RECOVERY OF METALS FROM A MIXTURE OF BRONZE AND BABBIT TURNINGS BY c. j; Thiel thesis FOR THE DEGREE OF BACHELOR OF SCIENCE IN CHEMISTRY COLLEGE OF LIBERAL ARTS AND SCIENCES UNIVERSITY OF ILLINOIS 1922 Finley ' V. AGO 0V/LEDG1IBN T To Professor W. S. Pat nam, under whose direction this investigation was carried oat, the writer wishes to express his gratitude for many kindly suggestions. Digitized by the Internet Archive in 2015 https://archive.org/details/recoveryofmetalsOOthie TABLE OJ? CONTENTS I. II. III. IV. V. Introduction Historical Experimental Summary Bibliography p . 4 p. 4 p . 5 p. 13 p . 14 4 Separation of Bronze and Babbit Turnings. I. Introduction This investigation was taken up on account of the large amount of v/aste product which is lying about. at many o,_ our metal industries and which, if sold as it is, would bring a very low price as scrap, but which, if properly separated, would command a higher price. The turnings which were used in this work ve^e ob- tained from the trimmings of castings. This mixture of bronze and babbit is obtained as follows: - Babbit is poured into a bronze casting. This cashing and the babbit core is then trimmed and turned until the desired size of the easting is reached. These trimmings and turnings are therefore composed of the outei* bronze cashing and the inner babbit core. II. Historical Up to the present date no work has been found to have been done on this subject, either in writing or experimenta- tion. The nearest relative article which could be found was that on the extraction of lead from a copper alloy. As oh is was a liquidation process, it could with all reasonableness be applied to the Separation of Bronze from Babbit. As taken from the ’’Foundry” of August 1921 the article states that: the presence of antimony would add to the diffi- culty of liquidating the lead from the copper, and if the ' . - j . 5 alloy fails to liquidate, no separation can be made, and it will have to be utilized by alloying small amounts with the regular alloys, allowing for the lead content. III. Experimen tal A. In the first place the ideal method would be by seme physical means as this would be the most economical from every standpoint, There are two ways open for such a separation, namely, a separation on a "Wilfley Concentrating Table," the action of which causes a heavier constituent of the mixture to go over the "concentrate" side, in ihis case bronze, and the other constituent of lower specific gravity to go over the "tailing” side , in this case babbit. For separation on the Wilfley Table, the difference in the specific gravity of the constituents need not be over .5, provided the size of the particles to be separated are uniform in size, or in other words , classified particles. The problem then is to produce or obtain metallic turnings in a uniform size by some means. This method was not tried because at the time it was impossible to get the use of the Wilfley Table, and the differ- ence in specific gravity ms too small. B. The second method is by the use of the electrostatic separator, vhieh is used so much today for the separation of certain minerals like lime nit e from Monazite. The electrostatic separation was tried, but the results were not very satisfactory. luring these tests the voltage was about 275. In the ■ 6 first trial the rod was set about two was a continual sparking. On the inches away as in the accompanying examination of the material in the illustration. At this distance there receivers, there was T nt a very noticable separation. Only powdered particles were attracted. This led to the belief that the sample was too coarse. Accordingly, the turnings were put in the ball mill and reduced to a finer mesh. The efficiency of this mill in reducing the size of the turnings was very low, for after running the mill for 15 hours only about five eighths of the sample went thru the twenty mesh sieve. A second trial was made with the separator, and this time several experiments were tried. 1. A high voltage was used with the rod two inches away from the revolving disc. The results were very much sparking and no separation. 2. A high voltage was used with the rod one inch away from the revolving disc. The results were less sparking, but still a very poor separation. 3. A low voltage was used with the rod. one inch away from the revolving disc. The results were fair. There was no sparking and the separation was the best ever obtained. Analysis was made of the separated particles, but since the composition varied so greatly, the report does’nt show much. The one thing to be noted however is that the bronze ' * turnings were present in the greater proportion on the attracted side, say five to one. Report of the Analysis. Attracted Portion av. cu = 50.1 Unattracted Portion av. cu = £9.8 C. A third way of separation is "by some chemical method, using some selective reagent , dissolving out the "bronze from which the copper could be crystallized in the form of some sal or perhaps electrolized and the zinc recovered by the same means. The residue of babbit smelted in some salts of tin or ant imony . This method was more satisfactory than any of the pre- ceeding ones, and was tried out as follows:- An electrolysis was made according to the following set The anode consisted of a mixture of the bronze and babbit held at 800°G for one half hour, poured into a sand mould which has the following dimensions 3 in. wide 4 in. deep i in. thick The cathode consisted of a sheet of pure copper three ' • * . , \ . . 10 Deposit 3.4 gr. Wt. of cathode = 13.4 gr. it. of sludge = .25 gr. Loss in wt. of anode = 5.7 gr. Total gain in wt . of cathode = 7.4 gr. .*. wt . of cu. taken from electrolyte = 1.95 gr. This method sh owed a way of recovering the copper from the alloy of "bronze and babbit. As a process for commercial work, the cost of installation and operation would be too great for the average manufacturing plant. So with the idea of com- mercialization in mind another method was looked for. D. A leaching process was tired on the mixture of bronze and babbit. First it was leached in a HC1 solution and then in a HgSO^solut ion for a period of forty eight hours. The total loss in weight was only a bait 1 fo, F. A liquidation process also proved of very little use, of because^the ratio of the babbit to the bronze. A small furnace with a sloping cast iron bottom and a top hole at the lowest point, which was kept open, was built. The cast iron plates were heated to redness. The babbit shaild melt, flow down the incline and be collected under the top hole. But this did not happen, due to there being only a small amount of babbit. When it did melt, it adhered to the bronze particles, instead of flowing down to the top hole. F. Fusion processes were tried which t eliminated with the foil owing re suit s . First Fusion 20 gr. metal 20 gr. niter ' 20 gr. litharge 20 gr. Sodium Carbonate Results: Ho button 11 Second Fusion 10 gr. NaCI 10 gr. Metal 5 gr. SnClg Results: Button 7 grs 12 $ Sn Third Fusion 10 gr. Metal 20 gr. IlagCOg Results Button 7 + grs 16$ Sn Fourth Fusion 20 gr. Metal 20 gr. NaHCOg 20 gr. NaCI Result s -Button with the following analysis :- Sn. 18$ Pb. 4.35$ Sb. Trace Zn. Trace Cu. 77.$ Fifth Fusion 20 gr. Metal 25 gr. HaHCOg 20 gr. Ha Cl Re suits -Butt on with the following analysis:- 12 Sn. 18f> Pb. 5/0 Sb. Trace Zn . Bone Cu. 76.74 fo The results from the fifth fusion, being the best ob- tained, the next step in the process was the recovery of the tin from the slag. This was tired out in various ways:- 1st. The slag was roasted at a temperature of 1100 °G together with a flux of Borax glass and charcoal. The results of this trial was negative. 2nd. A leaching process was tried on the roasted and unroasted slag with the following results 20.50 76.00 1.00 1.50 .50 .50 100.00 Qualitative Analysis of Soluble Portions of Roasted and xjn- roasted Slag. f> Soluble in HgO Ha Slag = Powdered Boiled 10 min. fo Soluble in HgO 70.00 f Soluble in HC1 21.00 fo Soluble in HgSO^ 1.50 f Soluble in HNO fo Soluble in la OH .50 fo Insoluble .50 Roasted Slag r Powder* Boiled 10 min. fa Soluble in HgO fo Soluble in EC1 fo Soluble in HgSO^ if. O 6.50 Soluble in HHC^ fo Soluble in BaOH fo Insoluble 100.00 V BIBLIOGRAPHY 14 Anodic solution of Cu. Chem. Abs . 1920 -1224. Electro-deposition of Cu. it ii it 1193. it ri ii 2084. Electro-chemical production of Cu. from ores. ii ii ii 2464. Electro-metallurgical process for extracting Cu. it IT ir 1345. ii t! ii 2838. ii II ii 2842. Electrolytic production of Cu. n IT it 253. Recovery from Brass 13. S. Patent 850601. Refining of Cu. n ii 353784. Refining and over poling of Elec- trolytic Cu. Chern. Abs . 1920-1384. Technical Analysis of Brass Price & Meade Metallic Alloys G. H. Gulliver Vol.I & II Chemical Analysis Scott Handbook of Metallurgy Schnabel & Louis Vol. II Qualitative Chemical Analysis V'. Hoyes Quantitative Chemical Analysis Talbot