected and arranged at the Imperial Institute. The object of these Monographs is to give a general account of the occurrences and commercial utilisation of the more important minerals particularly in the British Empire. No attempt has been made to give details of mining or metallurgical processes. HARCOURT, Chairman, Mineral Resources Committee. June 1919. vii CONTENTS CHAPTER I PAGE MANGANESE ORES : THEIR OCCURRENCE, CHARACTER, AND USES ... . i CHAPTER II SOURCES OF SUPPLY OF MANGANESE ORES (a) BRITISH EMPIRE : Europe : United Kingdom .... 23 Asia : British North Borneo ; Federated Malay States ; India ...... 32 Africa : Egypt (Sinai Peninsula) ; Cape Province ; Natal; St. Helena; Gold Coast; British East Africa 48 America : Canada ; Newfoundland ... 58 Australasia: New South Wales; Queensland; South Australia ; Tasmania ; Victoria ; New Zealand 64 ix x CONTENTS CHAPTER III PACE SOURCES OF SUPPLY OF MANGANESE ORES (continued) (b) FOREIGN COUNTRIES : Europe : Austria-Hungary ; Belgium ; Bulgaria ; France ; Germany ; Greece ; Italy ; Por- tugal ; Russia ; Spain ; Sweden ; Turkey . 69 Asia: Japan; Java; Philippines; Portuguese India 82 Africa : Belgian Congo ; " German " East Africa 85 America : (North, Central and South). United States ; Colombia and Panama ; Costa Rica ; Cuba; Hayti ; Brazil; Chile ... 85 REFERENCES TO LITERATURE ON MANGANESE 112 Note. Numerals in square brackets in the text rtiet tc/lkt Bibliography" at "the end. |p MANGANESE ORES CHAPTER I MANGANESE ORES: THEIR OCCURRENCE, CHARACTER AND USES THE importance of manganese in the manufacture of iron and steel is continuously increasing ; stricter demands as regards the chemical and physical qualities of manganese ores are being made, not only by metallurgists but also by those using such minerals in chemical industries ; the necessity for an increased production of high-grade manganese ore has become urgent, and new sources of supply are required. The effect of the war has been to increase the demand for iron-manganese alloys (more particularly for ferro-manganese, the consumption of which has grown largely in recent years), and at the same time to cut off or seriously curtail supplies of the ores necessary for their production. Ores of the metal are widely distributed, but there are only a few countries in which important deposits are known. Of these the principal are Russia (Caucasus), Southern and Central India, and East-Central Brazil, which have hitherto furnished practically the whole of the world's supplies of manganese-ore, properly so called. Among other countries which have already produced manganese-ore, or which are known to contain deposits of some prospective commercial value, the following may be mentioned : Austria-Hungary, France, Germany, Greece, Italy, Spain ; West Africa (Gold Coast), Egypt (Sinai Peninsula) ; Canada, the United States of America, Mexico, Nicaragua, Costa Rica, Colombia, Cuba, Chile ; Queensland. The leading producer of manganese ore before the war was Russia, followed closely by India, Brazil coming third. Owing to the closing of the Dardanelles and of the Russo- 2 ' MANGANESE ORES German -frontier; and to the disturbed conditions still pre- vailing, the Russian producers have temporarily lost their foreign markets. Prior to the war, Germany was the largest buyer of the high-grade Caucasian ore, the United Kingdom, Belgium and the United States coming next, in order of importance. The chief sufferer among the steel- making countries has been the United States, where the situation of the industry has admittedly been serious, owing to the cutting-off of Russian supplies and the deficiency in shipments from India. The shortage arising from these conditions was more particularly felt in 1914 and 1915, when the imports of manganese-ore from Brazil, although con- siderably increased, were not sufficient to meet the demands of the United States. In 1916, however, the export of ore from Brazil was increased nearly two-fold over that of 1914 ; and, as most of this was absorbed by the United States, it is to be inferred that the situation in that country has been considerably relieved, although prices there are still much higher than before the war. Not only is the United States dependent upon foreign countries for its supplies of manganese ore proper, the domestic production of which is even at the present time almost negligible, having regard to the enormous requirements, but large quantities of iron manganese alloys had to be imported in pre-war times, chiefly from the United Kingdom, and to a much smaller extent from Germany and other European countries, in order to supplement the domestic production of such alloys. The war has naturally had an adverse effect on the export of ferro-manganese from the United Kingdom. But for the deposits, in New Jersey, of the complex mineral known as franklinite (primarily a zinc ore from which man- ganese is obtained as a by-product), and of certain mangani- ferous iron ores of which the annual production has for some years averaged well over 500,000 tons (the Lake Superior region furnishing considerably over 90 per cent, of this output), the steel-making industry of the United States would be almost entirely dependent on extraneous sources of manganese. The Brazilian manganese ores, for which the United States has hitherto been the best customer, are estimated to be WORLD'S PRODUCTION 3 sufficient to supply the world's requirements for several centuries ; but the large development of the manganese industry in that country has been greatly obstructed by the distance of the deposits from the coast, difficulties and cost of transport, etc. During the three years immediately pre- ceding the war, the exports of Brazilian manganese-ore fell, and the present revived state of the industry, due to the acci- dental requirements of the United States, may or may not be a criterion for peace times in the future. However, as the figures for and since 1916 show, the Brazilian exports are capable of important increase in the event of a permanent improvement in prices. Russia also should be able to increase her output. It must therefore be expected that India will have to face strong competition with both Brazil and Russia when industrial conditions become more settled. The Russian (Caucasus) ore contains from 52 to 56 per cent, of manganese, the Brazilian from 49 to 54 per cent., averaging about 53 per cent., and the Indian from about 45 to 55 per cent., averaging possibly from 50 to 52 per cent. In general, shipments to Europe vary from as low as 37 per cent, to as high as 55 per cent, of manganese. Cargoes to Great Britain (which include Spanish manganiferous iron ore and small tonnages of ore from other minor sources of supply, in addition to the main supplies from the three chief producing countries) average probably nearly 50 per cent, of manganese. British and other European manufacturers of ferro-manganese find it advantageous to draw their ores from various sources in order to obtain certain mixtures. The British-Indian production of manganese ores ranked, as regards quantity, second only to that of Russia during the years immediately preceding the war. India, indeed, occupied the position of leading producer for the four years 1908-11, notwithstanding the fact that production of manganese-ore began in Russia so long ago as 1879, while the Indian industry was started fourteen years later and the rich deposits in the Central Provinces were not discovered until 1899. This remarkable result is attributable in large measure to superior organisation, stricter control, more suitable mining methods, lower railway freights and more adequate rolling-stock than 4 MANGANESE ORES have hitherto characterized manganese ore production in Southern Russia. But for the handicaps already mentioned, Brazil might several years ago have become a more serious competitor with British India in European manganese markets ; and, indeed, if there should be any further settled improvement in prices, the revival in the Brazilian industry, due to the requirements of the United States, may well prove to be more than a passing phase of its history. The production of manganese ore in the United Kingdom, which has only in one year exceeded 20,000 tons, is now almost negligible ; and, although the deposits are not yet exhausted, there is little or no prospect of our domestic production ever becoming important, even if prices should considerably advance. Not only are the deposits small, but the ore which they contain is of low grade. Among the most promising discoveries of manganiferous minerals in quite recent years are those which have been made in the west-central portion of the Sinai Peninsula. The existence of manganiferous areas in this part of Egypt was discovered in 1898, but it was not until 1913 that any deposits had been demonstrated to be of economic importance. Pre- parations for the exploitation of certain areas were com- menced in that year, and railway communication with the Gulf of Suez has since been established. The deposits are of considerable thickness, and extend over large areas ; but they appear to consist chiefly of manganiferous iron ore ; and it would seem premature to hazard an estimate of the average composition of the ore they are likely to yield. What appears to be an important deposit of high-grade manganese ore was discovered in 1915 about 75 miles west of Port Augusta, in South Australia. Should the results of the early exploratory work be confirmed by mining on a com- mercial scale, the present limited requirements of the whole Australian market might easily be met from this one source of supply, and there should be a substantial surplus for export. A promising discovery of high-grade manganese ore was made in 1914 at Dagwin, in the Wassaw district of the Gold Coast Colony, West Africa, and the deposit, which is situated WORLD'S PRODUCTION 5 quite close to the Government railway from the port of Sekondi, some thirty miles distant, is now being exploited. Particulars of this deposit are given later. The Canadian manganese ore industry has been checked in development by the insignificant domestic demand for the high-grade pyrolusite, of which the known deposits largely consist, the annual consumption in the home chemical industries being only about 20 tons ; while the absence of good transport facilities has rendered it more profitable to import ore of lower grade than to put high-grade. Canadian ore on the market. Deposits of low-grade manganese ore are stated to occur on the south side of Conception Bay and elsewhere in New- foundland. While it is permissible to suggest that prospecting in other parts of the British Empire may lead to important discoveries of manganese ore, it must be admitted that, in the majority of instances where promising deposits in our Dominions and Colonies have been reported, these have proved to be of only small economic importance. It is nevertheless hoped that the information contained in this monograph may be of practical value to companies concerned with the exploration of mineral concessions in British territory, to individual prospectors, and to users of manganese-ore throughout the Empire, especially manufacturers of iron and steel. World's Production of Manganijerous Iron Ores and Manganiferous Zinc Ores (1909-1915) (Long Tons) Year. Manganiferous Iron-Ore. United States.3 Germany. 1, 3 Greece. 3 Italy. Manganiferous Iron-Ore. Manganiferous Zinc-Ore. 1909 1910 1911 1912 1913 1914 1915 75.937 79,264 85,894 90,988 325,481 t 54,043 49,2H 23,664 14,081 t * 25,415 25,287 6,378 Nil 2 t t 843,689 619,735 522,357 868,501 672,146 445,827 801,290 141,264 137,173 109,296 104,670 102,239 100,198 159,318 1 Includes a certain amount of true manganese ore. a Figures not available. 3 Statistics from compilations by 17. S. Geol. Surv. and The Mineral Industry, excepting those for Greece and Italy, which are as in Rec. Geol. Surv. Ind., 46 (1915)- In 1916, the production of manganiferous iron ore in the United States was 548,803 tons, that for 1917 being 1,050,000 tons. MANGANESE ORES I -. I I nion o South Africa. Aus H "> 1 1 1 I 1 1 . 1 1 1 00 M 10 - O O >> M^ vq^ oo o< oo "* OO ^ O M O4 O *O O O 1>-OO v) rj- co O co O 04 o" >O O^ O O 00 VO 'J-VO U"> ?8 1 I I | | | I t^ N & O\ JT^ 04 00 f O CO M -rfOO POOO 00 o o 10 10 co co rC oo t^-oo N O O O O t^O M Tj-t^lOO O TJ- O coo *- ^- co N w M & O M IO t^ O^ M OO Ti- OJ CTl Tj- Tf O 04 t>. IO O IT) rj-" 00 O 00 M 04 00 O\ rJ-O oo O^ >o t^ co cooo o t-^ co O^ M Tt" COO M M Tf Tt-00 C^. Tl-00 >-^ to o -^- o ^ ^ O JZ 04 > f-00 M OO w 04 co Tj- ovo 4 O "C S G *j*tlis"ss 4-* rt r-i w > 5 I Cft D III 'S ^j o O-5 ^PQ^ "^ T3 Sl42'aS. 'S-S'S tj^t^^'S-M -Mrt000 //00000 /OOO f OOO 900,000 70OOOO 00,000 so q ooo <4OO t OOO 300,000 2OOOOO /ooooo DIAGRAM I. OUTPUT OF MANGANESE ORE BY THE THREE CHIEF PRODUCING COUNTRIES (INDIA, RUSSIA AND BRAZIL) 1909-1917. 2 7 8 MANGANESE ORES According to the practice by which all manganiferous ores containing less than 40 per cent, of manganese are classified as manganiferous iron ores rather than as manganese ore, a certain very small proportion of the Indian production should be classed under that heading. Of the ores mined in the United States, by far the greater proportion is very low in manganese (i to 8 per cent.). MANGANESE ORES Owing to its strong affinity for oxygen, manganese does not occur in the uncombined state in nature, although it has been found as an alloy in meteoric iron, the metal being one with which it is closely allied. As artificially prepared, metallic manganese is hard, brittle, and oi a light steel-grey colour, with reddish lustre, showing a fine granular structure when fractured. It cannot be forged. It oxidizes rapidly on exposure to moist atmosphere. It melts at about 1,245 C., and has a specific gravity of about 7-5, its atomic weight being 54-93. The metal owes its commercial value to its extensive use as a constituent of certain alloys, of which the most important is ferro-manganese. Mineralogy The minerals containing manganese in commercially im- portant quantity include the oxides (hydrous and anhydrous), the manganates, the carbonate and the silicate, other sources of the metal being manganiferous iron ores, manganiferous zinc ores, and manganiferous silver ores. Of the true man- ganese ores, the most important for metallurgical purposes are the oxides. The silicate and carbonate are comparatively unimportant. The following table gives the composition, specific gravity, hardness and manganese content of the more important manganese ores : MINERALOGY Mineral. Composition. Specific gravity. Hardness. Percentage of Manganese. Oxides ' Pyrolusite MnO 2 4-73-4-86 2-2-5 63 Braunite * Mn 2 O 3 + #SiOa 4.75-4-8 6-6-5 64*3 Manganite Mn 2 3 . H 2 4*2-4-4 4 62-5 Hausmannite Mn 3 O 4 4-7-4-86 5~5'5 72 Franklinite 2 (FeZnMn) O . (FeMn) 2 O 3 5-07-5-22 5'5-6'5 10-19 Manganates : Psilomelane . MnO 2 + MnO + BaO + 3-7-4-7 5-6 45-60 K 3 O + ^H 2 O Wad Impure earthy mixture of 3-0-4-3 1-6 5-5 hydrous manganese oxides passing into psilomelane Carbonate '. Rhodochrosite MnCO 3 3-45-3-6 3-5-4-5 47-8 (Dialogite) Metasilicate : Rhodonite MnSi0 3 3.4-3-68 5-5-6-5 41-86 1 Braunite. From 8 to 10 per cent, of silica is sometimes contained in this sesquioxide of manganese; and is supposed by some to be chemically combined, in which case it may be regarded as a silicate of manganese. 1 Franklinite is more strictly a manganiferous zinc ore. According to G. L. Barnebey[i], while various methods for the determination of the manganese contained in pyrolusite, the principal manganese ore, have been studied by chemists, the methods in use for determination of " available " oxygen have received but little attention. Results for the percentage of manganese dioxide obtained by responsible chemists have given differences of as much as five per cent, on a carefully prepared sample, while differences of one or two per cent, are quite common. The paper by Barnebey contains the results of a detailed study of the causes of such discrepancies, and recommends two accurate methods for the analysis of oxidized manganese ores. MANGANIFEROUS IRON ORES These contain a highly variable proportion of iron, usually exceeding 40 per cent. Such ores are mixtures of manganese oxides and iron oxides. It is customary to divide them hi to, (i) iron ores, (2) manganiferous iron ores, and (3) manganese io MANGANESE ORES ores. Manganese is not usually paid for when an iron ore contains less than 5 per cent. Mn, so that such an ore containing less than that percentage may be included in class (i). Ores with not less than 40 per cent, of manganese are included in class (3). Below that limit, down to 5 per cent, of manganese, the ore is called a manganiferous iron ore, although it may contain much more manganese than iron. In order to avoid this difficulty, the following classification, applicable to all ores containing over 50 per cent. Mn -f Fe, has been pro- posed [2] : Class. Mn Fe per cent. per cent. ' Manganese ores . . . 40-63 o-io Ferruginous manganese ores . 25-50 10-30 Manganiferous iron ores . . 5-30 30-65 Iron ores . . . . 0-5 45~7 Pyrolusite. This peroxide, otherwise known as " black manganese," crystallizes in the orthorhombic system, but the common form is a pseudomorph after manganite. The ore usually occurs massive or reniform, sometimes with a fibrous and radiate structure. It is often impure, containing iron, silica, lime, baryta, etc., with in many cases a little water. It is very soft, soiling the fingers. The mineral varies in colour from black to steel-grey and bluish-grey, and has a black streak v The bulk of the Russian (Caucasian) ore consists of pyrolusite. Braunite. This is an anhydrous sesquioxide of manganese, invariably associated with silica, whether mechanically mixed or chemically combined, the proportion of silica being some- times as high as 8 or io per cent. It crystallizes in the tetra- gonal system, occurring in pyramids resembling regular octahedra, and also occurs massive. Manganite. This is a hydrous sesquioxide of manganese, otherwise known as " grey manganese ore." It crystallizes in the orthorhombic system, the crystals being often of many times greater length than breadth, assuming a needle-like form. Its colour is steel-grey to iron-black, with sub-metallic MINERALOGY n lustre, and its streak reddish-brown to nearly black. ;When pure, it contains 10-23 P e r cent, of water. Hausmannite. This is a mineral, very low in oxygen, crystallizing in tetragonal prisms, frequently twinned, also occurring massive and granular. Its colour is brownish- black ; streak chestnut-brown. Psilomelane. This is a hydrous oxide of manganese, with or without varying amounts of baryta and potash. It is amorphous, the common form being rounded or botryoidal masses, usually with a smooth surface. It also occurs reniform and stalactitic. Its colour is iron-black, passing into dark -steel-grey and sometimes, as in India, to an almost bluish- grey. Its streak is often brownish-black, owing to a pro- portion of the lower oxide being present, and shining ; but in India, quite as commonly, it is black. Psilomelane is the most abundant of all the manganese ores found in India, constituting with braunite probably at least 90 per cent, of the ore exported. Wad, or " bog manganese/' In general, this cannot be considered as a true manganese-ore. It is a mixture of oxides of manganese (MnO 2 and MnO), with oxides of cobalt and copper, and sometimes of silver, these giving certain varieties a special value. Iron is also present, and the ore contains from 10 to 20 per cent, of water. It results from the decom- positioa of other manganese minerals, and occurs generally in damp, low-lying places. It is amorphous, earthy, soft and friable, and resembles psilomelane except as regards hardness. It is not so valuable as pyrolusite or psilomelane, but is some- times used in the manufacture of chlorine and of the pigment umber, and possesses value when used as a flux. Rhodochrosite, or Dialogite. This is a carbonate of man- ganese, often with carbonates of iron, calcium and magnesium in varying quantities. Rhonjbohedral crystals occur rarely, the mineral being more commonly found massive, globular, botryoidal, or encrusting. Its colour is white, pink, brownish, or yellowish-grey, with a rather pearly lustre ; streak white. The ore has been extensively mined in the French Pyrenees (Las Cabesses, etc.) and a few other localities. It must be roasted for removal of carbon dioxide before being charged 12 MANGANESE ORES into smelting furnaces ; and as, in the case of a comparatively pure ore, this leaves an oxidized product considerably higher in metallic manganese than much of the oxidized ores exported, it would be advantageous, having 'regard to freight charges, that carbonate ore should be roasted before shipment, where suitable fuel is cheaply available. Rhodonite. This is a pyroxene belonging to the triclinic system. It occurs either in crystals or massive, or as imbedded grains. The manganese may be in part replaced by iron, calcium, or zinc, and compact forms of the mineral sometimes contain an admixture of manganese carbonate. It is flesh- red, light brownish-red, greenish or yellowish (when impure), and often black on exposed surfaces owing to oxidation. It is one of the less important ores. Franklinite. This is a manganiferous zinc-ore of great economic importance found at Franklin and Sterling, New Jersey, U.S.A. It is of variable composition, resembling magnetite in appearance. It crystallizes in the cubic system, occurring in octahedra, also in rounded grains, and massive- Its colour and streak are black. " Manganiferous zinc resi- duum," used in large quantities in the United States in the manufacture of spiegeleisen, is a product consisting largely of iron and manganese oxides obtained from zinc volatilizing and oxidizing furnaces using New Jersey manganiferous zinc ores. The " residuum," which contains about 12 per cent, of manganese, is smelted in a blast furnace. Manganiferous Silver-Ores. These are mixtures of man- ganese and iron oxides, with small amounts of silver and lead minerals, the iron content as a rule exceeding that of manganese, although it may be altogether absent. In the United States they occur in the Rocky Mountain and Great Basin regions, the principal producing locality being Leadville, Colorado. They are mined in large quantities, some varieties being sufficiently high in manganese to be classed with man- ganiferous iron ores, while too low in silver and lead to be valuable for either. When too poor in all three metals to be directly valuable for any one of them, these ores are smelted with silver ores for recovery of the silver and lead, the iron and manganese acting as fluxes. METALLURGICAL USES 13 USES OF MANGANESE ORES These may be summarized as, (i) Metallurgical, and (2) Chemical. I. Metallurgical Uses The steel industry consumes at least 90 per cent, of the world's output of manganese ores and manganiferous iron ores, nearly three-quarters of that consumption being in the production of manganese-iron alloys (spiegeleisen and ferro- manganese) and manganese-iron-silicon alloys (silico-spiegel) [3]. The manganese-iron, or manganese-iron-silicon, alloy, added to the steel as it runs into the ladle, in acid processes of steel manufacture, has effects on the metal which have been sum- marized as follows [3] : (a) The prevention of over-oxidation of the steel by the reduction of small quantities of oxide in the bath. (b) The addition of the requisite amount of manganese necessary in the finished steel. , (c) The hindering of the formation of blow-holes. (d) The elimination of sulphur from the bath. (e) The making of iron slag fluid and easy to run off. (/) The addition of carbon to the bath, this, however, being incidental and not necessary. Allowance is made for the carbon added with the alloy when recarbonizing with pig iron, or by Darby's method in which powdered coal is utilized. The quantity of manganese alloy added varies with the oxidation of the bath and the amount of manganese required in the finished product, but averages about i per cent. To produce i unit of metallic manganese in the alloy, roughly about 2^ units of manganese-ore proper are required. In addition to the large consumption of such ore for the manu- facture of manganese alloys, the residues from manganiferous zinc ore (franklinite), and manganiferous iron-ores, are used for the production of spiegeleisen. Ordinarily, spiegeleisen is used solely in Bessemer practice ; but, to meet the curtailment of ferro-manganese supplies from Europe during the war, that lower alloy has been largely used in open-hearth steel-making in the United States, 14 MANGANESE ORES as a substitute for ferro-manganese. Substitutes tried in Germany during the war, including calcium carbide, are understood to have, in general, failed to give the results hoped for. H. M. Howe [4] points out that, apart from its deoxidizing and desulphurizing functions, the effect of manganese on the mechanical properties of steel appears to be due primarily to its retarding action on the transformations and on the coalescence of the micro-constituents into progressively coarser masses, which, while increasing the ductility, lessens the cohesion in general, including the hardness and the elastic limit, and thus lessens the effective strength. The retarding effect of manganese leads to finer structure and higher elastic limit, but lower ductility. At the present time, practically all spiegeleisen and ferro- manganese are produced in the blast furnace. The manu- facture of ferro-manganese in the electric furnace, as carried on at the recently constructed plant of the Iron Mountain Alloy Company, at Utah Junction, in Colorado, has been described by R. M. Keeney [5]. The furnace charge consists of a mixture of ore, coal and limestone in proper proportions for the reduction of manganese with a minimum slag loss. The plant contains one i,20O-k.w., three-phase furnace, and one i,8oo-k.w., three-phase furnace, giving a total capacity of 12 long tons of ferro-manganese per 24 hours. Power is supplied by the Colorado Power Company. The furnaces operate at from 75 to 100 volts. The electrode consumption is high, ranging from 150 to 250 Ib. per ton of product when using amorphous carbon electrodes. With dioxide ores, reduction takes place according to the reaction : MnO 2 + 2 C = Mn -f- 2 CO. Iron is added either as a constituent of the ore or in the form of iron turnings. Where cheap water power is available, the electric furnace method is likely to become an important factor in the pro- duction of high-grade iron-manganese alloys, although the cost of producing such alloys is higher than in the blast furnace. The principal manganese-iron and manganese-silicon alloys are as follows [3] : ALLOYS Spiegeleisen. Ferro- Manganese . Silico-Spiegel. Per cent. Per cent. Percent. Metallic manganese . 5-20* 20-85 a 18-20 (usually 20) (usually 80) Metallic iron . 70-85 8-60 60-70 Carbon .... 4-5 6-7 **5 Silicon .... '5 0-3-1-0 10*0 Phosphorus 0.033-0-035 0-055-0-23 O'O5~o-o6 1 Usual limits in U.S. practice are 15 to 25 per cent. Mn. z In U.S. practice, 60 to 80 per cent. Manganese-steel, an alloy discovered by Sir Robert Hadfield in 1883, has been described by him, roughly, as an alloy of iron with about 12 per cent, of manganese and ij- per cent, of carbon. For ordinary commercial use, this material is generally heat-treated, the treatment consisting in heating to about i, 000 C. and quenching in water. It is then very tough and strong, its tensile strength varying from about 54 to 63 tons per square inch, with 30 per cent, and in some cases 50 per cent, elongation. It is practically non-mag- netic [6]. The alloy is largely used for castings where tough- ness, strength and resistance to abrasive wear are required (such as the wearing parts of rock-crushers, ball mills, crushing rolls, dredge buckets, etc., also conveyer chains and buckets, screens, t railway crossings, etc.), and, as produced by various manufacturers, contains from n to 13*5 per cent, of manganese (usually from 12*5 to 13 per cent.), the proportion of carbon being from i to 1*3 per cent. Manganese-steel is so tough and hard that it cannot be machined. The highest grade ferro-manganese (containing 80 to 84 per cent, of manganese) is used in its production. Manganese-bronze has been described as essentially an alloy of copper (75 to 76 per cent.), manganese (16 to 17 per cent.), and tin (5 to 6 per cent.). When of this composition it is tough and malleable, and of a brass-yellow colour. The compositions which will give high tensile strengths are, however, very variable. The average " manganese- bronze " of commerce contains from about 57 to 60 per cent, of copper, 38 to 41 per cent, of zinc, traces to usually not more than i per cent, of manganese, often from 0*25 to i per cent. 16 MANGANESE ORES each of tin, iron and aluminium, and from o'l to 0*5 per cent, of lead. In some cases, not even a trace of manganese is shown on analysis, it having served its purpose as a deoxidizer, leaving behind the iron with which it was associated in the ferro-manganese added to the copper-zinc alloy. Aluminium up to 5 per cent, is stated to increase the strength and elas- ticity, giving the alloy a silver-white colour. The tensile strength of good commercial manganese-bronzes probably averages about 40 tons per square inch, with about 24 per cent, elongation. When forged, the alloy acquires great strength and toughness. Owing to its non-liability to corrosion, it is used for propellers and other parts of ships where that quality is of importance, while its tenacity renders it useful for other special purposes. Manganese German silver, or " silver-bronze," commonly contains 60 parts of copper, 15 parts of zinc, and 40 parts of ferro-manganese (with 70 to 80 per cent, of manganese)- For bearings, valves and cocks, the composition is frequently about 60 parts of copper, 10 parts of zinc, and 40 parts of ferro-manganese (containing 60 per cent, manganese). The addition of i j- per cent, of aluminium is said to give the alloy good casting qualities and non-corrodibility. Nickel is frequently added, also a small proportion of silicon. Manganin, an alloy used for electrical resistances, contains 82 per cent, of copper, 15 per cent, of manganese, and about 3 per cent, of nickel and iron. 2. Chemical Uses (a) Oxidizing Agents. Manganese dioxide is used in the manufacture of chlorine and bromine ; in glass-manufacture, as a decolourizer ; in dry electric batteries, Leclanche cells etc. ; in driers for varnish and paint ; and in the manufacture of permanganates of sodium and potassium, etc. (b) Colouring Materials. Manganese compounds are used in colouring glass, pottery, tiles and bricks ; in calico-printing and dyeing ; and for certain paints (brown, green and violet). (c) Flux. Manganese dioxide is used as a flux in the smelting of silver- and lead-ores. CHEMICAL USES 17 Chemical Requirements. For the production of chlorine, and, generally, for use as oxidizers, the peroxide (MnO 2 ) is desired by the chemist, who employs manganese-ore in this connection solely for its content of oxygen, and wishes to have a cheap, portable and easily-treated material with the maximum percentage of that element. The important con- siderations are, (i) freedom from impurities that are soluble in acid used for the decomposition of the ore, and so cause an unnecessary consumption of acid ; and (2) the amount of *' available " oxygen and the .ease with which it can be liber- ated. The presence of lime, in the form of carbonate, is objectionable, and this should not exceed about 2 per cent. ; indeed, the impurity may even be required to be entirely absent. Ferrous compounds are also objectionable, since they act as reducing agents, but phosphorus is harmless in ores used for the production of chlorine. The chemist buys his ore at so much per unit (i per cent.) of manganese peroxide. Japanese " brown-stone " ore, a pyrolusite, is specially suited for chemical purposes, and commands a higher price than others per unit of available peroxide. Generally, the man- ganese minerals best suited for chemical purposes are pyrolusite and psilomelane. Before the war, high-grade Russian pyrolusite was almost exclusively used in this country for the manufacture of dry cells, Leclanche cells, etc., the specification calling for 86 per cent. MnO 2 and not more than i per cent, of iron. In the United States the usual specifications of dry-battery manu- facturers prior to the war were that the ore must contain at least 85 per cent. MnO 2 , less than i per cent, of iron, and no copper. The worst features of California and other Western American manganese ores are the copper and high iron contents. Since the war began, ore of the desired high quality has not been obtainable in America in any considerable quantity, and makers of dry batteries in that country are now calling usually for ore containing at least 80 per cent. MnO 2 (minimum available oxygen, 1472 per cent.), less than i per cent, of iron, and less than 5 per cent, of copper, nickel or cobalt. The Russian supplies having been largely cut off, Indian ores have been employed in this country for the manu- i8 MANGANESE ORES facture of Leclanche cells, with possibly some from other sources ; but it has been found that these substitutes have generally given inferior results, the life of the cells being appreciably shorter. By careful selection, a uniformly good quality of ore for this purpose might be obtained in regular and sufficient quantities from Canada, and possibly from certain localities in India and other parts of the British Empire. For the silica- or flint-glass industry, the ore must be as free as possible from iron, and the Russian (Caucasian) ores are specially suitable for this purpose. The usual specification by American flint-glass manufacturers requires an ore running from 78 to 85 per cent. MnO 3 , with less than i per cent, of iron [7]. For chemical purposes generally, the basis of manganese peroxide demanded may be 60, 70 or even 80 per cent., the last being almost invariable in normal British practice. Metallurgical Requirements. The metallurgist buys man- ganese ore for its content of the metal, and does not require ores containing a high percentage of oxygen. A basis of 50 per cent, metallic manganese is common in Great Britain, with an allowance for each unit above and a penalty for each unit below that percentage. Ores required for the production of iron-manganese alloys should contain not less than 40 per cent, of manganese. Ores containing under 45 per cent, of that metal are saleable, but the metallurgist in Europe is becoming more and more insistent in demanding ores of high richness and purity, and desires an ore running as closely as possible to a minimum of 50 per cent, metallic manganese. Lime is not objected to, and indeed is sometimes paid for. Silica is penalized when it exceeds 8 or 9 per cent., the rate of deduction being normally about $d. per unit of silica per ton for imported Caucasian ore. Phosphorus should not exceed 0*20 per cent., and may be penalized in England even when it exceeds 0*15 per cent., the penalty for each o'oi or o 'O2 per cent, of phosphorus above the maximum being agreed. In Germany, there is usually a penalty for manganese below 50 per cent., but not generally a bonus for richer ore. Alu- mina should be low, anything above 10 per cent, being highly TRADE REQUIREMENTS 19 objectionable, especially in conjunction with high silica. Copper, lead, zinc and barium are objectionable when in any appreciable quantities. For acceptance by the British Ministry of Munitions (March, 1918), manganese-ore should contain not more than 10 per cent, of silica, 10 per cent, of iron, or O'l per cent, of phosphorus ; and the ore should contain the equivalent of at least 45 per cent, of metallic manganese, if it is to be used for making ferro-manganese. Pyrolusite is required for the manufacture of dry cells. Other oxides low in silica are in great demand for the manu- facture of ferro-manganese. Braunite is less desirable, having regard to its invariable association with silica, with which it is sometimes admixed to the extent of as much as 10 per cent. In America, the prices per ton of 2,240 Ib. paid by the Carnegie Steel Company, which govern the United States market for manganese ore, are based on a content of not more than 8 per cent, of silica or 0*20 per cent, of phosphorus. For each i per cent, of silica in excess of the limit, a deduction of 15 c. per ton is made, with fractions in proportion. For each 0*02 per cent, or fraction thereof of phosphorus in excess of the limit, a deduction is made of 2 c. per unit of manganese per ton. Payments for manganese and iron in domestic ores, delivered freight prepaid at Pittsburg or South Chicago, were made, at the outbreak of war, and so recently as July 31, 1917 [8], according to the following schedule : Price per Unit. Content of Metallic Manganese in Ore. Manganese. Iron. August 5, 1914. July, 1917- August 5, 1914. July, 1917. Per cent. Cents. Cents. Cents. Cents. Over 49 .."' 46-49 . 43-46 . . . 4~43 26 25 24 23 IOO 98 95 90 5 5 5 5 Not specified in statement quoted. Ores containing less than 40 per cent, of manganese, or more than 12 per cent, of silica, or more than 0*225 per cent. 20 MANGANESE ORES of phosphorus, are subject to acceptance or rejection at the buyer's option. Settlements are based on analysis of samples dried at 100 C. Not only the composition but also the physical properties and the condition as delivered are of importance in manganese- ores. For chemical purposes, the mineral should be sufficiently porous to allow of acid percolating through it, but of such density as to prevent crumbling in the stills. Lump ore (pyrolusite) from certain, somewhat limited, portions of the Caucasian deposits is particularly well suited for the purposes of the chemist, as also for those of the glass-maker ; but the annual production of this special quality is comparatively small, and there is a good jnarket for Indian pyrolusite and psilomelane for both these purposes. When intended for metallurgical purposes, the ore is usually shipped as ballast, and should be sufficiently hard and tough to withstand excessive disintegration in shipment. Indian and Brazilian ores are very suitable from this point of view, the proportion of rubble and fines produced between mine and destination being comparatively unimportant. Caucasian ores often arrive with 80 per cent, of fines. For smelting purposes, the ore should be in lumps, with a minimum of fines and dust, which block interstices in the furnace charge required for the passage of gases, and are driven into the flues, necessi- tating frequent blowing-out. Until November, 1909, manganese-ores for use in the iron and steel industry were divided into three grades for com- mercial purposes : first grade, 50 per cent. Mn and upwards ; second grade, 47 to 50 per cent. Mn ; and third grade, 40 to 47 per cent. Mn. From December, 1909, second-grade ore has been limited to 48 to 50 per cent. Mn, while the third grade has been restricted to ores with from 45 to 48 per cent. Mn [9]. The price per unit of manganese, and consequently per ton of manganese-ore, obtained on delivery c.i.f. at port of destination, is at present abnormally high owing to the war ; in pre-war times it fluctuated between qd. and izd. per unit for first-grade ore c.i.f. at United Kingdom ports between January, 1910, and July, 1914, the price per unit at the latter RELATIVE VALUES OF ORES 21 date being from q^d. to q^d. The price for second-grade ore similarly delivered was generally %d. per unit less than that for first-grade ore, a further reduction of %d. being made for third-grade ore. There are no current quotations in this country for man- ganese-ores, but the price for Indian c.i.f. United Kingdom ports in January, 1918, was nominally 41^. per unit, on a 50 per cent. Mn. basis, this high figure being due to the abnormal freight rates. In March, 1918, the f.o.b. price of manganese ore in India was about Sd. per unit (pre-war price, jd.), the c.i.f. price in the United Kingdom being 36^. per unit for manganese-ore with 50 per cent, metal content (pre-war price, nd. per unit). The c.i.f. price in the United Kingdom was still about $6d. per unit in March, 1919. Relative Values of Indian and Foreign Ores. Analyses of a large number of cargoes of manganese ores and manganiferous iron ores landed at Middlesbrough during the years 1897-1906 are tabulated in Memoirs, Geol. Surv. Ind., 37 (1909). The cargoes represented the manganese ores of India, Russia (Caucasus), Brazil and Chile, and the manganiferous iron ores of Greece and Spain. The following is a general summary of the analytical results : Moisture. The Indian ores contained less moisture than those of the other countries, twenty-two cargoes from the Central Provinces (with possibly some ore from Jhabua and Panch Mahals) containing 071 per cent, and four cargoes from Vizagapatam 076 per cent, of water. Some of the foreign ores contained such large quantities of moisture (Caucasus, 8-67 per cent. ; Brazil, 11-35 per cent. ; and Spain, 8 '44 per cent.) that it was necessary to reduce the analyses to their condition when dried at 100 C. before any fair com- parison could be made. Manganese. The Indian cargoes stood first as regards manganese contents, with Brazil a close second. Silica. The percentage was lowest in the Brazilian ores, the Indian coming next. Phosphorus. The Russian ores contained most phosphorus, Indian following. (The percentage of phosphorus in the Indian ores has since shown a tendency to increase, and, as 22 MANGANESE ORES now exported, the phosphorus content somewhat exceeds that of the Russian ores as shipped.) Iron. The Indian ores contained much less iron than the manganiferous iron ores of other countries ; but of the true manganese ores they contained the highest amounts of iron, in spite of the fact that they also contained the highest per- centages of manganese. The high iron content of the Indian ores is a point for or against them, according to the use to which the ores are to be put. High iron contents make it more difficult to manu- facture the very highest grades of ferro-manganese from the Indian ores (a point which should not be overlooked when considering the suggested placing of an embargo on the ex- port of manganese-ores from India and shipping locally-made ferro-manganese) ; but, if the very highest grades are not required, the iron is of considerable value. Both iron and manganese are of use in such case, and the buyer obtains the following totals of Mn + Fe when purchasing the ores of the different countries, assuming them to be of the average values shown by these analyses [10] : Mn + Fe per cent. India 57'*7 Brazil 54'9 Russia ..... S ^ 1 Chile 48*40 Greece . io . . . .47*99 Spain . .T . . p 44-27 CHAPTER II SOURCES OF SUPPLY OF MANGANESE ORES (a) BRITISH EMPIRE EUROPE UNITED KINGDOM. The manganese ores originally used in this country came from deposits in North Wales, where rhodochrosite predominates, and from the West of England, where the chief ores are pyrolusite and rhodonite. Manganese- ores occur also in Derbyshire, Warwickshire and Cumberland, and in Scotland ; but, from the evidence available at present, it appears unlikely that any great quantity of such mineral could be obtained from those areas [n]. The deposits in Devon and Cornwall are not exhausted, but they cannot be worked profitably even at current prices. The manganese ore now produced in Great Britain is obtained partly in the Lleyn Peninsula, Carnarvonshire, and partly in Merioneth- shire. The great expansion in the use of manganese has rendered domestic sources utterly inadequate for British metallurgical requirements ; and, as supplies of far richer ore can readily be obtained from other countries, it is highly improbable that the home deposits will ever be extensively worked. Carnarvonshire. In the Lleyn Peninsula, there are three mines, namely the Nant, the Benallt, and the Rhiw. At the Nant Mine, the undecomposed ore contains manganese in the form of carbonate with a small proportion of silicate, but at the outcrop this has been altered into a hydrated black oxide. It occurs as a bed, from 10 to 20 feet in thickness, inter- calated among the Ordovician (Lower Silurian) shales. The beds are much faulted and the ore is often slickensided. The o 23 24 SOURCES OF SUPPLY OF MANGANESE ORES ore has been stated [12] to average from 30 to 36 per cent, manganese, 7 to 10 per cent, iron, 18 per cent, silica, and O'3 to 0-5 per cent, phosphorus; but, according to Home Office statistics, the average yield is only about 30 per cent, manganese, with 10 per cent. iron. Both at Nant and at Rhiw there are extensive intrusions of syenite and greenstone in the shales. The Nant mine is worked through an incline from which several levels have been driven. At Benallt, where there are several beds of manganese ore, the shales have been folded into an anticline. This mine and the Rhiw have been exploited by adits and shafts, as well as by open workings. The total output from these mines since 1892 amounts to over 80,000 tons. Production in recent years is tabulated below. Merionethshire. Only a few tons of manganese ore are obtained annually from this county, where it occurs mostly as a bed of mixed carbonate and silicate between the grits and conglomerates of the Lower Cambrian formation. In the Llanbedr district, the bed varies in thickness from 10 to 20 inches, and is encrusted near the surface, and on the joints and cracks which traverse it, with black oxide of manganese, a decomposition product containing from 20 to 32 per cent, of manganese. This weathered crust, which consists essen- Output and Value of Manganese Ore from North Wales l Carnarvonshire. Merionethshire . Total. Year. Quantity. Value. Quantity. Value. Quantity. Value. Tons. (. Tons. Tons. 1912 3.934 3.136 236 235 4.17 3,371 1913 5. 2 9i 3.977 102 95 5.393 4,072 1914 3.437 2 2,931 IQIS 4,640 4,640 1916 5-14 6,020 1917 10,164 ~ 2,93 I3. 94 i Home Office Statistics. The 1917 figures are from returns made to the Ministry of Munitions. Home Office Statistics (Mines and Quarries, Pt. i, 1917) give a total of only 9,942 tons. Practically all from the Nant mine, Carnarvonshire, in this and following years. UNITED KINGDOM 25 tially of pyrolusite, is the richest part of the ore, and formerly it only was worked, the carbonate and silicate being rejected as useless. The ore when mined is broken into lumps about 2 inches across, and sent to glass-works at St. Helens, Lanca- shire, the use of the mixed carbonate and silicate in that industry having been found valuable. The bed of ore is traceable along the sides of the valleys of two rivers for many miles, and has been exploited in a number of shallow open- works, below which there appear to be considerable reserves. West of England. The ores formerly produced in this part of Great Britain were obtained chiefly from the neighbourhood of Launceston, in Cornwall, and Brenton, in Western Devon, and consisted chiefly of pyrolusite and rhodonite. The discovery of large deposits in Germany, about the middle of last century, lowered the price of manganese-ore to such an extent that the mines in the West of England were closed down ; and, with one or two exceptions, these have since been worked only intermittently. A description of the oc- currences would serve no useful purpose, as the manganese- ore industry in this part of Great Britain is unlikely to become of importance. Derbyshire. A few hundred tons of wad have been obtained from near Winster, where the mineral occurs in flats, pipes and pockets in the Carboniferous limestone, but so irregularly that it cannot be mined systematically. A shallow shaft is sunk, and the mineral is worked from this as far as practicable. The wad occurs with ochre and some barytes, and is carted to colour-works at Matlock. It is inferior in grade to the imported material. Possibly 10 tons a week could be raised at this place. The mineral is said to occur at other localities in the district. Scotland. Ores of manganese have been worked only on a small scale in Scotland, and no returns of production are available. The manganese minerals recorded as occurring include psilomelane, manganite and wad. Ireland. Manganese ore was formerly obtained in some quantity at Sutton, in County Dublin, and occurrences are reported from many other localities in Ireland ; but no deposits of importance are known. 26 SOURCES OF SUPPLY OF MANGANESE ORES The most productive years in the history of manganese ore mining in Great Britain were 1905-1907, the annual output varying in that period from 14,474 tons up to 22,762 tons. IMPORTS OF MANGANESE-ORE AND MANGANIFEROUS IRON- ORE INTO THE UNITED KINGDOM Diagram 2, p. 27, and the tables on pp. 28 and 29 show the quantity and value of (i) Manganese Ore and (2) Manganiferous Iron Ore imported into the United Kingdom during the years 1913-1916, together with the chief countries of origin. It will be seen that, while imports from Russia were entirely cut off in 1915 and 1916, imports from India not only improved in those years, but actually exceeded those for the last pre-war year. In this connection, however, it must be pointed out that shipments to the United States during 1915 and 1916 were abnormally low, while, of course, the Belgian market was lost. The great increase in values since the outbreak of the war has been chiefly due to abnormally high freight. The effect of the war on both the amount and the cost of manganiferous iron ore imported into the United Kingdom is clearly shown in the table. The average value per ton in 1913 was 16/3-6, while in 1916 it was 35/8-4. The comparative unimportance of manganese ore pro- duction in the United Kingdom is clearly shown in the following table : U.K. Production.! U.K. Imports.i Year. Quantity. Value. Quantity. Value. Tons. Tons. 1859 2 1,231 3,693 Not stated Not stated 1873 . 1883 . 1893 1903 T 8,671 1,287 1,336 818 57,766 2,976 762 656 25.777 22,362 121,773 231,864 ,314 335.984 466,327 1913 5,393 4,072 601,177 1,295,113 1914 . 3,437 2,931 479,435 1,001,654 1 Home Office Statistics. Mines and Quarries Reports. 2 Earliest year for which figures are available. Tons. (240/b) 5 foo.ood DIAGRAM 2. IMPORTS OF MANGANESE-ORE IN THE UNITED KINGDOM. TOTAL AND FROM CHIEF PRODUCING COUNTRIES (1913-1916). 28 SOURCES OF SUPPLY OF MANGANESE ORES v O Os vO COVO M o 00 00 N i-^oo o 00 1 " t>. M O O 10 O M vO M CO CO vg IN" N 4* M M OS M CO 00 Os (T .* MQ TT vO * o Os o . td I i O 00 i 10 ro vN ! 5 1 1 en N 1 M M I* Tf M Tf O O TfCO O N M co u-> j> O Os v? Os N rf ro 00 cs M co 1 II N vO ^ CO O f M o" 00 M CO H ^ IO O M 00 s; 2- J CO o | 33 i 1 cs oo 10 t-. Os o l> o _ 1 1 oo" 4 CO oo" oi CM" 'fc/) HI N Tf j^. r* CO CO CO 3 t^ 10 o oo to to o ^ ^ ^. | Os iO >OvO N Tf Tf M M o u CS O 00 0 Tf 1 CO 00 vO CO Tf Tf "o o 1 ! H ^ g "*.> iO 1 * H M CO O l^ t^ >O IO (N O M CS M 00 00 o CM O M rf VO" oo f 1 U Os 1 M" _ CO tn . ^^ OS CO ^ ^ , Tf t*^ O Os r^ *o Os O M M OsO 00 O O Os 1 ^ g oo co t> Os t^ r^ CO l^ 1 M ^ 1 ^ M Tf rOOO N N Os *0 i M 01 N CO CO vO en (4 en d t d o a ^J en en H- 1 ''i 1 3 J 1 _"f i .2 & to 1 * , . s j3 'S C/3 .^- e i tl o en O 1 1 1 . 1 PH be g 2 c/5 ^ ^, 4J O o ^ lr O IH 3 1 rt rt ^ " ^ 3 ^H en IH "rt H 'c/5 P _Tj .^ "tg ^ o "o ^ HIM! H il H IMPORTS INTO UNITED KINGDOM 29 1 oo vo vO O -SSI 1 00* I CO o c- N M * VO M ^ H . M t"**. oo Tt- 3 a M M I | 1 8J rt H 0* f*. ' f^ CO ^ 01 CO Tf f" 00 M 00 >O M ^ CO 00 M C4 N t^ ON s 2 O* CO f*. M~ fO >o CO* Jj ^ COOO M CO CO a M M 1 2 t> M 00 N *}- O * t>- 00 vO M 1 4- 1 ro t>. M* M* M O> M M CO M 0* o T}- ON ^ IO Tj- IO M CO I a oo O O s 5 i CO O^ O ON ^ w ti ^ CO M 3 s g*| 1 1 Tj- *l 9 *2 cooo* coo* nT 1 M~ A ** 00 M H M M 5 I 414,542 649,307 564,890 399,215 558,828 Tons. 138,454 120,607 125,865 117,246 96,296 60,018 288 2,755 Tons. 41,880 42,518 21,573 24,929 10,501 18,055 23,125 24,911 Tons. 644,660 800,907 670,290 633,080 8l5,47 682,898 450,416 645,204 Total . 169,969 288,374 49,78l 3,965,357 661,529 207,492 5,342,502 Provincial Averages 21,246 36,047 6,223 495,67 82,691 25,936 667,813 Notes: i. Gangpur. 2. Panch Mahals. (Ratnagiri produced 525 tons in 1910.) 3. Jhabua. 4. Balaghat, Bhandara, Chindwara and Nagpur. (Jubbulpore produced 300 tons in 1910.) 5. Sandur and Vizagapatam. (Bellary produced 500 tons in 1910.) 6. Chiefly Shimoga. (Chitaldrug produced 5,856 tons in 1909 and 1,803 tons in 1910 ; Kodur produced 3,307 tons in 1909.) * Statistical Abstract relating to India, 49, and .foe. Geol. Surv. Ind., 46, 47, 48. (See refs. [19] and [20].) The figures in the above table, except in a few cases, repre- sent tonnages won, and not tonnages railed. The returns for 1915 show the serious effect of the war on the Indian manganese ore industry. The total production in 1917 was 590,813 tons. (See Diagram 3.) Comparing the quinquennium 1909-13 with the previous five years, a substantial increase is shown, the average annual production of manganese-ore for the whole of India for 1904-8 having been only. 509,143 tons. The Central Pro- vinces is by far the most important producer of manganese ore, and the four chief producing districts of that province INDIA Tons. X year. Tons. (2240/fy O x f^j 1r) ^*> i VQ \Q ^ O)W>0)OV^i^3>^ &OOOOO t O- c!^\t^ /)^/ \5^ A^ \*!* S 00,000 7OOOOO 600,000 :/ v/ \ : \i; x d/ ^ 700000 00000 &oo,ooo 4OOOOO \ V V > i i 1 1 1 &oo ooo 4OOOOO DIAGRAM 3. PRODUCTION OF MANGANESE-ORE IN BRITISH INDIA (1909-1917). are responsible for the greater part of the increase shown, the Chindwara district taking its proper place for the first time in 1913, owing to the extension of the Bengal-Nagpur Railway into the Sausar tahsil. Bombay Presidency also shows a large percentage increase, due to the opening up of deposits in the Panch Mahals. Gangpur State in Bihar and Orissa shows a six-fold increase in the average annual pro- duction, but the figures record a change from a maximum in 1909 to a minimum in 1913. The Madras Presidency shows a small increase, which is the balance of a very great increase in the production of Sandur State and a nearly as great average decrease in that of the Vizagapatam district. Central India shows a great reduction in output, due to the working- out of the easily- won portions of the Kajlidongri deposit in Jhabua State ; while the Mysore output was reduced by nearly one-half, owing to a similar result in the great Kumsi deposit in Shimoga district. The bulk of the ore was shipped at Bombay, the other ports of shipment being, in order of importance, Mormugao, Calcutta and Vizagapatam. The heavy fall in the total exports for the year 1914-15 was due to the war, but there has since been a substantial recovery. (See Diagram 4, p. 42.) 42 SOURCES OF SUPPLY OF MANGANESE ORES The value, though not the amount, of the total exports during 1916-17 was greater than that of any preceding year. Exports to the United States reached their maximum in 1912-13, fell considerably in the following year, and in 1916-17 amounted to a little less than one-half of the average tonnage for the two years 1912-13 and 1913-14. Exports of Indian manganese ore to Germany have never been large, that country having been the principal market for Russian ores. Exports to Belgium prior to the war were second only to those made to the United Kingdom, and a steady increase had been shown for several years. France and the United States came next in order of importance as buyers of Indian ore. (In the table, values are expressed in pounds at the rate of 15 rupees to i, this having been maintained since January, 1898, with but slight variation.) Since 1892, there has always been an excess of production Tons. &> ;| F/'nonc/al Y&crr. Tons. (2240/b) i i i tl 3OOOOO - 800,000 7OO, 000 *\ ' ' - 7OO OOO 6OOOOO \o / \"~i / (^ / 600 000 soq ooo \o \^/ \^ / \ / SOO. OOO 4OOOOO 1 1 1 4OOOOO DIAGRAM 4. EXPORTS OF MANGANESE ORE FROM BRITISH INDIA, APRIL I, 1912 MARCH 31, 1917, SHOWING ADVERSE EFFECT OF WAR. INDIA 43 *J V 3 "* VO in O^ ^vo O vO CM ON vO O\vO N ^ Si 1 Si 1 vJcTX^ tO "*" M CO o" oo H Quantity. O O O O CM O M aj tO O CO M O 2 C^ 1 I M" 1 1 oo" tC CO ^^ iO \O N w 'O t- CO o. CO H $ H CO M 1 t^ 1 * O d ** vO **;! I i S i i p| i i 1 CO in >n H^ 1 1 O M Quantity. vO O *f) "*) O a^| r O I icocoTf! i ^ O* 1 1 o" 1 1 o" co t-C 1 1 CO CO CM" rr 1 o" 1 H 3 w vO O M oo Tf CO M ro ON co O co O M 5 ~- I M ^ ^ CM vO t^. ' 1 CM co 1 1 vo t^n M M ^ CM in vO *** ri H C* H 33 H O COO O t^ CO OOCOrf-CMVO >OO SMOOCOCMI jMirji i 1 1 in M ON *I I 2 tC. rj-vo vO if 1 I 1 ON co 1 1 CM o Tf M + 1 m "rt - O CMOOCO CMO OO t^ T}-t^.O ^lOOvO co^j- CO M 0* 1 3 M i i ^ M CM CM tC coco divo vo 1 1 CO H M CM CM CM O CM CM M M n M ^""' tn _c/5 ,3 ON 33 t>- COOO OO ON CM CO O CO I 1 P oo" O t^ cooo"oo" t^vo"vO~ ' 1 CM M M M ON oo" M r ^ H s s 1 crt O CH t coO t^-T^O >OOO ""t* vO vO CO Tt:O co CM t^ >O oo *:;| ^ *J V 1 M ro "^"00 ON t^ F^ T^ ^* 1 1 CO CO CM CM VO CM vO i o d 33 MOO coO O O M O ,X CMOO CM >O>OO t^-O gONCOOCMCMOOvOCMvO| I s ^1 1 Ot P M CO M CM C^ COO COOO 1 1 M t^* M CM VO (S H M M CO o Is & g "^ 00 1 o 19 II 8 4j ^j '20 pj 62 !>oj^j ^*G c'p'SScjOdS^d Sj3 p.-,. i'8o 0*43 Silica SiO a i *:' 13*85 n'37 58 SOURCES OF SUPPLY OF MANGANESE ORES No. i. No. 2. Per cent. Per cent. Alumina Al a O, . 7*58 6*07 Lime CaO . 0*56 0*22 Baryta BaO . 2-35 3*78 Phosphorus pentoxide P 2 5 . 0*07 trace In both cases the percentage of phosphorus was satis- factorily low. NORTH AMERICA CANADA. 'Ores of manganese have been mined in the Provinces of Nova Scotia and New Brunswick since 1864, the mineral being notable for its purity, high manganese content, and low phosphorus. Between 1880 and 1890, shipments of high-grade pyrolusite averaged 1,500 tons annually, the mineral of the deposits worked during that period occurring in rich aggregates of very pure ore, the individual pockets, however, being of limited extent, rendering mining difficult. The production during the present century has been quite unimportant, being only 25 long tons in 1914, 179 tons in 1915, 874 tons in 1916, and 180 tons in 1917. The domestic consumption of high-grade pyrolusite is less than 20 tons a year, and consequently the home market has hitherto offered little inducement for active development of domestic resources. Indeed, some 1,300 tons of mineral of lower grade is imported annually, the bulk of which is used in the dry battery, glass and varnish industries. For the first-mentioned purpose, the specification in England is 86 per cent, manganese dioxide, and not exceeding i per cent, iron ; and, as much of the Canadian mineral complies with these requirements, there appears to be no reason, other than temporary lack of good transport facilities, why imports of lower -grade mineral should not be superseded by high-grade Canadian material in the chemical industries mentioned. British Columbia. -A deposit of manganese ore, which appears to have considerable prospective value, is now being developed in a locality about 6J miles from Kaslo, in this Province, the property lying on a hillside immediately above the Kaslo and Nakusp Railway. A few shallow pits have BRITISH COLUMBIA. NOVA SCOTIA 59 shown that the ore occurs on the surface or a few feet below, forming a layer from i to 3^ feet in thickness in the soil. So far the deposit has not been found to be closely associated with or bounded by any rock in-place. The ore, being prin- cipally wad, can be extracted by pick and shovel. The thin layer of soil covering the deposit also contains manganese in varying quantities. It was estimated in 1917 that from 3,000 to 5,000 tons of ore were ready for extraction, averaging 42*06 per cent, manganese ; i per cent, iron ; 4 per cent, silica ; 0*01 per cent, phosphorus ; and 13*12 per cent, mois- ture ; and it was anticipated that further development would expose a considerable further tonnage of ore. Farther down the hill and almost at the same level as the railway track/ in some small exposures, manganese ore has been found to occur underlying a layer of soft decomposed limestone, which has been eroded away farther up the hill, leaving the ore exposed on the surface [34]. l Nova Scotia [35]. -The most important manganese-bearing section is that near New Ross, Lunenburg County, from which the whole of the small production for 1917 was derived. Two mines are being operated in this district, and two well- defined lodes have been worked, carrying extremely pure pyrolusite, with a little manganite and psilomelane. Some iron oxide occurs on one wall, but this is easily separated. The New Ross pyrolusite contains about 58 per cent, metallic manganese (MnO averaging from 85 to 90 per cent.), and this degree of purity is about the average of Canadian man- ganese-ores. The ore shipped by the Rossville Manganese Company, Ltd., from which 179 tons were produced in the year ended September 30th, 1917, has averaged 92 per cent, manganese dioxide and less than 2 per cent, iron [36]. The lodes of New Ross occur in a biotite granite, the width of the vein in what is known as the New mine varying from i inch up to 6 feet. A sorting and washing plant has been installed to prepare the ore for market, air separation being used for 1 Deposits of manganese ore have recently been discovered on Vancouver Island, B.C., in a belt of rock extending from Mount Sicker to Cowichan Lake, a distance of about 40 miles, the majority of the samples showing over 40 per cent, of manganese. Assays show a high content of silica, but phos- phorus is quite low. Development is proceeding. 60 SOURCES OF SUPPLY OF MANGANESE ORES the finer grades. The existence of an important ore-body has been proved, but work has ceased, owing largely to the distance over which the mineral has to be hauled (about 50 miles) to the nearest shipping point, and the lack of a good road. At the Tenny Cape Mines, in Hants County, where the most important deposits of manganese ore in Nova Scotia occur, high-grade fibrous pyrolusite is associated with psilo- melane, manganite also being met with in small quantities. The ore occurs in flat nodules, seams and lenticular pockets, the seams varying in thickness from i to 6 inches, and the pockets from i inch to several feet, some of the latter being said to have produced as much as 1,000 tons of ore. The deposits occur along an outcrop of dolomitic limestone asso- ciated with a layer of red shales, which dips steeply and is generally less than 300 feet in thickness. This layer (which is underlain by a massive sandstone of Devonian age) is much brecciated, and the ore is found in the brecciated portions, between the fragments and surrounding them, and in the large solid masses along bedding planes and cross fractures [37]. The ore of the Tenny Cape mine, proper, is said to carry from 88 to 95 per cent, of manganese dioxide, and to be free from deleterious elements. The mine is not now worked, but it is stated that considerable ore is still available for extraction. There was no output of manganese ore in Nova Scotia in 1914-15, or in 1918, but 544 tons were produced in 1916, and 180 tons in 1917. New Brunswick. .Manganese deposits occur throughout the southern part of this Province, in the area underlain by Carboniferous limestone. The most important deposit occurs at Markhamville, near Sussex, King's County, where the ore is described [38] as crystalline pyrolusite and manganite, with small amounts of psilomelane in some places, the deposits being in the form of irregular pockets, or in flat lenticular layers generally following the bedding planes of the limestone. The Markhamville mine has produced some ore of the highest grade known, much of the pyrolusite containing from 96^ to 98! per cent, of manganese dioxide, with only one-half of i per cent, silica and three-fourths of i per cent, iron [39]. NEW BRUNSWICK 61 The large amount of available oxygen and the freedom from impurities have caused it to be highly prized by glass-makers. The manganite with which it is associated is said also to be of high grade and to have been used for steel manufacture. Among smaller deposits of manganese-ore in New Brunswick is that discovered at Jordan Mountain, 17 miles from Mark- hamville, where the ore occurs near the contact of the lower Carboniferous sediments with pre-Cambrian crystalline rocks (gneiss and felsite). The deposit is a lens conformable with the bedding of the enclosing strata, the mineral consisting of fine-grained and massive pyrolusite mixed with manganite. Analyses of ore from the Jordan Mountain deposit have been reported as follows : No. i. No. 2. Per cent. Per cent. Manganese dioxide MnO 2 . . 86*08 Metallic manganese Mn . . 54*57 5/37 Silica SiO 2 . . 2' 86 0*23 Phosphorus P . 0*15 Sulphur S . . 0*61 Iron oxide Fe a O s . . 0*87 One of the more important deposits of manganese-ore in New Brunswick occurs at Dawson Settlement, about 5 miles west of Hillsborough in Albert County and i mile from the Salisbury and Albert Railway [40]. The ore has been deposited as a form of sinter surrounding some springs which issue from the hillside. The deposits vary from 150 to 500 feet in diameter, and are thickest (26 feet) close to the springs, becoming thinner as the edges of the ore masses are approached. The amount of ore present in these deposits has been estimated to be about 170,000 tons. When this deposit was worked some years ago, it was found necessary to briquette the manganese ore on account of its soft and crumbly nature. Mining operations, however, were not continued for long, and no further development of this deposit has been recorded. Quebec. -A spathic iron-ore rich iri manganese occurs in the Kestapoca chain of islands, an average sample from Flint 62 SOURCES OF SUPPLY OF MANGANESE ORES Island yielding 25 per cent, of iron and 24 per cent, of man- ganese carbonate. These deposits are easily accessible, and may permit of profitable working. It is advantageous, where suitable fuel is cheaply available, to roast such ores before shipment, having regard to freights. Deposits of manganite, said to be of considerable size, occur on Amherst Island, one of the Magdalen group, and some exploratory work has been done. Alberta. -Deposits of low-grade manganiferous material are reported to occur in the Cypress Hills, but according to the Canadian Geological Survey [41] these contain on an average only about 5 per cent, of manganese, and appear to be of little or no value. The following are some analyses of Canadian manganese ores : - Percentage of Nature of Ore. Mn0 2 . Mn (total). Fe^0 a . Si0 2 . P. Cape Breton Co. f Morrison Mine, Loch Lo- mond Boularderie Island . 91-84 44*33 0-12 35-5 2-91 * IO-OO 1 Pyrolusite. Wad. Colchester Co. : Londonderry . 67-10 4-08 __ Hants Co. ' Tenny Cape . . . Cheverie 85-54 90-15 56-97 1-18 2-55 3 . 27 1 2-80 1 o-34 o-45 Pyrolusite. Pietou Co. : Springville 14-41 9-10 48-22 0-02 Albert Co. t Dawson Settlement 45-81 13-65 5-36 0-05 King's Co. ! Markhamville 97*25 0-85 Pyrolusite. St. John's Co. i Quaco Head . 7^-54 58-20 2-19 8-37! O-O2 Pyrolusite. Silica and insoluble matter. NEWFOUNDLAND. -Extensive deposits of low-grade mangan- ese ore have been reported to occur along the south side of Conception Bay, in conjunction with limestone, near the base of the Cambrian series [42]. N, C. Dale states that NEWFOUNDLAND. WEST INDIES 63 there are occurrences at Manuels, Topsail, Long Pond, Chapel Cove and Brigus within 10 miles of each other on Conception Bay [43], other occurrences are found some 50 miles to the north-west on Smith Sound in Trinity Bay, and occurrences are reported also some 50 miles to the south-west on Placentia Bay. There is a good exposure in Manuels Brook, where the ore consists of a nodular deposit of complex manganiferous carbonate. Various attempts have been made to work the deposits, but no regular mining appears as yet to have been done. A sample of manganese-ore from Conception Bay examined at the Imperial Institute was shown by analysis to consist of impure manganite, containing 38*0 per cent, of manganese, 17*56 of silica, 2*00 of iron, and o'loo of phosphorus. WEST INDIES : Jamaica.* Pyrolusite occurs at Marshall's Hall, in the parish of Portland, County of Surrey. It has been briefly described by J. G. Sawkins [44] as occurring in the Lower Tertiary Conglomerate Series, near an intrusive dyke. The quantity is said to be moderate, but the mineral commanded a price of 8 per ton in England at the date of his report (1869). No mining operations had been under- taken. Referring probably to the same deposit, L. Barrett [45] reports the occurrence on the west bank of the Dry River (Marshall's Hall) of large blocks of pyrolusite embedded in porphyry, quantities being scattered over the surface and in the streams. No excavations had been made, and conse- quently the mode of occurrence of the mineral had not been ascertained. It existed in considerable quantities, and he believed that it might be worked with profit if it were not situated at so great a distance from the coast. (The direct distance from the nearest point of the coast appears to be only about 10 miles.) Barrett mentions also manganite as occurring in a very interesting manner on the banks of the Guava River in the same parish, where many small veins could be seen in the process of formation. Numerous fissures are stated to cross the bed of the river through which issued jets of hot water having a temperature of 132 F. The sides of these openings were lined with crystals of calcite, enclosing a central rib of manganite, presenting the appearance of a small mineral vein. In some places the fissures were com- 64 SOURCES OF SUPPLY OF MANGANESE ORES pletely closed by these minerals, but at others the thermal water still issued. Sawkins (loc. cit.) mentions the occurrence at Boston of a deposit of manganese ore associated with a large proportion of oxide of iron, of which he made no analysis. Near this deposit were larger ones consisting of iron oxides. St. Thomas Island. -In 1896, it was reported that a deposit of manganese-ore of good quality and considerable extent had been found on this West Indian island ; but no ore appears to have been exported. AUSTRALASIA New South Wales. -Ores of manganese occur in consider- able quantity in different localities and formations, but the deposits are situated at such distances from the coast that the cost of land-transport added to freight to Europe has hitherto prevented exploitation. The question of the extent and character of the manganese-ore deposits, not only of New South Wales, but of all the States of the Commonwealth, will become of more serious importance with the development of the iron and steel industry in Australia. The domestic supply of manganese ore will almost certainly be ample for the requirements of that industry, even if it should assume large dimensions. The output in 1915 was 713 tons, valued at 535, and, in 1916, 1,924 tons, valued at 1,443, t ne whole of the production in both years being obtained from deposits at Grenfell. The total recorded output of manganese ore up to the end of 1916 amounted to only 3,213 tons, valued at 364u. Queensland. -This is one of the more important parts of Australia, at the present time, as regards production of manganese-ore. The output has hitherto been small, amount- ing to 4,600 tons in 1902, but averaging only a little over 1,000 tons a year for the period 1903-11. The production in later years has been as follows : 1912, 308 tons ; 1913, 27 tons ; 1914, 6 tons ; 1915, 200 tons ; 1916, 643 tons (valued at 2,793) ; and 1917, 21 tons (valued at 105). The output is taken by the Mount Morgan gold mine, and utilized for the chlorination process, QUEENSLAND 65 The Queensland ore has been obtained chiefly, and in recent years entirely, from the Gladstone district, where it occurs in ferruginous slates, schists, quartzites and other altered sedimentary rocks intersected by igneous dykes and supposed to be of Per mo -carboniferous age. The deposits are sometimes lenticular, their longer axes parallel with the cleavage of the rocks, running from north to south ; but in general they are irregular in shape and occurrence. The Gladstone manganese ore area is roughly 15 miles in length by 12 miles in greatest width. The outlet for ore is by the Calliope River to Rockhampton, to which place there is also railway communication. Most of the country within the manganese area is less than 100 feet above sea-level, the highest hills being not much over 500 feet in altitude. The most important producing mine in the Gladstone district is the Mount Miller, the workings of which are situated in a hill rising 400 feet above the Calliope River. The ore- body here is extremely irregular in strike, dip and thickness, the width of clean ore varying from 3 feet up to 21 feet. The ore consists chiefly of psilomelane, but it contains also pyrolusite and probably braunite. It is massive, and mostly steel-grey, silica and country rock being the chief impurities. The output from the Mount Miller mine from May, 1895, to the end of 1903 was 5,553 tons, of which 1,350 tons mined in 1903 aver- aged 74*1 per cent, of manganese dioxide. The average annual production was approximately 1,000 tons down to 1911, since which it has dwindled. In his Report for 1914, the Assistant Government Geologist remarks on the comparatively high manganese percentage of the ore in the deeper levels of the Mount Miller mine. Al- though the ore averages nearly 20 per cent, of silica, he thinks that, in times of acute shortage, it might be valuable as a substitute in certain industries other than that for which it is now mined. At the date of his Report, 35,350 tons of ore containing from 18 to 51 per cent, of manganese were de- veloped in the Mount Miller mine, but only a few hundred tons of first-grade shipping ore had been exposed. Deposits have also been worked in the same district at Auckland Hill, occasional small shipments having been made 66 SOURCES OF SUPPLY OF MANGANESE ORES from the mine of that name since 1895, the ore averaging about 65 per cent, manganese dioxide. Several manganese ore deposits have been worked from time to time in the Rockhampton district, between that town and Emu Park, to supply the Mount Morgan gold mine. The main workings in this district are at Coorooman, where the ore produced contains from 60 to 70 per cent, of manganese dioxide. The output of the district has never been large. Deposits occur also in the Maryborough, Ipswich and Darling Downs districts, but there has hitherto been no pro- duction worth recording from these localities. In the Ipswich district, a manganiferous outcrop extends over an area of 6 square miles. Near Gympie, during 1914-15, attention was given to the manganese-ore occurrences of Pie and Eel Creeks, where a certain amount of prospecting was done and several hundreds of tons of ore were mined. Further prospecting in this area would probably disclose other deposits [46]. South Australia. -The mining of manganese ore in this State began in 1882, when 131 tons were produced. Between that date and 1895, production was recorded every year, the highest output being 2,764 tons in 1890. Between 1895 and 1914, only 160 tons were raised. The industry appears again to be attracting some attention, 250 tons, value 563, having been produced in 1915, while the value of the output for 1916 has been returned as 2,700 [47-2], the tonnage not being stated. Deposits of manganese ore at Pernatty Lagoon attracted attention in 1916 [47-1], the main group of leases and claims being situated about 4 miles north-east of the " 71 mile," or Woocalla, on the Port Augusta to Kalgoorlie Railway. The ore occurs as pockets in dolomite and the overlying soil. Analyses of twelve samples show percentages of metallic manganese ranging from about 45 to 56, and percentages of peroxide ranging from about 65 to 89. In eight of the samples the phosphorus percentage is less than 0*01, and the highest recorded for the twelve samples is 0*09. The sulphur per- centage ranges from 0*09 to 0*58. The deposits consist in part of manganiferous iron-ore, a TASMANIA. VICTORIA. NEW ZEALAND 67 sample of which showed 27*67 per cent, of manganese, 34*04 of iron, 0*13 of phosphorus and 0*13 of sulphur. There is an overburden averaging as a rule less than 2 feet in thickness. It is estimated that in mining operations from I to 2 tons of waste are removed per ton of good ore, but, if a market could be found for the manganiferous iron ore, there would be less waste. A feature of special interest is the presence in the deposits of material containing over 89 per cent, of manganese peroxide. The deposits at Pernatty Lagoon are being worked by the Australian Manganese Company, whose agents have reported that a shipment of 117 tons made recently to Liverpool assayed over 85 per cent, of manganese dioxide and under 3 per cent, of iron. Operations have been hampered by shortage of water and lack of carters from the mine to the nearest railway station, but it is now expected that a monthly output of 400 tons can be maintained. Tasmania. Deposits of manganese ore are reported to occur at Zeehan, in the west of the island, but no production has been recorded. Victoria.-^Both manganese ore and manganiferous iron ore occur in large masses in Eastern Gippsland, but there is practically no production. The output of manganese ore for 1915 amounted to only 97 tons, value 337, and in 1916 to only 85 tons, value 300 ; while the total production of the State to the end of 1916 has been only 247 tons, value 919. The output is obtained from deposits at Heathcote, Bendigo District. New Zealand. -Manganese ore has been found in fair quantity in the North and South Islands, the more notable deposits occurring at Tikiora, near the Bay of Islands ; Waiheke Island, in the Hauraki Gulf ; Paraparaumu, about 30 miles north of Wellington, and Taieri Beach, Otago [48]. The Otago ore shows over 90 per cent, of manganese dioxide. There is no home market for manganese ore, and, notwith- standing the offer of a bonus for the manufacture within the Dominion and export to a foreign market of spiegeleisen or manganese-bronze, there has been practically no production 68 SOURCES OF SUPPLY OF MANGANESE ORES since 1907. From 1878-1907, over 19,000 tons of manganese ore, value 61,000, were exported. It is officially recognized that, even at the unusually high prices current in 1917, the shipment of manganese-ore from New Zealand to the northern hemisphere is hardly com- mercially possible until ocean freights and insurance are considerably reduced. CHAPTER III SOURCES OF SUPPLY OF MANGANESE ORES (continued) (b) FOREIGN COUNTRIES EUROPE AUSTRIA-HUNGARY (including Bosnia and Herzegovina). -The production of manganese ore in Austria-Hungary has never been conducted on a large scale, and the output for the years 1911-13 showed a considerable falling-off as compared with that for the previous decade, the annual average for the three years in question being only 15,000 metric tons for Austria- Hungary, while that for Bosnia-Herzegovina was 4,316 tons, Later statistics are not available for Austria, but for 1914 the production of manganese ore in Hungary was 11,413 metric tons, and in Bosnia-Herzegovina 4,120 tons. It would appear certain that the output of manganese-ore from the well-known deposits must have appreciably increased since extraneous supplies were cut off by the war. The ore is generally of low grade. The chief producing centres are the Bukovina and Krain, and these, while of comparatively small importance in normal times, must have been of considerable value to Austrian steel-works during the war. A description of the geology and occurrence of the manganese ore deposits of the Drona Vatra district, in the Bukovina, and the methods of working adopted, was furnished recently by H. K. Scott [49]. From this it would appear that the deposits in the Bukovina, while not of high grade, are richer than any continuously worked in the Austrian Empire or in Germany. They occur in the neighbourhood of Jacobeni, in the south-west of the Bukovina, near the Roumanian and Hungarian frontiers, and have been known for three-quarters of a century, although originally worked for their iron content. 69 70 SOURCES OF SUPPLY OF MANGANESE ORES In 1902, Jacobeni was connected by a branch railway with the main line from Bucharest to Lemberg, Cracow and Vienna, and the output of manganese-ores was consequently increased. The ore occurs in lenses, consisting of both oxide and car- bonate, the average assay being 33 per cent, of manganese, with phosphorus present. The richer ore is separated by hand-picking, the remainder being crushed and concentrated by jigging. The lenses of ore already developed guarantee an annual output of 50,000 tons for three years, while further quantities will doubtless be proved at lower levels. Before the war, the Witkowitz Company, in Austrian Silesia, was a large buyer of the concentrate for ferro-manganese production, while the hand-picked ore was bought by glass- and chemical- makers. Schemes were in hand for more extensive develop- ment of the mines. Deposits of manganese-ore occur also in Carniola, Bohemia, Istria, Styria and other parts of the former Empire. BELGIUM. There has been no production of manganese ore in Belgium since 1909. The highest annual output recorded since the beginning of the present century was 14,440 metric tons, the average annual output for the period 1900-9 being about 5,600 tons. Manganiferous iron ores are mined chiefly in the Province of Liege. Of the total quantity of manganese ore exported from India during the two years from April ist, 1912, to March 3ist, 1914, the proportion received by Belgium was 25*16 per cent., the figures for 1912-13 being 171,066 long tons, value 184,287, and, for 1913-14, 187,821 tons, value 212,308, Belgium being, next to Great Britain, the largest buyer of the Indian ore. Belgium has also been a large purchaser of Russian man- ganese-ore, her imports in recent years having been as follows : 1912, 193,500 tons ; 1913, 182,500 tons ; 1914, 154,467 tons. The Russian exports to Belgium in the first two of these years represented 19*15 per cent, of the total tonnage exported. The large reduction in 1914 was, of course, due to the war. Of recent exports of manganese ore from Brazil, Belgium received the following quantities : in 1911, 34,840 tons ; 1912, 10,900 ; 1913, 11,800. In 1914, 10,600 tons of Brazilian ore had been received before the war started. Belgium was BULGARIA. FRANCE 71 third in order of importance as a purchaser of Brazilian ore, the United States ranking first, and Great Britain second. BULGARIA. -The Bela manganese ore deposit is situated about 7J miles south of Varna, near the Black Sea, occurring in strata of Tertiary age consisting of clays approximating in places to a sandstone. The ore is described [50] as wad, occurring in lenses varying in thickness from in. to 6 in. or more, over a width of 10 feet to 20 feet of the clay, the deposit containing a large quantity of mineral with 35 per cent, of manganese in the dried ore. This cannot be shipped at a profit in the raw state, but' might be profitably handled if the ore were sintered or briquetted. The percentage of phosphorus is high, that of manganese low, while in its raw state the ore contains upwards of 20 per cent, of moisture, and on exposure to the atmosphere disintegrates, passing into a physical condition undesirable for blast-furnace use. Manganese ore also outcrops at Dobra Nadejda, 2 miles from the station of Jambouli, pyrolusite occurring in beds from i to 4 feet in thickness, with an andesite foot-wall and a limestone hanging- wall. The ore is of low grade. FRANCE. -The domestic production of manganese ore in France has never been of important size, and heavy imports have been required. Recent figures for imports are as follows : 1911, 235,400 metric tons ; 1912, 225,379 metric tons ; 1913, 258,929 metric tons. Complete statistics are not available for imports in 1914 ; but, of the quantity received, 103,847 tons came from India and only 23,951 tons (or about half the normal quantity) from the Caucasus. The imports from India in 1915 were on a much-reduced scale, owing to the war and the requirements of Great Britain. The production of manganese ore in France in 1913 was 7,732 metric tons. Later statistics are not available. The chief occurrences of manganese ore are at the Las Cabesses mine, Department of Ariege (Pyrenees), and the Romaneche and Grand Filon mines, Department of Saone et Loire. The Las Cabesses mine formerly produced con- siderable quantities of carbonate ore, which occurred there as a mass about 200 feet in length and 165 feet in width* 6 ?2 SOURCES OF SUPPLY OF MANGANESE ORES This had been opened to a depth of about 230 feet by the year 1893. Such of the carbonate ore as was sold raw con- tained an average of 40 per cent, of manganese, 5*9 per cent. of silica, and 0^048 per cent, of phosphorus. Calcining in kilns brought up the content of manganese to 54*3 per cent., increased the silica to 9*3 per cent., and reduced the phosphorus to 0*041 per cent., the calcined product showing a loss in weight of about 32 per cent, on an average for the year 1893. The mine ceased work in 1904, since when the chief producers have been the Romaneche and Grand Filon mines, which yield pyrolusite. GERMANY. Almost the entire German production of manganese ore has been obtained from the neighbourhood of Coblenz, the principal mines being the consolidated Schloss- berg, Amalienshohe, Concordia and Elisenhohe. The ore occurs usually in pockets. There are also a number of man- ganiferous iron ore deposits, in the region of Siegen and Nassau, the mineral from which is largely used for the making of spiegeleisen. In 1911, the total production of these deposits was over 3,000,000 tons, of which, however, only an insignifi- cant proportion contained 30 per cent, of manganese, while only about one- tenth had a content exceeding 20 per cent., the remainder assaying as low as from 2 to 12 per cent. In 1912, there was an output of low-grade ores, mainly from the Bonn district of Prussia, amounting to 92,474 metric tons, the production in 1913 being 330,797 tons, an increase which may be not without sinister significance. The only deposit producing before the war what is com- mercially considered as manganese ore was that at Giessen, and the output from this source was only a few hundred tons [51]. Imports of foreign manganese ores into Germany rose from 223,709 tons in 1903 to 523,132 tons in 1912, about 64 per cent, of the tonnage in 1912 coming from Russia, about 24 per cent, from India, about 6 per cent, from Spain, and about 4 per cent, from Brazil. In 1913 [52], the total imports of manganese ore were 680,371 tons. The cutting-off of foreign supplies at the outbreak of the war rendered it necessary to exploit more rigorously the domestic sources of manganese ore suitable for f erro-manganese GERMANY. GREECE 73 production ; but, having regard to the abnormally high imports of Russian and Indian ores in 1913, also to the invasion of Belgium and Northern France and the seizure of the large ore-stocks of those regions, as well as to the great decrease of German exports of steel and of iron-manganese alloys, the ferro-manganese situation in Germany probably did not become acutely serious for several months after the war started. Substitutes for iron-manganese alloys as re-car- burizers of steel have been tried, but according to F. Jovic [53] these proved more costly and yielded such inferior results that their use was abandoned. The total amount of manganese ore (over 30 per cent, manganese) smelted in Germany during the year 1913 was 700,832 tons [54]. In a paper read before the American Institute of Mining Engineers [55], F. H. Wilcox stated that during the year 1916 piles of slag from old ferro-manganese furnaces in West- phalia, running from 5 to 14 per cent, manganese, were drawn upon, and that U.S. Consul Albert, of Brunswick, Germany, had reported that the village of Adenslidt had been demolished to secure ore running about 22 per cent, manganese. He also remarked that complaints had lately been reported from Dutch sources in regard to the quality of German steel, which was said to be daily proving worse and becoming hard and brittle. The deterioration was attributed to lack of skilled workmen and of manganese. GREECE. Important deposits occur on the islands of Milo and Andros, but the quantity of true manganese ore mined is small, the output from these islands and other localities consisting very largely of manganiferous iron-ore. The Kassandra mines in the province of Salonika (until a few years ago included in the Turkish Empire) formerly yielded about 60,000 tons of pyrolusite annually, but no information is available as to their present output. The production of manganese ore in Greece reached a total of nearly 15,000 metric tons in 1902 ; between that year and 1908, the annual output averaged about 7,500 tons. Since then the pro- duction has become greatly reduced, sales averaging only about 500 tons per annum for the period 1913-15. It appears, 74 SOURCES OF SUPPLY OF MANGANESE ORES however, that 1,315 tons of ferro-manganese were produced in 1914, and 1,041 tons in 1915 [56]. ITALY. Deposits of manganese ore occur in Liguria, Tuscany and elsewhere, but the output is small owing to the high percentage of silica in the ore, as well as to lack of transport facilities. The annual production of that class of ore for the period 1902-11 varied from about 2,000 metric tons up to a maximum of about 5,400 tons (in 1905), the output in the year immediately preceding the war being only 1,649 tons - For 1915, however, the production of manganese ore has been reported at 12,577 metric tons. There has been a considerably larger production of man- ganiferous iron ore, sometimes exceeding 25,000 tons in a year. In 1911, however, the output of that class of ore fell to 6,482 metric tons, and in 1912 there was no production. Statistics for later years are not available. The mangani- ferous iron ore industry in Italy no doubt suffered owing to her war with Turkey, and may not recover for some time after the European war. PORTUGAL. The production of manganese ore in Portugal has never been of considerable importance, and statistics for recent years are not available. RUSSIA. The great bulk of the manganese-ore hitherto exported has been obtained from deposits at Tchiatouri (Chiaturi) in the province of Koutais, district of Sharepan, on the southern slope of the central part of the Caucasus moun- tains. These deposits are said to have been discovered in 1848, but the first shipment of manganese-ore recorded was made in 1879. In the decade 1904-13, the Tchiatouri deposits yielded about 75 per cent, of the total Russian production. The Nikopol district, in the government of Ekaterinoslav, South Russia, where manganese-ore deposits occur in the vicinity of the Dnieper River, about 100 miles from the Gulf of Odessa, has contributed steadily and progressively to the production since 1886, the output for the decade 1904-13 amounting to over 24 per cent, of the total Russian pro- duction. Of the Nikopol output, 80 per cent, is delivered to South Russian metallurgical works, the balance of 20 per cent, going normally to Germany [57]. The small remainder RUSSIA 75 of manganese ore produced in Russia is obtained from deposits in the central part of the Urals (governments of Perm and Orenburg), this output being of only local importance, going to Urals works. Until the outbreak of the war, Russia had always been the chief producer of manganese ore except for the short period 1908-11, when its output was exceeded by that of India. The war has very seriously affected the Russian industry, practically bringing it to a standstill, exports through the Dardanelles to Great Britain and the United States, as well as into Germany (the largest buyer of Russian ores), having been entirely suspended. The total production of manganese ore in Russia from 1879-1913 amounted to over 12,500,000 long tons. Statistics for recent years are given in the table (p. 6) showing the world's production in long tons. The figures therein show that the highest output attained was reached in 1913, when 1,289,370 long tons were produced, the previous best years having been 1906-7, when the yield averaged just over 1,000,000 tons. In 1914 the production was more nearly normal, amounting to 725,450 long tons, but it has been roughly estimated [58] that the production for 1915 was only 50,000 tons and for 1916 only 150,000 tons. The development of the industry is hampered by faulty organization, primitive and wasteful methods of mining, and lack of adequate transport facilities, which not only prevents the opening up of new deposits, but involves high railway charges to the ports of shipment. Large schemes are said to have been under consideration for bettering the position of the industry after the war, including improved mechanical equipment for transhipping ore, at Poti and Batoum, and the transformation generally of the latter port. Tchiatouri Deposits. The ores of the Tchiatouri district are of sedimentary origin, and the deposits are distinctly stratified, the regional rocks being Cretaceous and Tertiary sediments regularly bedded and lying almost horizontally. The total area in which mines occur is said to be about 55 square miles, of which about two-fifths is believed to contain high-grade ore. The average thickness of the manganiferous bed is from 6 to 7 feet, but only about one-half of this is 76 SOURCES OF SUPPLY OF MANGANESE ORES valuable. Harder [61] estimates that these deposits contain about 110,000,000 metric tons of manganese-ore. H. K Scott, however, estimates the amount available at about 22,000,000 tons [59]. The ore consists mainly of pyrolusite, but psilomelane and wad also occur. The average percentage of manganese is from 40 to 45, this being raised to about 51 or 52 per cent, by cleaning and sorting. Phosphorus averages about 0*16 per cent., and silica not more than 8 per cent. The ore is softer and more friable than that produced in India, and disintegrates to a serious extent during mining and transportation, this rendering a heavy percentage of the mineral unsuitable for shipment for use in . blast furnaces. The ore is hand-sorted at some mines, whilst at others it is screened to get rid of the siliceous gangue and then roughly concentrated on tables or jigs [60]. The ore thus prepared is classified as " very rich," " rich," and " medium," the sorting process yielding about 33 per cent, suitable for ship- ment. It has to be transported from i to 6 kilometres in mine-trucks and 40 kilometres by narrow-gauge railway, and reloaded into broad-gauge wagons for transport to Poti, on the Black Sea (about 90 miles from Tchiatouri), where two- thirds of the ore is shipped, the remainder being exported through Batoum (about 126 miles from the mines). The cost of the ore delivered at Poti, including port charges, is nor- mally 23/8*5, and at Batoum 23/11*5 per ton, including 6/o'5 for actual mining [61]. Nikopol Deposits. These are horizontal beds in Oligocene strata, granite and gneiss occurring at no great depth below. The manganiferous area is estimated at about 8 square miles, the beds averaging from 3 to 5 feet in thickness. The avail- able ore is estimated at about 7,400,000 metric tons, but H. K. Scott and others are of opinion that many times this amount is available. It occurs as nodules of psilomelane and pyrolusite in a bed of sandy clay, and, as exported, averages 46 per cent, of manganese, 12 per cent, of silica, 0*25 per of phosphorus, and i per cent, of iron. The better class is said to contain about 57 per cent, of manganese [62]. The Ural District. This has been a steady, although small, producer of manganese ore since 1882. An exceptionally RUSSIA 77 large yield was obtained in 1912, when the output amounted to 21,487 tons. Attention has recently been drawn to a new region, the Gaisinsk district, province of Podolia, South-West Russia, 221 miles by rail from Odessa, where there are deposits of pyrolusite apparently of large size and high grade. The Podolia manganese region comprises an area of about 30 square Tons. 240 /b) $4 Y ear. Tons. (S>B40/t.) (000 000 3OOOOO 800 f OOO 7OOOOO ff oqooo so q ooo 4OO f OOOl- 3OOOOO Poo, ooo fooooo woqooo Boqooo # oqooo ?oqooo 6 oqooo so q ooo 4OOOOO 30 q ooo 20 q ooo looooo DIAGRAM 5. EXPORTS OF MANGANESE ORE FROM TCHIATOURI. TOTAL AND TO PRINCIPAL COUNTRIES (1912-1914) 78 SOURCES OF SUPPLY OF MANGANESE ORES miles, and it is very advantageously situated as regards not only German and Austrian markets, but also exportation of ore from Odessa and Nikolaiev. Distribution of Russian (Caucasus) Ores. The Tchiatouri ores, constituting about three-fourths of the total Russian production, were distributed during the years 1912-14 as follows [63]. (See Diagram 5, p. 77) : To 1912. 1913- 1914. Germany Austria Belgium. . France Great Britain Italy United States Tons. 322,500 40,000 193, 5 42,200 202,000 96,300 Tons. 412,000 25.4 182,500 55.i 246,500 7,400 137,700 Tons. 326,403 32,435 154,467 23.951 107,030 34,54 8 Total Expo] Unexported -ts 896,500 17,000 1,066,600 10,000 678,834 i5. 96 Taking the two years immediately preceding that of the commencement of the war, and grouping the countries according to their attitude in 1914, the percentages of the total Tchia- touri actual exports of manganese-ore work out as follows : To Years 1912-1913. A Hied Countries ' United Kingdom . ... Belgium ... ... France ... ... Italy .... ... Percentage of total quantity exported. 22-85 I9-I5 4-95 0-38 Total . ... 47-33 Enemy Countries t Austria ... ... Germany ... ... 3-33 37-42 Total . . . . . 40-75 Neutral Country ' United States . . . . 11-92 Grand Total IOO-OO The chief operating companies in the Tchiatouri manganese- field before the war are stated [64] to have been the Schalker Gruben und Hiitten Verein, of Gelsenkirchen, Germany (which RUSSIA. SPAIN 79 consumed its own ore) ; Forward Bros. (English) ; Panassie (French) ; and the Industrial and Commercial Company, of Antwerp. The Belgian company has a plant capable of producing 100,000 tons of 53 per cent, to 54 per cent, washed manganese-ore per annum. Numerous other small properties are being worked in crude fashion. The great increase in German buying of Russian man- ganese-ore in the year immediately preceding the war and during that part of 1914 when the Russo-German frontier was not yet closed,, is perhaps not without special significance. ,- :? . Recent information from Russia states [65] that while less than 32,758 metric tons of manganese ore were sent away from Tchiatouri in 1915, 255,111 metric tons were despatched from the district in 1916. The Russian works, which for- merly obtained their principal supplies from the Nikopol mines, at the rate of about 32,758 metric tons per annum, increased their demands to 196,552 tons in 1916, and, the Nikopol mines being unable to meet this requirement, the bulk of the ore was obtained from Tchiatouri. Of the 255,111 tons despatched from Tchiatouri in 1916, about 49,138 tons were added to the stocks at the port of Poti, where at the end of that year 131,035 metric tons were stored. The total stock of manganese ore in the Caucasus at the end of 1916 was about 917,246 metric tons, as against 1,716,000 tons in hand at the end of 1914 [66]. SPAIN. The deposits of manganese ore chiefly worked hitherto are situated in the province of Huelva, the mineral being a carbonate. About the beginning of 1915 [67] a man- ganese field was opened in Sevilla and another in Ciudad Real, and shortly afterwards new workings were opened in Huelva (where the known deposits had to a large extent become exhausted), Gerona and Oviedo. In Sevilla the manganese beds lie along the Silurian slates, and in Ciudad Real are the bases of little Tertiary hills interbedded with the Miocene limestone. A few years ago, new deposits were discovered in the province of Teruel, where the ore is a silicate containing 33 per cent, of manganese and from 30 to 37 per 8o SOURCES OF SUPPLY OF MANGANESE ORES cent of silica. This has been exported to Belgium and Luxembourg, and smelted with aluminous iron ores. Spanish manganese-ore is commonly sold on the basis of its percentage of manganese dioxide. The annual output of manganese ore exceeded 100,000 tons during the years 1897-1900, but the production has since been irregular and decreasing. In 1907, exports made a notable recovery, amounting to 68,000 metric tons ; but the period 1909-11 was the worst on record, production averaging only about 7,300 tons a year. Subsequent production and shipments have been as fol- lows [68] : Year. Output. Exports. Me trie tons. Metric tons. IQI2 . . 19,936 29,764 1913 21,594 27,793 1914 - - i 8,965 1915 14,328 9,I3 6 1916 . . 14,1782 6,815 1917 57,474 a l 1 Statistics not available. Official. There is normally a large export of manganiferous iron ores, but the production in 1917 amounted to only 50 tons. SWEDEN. The chief producing districts are Undenas (Bolet), West Gothland, Wermland, and Jonkopings. Three types of manganese ores occur : (i) pyrolusite with manganite, (2) hausmannite with braunite, and (3) carbonate and silicate of manganese accompanying iron ores. The annual output, which is comparatively small, is given in the table showing the world's production. The difficulty attending the lack of manganese in Sweden since the outbreak of the war appears to have been to some extent overcome by the use of ferro- silico manganese. Ferro-manganese is also produced in Sweden in the electric furnace, but it is not suitable for all purposes, on account of the comparatively high silicon con- tent [69]. SWEDEN. TURKEY 81 The production of ferro-alloys in the electric furnace in Sweden for recent years has been as follows * : (Metric Tons) 1913- 1914. 1915- Ferro-silicon .... 9,863 8,732 11,819 Silico-manganese iron i,375 i,34 2,328 Ferro-manganese 293 947 In addition there was a small production of ferro-chrome (averaging about 770 metric tons per annum for the three years). The combined production of ferro-silicon and silico- manganese iron in 1917 was 18,000 tons, and in 1918, 11,600 tons. TURKEY. The output of manganese-ore in European Turkey has been principally obtained from the Kassandra mines in the province of Salonika (now included in the King- dom of Greece), which formerly yielded about 60,000 tons of pyrolusite annually. A similar amount is said to have been obtained from deposits in the Phlinika district, Asia Minor, which yielded ore containing 52 per cent, of manganese. Small quantities of ore are also obtained from the vilayets of Trebizonde and Aidin. According to E. Halse [70], important deposits of manganese ore in serpentine were opened up, not long before the war, in the vilayet of Aidin ; and he has personally examined deposits of that ore at Pirga, in the vilayet of Trebizonde. These latter occur, about 500 feet above sea-level, a few miles from Surmeneh on the Black Sea. The ore, chiefly psilomelane and manganite, fills irregular pockets, pipe-like openings and fissures in limestone, and occurs in lumps mixed with red and yellow clay, fragments of limestone, etc. A few of the deposits at Pirga had been worked on a small scale about 23 years before, but nothing was seen in any way comparable with the Caucasian (Tchiatouri) deposits. Many stringers of man- ganese ore occur also in the altered porphyry, but these are unworkable. i Quoted from Statistical Report, 1916 Iron, Steel and Allied Trades Federation. 82 SOURCES OF SUPPLY OF MANGANESE ORES Statistics of production for recent years are not available. The official report of the Department of Mines and Forests of Turkey, for the fiscal year ending March, 1909, gave the production of manganese-ore in 1908 as 14,349 metric tons, value 19,617 ; and in 1909 as 7,578 metric tons, value 10,000. It is stated that shipments of ore containing 85 per cent, of manganese dioxide and less than i per cent, of iron have been made from Turkey to the United States. This was probably used in the manufacture of dry electric batteries. A selling basis of 45 per cent, of manganese is common in the case of Turkish ores, which are somewhat more variable than the high-grade ores of Russia, India and Brazil. ASIA JAPAN. There are numerous occurrences of manganese-ore in Japan, and the country has been a steady producer for many years, the output for 1896 amounting to 17,967 metric tons, the highest production recorded being 54,339 tons in 1906. The production in later years is stated in the table showing the world's production. Manganese-ore is widely distributed in Japan, occurring in most of the provinces, but the deposits do not appear to be extensive. Among the well-known mines are the Mirika, in Hokkaido, the Takasaki in Aomori prefecture, and the Kita- yama in Kyoto. The manganese-ore of economic importance is most probably a mixture of oxides (psilomelane, pyrolusite, etc.). The ore occurs mostly in rocks of the Palaeozoic age, but also, less widely distributed, in the Tertiary and still later formations. In the older rocks it is found, as a rule, exclusively in the zone of oxidation, and is easily mined by open cuts or shallow pits. In the majority of cases, the deposits are lenticular or irregular in form, varying in size from a small lump up to a mass weighing a hundred or more tons. The most widely distributed and economically important ore is for the greater part found in quartzite, hornstone, radiolarian slate, or schalstein [71]. Alabandite (MnS) associated with rhodochrosite occurs in large quantities in the silver veins at Innai, in the province of Akita [72]. The ores exported JAPAN. JAVA. DUTCH-BORNEO 83 are fairly high grade, and average about 52 per cent, of man- ganese and from O'i6 to 0-8 per cent, of phosphorus. The selling basis for Japanese manganese-ores, which are rather more variable than those exported from Russia, India and Brazil, is commonly 45 per cent, of manganese. At Hamburg they have realized prices ranging from 2 los. to 5 155. per ton according to quality. According to G. T. Holloway [73], the Japanese " brown- stone " ore (pyrolusite) is specially suited for chemical purposes, and fetches a higher price than others per unit of manganese. It varies in composition from about 43 to 56 per cent, of manganese, 7 to 10 per cent, of silica, and carries about 0*5 per cent, of phosphorus. It is commonly sold for its value in available peroxide, the schedule being agreed at so much per ton if from 85 to 90 per cent, manganese dioxide, or so much if from 75 to 85 per cent., 70 to 75 per cent., or 65 to 70 per cent. Japanese brown-stone containing 87 per cent, of manganese dioxide (about the best obtainable) fetches about twice as much as 70 per cent, ore ; while certain Continental pyrolusites, containing about 50 per cent. of available manganese dioxide, and stated to be marketable in the United States, fetch only about one-fifth as much as the 87 per cent. Japanese ore. In 1917, the United States imported 2,745 tons from Japan. JAVA. Deposits of manganese ore have been worked in the Regencies of Pengasih and Nanggolau, but the production is of unimportant size. Occasional shipments have been made to the Mount Morgan gold mine, Queensland. DUTCH-BORNEO. Manganese ore is known to occur at Gunong Bessi ( = iron hill) in South Borneo. About i miles north-west of Pengaron, there is an isolated hill, about 150 feet in height and 2,500 feet in circumference, described by Pose- witz [15] as lying near a dyke of augite-andesite, cutting late Tertiary sandstone strata. The hill is covered with a thick layer of earth and numerous boulders, many of which measure from 1,500 to 2,000 cubic feet. These boulders consist of a very hard steel-grey manganese dioxide, usually with a blackish deposit of wad on the surface. The occurrence was confirmed as early as 1858. A detailed investigation carried out in 84 SOURCES OF SUPPLY OF MANGANESE ORES 1883 showed that these boulders were derived from a vein about 30 feet in thickness, traversing a grey andesitic tuff, and having the same strike and dip as the coal-seams of Pengaron. According to Hooze, it is a case of lateral secretion. The amount of manganese peroxide in the ore is very variable, samples taken by Hooze assaying up to 787 per cent. An analysis made at Freiberg, in Saxony, gave 97*27 per cent, of manganese dioxide. C. M. Schwaner found small quantities of psilomelane in different localities of the former kingdom of Bandjermassin, in South-East Borneo [15]. PHILIPPINES. The most important and best-known deposit of manganese-ore in these islands occurs in the eruptive conglomerate region of Nagpartion, in the province of Ilocos Norte. The occurrence is described [74] as a system of veinlets of pyrolusite between boulders of eruptive material. The matrix is a soft and yielding tuff. This material has been decomposed, resulting in a concentration of nodules of pyro- lusite in the depression between the adjacent hills of tuff. The original veinlets are only from 5 to 50 mm. in width. Developments between Punta Negra and Punta Blanca have indicated that, although the lateral extent of the nodule concentration is considerable, the thickness of the deposit is small. The nodules are of very good quality, containing 77 '5 P er cent, of manganese dioxide, only 0*02 per cent, of phosphoric anhydride, and ri per cent, .of silica. Two other deposits are known, one in the island of Masbate, which is said to be of promising appearance. Up to the end of 1915 [75] the only production of manganese ore in the Philippine Islands that had been recorded was in the year 1909, when ore to the value of 1,300 was mined. In 1917, from 2,000 to 3,000 tons of ore were shipped from deposits in Ilocos Norte. Japan has been mentioned as a possible buyer of such ore from the Philippines. Lack of shipping facilities is a great difficulty. PORTUGUESE INDIA. Deposits of manganese ore, usually psilomelane or pyrolusite, separate or associated, are widely distributed in Goa ; but they occur so irregularly, and are so variable in composition, that they are of comparatively CONGO. UNITED STATES 85 little importance. In all cases they are overlaid by a thick bed of true laterite, which enhances the cost of quarrying to such an extent as to render the operation barely profitable. The ore hitherto produced has not been of high grade. Exports for 1907 amounted to about 12,580 tons, but the fall in the market-price of manganese-ore in 1908 resulted in a general suspension of work. During the period 1909-13, an average of 3,250 tons of ore won in Goa was annually exported from Mormugao, the quantity for 1913, however, being only 1,556 tons [76]. AFRICA Belgian Congo. Manganese ores have been found in the Katanga, where they are frequently associated with the iron deposits, but their economic value has not yet been proved. A rather large deposit in the valley of the Fungwe River consists of lenses of high-grade manganese-ore and quartz at the contact of biotite granite and norite with an older muscovite granite. This deposit has been variously described as a contact deposit, or perhaps a magmatic segregation, or a vein [77]. " German " East Africa. Manganese ore occurs in the Unata district, some 25 kilometres west-north-west of Ikoma ; and psilomelane has been found in the Kipengele Hills, in the Livingstone Mountains. AMERICA UNITED STATES. The proportion of manganese ore proper mined in the United States before the war was a quite negligible quantity, being only about the same as that of the United Kingdom. E. C. Harder [78] explains the fact of the man- ganese mining industry in the United States never having attained importance as being due to the small extent and the discontinuous and scattered nature of most of the de- posits. Nearly all the ore mined must be either washed or sorted, or both. The small extent of the pockets of ore does not encourage companies to erect expensive concen- trating plants. In general, the ore is low in manganese and high in silica. 86 SOURCES OF SUPPLY OF MANGANESE ORES The following table, compiled from various official sources, shows the insignificance of the manganese ore output of the United States in recent years : (Long Tons) State. 1912. 1913. 1914. 1915. 1916. California . , 501 2,5 6 3 i3.4 4 * South Carolina 410 Georgia 3,168 Virginia . 1,664 i 4,0481 i.7 2 4 1,620 Other States 2,358 Total .... 1,664 4,048 2,635 9,79 26,966 1 Includes Tennessee and California. (1913 figures include small produc- tions in 1911-12.) In 1917, California produced 15,515 tons, the estimate for 1918 being 25,000 tons. * Calif. State Mining Bureau, Press Bull. 43, Dec. 3rd, 1917. It will be seen that the marketed domestic production of manganese ore increased, owing to the cutting-off of supplies from Russia and short shipments from India, from an average of only about 2,800 tons a year for the three years 1912-14 to about 27,000 tons (the actual weight was probably about 33,000 tons) for 1916, the production for that year being the highest till then reached since 1888. The estimate, of course, does not include the manganiferous iron ores containing less than 40 per cent, of manganese. The domestic production of manganese-ore marketed in 1917 is estimated at 122,275 tons [79]. According to The Mineral Industry [80], the 1916 output came largely from seven States, the order in production being probably California, Arkansas, Arizona, Georgia, Virginia, Utah, Colorado. It is remarked that the year in question was the first in which a Western State remote from the steel- producing centres has contributed the largest amount of manganese-ore. The activity among manganese mines in California is stated to be due largely to the market for ores provided by the Noble Electric Steel Co. at Heroult, Shasta County, California. California. The characteristic occurrence of manganese ore in California, as described by E. C. Harder [81], is in the CALIFORNIA. VIRGINIA 87 form of porous black oxide, associated as layers and pockets with the jasper lenses of the Franciscan formation of the Coast Ranges. Smaller deposits are found in the Sierra Nevadas, in veins in the Calaveras formation, as fragments disseminated in auriferous gravels, or in deposits associated with igneous rocks. Recent investigations by the California State Mining Bureau have proved the occurrence of important deposits of manganese ore, in Inyo and San Bernadino counties, as replacements in limestone or along contacts between lime- stone and granite. The deeper workings of the Ladd and Merchant Mines in San Joaquin and Alameda counties are yielding the grey carbonate of manganese, rhodochrosite, as a commercial ore [82]. Siliceous manganese ores are very common in California. Virginia. The largest deposit of high-grade manganese ore hitherto discovered in the United States appears to be that at Crimora, Augusta county, Virginia, from which some 350,000 tons of ore have been produced during the past thirty-five years. The deposit is described by E. C. Harder [83] as consisting of manganese ore masses of various sizes scat- tered through variegated clays in a canoe-shaped syncline of the Cambrian quartzite. The basin has a general north- south trend, and is about half a mile in length, several hundred yards in width, and 200 feet in depth. It occupies a flat area bounded on the east and north by spurs of the Blue Ridge. The clays are for the most part residual from the upper Cam- brian shale, and are white, yellow, orange, brown and black in colour. In general they are stiff, but here and there are masses of yellow sandy clay, or white sand, or fragments of undecomposed sandstone. The black manganiferous clay generally occurs in separate beds, lenses, or irregular pockets, or interlaminated with the other clays, while the light-coloured clays as a rule are intimately intermixed. Stiff orange and yellow clays are the most abundant, and contain most of the ore. The residual clays are covered by a layer of drift averag- ing about 15 feet in thickness. The ore is hard and of three varieties : (i) kidney ore of bluish-black psilomelane in stiff orange and yellow clay ; (2) irregular pockets of pyrolusite and psilomelane in man- 7 88 SOURCES OF SUPPLY OF MANGANESE ORES ganiferous clay ; and (3) replacements and cavity fillings of psilomelane and pyrolusite in sandy clay. The kidney ore is the most abundant and occurs in lumps of rounded, irregular shapes, a few inches in diameter. An analysis of the best quality of ore from the Crimora mine shows 57-291 per cent, of manganese ; 0-373 per cent. of iron ; 2*132 per cent, of silica ; 0-075 per cent, of phos- phorus. Average analyses of actual shipments during 1887 and 1888 indicate that the average percentage of manganese is slightly under 50, the percentage of silica being rather high and at times excessive, that of phosphorus satisfactorily low, iron varying from 2 up to as much as, exceptionally, 4-5 per cent. Virginia appears to possess a larger number of deposits of manganese ore than adjacent States, and, owing to this fact and to the proximity of markets, it has supplied a large part of the domestic production. For the period 1880-1914 the average proportion was 61 per cent., and of this ore nearly two-thirds is said to come from the Crimora mine [84]. No other deposit in this region, from Maryland to Alabama, has yielded more than 50,000 tons of manganese ore. The ma- jority of those that are known have been, or are being, worked, and D. F. Hewett [85] is of the opinion that they are unlikely to average more than 10,000 or 15,000 tons each in total production. Georgia. This was formerly (from 1866) one of the principal producing States, her strongest competitors being Virginia and Arkansas ; but there had been no important production in that State since 1902 until the year 1915. The commercially valuable deposits of Georgia are entirely limited to the northern part of the State, and to certain areas in the Palaeozoic group [86]. Arkansas. Some attention is now being given to certain deposits of manganese-ore, hitherto unexploited, in the Ouachita Mountains, west-central Arkansas. According to H. D. Miser [87] the ores occur as nodules, pockets and short irregular veins varying in width from less than an inch to, rarely, 4 feet. The ore bodies are described as being scat- tered through hard novaculite, the ore being generally con- ARKANSAS. MONTANA 89 fined to two stratigraphic horizons in it, occupying bedding planes or joint cracks, or forming a cement in a novaculite breccia. Most of the ores contain too much phosphorus for use in the manufacture of ferro-manganese, and too much iron for use in the chemical and dry battery industries. It is stated in The Mineral Industry [88] that several prospects now show a width of 3 feet and over of solid psilomelane, the ore giving returns of 50 to 60 per cent, of manganese, up to 8 per cent, of silica, and about 0-2 per cent, of phosphorus. The deposits have hitherto been worked only in a small way, and only a few hundred tons of ore therefrom have been marketed. The Batesville field, in Independence and Izard counties, Arkansas, the output from which was negligible before the war, is now producing about 2,000 tons a month of hand- cobbed and fine-washed manganese-ore [89]. The ores, which comprise various oxides, occur in a residual clay derived from the decay of a bed of overlying limestone, the distribution of the ore in the clay being irregular. The pockets are some- times comparatively solid bodies separated only by thin seams of clay, containing from 50 to 500 tons of ore ; or they may consist of large and small masses of ore imbedded in greater or lesser quantities in certain places in the clay ; whilst the ore has been found also in the form of small nodules or grains, disseminated throughout the clay. Most of these pockets of " wash dirt " contain from 5 to 25 per cent, of manganese ore. Some ore has also been found in its original form in broken limestone boulders that have not yet disintegrated. The ore classed as " high grade " runs from 40 to 58 per cent, of manganese, the " low grade " from 40 to 17 per cent. Montana. It was reported in 1917 that large deposits of manganiferous iron ore, averaging from 30 to 40 per cent, of manganese, had been discovered in Western Butte, Mon- tana [90]. The desirability of exploiting all the available sources of manganese in the United States during the war has resulted in the manganiferous gangue of the silver-zinc lodes of these Montana ores, formerly regarded as waste, being worked as a source of manganese. With prices for go SOURCES OF SUPPLY OF MANGANESE ORES manganese oxides in the United States as at present, this is economically practicable. The manganiferous mineral in the outcrops and upper portions of the lodes is low in manganese and very high in silica, reserves of such material assaying as follows [91] : Tons. Mn SiO 2 per cent. per cent. 26,000 .... 40-0 10 132,000 .... 24-0 50 270,000 .... 11-5 73 It is regarded as possible that the second-class might be concentrated. The greater part of the manganiferous material, however, lies below the oxidized zone, and consists of the carbonate of manganese (rhodochrosite) and the silicate (rhodonite). In the Emma mine, the carbonate ore carries from 34 to 41 per cent, of manganese and only i per cent, of silica, and the manganese content is increased by a light roasting, which drives off carbon dioxide. Several thousand tons of this ore are said to be available, and large additional quantities are likely to be developed. The amount of lower-grade material, averaging 15 per cent, of manganese, is estimated at several million tons. The manganese ore output of the Emma mine was recently stated to be about 300 tons a day [92], but the average analysis is not available. Most of the manganiferous lodes at Butte carry less than 40 per cent, of manganese ; they are high in silica, and contain from 3 to 4 per cent, of iron. A plant for the mechanical concentration of manganese-ore has been in continuous operation by the Philipsburg Mining Company, at Philipsburg, Montana, since January 1918 [93]. The manganese mineral occurs in a limestone formation and consists chiefly of a nodular variety of pyrolusite and psilome- lane. A fair average of the assays is said to be as follows : Manganese Silica per cent. per cent. Heads : V . . : Y . 32 35 Washed ore (coarse) . . > . 41 18 Concentrate . . . * ' 49 9 COLORADO. NEVADA 91 The plant is described in the article from which these figures are quoted. Colorado. Two great lenses of manganiferous iron ore, estimated to contain more than three-quarters of a million tons of ore averaging from 12 to 15 per cent, of manganese, 38 per cent, of iron, i to 2 per cent, of silica, and low in phosphorus, are reported [94] to have been recently found in the Red Cliff or Battle Mountain mining district, 20 miles north-north-west of Leadville, Colorado. The principal ore bodies occur as lenses parallel with the bedding of the enclosing Carboniferous limestone, which dips 15 to the north-east, and it is considered probable that other ore bodies will be found. In San Miguel county, Colorado, a high-grade manganese-ore deposit is being de- veloped, from which it is claimed that large shipments can be made of ore with 85 per cent, of manganese dioxide and less than i per cent, of iron, such as had been imported from Turkey [95]. This is close to the British specification for manganese-ore for dry batteries. Nevada. Deposits of manganese ore in the Ely and Siegel districts, White Pine County, Nevada, have recently been examined by the United States Geological Survey [96]. The ore extends from the surface to a depth of 50 feet or more. Practically all the deposits occur in limestone and are associated with bodies of jaspery quartz. The ore bodies are irregular pipes, pockets and lenses ranging from a few feet to 70 feet or more in length, and from a few inches to 10 or 20 feet in width. Several of the larger bodies contain from 500 to 1,000 tons or more. The bulk of the ore is composed of the softer manganese oxides, pyrolusite being predominant in some mines and wad in others. The ore mined contains from 36 to 45 per cent, of manganese, 3 to 5 per cent, of iron, 3 to 16 per cent, of silica, a moderate amount of lime, and a little phosphorus. Most of the ores contain more or less silver. Small shipments of ore have been made, and it is estimated that about 25,000 tons are now in sight, of which, however, only one-fifth is high-grade manganese-ore, the remainder containing a high percentage of silica, and a con- siderable amount of iron. 92 SOURCES OF SUPPLY OF MANGANESE ORES Utah. Several deposits of manganese ore occurring in southern Utah, near Monroe, Sevier county, and near Marys- vale, Piute county, have recently been examined by the U.S. Geological Survey [97]. These deposits lie along the eastern boundary of Sevier Valley, at the base of Sevier Plateau, which is underlain by igneous rocks, chiefly Tertiary tuffs and lavas. The Loring deposit lies 6 miles south of Monroe, near the base of Monroe Peak. Assays of small shipments made in 1916 showed the ore to contain 35 per cent, of man- ganese, 6-6 per cent, of silica, and 8-57 per cent, of iron. The ore occurs in cracks and crevices of weathered igneous rock, under an overburden having a maximum depth of 16 feet. Small lenticular masses of manganese and iron oxides in tufa have been found a short distance east of Monroe. Near the mouth of Manning Canyon, 10 miles south-east of Marys- vale, a deposit of manganese-ore has been exposed in several open cuts, its outcrop being traceable for 400 feet. The enclosing rocks are lavas of several varieties, but most of the ore is disseminated through a flow of rhyolite which ranges in thickness from 8 to 30 feet. Small shipments of man- ganese-ore have been made from a deposit near Junction, Piute County, and from a deposit near Pahreah, Kane County, Utah. Manganese-ore occurs also in other States, notably Arizona and Tennessee, where production is increasing. The activity in manganese ore mining in the Western States is attributed partly to the operation of electric reduction plants in California and Washington, but more largely to the low percentage of iron in some of the Western ores [98]. Few Eastern American mines that operate residual products can produce at a profit in large quantities ore that contains less than i per cent, of iron, and therefore most of the Eastern mines ship their product to Eastern furnaces to be reduced to ferro-manganese. The inaccessibility of most Western deposits makes it unprofitable to ship ore to Eastern makers of ferro-manganese, even at the high prices they are now offering for manganese ore. At prevailing prices for the high-grade ores, these may be profitably shipped as far east as New York. IMPORTS : UNITED STATES 93 It has yet to be proved that the United States deposits of high-grade manganese ore are sufficiently extensive and occur under such conditions as to allow of increasing and profitable exploitation after the war, when the Indian and Russian ores are again freely available. In order to supply the enormous deficiency between the domestic output and the requirements of high-grade mangan- ese-ore, foreign supplies have had to be depended upon, the principal contributors to American imports being, in order of importance prior to the war, British India, Russia and Brazil. Imports of Manganese Ore into the United States (1912-16) l (Long Tons) From 1912. 1913- 1914. 1915- 1916. 1917.2 British India Russia Brazil Other CountrievS 128,645 83,334 81,580 7,102 141. 5 8 7 124.337 70,200 8,966 103,583 52,681 113.924 13,106 36,45 nil 262,584 21,748 51,960 nil 495,179 29,182 48,975 nil 5*2.5*7 68,480 Total . 300,661 345. 90 283,294 320,782 576,321 629,972 The percentages of imports of the mineral into the United States from the three principal sources of supply during the same years were as follows : From 1912. 1913. 1914. 1915. 1916. 1917. o/ /o o/ /o % % % % British India ; i ' 42-8 41-0 36-6 12-5 9-0 7-8 Russia 27-7 36-0 18-6 o-o O'O O'O Brazil 27-1 20-3 40*2 81-8 85'9 81-4 From these two tables and Diagram 6 (p. 94) it will be seen that, in the pre-war years 1912-13, the imports of manganese ore from India were larger than those from any other country, while in 1912 imports from Russia and Brazil were practically 1 Min. Resources of the United States, U.S. Geol. Survey. The figures for Brazilian exports to the U.S. in 1915 and 1916 are as quoted from Report of the Brazilian Ministry of Finance in the Bulletin of the Pan-American Union, after conversion from metric tons, 2 The Mineral Industry, 1917. 94 SOURCES OF SUPPLY OF MANGANESE ORES DIAGRAM 6. IMPORTS OF MANGANESE ORE INTO THE UNITED STATES. TOTAL AND FROM CHIEF PRODUCING COUNTRIES (1912-1917). of equal amount. In 1913, the imports of manganese ore from Russia had increased by more than 8 per cent, of the total im- ports, while those from Brazil had decreased by nearly 7 per cent. After the outbreak of war the situation was completely changed, Russian exports ceasing with the closing of the Dardanelles, while supplies from India were greatly curtailed. In these cir- cumstances the imports from Brazil were very largely increased, exceeding in 1916 the total imports of manganese ore into the United States in the previous record year, 1913. In 1916, there was, also, an appreciable increase in the imports from India, as compared with 1915, while the imports from the minor sources (chiefly Japan, Cuba and Panama) were more thai} IMPORTS: UNITED STATES 95 three times as great as in 1915 [98]. (See JAPAN, and CUBA.) Under war conditions Brazil is able to supply the United States with most of the manganese ore required, but it is a matter for conjecture whether she can retain her present position as chief supplier of American requirements when India and Russia are again in competition under more normal conditions, and the price of delivery becomes once more a deciding factor. At present American producers of ferro- manganese are almost entirely dependent on ores from Brazil, with the result that 'price has become a secondary consideration. Sales of Brazilian ore were made in 1915 at as high as 44 cents per unit at Rio de Janeiro, equal to about 56 cents at United States Atlantic ports [99]. A year before, it was sold at 18 cents at Philadelphia. A contract for the delivery of 200,000 tons of Brazilian ore during 1917 is said to have been placed at $23 per ton f.o.b. Brazilian port, from which the freight rate to Baltimore is $12 per ton, making a total of $35 per ton [98]. The War Industries Board of the United States have fixed a price schedule for manganese ore, excluding chemical ores required for dry batteries, etc. For ore containing from 39 to 39 '39 per cent, of manganese, the price is $i per unit, with an addition or deduction of 2 cents for every per cent, over or under that proportion between 35 and 54 per cent. While the production of manganese ore proper in the United States has until quite lately been so insignificant, there is a great output of manganiferous iron-ores, large deposits of which occur in the New England, Appalachian, and Lake Superior regions. Of these, the Lake Superior Iron District has been the chief producer of such ores, having hitherto furnished at least 90 per cent. Deposits of minor importance are found in the southern Mississippi Valley, and in the Rocky Mountain region, there being a quite useful production in Colorado. The production of manganiferous iron-ores exceeded 1,000,000 tons in 1906, and has averaged more than half-a-million tons over a long series of years. The output for 1914 fell to 445,827 tons (having been over 96 SOURCES OF SUPPLY OF MANGANESE ORES 672,000 tons in 1913 and 868,500 in 1912), but recovered to 801,290 tons in 1915. (For later figures, see Footnote, p. 5.) The manganiferous iron ore output of the Lake Superior district contains from 12 to 25 per cent, of manganese, and is used, principally, either for making spiegeleisen, or for mixing with high-grade imported ore in the making of ferro- manganese. Some of the manganiferous iron ores of this and the Appalachian region are so low in manganese that they are classed as iron-ores, and are used in the blast-furnace for the production of " high-manganese" pig iron. E. C. Harder [100] reckons among the most important deposits of manganiferous iron-ore in the United States those of the Cuyuna iron-ore district of Minnesota, from which the first shipment of manganiferous iron ore was made so recently as 1913. There appear to be a number of separate deposits in the Cuyuna Range, possibly fifteen, of ore ranging from 1 to 35 per cent, manganese, 20 to 50 per cent, iron, and 8 to 16 per cent, silica. The largest deposit known in the district is estimated to contain about 3,000,000 tons, but the deposits of ore with more than 15 per cent, manganese appear to be smaller and to range from 100,000 to 500,000 tons. The reserves of ore with more than 10 per cent, of manganese are estimated to exceed 4,000,000 tons, and it is believed that further exploration by drilling will reveal other deposits of similar material. Those already known in the district are regarded as constituting the greatest localized source of manganiferous iron-ore in the United States. In addition, the manganiferous zinc ores of New Jersey, already referred to, have been extensively mined, the annual production for several years past having exceeded 100,000 tons, and reaching the exceptionally high total of 159,318 tons in 1915. It has nevertheless been necessary to import not only very large quantities of foreign manganese ores, but also a great amount of iron-manganese alloys, more particularly ferro- manganese, such imports amounting normally to something like one-half of the domestic production of such alloys, as will be seen from the following table based on official figures : ALLOYS: UNITED STATES 97 Year. 1913- 1914. 1915- 1916. 1917. Production : Ferro-manganese : > Spiegeleisen . Tons. 119,496 110,338 Tons. 106,083 79,935 Tons. 146,542! 93,282 Tons. 221,532 194,002 Tons. 257, 8 42 188,852 Total Production . 229,834 186,018 239,824 415,534 446,694 Imports ' Ferro-manganese ,...,, Spiegeleisen 128,070 77 82,997 2,870 55,263 200 90,928 nil 45,381 nil Total Imports 128,147 85,867 55,463 90,928 45,38i Total of Production and Imports . ' ."" . . .' 357.981 271,885 295,287 506,462 492,075 1 Metal Statistics, New York, 1918, gives 149,521 tons. It will be seen that, whereas the domestic production of iron-manganese alloys (ferro-manganese plus Spiegeleisen) in 1917 was nearly twice that for 1913, the imports of such alloys amounted roughly to only one-third of the total for that year. The rapidity of the increase in the consumption of ferro-manganese in the United States in recent years will be seen when it is mentioned that the imports of that alloy into the country averaged only 66,642 tons per annum for the 10 years 1902-11, while the domestic production for the same period averaged only 57,990 tons. The figures for 1912 were 99 I 37 tons and 125,378 tons respectively. The average value per ton of the imported ferro-manganese was $44.37 in I 9 I 3, $4*-33 in 1914, $60.31 in 1915, $101.62 in 1916, and $134.58 in 1917, the figures representing value at foreign port, without freight or duty. The average monthly price of the alloy at eastern seaboard, based on actual sales, was $58.04 in 1913 and $161.37 m 1916. In 1917, British ferro-manganese was sold at from $325 to $375 per ton at eastern seaboard. The price of Spiegeleisen carrying 20 per cent, of man- ganese ranged during the year 1916 from $52 per ton (in July) to $40 (in December) [101]. In 1917, it was sold at about $65 per ton. The price in 1914 was about $25. During 1916 approximately 43,800,000 tons of steel of all grades were produced in the United States. Making the 98 SOURCES OF SUPPLY OF MANGANESE ORES reasonable assumption that stocks at the beginning and at the end of the year were approximately the same, D. F. Hewett [102] suggests that 312,000 tons of ferro-manganese and 194,000 tons of spiegeleisen (that is to say, the total amounts of the two alloys imported into and produced in the country) were consumed to make 43,800,000 tons of steel. The Sub-Com- mittee on Ferro-Alloys of the Advisory Commission of the United States Council of National Defence estimated that for the year 1917 more than 45,000,000 tons of steel would be produced, and the Sub-Committee wished to count on 400,000 tons of ferro-manganese and approximately 200,000 tons of spiegeleisen. In order to make that quantity of ferro-manganese, nearly 850,000 tons of high-grade manganese- ore, with more than 45 per cent, manganese, and 500,000 tons of manganiferous iron-ore and manganiferous zinc residuum would be needed. It was expected that the imports of ferro- manganese in 1917 would be lower than in 1916, and that, in order to obtain the 400,000 tons of ferro-manganese, 700,000 tons of ore would have to be produced or imported. Actually, 629,972 tons of ore were imported into the United States in 1917, the remainder of the ore consumed being supplied from United States mines, working at full capacity [103]. (The Brazilian Ministry of Finance, Office of Com- mercial Statistics, has published figures showing that 524,434 long tons of manganese ore were exported to the United States in 1917. This represents 83*2 per cent, of the total imports of manganese ore into the United States during that year. According to The Mineral Industry, 1917, however, only 512,517 tons of Brazilian ore were actually received in that year.) With open-hearth furnaces working to the limit of their capacity, the shortage of foreign ferro-manganese supplies has had a serious effect upon the American steel industry, and spiegeleisen has of necessity been extensively employed as a substitute for the higher alloy. Normally, in American practice, the open-hearth process uses ferro-manganese of 80 per cent. Mn, while the Bessemer process uses spiegeleisen with 20 to 30 per cent. Mn. The prevailing high prices of manganese alloys have caused attempts to be made to use an alloy of iron, carbon ALLOYS: UNITED STATES 99 and silicon to replace part of the ferro-manganese commonly added, and it has been claimed that experiments have proved satisfactory. The role of manganese is largely as a deoxidizer, and J. E. Johnson [104] has stated that experiments in the use of ferro- silicon as a substitute have not been very successful, at any rate to a greater extent than as a substitute for about 25 per cent, of the ferro-manganese. The silicon appears to be less efficient as a deoxidizer, and it has been his experience that oxygen remains in metal when 2 or 3 per cent, of silicon is present, whereas it would immediately vanish in the presence of i per cent, of manganese. Aluminium as a deoxidizer could not be used in large quantities. Another important consideration is the fact that manganese seems to affect the rolling properties of the steel. Johnson does not believe that any adequate substitute is possible. Describing his preliminary studies on the concentration of manganese ores, E. A. Hersam, Professor of Metallurgy at the University of California, has made the following observa- tions [105] : Californian ores are usually low in manganese, high in silica, and laden with gangue minerals ; phosphorus is below 0'2 per cent, (the penalty limit). Steel makers demand a 48 per cent, ore, for which $50 per ton was paid (January, 1918), but the sorting of ores to this percentage is wasteful. Standard concentration by jigs, classifiers, shaking tables and vanners is commercially questionable. Judging by tests that have been made in the University of California laboratory, with a Wetherill machine, magnetic concentration is prac- ticable ; drying or calcining of the ore may be desirable. A recovery of 80 per cent, of the manganese in a marketable product may be expected. Flotation tests have not been favourable, the tailing frequently containing more manganese than the original ore. Electrostatic separation is incomplete and not likely to be important. The chemical extraction of the raw or roasted ore by sulphuric acid seems feasible ; recovery of the manganese by electrolysis contains many elements of success. He believes that the essentials of man- ganese ore-dressing are careful crushing and dry magnetic concentration ; where the ore bodies are of sufficient magnitude, loo SOURCES OF SUPPLY OF MANGANESE ORES chemical extraction may, in certain instances, be found profitable. COLOMBIA AND PANAMA. Deposits of manganese ore occur in a region situated on the Caribbean coast extending from Puerto-Bello in an easterly direction for 35 miles towards Point San Bias. The Soledad mine, situated 35 miles south- east of Nombre de Dios, has furnished most of the ore hitherto exported from this region. The ore consists chiefly of psilo- melane, with some braunite and pyrolusite, and occurs in irregular lenticular masses, varying in size from a few inches up to 50 feet, in a decomposed shale. After hand-picking, washing and screening, the ore exported generally contains 57*8 per cent, of manganese, 4'i8 of silica, 273 of water, and o'o6 of phosphorus. The principal exports have always been made from Panama. No statistics of production are available. In 1916 it was reported [106] that an American syndicate had recently opened a manganese mine at Madinga, on the Gulf of San Bias, in the Province of Colon, Colombia, about 70 miles east of the city of Colon, and that a trial shipment of some 900 tons had been made to New York. It was estimated that shipments of 1,500 tons a month could probably be made, if vessels were available. A wharf had been built in deep water near the mine. Beyond that, nothing definite can now be stated regarding the develop- ment of the mine. Several manganese deposits on the Atlantic coast of the Republic of Panama are stated [107] to have been opened up during 1916, ore to the value of about 68,500 being shipped to the United States. Further expansion of the industry is regarded as probable, other claims having been located through- out the country. COSTA RICA. Only one manganese mine appears to be in operation in Costa Rica, although other claims are said to have been selected. The mine is situated at Playarreal, in the Province of Guanacaste, and the ore is stated to average 55 per cent, metallic manganese (80 to 83 per cent, manganese dioxide). Shipments began in May, 1916, the output being about 300 tons a month. It was expected that an equipment CUBA |; ^,v>;:,Y^ with a capacity of 3,000 to 5,000 tons a month would be completed by July ist, 1917. The port of shipment is about 2 miles south of Braxilito, considerably north of the Pacific port of Punta Arenas [108]. CUBA. The manganese industry of Cuba commenced some twenty years ago. There are three principal groups of de- posits : the Cristo and the Ponupo, worked by Aguilera and Company, and the Cauto, worked by the Cauto Mining Com- pany, a Rogers-Brown (United States) interest at San Nicolas, north of Santiago, Province of Oriente. The Ponupo, the largest of these groups, is said [109] to have produced up to the present about 2,000,000 tons of ore (probably for the most part manganiferous iron-ore) and to be still producing about 3,000 tons per month of a fair grade of " furnace ore" averaging about 43 per cent, of metallic manganese. 1 According to the same authority, the Cristo group is pro- ducing a small amount of ore that runs about 46 per cent, of manganese. The present production is about 4,000 tons monthly. The Cauto group is said to be mining about 2,000 tons of ore per month, containing [no] from 43 to 47 per cent, of manganese, 9 per cent, of silica, 2 per cent, of iron, and 0*05 per cent, of phosphorus, small lots (classed as " dioxide ") being selected for ship- ment which contain from 85 to 87 per cent, of manganese dioxide. Deposits on the south coast, in the San Maestro range, extend over a distance of 100 miles, and there were 88 mines in the province of Santiago de Cuba in 1907. The manganese industry in Cuba has been hampered by lack of labour and inadequate facilities for land and sea trans* port. Practically all the ore produced in recent years has been shipped to Baltimore, United States, where the demand for " furnace ore " is still strong. There is a prospect of a considerable revival in the industry, which has been appreciably helped by the European war. The Commerce Report already referred to gives the declared exports of 1 U.S. Cornm . Rept., March 25, 1918, gives production of the Ponupo group at that date as about 5,000 tons of ore per month, averaging from 38 to 40 per cent, manganese, and rather low in silica and iron. u. SOURCES : OF StfPPLY OF MANGANESE ORES " manganese-ore " from the Santiago Consular district to the United States in 1915 as 5,144 tons, value 18,187. ^ n 1916, the United States received from Cuba, 30,563 tons, and, in 1917, 44,571 tons, according to The Mineral Industry, 1917. None of the ore is treated at the mines, except by washing for removal of dirt. The " furnace ore " is shipped in bulk and the " dioxide " in sacks. Large undeveloped deposits are said still to remain awaiting attention, and the outlook, if the demand and good prices continue, is considered to be quite favourable. HAYTI. There are said to be extensive deposits of man* ganese-ore in Coteaux, province of Cayes, conveniently situated for shipment. A concession for the working of these deposits was granted about 1905, but no production of any importance appears to have been made up to the present. BRAZIL. Manganese ore was discovered in the State of Minas Geraes in 1888, and fully 95 per cent, of the total Brazilian production has come from the Miguel-Burnier and Lafayette (or Queluz) districts of that State, the Wigg mine in the former and the Morro da Mina mine in the latter district having been the principal producers. The Miguel-Burnier district was the first to be developed, and for some years was the more important producer ; but the highly successful development of the Morro da Mina mine, which became a producer in 1902, has caused the Lafayette district to assume the leading position. Manganese-ore has also been found in the States of Bahia and Matto Grosso, but the deposits in the latter State have not yet been mined, owing to their distance from the coast and prohibitive cost of transport. The exports of manganese ore from the beginning of pro- duction in 1894 to the end of 1913 amounted to 2,579,805 long tons [in], the highest tonnage in any one year of that period being 249,954 tons, in 1910. The following statistics of exports for the years 1913-16 are as compiled from various sources. (See Diagram 7, p. 104) : BRAZIL (Long Tons.) 103 Exported to 1913. 1914. 1913- 1916. United States * > Great Britain * , > . Germany a -V .." Belgium 2 . ' ,. . France a . Other Countries (by deduction) . 70,200 18,792 5,000 n, 600 7,098 7,640 113,924 46,494 10,400 11,200 i,338 262,584 14,515 6,933 495,179 Total 8 .... 120,330 180,680 284,032 495< I 79 1 Official figures of actual receipts. * U.S. Comm. Repts. (The French tonnage for 1913 is as given in French Customs statistics.) E. C. Harder (loc. cit.) gives the total tonnage exported in 1913 as 180,738 long tons. With the exception of a small quantity produced in the State of Bahia, the Brazilian output of manganese-ore has come from the State of Minas Geraes. The great increase in the exports of Brazilian manganese ore to the United States has, of course, been due to the cutting- off of Russian and the serious shortage of Indian supplies owing to the war. In 1916, the United States obtained 80 per cent., and in 1917 83*2 per cent., of its manganese-ore requirements from Brazil. The value of the Brazilian output in 1916 was approximately 1,495,800, or nearly 3 per ton, at Rio de Janeiro [112]. The exports of manganese-ore from Brazil during 1917 amounted to 524,434 tons. 1 Formerly all Brazilian manganese ore was shipped from Rio de Janeiro ; since the beginning of 1917, however, extraction of manganese- ore has been proceeding in the State of Bahia, where several American companies have acquired interests, and the exports from the port of Bahia amounted during that year to 32,860 tons [113]. The Morro da Mina mine is now not only the most important in the State of Minas Geraes, but, according to F. L. Garri- son [114], probably the largest manganese mine in the world. It is owned and worked by Brazilians, the next largest mine, the Cocuruto, being controlled by Belgian interests. 1 The actual receipts in the United States during the year from Brazil amounted to only 512,517 tons, according to The Mineral Industry, 1917, p. 418. 8 104! SOURCES OF SUPPLY OF MANGANESE ORES Tons. Year. I Tons. (240/6) SO 0000 400 OOO 300000 ZOO OOO IOO f OOO sooooo 4OOOOO 3OOOOO SOOOOO /OOO 00 DIAGRAM 7. EXPORTS OF MANGANESE ORE FROM BRAZIL. TOTAL AND TO PRINCIPAL COUNTRIES (1913-1917) The Minas Geraes Deposits. The ores of Minas Geraes have been separated into two classes [in] : (1) Those occurring in a complex of granite, gneiss and crystalline schist ; (2) Those occurring in overlying metamorphosed sedi- ments, with which the important Brazilian iron ores are also associated. I. The Crystalline-complex Ores. These are large irregular bodies of manganese dioxide, enclosed in, or bounded by, BRAZIL 105 gneiss, granite or crystalline schist. Individual masses may be several hundred yards in the larger diameter. While irregular in shape, they are usually somewhat elongated, suggesting lenses. They occur scattered through the crystal- line complex without any apparent regularity, but most of them appear to have either gneiss or crystalline schist on one or both bounding walls. The manganese oxide composing these lenses is usually amorphous, occurring mainly as psilo- melane and wad, although pyrolusite is also found. It is considered that all the manganese-oxide deposits in the areas of the crystalline complex are surface-oxidation products of manganese silicate and carbonate rock. Most of the ore is hard ; but soft material, mainly wad and pyrolusite, also occurs in abundance irregularly intermixed with the hard ore. 2. The Sedimentary Ores. These occur as definite beds associated with the iron formation. The principal bed, on which the Wigg mine is situated, is from 2 to 3 miles in length, with a maximum thickness of over 6 feet. Its strike and dip are parallel with that of the enclosing sediments, showing that it was laid down as a sedimentary deposit. At the Wigg mine the ore bed is bounded on one side by soft siliceous iron-formation, with a contact zone of mixed soft crystalline haematite and manganese oxide, and on the other side by a ferruginous schist associated with the iron formation. The dip is generally steep. At the Rodeio mine, east of Miguel-Burnier, the manganese- ore bed is of smaller longitudinal extent, but of greater thick- ness than at the Wigg mine, and shows less definitely its relation to the enclosing rocks. The manganese-ores associated with the sedimentary rocks consist of finely crystalline and amorphous manganese oxides, probably a mixture of pyrolusite and psilomelane ; and these ores are of somewhat higher grade than those occurring in the crystalline complex. E. C. Harder quotes the following as typical analyses of ore from mines in the State of Minas Geraes : 106 SOURCES OF SUPPLY OF MANGANESE ORES I^afayette District. Miguel-Burnier District. Wigg Mine. Piquery Mine. Sao Gonzalo Mine. Average. Cargo. Mn SiO 2 . P Moisture Per cent. 49-00-51-00 5-00- 7-00 0-08- o-io 3-00- 5-00 Per cent. 50-00-54-00 I-OO- 2*OO 0-12- 0-15 3-00- 5-00 Per cent. 50-00-54-00 I-OO- 2-00 o-oi- 0-03 I5-00-20-OC Per cent. 55-H-55-02 0-53- 1-25 0-03- O-O2I 4-95- 4-74 J. T. Singewald, Jr., and B. L. Miller [115] contrast the modes of occurrence of the deposits in the Miguel-Burnier and Lafayette districts. The deposits of the former district extend as a narrow belt about 10 miles in length, parallel with the Ouro Preto branch of the Brazilian Central Railroad, and lie at the southern edge of the great iron-ore region of central Minas Geraes. The ore bodies occur as lenses or beds inter- calated in a series of sedimentary strata showing a rapid succession of itabirite schist, calcareous schist and limestone. Stratigraphically, they are found in the upper part of the Itabira iron-formation and in the lower part of the over- lying Piracicaba schist, formations probably of Algonkian age. The ores are very high-grade manganese oxides, chiefly a mixture of psilomelane and pyrolusite, averaging 50 per cent, manganese, i per cent, silica, and 0^03 to 0*05 per cent, phosphorus. It is mentioned, as the great drawback of the district, that the beds are steeply dipping and narrow, rarely over 6 feet in width, so that expensive underground mining must be resorted to, and the individual deposits are relatively small. As to the origin of the ores, they quote two views which have been advanced: (i) that by H. K. Scott [116], who holds that, whatever may have been the original state of the manganese ore bed, there can be no doubt that in its present condition, and down to the level to which it has been worked, it is a residual deposit from which the other elements have been leached out ; and (2) that by E. C. Har- der [117], who regards the source of the manganese as doubtful, but thinks it may very well have been derived from deposits of manganese ore in the crystalline complex, such as now occur to the south near Lafayette. Decomposition of such deposits may have yielded a large amount of residual man- BRAZIL 107 ganese oxide, which was transported and deposited as beds or lenses in the sedimentary series. Their origin would, thus, be very similar to that of the iron-ores with which they are closely associated. The view taken by Singewald and Miller is that, while one cannot positively state that the ores were not laid down in the form of manganese oxides as integral parts of a sedimentary series, their relations to the associated limestones are such as to make their interpretation as residual products of decomposition and replacement of manganiferous limestone the more probable explanation of their origin. As to the Lafayette district (the railway station of that name being about 20 miles south of Burnier) they remark that the geology differs markedly from that of the Miguel- Burnier. It lies to the south of the area underlain by the great iron-bearing series, and its ores are found in the base- ment complex of supposed Archaean age which underlies a large part of the State of Minas Geraes. The rocks making up this complex are chiefly granite and gneiss, with which are associated amphibolite, and micaceous and quartzose schists. There are also small intrusions of diorite and gabbro, mostly in the form of dykes. The granite seems to be intrusive into the gneiss and schist, but the relations between the schist and gneiss are not clear. The manganese deposits occur as elongated masses of more or less lenticular shape within the rocks of the basement complex, and represent residual products of decomposition of an original manganiferous rock made up of manganese carbonate and silicates. The immediate wall-rock of the deposits has likewise undergone decomposi- tion, in many places being nothing more than a clay in which the original rock texture is poorly preserved. In most cases, however, it seems to have been either gneiss or schist. The Morro da Mina mine is located on a hill 2 or 3 miles north of the town of Queluz, which is situated about 3,600 feet above sea-level and rises to a height of about 650 feet above the surrounding country. The ore bodies occur at the top and on the flanks of the hill as a series of more or less overlapping lenses extending in a direction N. 35 W., with a vertical dip and a pitch of 45 to the south-east. Of the ore bodies developed, the four largest have maximum dimen- io8 SOURCES OF SUPPLY OF MANGANESE ORES sions of 200 by 30 metres, 420 by 120 metres, 140 by 70 metres, and 100 by 20 metres, respectively, and, at the date of the paper by Singewald and Miller, the first two of these had been cut by a development adit 130 metres below the summit of the hill, indicating that the ores extend at least to that depth. Since it became an important producer in 1902, the mine has yielded a total considerably exceeding 1,000,000 tons, its production in 1915 being about 200,000 tons. Development work is said to have proved an ore reserve of 10,000,000 tons. In addition to the ores in situ, a large part of the hillside below the ore outcrops is covered with rubble ore derived from them, and in recent years about one-third of the output has come from workings in this rubble. The ore consists for the most part of psilomelane, which occurs most commonly in a more or less drusy, massive form. Mammillary, botryoidal and concretionary forms are abundant. Associated with the psilomelane is a considerable amount of manganite and pyrolusite, which occur for the most part as cavity linings and fillings in the psilomelane. The average composition of Morro da Mina ore, as shipped, is stated by the same authorities to be as follows : Per cent. Water at 100 C. . . .2-50 Volatile 12-40, chiefly oxygen. Insol. Residue . . . .3*46 FeA-Al 2 O s .... 875, alumina about twice ferric content. Silica (SiO 2 ) '. . "I 176 Phosphorus (P) . . . . 0-069 Sulphur (S) . . ".V absent Manganese (Mn) J r VV \ 50*47 The ore is mined for the most part in open cuts, the ore body being stripped of such overburden as it may carry. The Bahia Deposits. These occur about 16 miles west of Nazareth, a town on tide-water about 30 miles west of the city of Bahia. Ore has been shipped from three mines in this district. It is mainly psilomelane, occurring as lumps BRAZIL 109 and large masses in clay or soft earth. Some masses are botryoidal, but most are angular, usually ranging from mere particles up to a foot or two in diameter, those shipped having about the size of a fist. The average analysis of ore from the principal mine, the Pedras Pretas, is as follows : Manganese, 43 to 49 ; silica, 3 to 4 ; phosphorus, 0*016 ; moisture, 2 to 3 per cent. According to F. L. Garrison [118], the manganese- ore shipped from the State of Bahia seldom exceeds 4 per cent, in silica, 5 per cent, in iron, and 0*017 P er cen t- m phos- phorus. According to The Mineral Industry [119], Brazilian man- ganese-ore averages 50 to 53 per cent, manganese ; 3 to 3*5 per cent, iron ; and 0*03 per cent, phosphorus. The development of the Brazilian manganese ore industry has been retarded by the distance of the more important mines from the nearest port, and the consequent heavy railway and other charges. With low rates of exchange, the Brazilian ores could compete on equal terms with those of India and Russia on the London market in pre-war times, but with high rates they were at a considerable disadvantage. The important factor of railroad transportation to the sea- port has been discussed by Kirby Thomas [120]. The man- ganese ore deposits of Minas Geraes lie in the southern part of that State, from 300 to 400 miles north of Rio de Janeiro, and are reached by the Brazilian Central Railroad. This railroad is owned by the Government, and is stated by Thomas to be inefficiently managed and of faulty construction. New equipment, recently installed, enabled the railroad to bring down 500,000 tons of ore, a distance of 350 miles, to the port of Rio de Janeiro during the year 1916 ; and it is considered that with better management 150,000 to 200,000 tons more could be transported annually. Another factor affecting the transport of the Ore consists in the limited and expensive arrangements for loading at the harbour in Rio, which has no facilities for loading bulk ores, while the transport of the material from shore to ship is under control of a hindering concession. The port conditions are such that it is necessary to unload the ore from the railroad cars on to lighters, transport it to islands in the harbour, no SOURCES OF SUPPLY OF MANGANESE ORES and from there transport it to lighters or ships. A plan to construct a dock at a harbour west of Rio has been considered, but has not materialized, chiefly owing to the failure of the leading interest to co-operate, and partly to the considerable expenditure involved. It was reported recently [121] that an export tax of 8 per cent, on manganese-ores was under discussion by the State authorities in Minas Geraes. CHILE. This country was formerly a considerable producer of manganese-ore, and is known to contain important deposits of both rich and medium-grade ores, which are said to be by no means exhausted. The competition of Indian ore resulted in the collapse of the industry, and there has been practically no production since 1905. It is considered certain, however, that the mines will be re-opened. The development of the Chilean iron-ores is now proceeding actively, and this, together with the opening of the Panama Canal, may revive the man- ganese industry. The total exports of manganese ore from Chile between 1885 and 1905 amounted to 549,716 tons. Omitting the year 1885, when the industry was in its infancy, and the years 1904-5, when it was moribund, the average annual export was about 30,000 tons. No adequate description of the Chilean manganese ore deposits has appeared until quite recently. According to E. C. Harder [122], the ores may be classed as follows, accord- ing to their geological occurrence : (1) Interbedded with jasper and chert in a limestone- chert formation. (2) Interbedded with red sandstone, shale and limestone, which in turn are interlayered with massive volcanic flows. (3) Veins in volcanic flows. The sediments and volcanic rocks with which the ores are associated are of Mesozoic age. To type (/) belong the ores of the Carrizal District, which is about 350 miles north of Valparaiso. Here the manganese ore occurs in a belt several miles in length, in from one to four parallel beds, varying up to 4 or 5 feet in thickness, CHILE in separated by a few feet of chert or jasper. The ore in the northern part of the belt is dense, hard, black psilomelane with conchoidal fracture, and usually contains much silica in the form of chert. In the southern part, the ore is hard, bluish-black braunite, with some psilomelane and an admixture of soft black oxide. The manganese mines occur along a branch of the railway from the port of Carrizal, distant about 50 miles. To type (2) belong the ores of Las Cafias, La Liga, Arrayan and Corral Quemada, where they occur in from one to three parallel beds, usually averaging where mined from i-J- to 3 feet in thickness, and separated by only a few feet. In most places the ore beds consist of pure, granular to finely crystalline, bluish-grey or bluish-black pyrolusite, generally compact but soft. To type (3) belong the ores of Aculeo and Los Chorros, as to which no useful information is available. Most of the manganese ore exported from Chile has come from the Carrizal and Corral Quemada districts, but a con- siderable quantity has been shipped from Las Can as and La Liga. The following are analyses of manganese ore from the more important districts : Carrizal District. Province of Coquimbo. Coquim- bana. Huas- quiua. Mina Alta, lyas Cafias. Mina Po- tosi, I^as Cafias. MinaEs- trella, I ari us Countries Washing and Drying Cocoa Yields and Expenditure Coramercin .UBBER. By HAROLD BROWN, Technical Super- intendent, Scientific and Technical Department, Imperial Insti- f 24 ^. With Illustrations. 6s.net. CON FKNTS: Introduction Rubber in British Africa The Principal Rubber-yieki.ng U-\ The Tapping of Rul)ber Plants The Preparation of Rubber- -The Chemistry of Rubber-- itistics of Consumption and Prices The Para Rubber Tree The Ceara Rubber Tree TH rican Rubber Tree The African Rubber Vines The Centra] American Rubber Tree TL< sam Rubber Tree and Other Species of Ficus, iOTTON AND OTHER VEGETABLE FIBRES Their Production arid Utilisation. By ERNJ;ST GOULDING D.Sc., F.I.C., Scientific and Technical Department, Imperia Institute. Pp. x -f- 231. With Illustrations. 6s, net. CONTENTS : tntroductory Cotton Cotton Production in the Principal Countries and th lief Commercial Varieties Cotton Growing in British West Africa and Other Paris of th. iiUh Empire Flax Hemp Sunn "Hemp Ramie- jute and Jute Substitutes -Manila Hemp- mana Fibre Sisal Hemp Mauritius Hemp Bowstring Hemp New Zealand HempBrush iking Fibres- Flo ssesKaffia Paper-making Materials, etc.