INDUSTRIAL A N D ENGINEERING CHEMISTRY
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Vol. 16, No. 6
Germanium in Smithsonite and Mine Waters' From the Hudson Mine, Livingston County, Kentucky By John Hughes Muller UNIVERSITY OF PENNSYLVANIA, PHILADELPHIA, PA.
INCE the discovery of
then distilled in a slow The smithsonite from the Hudson mine, near Salem, Livingston germanium in 1886 current of chlorine. The Countb, Kentucky, contains 0.01 per cent germanium dioxide. The this rare metal has chilled receiver contained ore is practically free from both arsenic and lead, elements commonly been reported in very few some water, into which the present in large amounts in the germanium-bearing blendes of minerals except in spectroend of the condenser tube Wisconsin and Missouri. scopic traces. Up to the dipped, the apparatus being Germanium is present in the mine water of the Hudson mine, and, present time the minerals in so constructed as to allow calculating on the totalsolids in this water, amounts to 0.29 per cent of which it has been found the raising or lowering of the residues obtained by simple evaporation of the water. The mine have invariably been the condenser without interwater is used in washing the ore at the mine and during this operablendes, chiefly those of silrupting distillation. When tion takes up more of the germanium present in the ore. This ver, zinc, or copper.2 This about two-thirds of the acid wash water contains I part per million germanic oxide, which repsolution had been distilled paper concerns the finding resents about 0.5 per cent of the total solids in the wash water. over, all or nearly all the of small amounts of gerThe conversion of waste zinc oxide to sulfate at the Trenton germanium had collected in manium in the smithsonite plant results in the production of mother liquors containing germathe receiver. At this point deposits from the Hudson nium in an easily recoverable form, as the action of hydrogen sulfide mine in Livingston County, the receiver was changed removes all the germanium contaminated with little else than free and further distillates were Kentucky, together with sulfur and small amounts of arsenic sulfide. The yield of germanic collected 'until no germathe discovery of workable oxide from the crude zinc oxide is about 0.006 per cent. amounts of the same metal nium could be detected. in the mine waters of the The acid distillates were brought to 6 N acid concentration and were saturated with same l ~ c a l i t y . ~ The Hudson mine is worked a t a depth of 90 feet and was hydrogen sulfide under pressure, allowing 24 hours or more for first opened by the American Spar Company in 1905; the complete precipitation of the sulfide. The sulfide, of course, smithsonite was not marketed, however, until 1916. The contained free sulfur as well as germanium sulfide, owing to carbonate ore is treated a t the mine in log washers, and the the action of hydrogen sulfide upon the free chlorine. The concentrates, containing 36 to 40 per cent zinc oxide, are mixture was filtered out and washed with dilute sulfuric acid shipped to Trenton, where they are mixed with coal, reduced, saturated with hydrogen sulfide. The filtrates and wash and the zinc is then fumed over as the finely divided oxide, water combined were saved and retreated with hydrogen which is collected in various degrees of fineness by the usual sulfide, recovering the small amount of germanium sulfide which escaped precipitation and which dissolved in the bagging process. ~ a s h i n g . The ~ precipitated sulfide, together with free GERMANIUM IN SMITHSONITE sulfur, was treated on the filter with a little cold, dilute The smithsonite is yellowish brown, fairly hard, and com- .ammonia, by means of which the very soluble germanic pact. A complete analysis of the ore showed that nearly all sulfide was largely removed from the sulfur. The ammonithe iron it contains has been altered to limonite and that i t is acal solution was collected in a weighed crucible, in which it quite free from arsenic and lead and contains less than 0.1 was evaporated and converted to the oxide by frequent treatper cent sulfur. These facts are important, as all the natu- ment with nitric acid followed by evaporation and ignition to rally occurring germanium minerals contain these elements constant weight. The residue of germanium dioxide, pure in notable quantity. white in color, was confirmed for germanium in each case by The small germanium content of the mineral was deter- digestion with an excess of pure water, filtering, and repremined from 250-gram samples; the average of 0.01 per cent cipitating the sulfide from the acidified solution. The represents the mean of a number of analyses in which the strongly ignited oxide dissolved completely in pure waterhighest value found was 0.018 and the lowest 0.006 per cent. a peculiarly characteristic reaction-and the white sulfide The picked samples of ore never contained less than 0.01 obtained from the acidified solution, when introduced into an per cent, though the concentrates shipped from the mine aluminium and caustic soda hydrogen generator, gave hydrogave the lower value in several cases. The weighed material gen containing germanium hydride, from which brilliant silin the fo7m of a coarse powder was placed in a distilling flask, very mirrors of metallic germanium were obtained. The connected with a splash trap, Liebig condenser, and well- germanium sulfide was dissolved in a little dilute caustic cooled receiver, and digested with sufficient hydrochloric acid soda before being introduced into the generator, and the latto decompose the mineral. Excess of the acid was then added ter, of course, was tested in blank before the solution of the to approximately 20 per cent concentration and the whole sulfide was allowed to run in.6 Attention should be called to the fact that germanic oxide remains easily soluble in water, 1 Received December 20, 1923. even after fusing to a glassy mass at 1100" C. This behavior, 2 Winkler, Ber., 19,210 (1886); Kruss, Ibid ,2l,131 (1888); Hillebrand together with the precipitation of the white sulfide from JOURNAG, 8, 225 (1916); Buchanan, Ibzd., 9, 661 (1917); and Scherrer, THIS Penfield, Ant. J . Sa., [3]46, 107 (1893); Urbain, Comfit. rend., 160, 1758 this solution after acidifying with sulfuric acid, constitutes (1910); Prior and Spencer, Minerdog. Mag., 12, 54 (1898); Chem. Zenlr., a characteristic test for germanium. 70, (11) 268 (1899); Bardet, Compt. rend., 158, 1278 (1914); Pufahl, Metall
S
u. Ere, 19, 324 (1922). The ore and mine water samples were obtained through the kindness of the Trenton Zinc & Chemical Co., Trenton, N. J., and the work was greatly aided by the interest and cooperation of E. A. Slagle of that organization. 8
4 For precautions in washing germanium sulfide, as well as the method used in recovering the small amount of germanium in the filtrate and wash water, see Dennis and Papish, J. Am. Chem. Soc., 43, 213 (1921). 6 Muller and Smith, Ibid., 44, 9 (1922).
June, 1924
INDUSTRIAL A N D ENGINEERING CHEMISTRY GERMANIUM FROM ZINCSULFATE LIQUORS
ANALYSIS OF MINE SHAFTWATER The water was taken from the same shaft from which the smithsonite samples had been collected. The sample was muddy and filtered slowly, giving a filtrate that was colorless, odorless, and neutral to litmus. Six kilograms of the filtered water, rendered slightly alkaline with sodium hydroxide, were reduced to small bulk and washed into a distilling flask with 250 to 300 cc. of 20 per cent hydrochloric acid. The germanium was distilled out of this solution, all the precautions mentioned under the analysis of the ore being observed. A complete analysis for metals other than germanium was also made, which need not be shown. The following facts are of interest, however: The water contained 136.6 parts per million of total solids (ignited); of this solid residue 0.29 per cent was germanium dioxide, representing 0.4 part per million germanium dioxide in the water; lead and arsenic were totally absent. The germanium present in the mine water must either have been dissolved from the ore of the mine or already present in the water entering the shaft. In order to find out which was more likely to be the case, the following experiments were made : (1) Five-hundred grams of the ore of known germanium content were reduced to a very fine powder and digested with hot water for several days; 0.200 gram of pure germanic oxide, or 'about 86 per cent of the germanic oxide in the ore, passed into the aqueous filtrate. The ore in lump form (2 kg.) failed to yield more than about one-fortieth of its germanium content by simple extraction with water. ( 2 ) The water pumped from the mine shaft is used in the log washers for the concentration of the ore. A quantity of this wash water was separately analyzed for germanium. The results of this analysis are of interest because the germanium content was nearly double t h a t present in the water taken from the mine shaft. The analysis of the solid residue from 9 kg. of the filtered water from the washers gave 0.0090 gram of germanium dioxide or 1 part per million, representing about 0.5 per cent of the ignited total solids present in the water.
From these results it appears reasonable to believe that most of the germanium found in the mine water was derived from the smithsonite of the mine rather than from an outside source, and a t the same time explanation is found for the fact that the concentrates from the log washers gave lower values for germanium than the picked samples of ore from the mine. The discovery of germanium in the ore and mine water naturally suggested the analysis of various products produced from the ore a t the Trenton plant. Results of these analyses follow: Furnace clinker Flue deposit Zinc oxide from pipes near bag house Zinc white from bag house (finished product)
Germanium Oxide Per cent 0.009 0.004 0.010 0 015
It is evident that the germanium does not remain in the residues of the furnace, but distributes itself throughout, and it is interesting to note that the burning of germanium containing zinc results in the production of germanic oxide in such fine state of division that it passes along with the oxide of zinc into the product of the bag house. The crude zinc oxide from the flue dust and deposit in the pipes near the bag house are the most workable sources of germanium, for the following reasons: first, this oxide is ordinarily regarded as wasbe and cannot be recovered except by a reburning operation; second, the conversion of this crude oxide to sulfate allows the concentration of germanium in the mother liquors of the sulfate crystallizations and a t the same time permits the utilization of the zinc as commercial white vitriol.
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The material used here was crude, discolored zinc oxide obtained from the furnace flues and pipes near the bag house. About 45 kg. (100 pounds) of this oxide known to contain 0.01 per cent germanic oxide were taken for an experimental run a t the plant. The fine powder was sifted into an excess of crude sulfuric acid, the known quantity of acid being so diluted as just to allow complete solution of the sulfate a t boiling temperature. The heat of reaction was more than sufficient to bring the reacting mass to this temperature, and on cooling about two-thirds of the total zinc crystallized out as sulfate. The mother liquor was collected in barrels and saturated with hydrogen sulfide in presence of excess sulfuric acid. The precipitate was pale yellow in color, consisting of germanium sulfide and some free sulfur, together with some arsenic sulfide derived from the crude sulfuric acid. The precipitate contained only traces of other metals of the hydrogen sulfide group. It was small in bulk and could be easily handled in a 2-liter flask; it was not washed, but simply allowed to settle and the bulk of supernatant solution siphoned off. The mass of sulfides was then washed into the distilling flask with a little water and the suspension subjected to the action of chlorine in the cold. Hydrochloric acid was then added to 20 per cent concentration and the germanium distilled off in a slow stream of chlorine. The several distillates obtained were treated as already described for the recovery of their germanium content, the combined precipitates of sulfide being converted to dioxide in the usual manner. The 45 kg. of original oxide gave 2.75 grams, or 0.006 per cent, of pure germanium dioxide, which represents more than half of the total germanium known to be present. This oxide was pure white, and after ignition to the highest temperature of the blast lamp was completely soluble in 500 cc. of water a t boiling temperature. Further test of the purity of the oxide was made by reprecipitating the sulfide from this aqueous solution after adding enough concentrated sulfuric acid to make the solution 6 N . The sulfide was pure white, soluble in dilute ammonia, dilute caustic soda, and dilute hydrofluoric acid in presence of hydrogen sulfide.6 Portions of the sodium hydroxide solution were introduced into an aluminium and caustic soda generator and the evolved hydrogen was tested for germanium hydride. Brilliant mirrors of metallic germanium were obtained.6 CONCLUSION The existence of germanium in a carbonate ore is new and interesting in itself, as it indicates that the soluble germanic oxide, probably derived from the metamorphosis of germanium-bearing blendes in the vicinity, is carried some distance in aqueous solution. Carbonated waters containing the bicarbonates of zinc, manganese, calcium, and ferrous iron can thus carry germanic oxide in solution, part of which 'may be subsequently precipitated in deposits of smithsonite, rhodochrosite, limestone, or siderite, and the natural waters of the same locality may still retain part of the germanic acid held in solution. 6
Muller, J . Am. Chem. Sac., 43, 2549 (1921).
Modification in Peruvian Import Duties-The following articles have been reclassified under the Peruvian tariff and made subject to new import duties: Soap chips, formerly dutiable a t 0.25 sol per gross kilo, now dutiable a t 25 per cent ad valorem; varnishes with base of turpentine and asphalt pitch not formerly specified, now classified under item 1163 a t the rate of 0.50 sol per legal kilo; chlorate of magnesia for industrial purposes (formerly included under item 2121 salts of magnesia, not specified, a t 2.00 soles per net kilo), now dutiable a t 10 per cent ad valorem only provided it is imported in quantities exceeding 500 kilos.
