THE PRODUCTION OF ALLOYS OF TUNGSTEN AND OF MOLYB¬ DENUM IN THE ELEC- <3 TRIC FURNACE •"i "5 ^ THESIS Presented to the Faculty of the Department of Philosophy of the University of Pennsylvania in partial fulfillment of the requirements for the Degree of Doctor of Philosophy CHARLES LAWRENCE SARGENT Peace Dale, Rhode Island 1900 PHILADELPHIA Avil Printing Company 1900 Return this book on or before the Latest Date stamped below. A charge is made on all overdue books. U. of I. Library 11148-S INTRODUCTION. With the introduction of the electric furnace, the new field of chemistry at high temperatures was opened to inves¬ tigation. In the past few years this has [received much attention, especially by Moissan, who has succeeded in reducing the most refractory oxides, also in volatilizing many of them as well as certain metals which had been considered infusible. Moissan (La Four Electrique , p. 246) describes a method of preparing alloys of vanadium, using the pentoxide as the source of vanadium. Bernoulli (Pogg. Annal. hi, p. 573) prepared alloys of tungsten with copper, lead, bismuth, cobalt, nickel, etc. His method of working consisted in mixing the oxides of the two metals with lampblack, placing the mixture in a cru¬ cible and then heating it in an ordinary furnace. Proceeding in this manner he was not able to obtain alloys containing rmore than 10 per cent of tungsten. Knowing the comparative ease with which tungsten and molybdenum are reduced from their oxides, it was thought T-that it might be possible to mix these oxides with oxides of pother metals and then reduce the mixture in the electric furnace, obtaining as a final product an alloy of the two metals. In the following experiments the furnace used was of the type known as the “ Moissan.” The carbon for the reduc¬ tion was prepared by ignition of cane sugar. The cru¬ cibles were made of graphite modeled in the form of an assay scorifier. This shape is preferable, as it allows the arc to play directly on the bottom of the crucible. For some ( 3 ) '157o0 V 4 of the experiments these crucibles were lined with magne¬ sium oxide, thus preventing the hot metal from absorbing any of the graphite. Unless otherwise mentioned the graphite crucibles were used. After each reduction the furnace was closed and allowed to cool before removing the crucible containing the fusion. PRELIMINARY EXPERIMENTS. Before taking up the work of forming alloys, the follow¬ ing experiments were conducted with tungstic acid ; the object being to obtain the best conditions for its reduction. Experiments /, If III. io grams of tungsten trioxide .... Voltage, 58-70. 20 “ “ carbon.Amperage, 55-125. Time, 7 minutes. The product was a black granular mass, but it contained no tungsten. This was probably due to the large excess of carbon. Experiment IV 3 grams of tungsten trioxide ..... Voltage, 65. 3 “ “ carbon.Amperage, 150. Time, 2 minutes. Obtained as the product, a metallic button containing 88.45 per cent of tungsten. Method of Analysis. The metal was mixed with sodium carbonate and potas¬ sium nitrate and fused. The fusion was taken up with water, then acidified with nitric acid, evaporated to dryness, heated to about 175 0 C., a small amount of nitric acid added and then taken up with water. The tungsten trioxide remain¬ ing insoluble, was filtered off and weighed as such. Experiment V. 3 grams of tungsten trioxide .... Voltage, 70-75. 2 “ “ carbon.Amperage, 120-160. Time, 3 minutes. The button contained 90.39 per cent of tungsten. Experiment VI. 3 grams of tungsten trioxide .... Voltage, 65-80. 1 gram of carbon.Amperage, 75-150. Time, 3 minutes. The button contained 92.54 per cent of tungsten. Experiment VII. 3 grams of tungsten trioxide .... Voltage, 70-90. 4 “ “ carbon.Amperage, 150-200. Time, 6 minutes. The button obtained contained 86.60 per cent of tung¬ sten. Experiment VIII. 3 grams of tungsten trioxide .... Voltage, 70-80. 4 “ “ carbon.Amperage, 110-175. Time, 3 minutes. The button gave, upon analysis, 86.52 per cent of tung¬ sten. ExpSrime?it IX. 3 grams of tungsten trioxide .... Voltage, 65-80. 2 " “ carbon.Amperage, 100-170. Time, 3^ minutes. The button contained 89.42 per cent of tungsten. 6 Experiment X. 3 grams of tungsten trioxide .... Voltage, 65-70. .5 “ “ carbon.Amperage, 100-125 Time, 3^ minutes. No metal was obtained. From the above results the amount of carbon used appears to influence the purity of the resulting metal, more than variations in the strength of the current and time of its action. Attempts to prepare pure tungsten failed. The metal always contained carbon, and showed traces of unreduced oxide. The carbon was probably absorbed from the cru¬ cible. Impure tungsten was prepared as above and then placed in a crucible lined with magnesium oxide, to see if it would be possible to burn off the carbon. Instead of the carbon being burned out, the metal was oxidized to tungsten trioxide and the magnesium volatilized. When a crucible, with magnesium oxide lining, was used for the reduction of the tungsten trioxide mixed with carbon, no metal was obtained. Alloys of Tungsten and Bismuth. The oxide of bismuth used was prepared by ignition of bismuth nitrate. Experiment I. 3 grams of tungsten trioxide .... Voltage, 60-70. 1 gram of bismuth oxide.Amperage, 120-150. 4 grams of carbon.Time, 2 minutes. The current was interrupted at the expiration of two minutes, because the bismuth was being volatilized. The button gave 88.00 per cent of tungsten and .59 per cent of bismuth. ■t 7 Method of Analysis . The metal was oxidized with nitric acid, evaporated to dryness, heated to about 175 ° C., and then taken up with nitric acid and water. The tungsten trioxide remained insoluble and was filtered off. In the filtrate the bismuth was determined by precipitating with ammonium carbonate in the usual manner. Experiment II. 2 grams of tungsten trioxide .... Voltage, 70-85. 2 “ “ bismuth oxide.Amperage, 100-125. 3 “ “ carbon .Time, 2 minutes. The metal gave upon analysis 91.63 per cent of tungsten and .64 per cent of bismuth. Experiment III. 1 gram of tungsten trioxide .... Voltage 75-80. 3 grams of bismuth oxide.Amperage, 75-110. 3 “ “ carbon.Time, 2 minutes. The button gave 91.12 per cent of tungsten and .51 per cent of bismuth. Other experiments were tried, placing the bismuth oxide at the bottom of the crucible and the tungsten trioxide on the top. By this procedure it was thought that the tungsten trioxide would be first reduced, and then as the bismuth oxide was acted upon the bismuth would junite with the tungsten before being volatilized. Working in this manner no metal was obtained containing more than a trace of bismuth. Tungsten and Copper. Experiment /. 3 grams of tungsten trioxide .... Voltage 64-80. 1 gram of copper oxide.Amperage, 100-160. 3 grams of carbon ........ Time, 4 minutes. 8 The copper was driven off and a nonhomogeneous mate¬ rial was left, which showed traces of copper when tested qualitatively. Experiment II. 2 grams of tungsten trioxide .... Voltage, 78-80. 2 “ “ copper oxide.Amperage, 100-150. 3 “ “ carbon.Time, 4 minutes. Nothing of a metallic nature was obtained. Experiment III. 1 gram of tungsten trioxide .... Voltage, 80-85. 3 grams of copper oxide.Amperage, 75-100. 3 “ “ carbon.Time, 4 minutes. No metal was obtained. In the above experiments the oxides and the carbon were intimately mixed before placing in the crucible. Experiment IV. In this experiment the copper oxide was placed in the bottom of the crucible and the tungsten trioxide on top. 2 grams of tungsten trioxide .... Voltage, 78-80. 2 “ “ copper oxide.Amperage, 100-125. 3 “ “ carbon.Time, 5 minutes. After running the above length of time, cooled and removed the button from the furnace. Portions of the material were not reduced, so reheated for a period of three minutes; at the end of this time a nonhomogeneous mass was obtained, portions of which gave the test for copper and others did not. Experiment V. Material arranged as in Experiment IV. 2 grams of tungsten trioxide .... Voltage, 60-70. 2 “ “ copper oxide.Amperage, 100-150. 3 “ “ carbon.Time, 5 minutes. 9 After running for five minutes, the mixture was taken from the crucible, mixed with more copper oxide, replaced in the crucible and again treated with a current of 50 volts and 50 amperes. This gave a copper colored button which was malleable. The button gave, upon analysis, 18.24 P er cent °f tung¬ sten, 77.73 per cent of copper and 3.23 per cent of carbon. Method of Analysis. The metal was oxidized with aqua regia, evaporated to dryness, heated to 175 0 C., moistened with nitric acid and taken up with water. The tungsten trioxide was filtered off, ignited and weighed. In the filtrate the copper was deter¬ mined by the electrolytic process. The carbon was deter¬ mined by burning the finely divided metal in oxygen. Experiment VI. 3 grams of tungsten trioxide .... Voltage, 60-80. 3 “ “ copper oxide.Amperage, 75-150. 4 “ “ carbon.Time, 5 minutes. After five minutes I removed the assay from the furnace and added three grams of copper oxide and two grams of carbon. Reheated until fumes of copper were noticed coming off Obtained a button which had no coppery appearance. It gave, upon analysis, 74.86 per cent of tungsten, 18.91 per cent of copper and 3.18 per cent of carbon. Experiment VII. The following experiments were made using a crucible lined with magnesium oxide : 2 grams of tungsten trioxide .... Voltage, 60-70. 4 “ “ copper oxide.Amperage, 125-150. 4 “ “ carbon.Time, 2 minutes. The copper was driven off and the unreduced tungsten trioxide left behind. IO Experiment VIII. 2 grams of tungsten trioxide .... Voltage, 65-68. 2 “ “ copper oxide.Amperage, 125-130. 3 “ “ carbon . . 6 .Time, 3 minutes. No metal was obtained, the copper being driven off, also some of the lining of the crucible, leaving tungsten tri¬ oxide behind. Experi?nent IX. In this experiment, a carbon crucible was used for the first fusion; in the refusion a crucible with a magnesium oxide lining was used. 2 grams of tungsten trioxide .... Voltage, 65. 3 “ “ copper oxide.Amperage, 125. 2 “ “ carbon.Time of first fusion 3 minutes. After three minutes removed the brownish black material from the crucible, mixed with two grams of tungsten tri¬ oxide and two grams of carbon. Reheated until the copper began to volatilize. The fusion was slightly copper colored, somewhat mal¬ leable but very granular. Specific gravity, 8.39. Analysis gave 79.44 per cent of copper and 15.48 per cent of tung¬ sten. The carbon was not determined. Tungsten and Manganese. Experiment I. 3 grams of tungsten trioxide .... Voltage, 80-85. 3 “ “ manganese dioxide , . . Amperage, 100-110. 4 “ “ carbon.Time, 5 minutes. A nonhomogeneous mass was obtained. Mixed this with more carbon and reignited for three minutes with a cur¬ rent of 60 volts and 75 amperes, using a lime crucible for the reignition. The material obtained had no metallic appearance. Experiment II. In this experiment I used a lime crucible. 2 grams of tungsten trioxide .... Voltage, 60. o o o J 2 “ “ manganese dioxide . . . Amperage, 50. 3 “ “ carbon.Time, 5 minutes. Obtained a black porous mass which crumbled easily to a black powder. Tungsten and Chromium. Experiment I. 2 grams of tungsten trioxide .... Voltage, 72-80. 2 “ “ chromic oxide.Amperage, 100-160. 2 “ “ carbon.Time, 5 minutes. This experiment was run using a lime crucible. The globule of metal which was formed was very hard and brittle, the surface being covered with a layer of chromic oxide. This globule was broken and the interior portions were found to be of a grayish color, having a specific gravity of 8.96, and gave when analyzed 2.87 per cent of chromium and 97.64 per cent of tungsten. Method of Analysis. The metal was pulverized, fused with sodium carbonate and potassium nitrate and the fusion taken up with water. The tungsten trioxide was thrown out of the solution by means of nitric acid, the solution evaporated to dryness and heated to 175 0 C. This residue was moistened with nitric acid, taken up with water and the tungsten trioxide remaining insoluble was filtered off, ignited and weighed. In the filtrate from the tungsten trioxide the chromium was determined in the usual manner. Experiment II. 2 grams of tungsten trioxide .... Voltage, 72-85. 2 “ “ carbon.Amperage, 100-150. 1 gram of chromic oxide.Time, 5 minutes. 12 In the above experiment a carbon crucible was used. The fusion had a metallic appearance in places. Replaced it in the furnace and reheated for five minutes more, with a cur¬ rent of 80 volts and 125 amperes. Obtained a black mass. Attempts to prepare alloys, with a large percentage of chromium and a small percentage ot tungsten, were all un¬ successful. Tungsten and Cobalt. Experiment I 2 grams of tungsten trioxide .... Voltage, 80-85. 2 “ “ cobaltic oxide.Amperage, 100-125. 2 “ “ carbon.Time, 3 minutes. A nonhomogeneous mass was obtained. Experiment II. 2 grams of tungsten trioxide .... Voltage, 70. 2 “ “ cobaltic oxide.Amperage, 125. 1 gram of carbon.Time, 3 minutes. In this experiment a lime crucible was used, but the in¬ tense heat cracked it and the material was lost. Experiment III . 2 grams of tungsten trioxide .... Voltage, 70-80. 2 “ “ cobaltic oxide.Amperage, 125-150. I gram of carbon ......... Time, I minute. Used a lime crucible and obtained a button, which was strongly magnetic, very tough and tenacious. Specific gravity of 10.96. Analysis gave 51.86 per cent of tungsten and 48.26 per cent of cobalt. Method of Analysis. Decomposed with aqua regia, evaporated to dryness, heated to 175 0 C., took up with nitric acid and water, 13 filtered off the tungsten trioxide, ignited and weighed it as such. In the filtrate I determined the cobalt in the usual way. Experiment IV 1 gram of tungsten trioxide .... Voltage, 65-70. 3 grams of cobaltic oxide.Amperage, 110-130. 2 “ “ carbon.Time, 2 minutes. Used a lime crucible, which was cracked during the heating so lost a portion of the material. The metal that was obtained was strongly magnetic, very tough and hard to fracture. The metal could be easily filed, and had a specific gravity of 8.92. It gave upon analysis 29.24 per cent of tungsten and 70.10 per cent of cobalt. Tungsten and Nickel. Experiment I. 1 gram of tungsten trioxide .... Voltage, 65-80. 3 grams of nickel oxide.Amperage, 100-135. 2 “ “ carbon.Time, 2 minutes. I used a lime crucible for the fusions, and obtained a button that was strongly magnetic, not very hard, and easily filed. Specific gravity 7.31. The analysis gave 100.65 per cent of nickel and no tungsten. Experiment II. 2 grams of tungsten trioxide .... Voltage, 68-80. 2 “ “ nickel oxide.Amperage, 100-135. 2 “ “ carbon.Time, 2 minutes. This experiment was conducted, using a crucible lined with magnesium oxide. A globule was obtained that was 14 slightly magnetic, could be filed and was very tough. Its specific gravity equaled 10.66. The analysis gave 50.22 per cent of tungsten and 49.88 per cent of nickel. The method of analysis was the same as that used with the alloys of tungsten and cobalt. Experiment III. 3 grams of tungsten trioxide .... Voltage, 75-90. 2 “ “ carbon.Amperage, 100-175. 1 gram of nickel oxide.Time, 1 r / 2 minutes. In this experiment a magnesium oxide lining was used in the crucible. The resulting button was very hard and nonmagnetic, extremely brittle and easily pulverized. Spe¬ cific gravity of 12.66. The analysis gave 91.19 per cent of tungsten and 8.08 per cent of nickel. Experiment IV 4 grams of tungsten trioxide .... Voltage, 70-80. 2 “ “ carbon.Amperage, 75-100. 1 gram of nickel oxide.Time, 2 minutes. The crucible used had a magnesium oxide lining. The globule was dark colored, upon breaking this I found that the interior was a black pulverent mass, which contained no metal. This was probably due to an insufficient amount of current being used. Tungsten and Tin. Experiment I. 1 gram of tungsten trioxide .... Voltage, 70. 3 grams of stannic oxide.Amperage, 100. 2 “ “ carbon.Time, 1 minute. I used a crucible lined with magnesium oxide. The tin was volatilized, leaving the tungsten in the crucible. 15 Experiment II. 2 grams of tungsten trioxide .... Voltage, 68. 2 “ “ stannic oxide.Amperage, 75. 2 “ “ carbon.Time, 1 minute. In this experiment I used a crucible prepared in the same way as the one used in Experiment I. The stannic oxide was placed in the bottom of the crucible and the tungsten trioxide on top. At the end of one minute the crucible contained a mass that resembled tungsten trioxide. The current was turned on again and allowed to act for another minute. A small amount of yellow residue was obtained that contained only tungsten trioxide. Experiment III. 3 grams of tungsten trioxide .... Voltage, 70. 2 “ “ carbon.Amperage, 75. 1 gram of stannic oxide.Time, 2 minutes. Used the magnesium-lined crucible, placing the stannic oxide in the bottom. At the expiration of two minutes there was apparently no reduction. Replaced the crucible in the furnace and ran for three minutes longer, with a cur¬ rent of 90 volts and 75 amperes. The material did not reduce, so removed it, mixed with more carbon and ran for two minutes longer. At the conclusion of this run the crucible contained only tungsten trioxide. Experiment IV. 5 grams of tungsten trioxide .... Voltage, 70. 5 “ “ stannic oxide.Amperage, 100. 5 “ “ carbon.Time, 2 minutes. In this experiment I used a graphite crucible. No metal was obtained, but a black, pulverent mass was left in the crucible; it was probably an impure carbide of tungsten. i6 From the above results it appears to be possible to pre- ' pare alloys of tungsten, starting from the oxides with those metals that require a high temperature for their volatiliza¬ tion. In the case of those requiring a low temperature, the oxide is apparently reduced and the metal driven off before the tungstic oxide is reduced. Doubtless alloys of tungsten and the lower fusing metals could be prepared by starting with the metals and melting them together; but if this is attempted in the electric furnace the intense heat drives off the lower fusing metal, leaving the one with a higher fusing point in the furnace. ALLOYS OF MOLYBDENUM. Molybdenum and Bismuth. Experiment 1 . 4 grams of molybdenum trioxide . . . Voltage, 65-70. 4 “ “ bismuth oxide.Amperage, 90-120. 1 gram of carbon.Time, 2 minutes. The metal obtained was very hard. Specific gravity of 6.81. It gave upon analysis 91.61 per cent of molybdenum, 6.50 per cent of bismuth and 2.28 per cent of carbon. Method of Analysis. The alloy was decomposed with nitric acid, the molyb¬ denum trioxide filtered off, and the bismuth precipitated in the filtrate by means of ammonium carbonate. The molyb¬ denum trioxide was dissolved from off the filter with ammo¬ nium hydrate, and this solution united with the filtrate from the bismuth. In the combined filtrates I determined the molybdenum by precipitating it with lead acetate, accord- 7 ing to the Chatard method as modified by Brearly ( Ch . News , Vol. 78, p. 203). The carbon was determined by burning the metal in oxygen. Experiment II. 2 grams of molybdenum trioxide . . Voltage, 60-70. 8 “ “ bismuth oxide.Amperage, 75-110. 1.5 “ “ carbon.Time, 2 minutes. After heating for one and one-half minutes a granular mass was obtained. It was re-fused for one minute in a crucible lined with magnesium oxide. The mass fused together and gave a very hard metallic button, with a spe¬ cific gravity of 8.91, and upon analysis it gave 92.00 per cent of molybdenum, 4.81 per cent of bismuth and 3.90 per cent of carbon. Experiment III. 6 grams of molybdenum trioxide . . Voltage, 70-80. 2 “ “ bismuth oxide.Amperage, 100-150. 1 gram of carbon.Time, 2 minutes. A crucible with magnesium oxide lining was used in this experiment. The analysis showed 97.91 percent of molyb¬ denum, 1.10 percent of bismuth and 1.21 percent of carbon. Molybdenum and Coppell Experiment /. 2 grams of molybdenum trioxide . . Voltage, 70-85. 6 “ “ copper oxide.Amperage, 100-150. 2 “ “ carbon.Time, 2 minutes. I used a carbon crucible, placing the oxide of copper at the bottom and the molybdenum trioxide on top. The fusion was in two layers, the lower one being copper and the upper molybdenum. Reheated, hoping to bring the i8 two in union; the only change brought about was the vola¬ tilization of the copper. Experiment II. 4 grams of molybdenum trioxide . . Voltage, 65-70. 4 “ “ copper oxide.Amperage, 80-100. 3 “ “ carbon.Time, 2 minutes. The material was arranged in the crucible the same as in Experiment I, and a nonhomogeneous mixture was obtained. The oxides were reduced but the metals did not alloy. Experiment III. 6 grams of molybdenum trioxide . , Voltage, 60-80. 2 “ “ copper oxide.Amperage, 80-125. 2 “ “ carbon.Time, 1^ minutes. The oxides and carbon were intimately mixed before being put in the crucible, and I obtained a porous mass attached to the sides of the crucible. This was removed, ground to a powder and re-fused in a crucible lined with magnesium oxide. The lining absorbed the molten metal. Experiment IV. 2 grams of molybdenum trioxide . . Voltage, 70-80. 6 “ “ copper oxide.Amperage, 100-130. 2 “ “ carbon.Time, 2 minutes. The oxides were reduced but the metals did not alloy. Experiment V. 4 grams of molybdenum trioxide . . Voltage, 65-75. 4 “ “ copper oxide.Amperage, 100-125. 2 “ “ carbon.. Time, 2 minutes. The oxides were mixed. The fusion gave a mixture of the two metals but no alloy. x 9 Molybdenum and Manganese. Experiment I. 4 grams of molybdenum trioxide . . Voltage, 75-85. 4 " “ manganese dioxide . . . Amperage, 100-150. 3 “ “ carbon.Time, 2 minutes. A button, having a specific gravity of 7.08 was obtained. Upon analysis it gave 7i.07per cent of molybdenum, 14.36 per cent of manganese, 9.60 per cent of iron and 4.34 per cent of carbon. The iron in this alloy came from the man¬ ganese dioxide. Method of Analysis. The finely divided alloy was fused with sodium carbonate and a little potassium nitrate. Took up the fusion with water, filtered off the ferric oxide and the hydrated oxide of manganese, dissolved these latter in hydrochloric acid and separated them by the usual method. The filtrate from the above oxides was treated with ammonium nitrate and evaporated nearly to dryness, the manganese hydrate filtered off, and in the filtrate the molybdenum determined by precipitating with lead acetate. The carbon was deter¬ mined by ignition in a current of oxygen. Experiment II. 2 grams of molybdenum trioxide . . Voltage, 70-80. 6 u “ manganese dioxide . . . Amperage, 100-130. 3 “ “ carbon.Time, 2 minutes. The resulting alloy had the specific gravity 6.9. Analysis: 60.08 per cent of molybdenum, 21.11 per cent of manganese, 16.64 P er cent °f iron and 2.99 per cent of carbon. Experiment III. 6 grams of molybdenum trioxide . . Voltage, 68-75. 2 “ “ manganese dioxide . . . Amperage, 100-no. 3 “ “ carbon.Time, 2 minutes. 20 The metal clung to the sides of the crucible so it could not be separated without removing graphite from the crucible. Molybdenum and Chromium. Experiment I. 5 grams of molybdenum trioxide . . Voltage, 70-85. 2 “ “ chromic oxide.Amperage, 75-100. 2 “ “ carbon .Time, 4 minutes. In this experiment a carbon crucible was used. The oxide and carbon were thoroughly mixed before placing in the crucible. The chromic oxide melted and portions of it enclosed some of the molybdic oxide, so the latter was not acted upon. Experiment II. 5 grams of molybdenum trioxide . „ Voltage, 70-85. 2 “ “ chromic oxide ..... Amperage, 75-150. 2 “ “ carbon.Time, 4 minutes. In this experiment a part of the molybdenum trioxide, unmixed with carbon, was placed in the bottom of the cru¬ cible. On top was placed a mixture of the chromic oxide and the balance of the molybdenum trioxide, mixed with carbon. This gave a granular nonhomogeneous mass. Experiment III. 2 grams of molybdenum trioxide . . Voltage, 70-90. 6 “ “ chromic oxide.Amperage, 100-150. 2 “ “ carbon.Time, 3 minutes. I used a carbon crucible, arranging the material as in Ex¬ periment II. This gave a button, which was very hard and brittle. Specific gravity 6.53. The analysis showed 12.82 per cent of molybdenum, 76.71 per cent chromium, 7.52 per cent iron and 2.55 per cent carbon. 21 Method of Analysis. The metal was fused with potassium bisulphate and then with sodium carbonate and potassium nitrate. The fusion taken up with water, and the ferric oxide filtered off. In the filtrate the chromium was determined and in the filtrate from this the molybdenum was precipitated with lead ace¬ tate. Experiment IV. 4 grams of molybdenum trioxide . . Voltage, 70-80. 4 “ “ chromic oxide.Amperage, 90-130. 3 “ “ carbon.Time, 3 minutes. Used a graphite crucible and obtained an alloy that was very hard and brittle. Specific gravity of 7.65. Steel gray color. Analysis gave 39.96 per cent of molybdenum, 53.24 per cent chromium, 6.22 per cent iron and a trace of carbon. Molybdenum and Tin. Experiment I. 2 grams of molybdenum trioxide . . Voltage, 70-80. 6 “ “ stannic oxide.Amperage, 100-125. 3 “ “ carbon.Time, 2]/ 2 minutes. No alloy was obtained. The tin was volatilized, leaving behind a mixture of molybdenum and molybdenum tri¬ oxide. Experiment II. 4 grams of molybdenum trioxide . . Voltage, 70-85. 2 “ “ stannic oxide.Amperage, 80-125. 3 “ “ carbon.Time, 3 minutes. No metal was obtained, the tin being volatilized. Experiment III. 6 grams of molybdenum trioxide . . Voltage, 70-90. 2 “ “ stanni'c oxide.Amperage, 80-150. 3 “ “ carbon.Time, 3 minutes. 22 In this experiment used a crucible lined with magnesium oxide, and obtained a nonhomogeneous mass, which fused together with the lining of the crucible. Molybdenum and Nickel. Experiment I. 2 grams of molybdenum trioxide . . Voltage, 70-80. 4 “ “ nickel oxide.Amperage, 75-125. 2 “ “ carbon.Time, 2 minutes. The crucible was lined with magnesium oxide for this fusion. The metal obtained was very hard and brittle, non¬ magnetic, and had a specific gravity of 7.61. Upon analysis it gave 17.72 per cent of molybdenum, 80.93 P er cen ^ °f nickel and 1.63 per cent of carbon. Method of Analysis. The alloy was decomposed with nitric acid and the nickel precipitated with potassium hydrate. In the filtrate the molybdenum was estimated with lead acetate. Experiment II. 3 grams of molybdenum trioxide . . Voltage, 80-90. 3 “ “ nickel oxide.Amperage, 100-150. 2 “ “ carbon.Time, 2 minutes. Used a crucible with magnesium oxide lining; the lining broke and the material was lost. Experiment III. 4 grams of molybdenum trioxide . . Voltage, 75-80. 2 “ “ nickel oxide.Amperage, 100-150. 2 “ “ carbon.Time, 1 minute. The fusion was carried on as in Experiment II, and gave an alloy that was soft and easily filed. Nonmagnetic. Spe¬ cific gravity of 8.00. 23 Analysis: 65.10 per cent of molybdenum and 3472 per cent of nickel. Experiment IV 4 grams of molybdenum trioxide . . Voltage, 80-90. 2 “ “ nickel oxide . . , . . . Amperage, 75-150. 2 “ “ carbon.Time, 1 minute. A graphite crucible was used in this experiment placing the molybdic oxide at the bottom. The metal was left in small globules clinging to the sides of the crucible. These globules were collected and refused; gave a black, porous, nonmetallic mass of impure carbides Experiment V. 4 grams of molybdenum trioxide . . Voltage, 73-75. 2 “ “ nickel oxide.Amperage, 140-160* 2 “ “ carbon.Time, 1 minute. In this experiment a graphite crucible was used, the material being arranged as in the preceding experiment. The alloy was hard, brittle and nonmagnetic. Specific gravity, 8.88. Analysis : 50.20 per cent of nickel, 42.48 per cent of molybdenum, 3.05 per cent of carbon and 4.04 per cent of silica. The silica probably came from the material used in the manufacture of the graphite crucible. Molybdenum and Cobalt. Experiment I, 2 grams of molybdenum trioxide , . Voltage, 68-75. 4 “ “ cobaltic oxide.Amperage, 100-175. 2 “ “ carbon.Time, 1 y 2 minutes. Used a crucible with magnesium oxide lining. The alloy was very hard, tough and magnetic. Specific gravity of 7 - 32 . 24 The alloy when analyzed gave 17.06 per cent of molyb denum and 82.34 per cent of cobalt. Method of Analysis. The metal was decomposed with nitric acid and then treated as under the nickel and molybdenum experiments. Experiment II. 3 grams of molybdenum trioxide . . Voltage, 70-90. 3 “ “ cobaltic oxide.Amperage, 100-160. 2 “ “ carbon.Time, 1 y 2 minutes. Used a magnesium oxide lining in the crucible, and ob¬ tained an alloy that was very hard, tough and magnetic. Specific gravity of 6.44. Analysis: 35.64 per cent of molybdenum, 62.91 per cent cobalt and 1.79 per cent carbon. Experiment III. 3 grams of molybdenum trioxide . . Voltage, 75-80. 3 “ “ cobaltic oxide.Amperage, 175-190. 2 “ “ carbon ........ Time, 1 y minutes. In this experiment I used a graphite crucible, and ob¬ tained an alloy that was hard and slightly magnetic. Spe¬ cific gravity, 6.94. The alloy was very brittle and easily pulverized. Its analysis gave 47.10 per cent of molybdenum and 52.30 per cent of cobalt. Experiment IV. 4 grams of molybdenum trioxide . . Voltage, 75-95. 2 “ “ cobaltic oxide.Amperage, 125-175. 2 “ “ carbon.Time, 1J/2 minutes. The crucible was lined with magnesium oxide. An alloy was obtained that was very hard, brittle and feebly mag¬ netic. Specific gravity of 7.14. 25 The analysis gave 54.57 per cent of molybdenum and 45.35 per cent of cobalt. Experiment V. 4 grams of molybdenum trioxide . . Voltage, 70-100. 2 “ “ cobaltic oxide.Amperage, 110-150. 2 “ “ carbon.Time, 1 *4 minutes. Used a graphite crucible, placing the molybdic oxide in the bottom. Gave an alloy that was soft enough to be filed, but was brittle and slightly magnetic. Specific gravity of 6.55. It gave upon analysis 49.47 per cent of molybdenum and 50.86 per cent of cobalt. From these experiments it would seem that cobalt and molybdenum can alloy in almost any proportion. REDUCTION OF COLUMBIUM AND TANTALUM OXIDES. Reduction of Columbium Oxide. Experiment L 1 gram of columbium oxide.Voltage, 80. 2 grams of carbon.Amperage, 100. Time, 2 minutes. The current was allowed to act for two minutes, upon allowing to cool there was no indication of metal, so added more carbon and reheated for eight minutes. A small amount of metallic substance was obtained with a specific gravity of 3.43. Experiment II. 1 gram of columbium oxide ...... Voltage, 90. 2 grams of carbon.Amperage, 150. The oxide was volatilized. 26 Experiment III. I gram of columbium oxide.Voltage, 75. carbon. ...... Amperage, 75, Time, 15 minutes. At the expiration of fifteen minutes, a grayish metallic substance was obtained having a specific gravity of 6.61. Analysis of the product gave 88.23 P er cent columbium. Method of Analysis . The metal was fused with potassium acid fluoride, the fusion dissolved in sulphuric acid, diluted with water and boiled. The columbium came down as oxide, was filtered off, ignited and weighed as the pentoxide. Lack of material prevented further experiments being made. Reduction of Tantalum Oxide. Experiment I. 4 grams of tantalum oxide .... Voltage, 70-90. 2 “ “ carbon.. Amperage, 75-150. Time, 2 minutes. I used a crucible lined with lime in this experiment, but no metal was obtained, the lining was melted and the oxide volatilized. Experiment II. 3 grams of tantalum oxide.Voltage, 60-70. 1^2 “ “ carbon .Amperage, 75-150. Time, 2 minutes. In this experiment a graphite crucible was used, and after running for two minutes the oxide was not reduced. More carbon was then added and the mixture heated again for one minute with a current of 70-90 volts and 100-200 amperes. Nearly all of the material was driven off, and 27 only one small globule of metal was obtained. This had a specific gravity of 3.18. Experiment III. 3 grams of tantalum oxide.Voltage, 65-90. 3 “ “ carbon.Amperage, 75-125. Time, \]/ 2 minutes. A carbon crucible was used. After running for one and one-half minutes, the oxide was unchanged, the carbon being all burned. The oxide was again mixed with two grams of carbon and the whole moistened and pressed together very firmly. After drying this mixture it remained caked together. This caked material was placed in the crucible and heated, with a current of 64-85 volts and 75- 150 amperes, tor five minutes. No metal was obtained and only a very little of the material was left in the crucible. Experiment IV. 3 grams of tantalum oxide.Voltage, 60-90. 3 “ “ carbon.Amperage, 75-150. Time, 5 minutes. No metal was obtained, while the oxide was all volatilized. Experiment V. 3 grams of tantalum oxide.Voltage, 60-90. 3 “ " carbon.Amperage, 70 160. Time, 3 minutes. The oxide and carbon were thoroughly mixed, moistened and pressed together. After drying, the mixture was placed in a carbon crucible and then heated. At the expiration of three minutes heating the current was interrupted and the crucible allowed to cool. Only a small amount of unreduced oxide was found in the crucible. From this experiment it would appear that the carbon is burned without acting upon the oxide, and the latter is simply volatilized. 28 Experiment VI. 1.73 grams of tantalum oxide . . . Voltage, 80-90. 2 “ “ carbon.Amperage, 100-125. Time, 1 minute. A few small globules of metallic substance were obtained, having a specific gravity of 4.27. These gave upon an¬ alysis 98.92 per cent of tantalum. Lack of material prevented further investigation in this direction. ACKNOWLEDGMENT. This investigation was undertaken at the suggestion of Professor Edgar F. Smith, and was done under his direc¬ tion. I take this opportunity to sincerely thank him for his ever ready advice, encouragement ancfconstant interest throughout the work.