Mar., 1916
T H E J O U R N A L OF I N D U S T R I A L A N D ENGINEERING CHEMISTRY
RECOVERY OF GALLIUM FROM SPELTER IN THE UNITED STATES By W.
F. HILLSBRAND AND
J. A. SCHERRER
Received February 5, 1916
Some months ago a few grams of gallium of American production were received b y one of us (S.) from Mr. F. G. McCutcheon, Chemist of t h e Bartlesville Zinc Company, Bartlesville, Oklahoma. Recently the other (H.) received 5 0 g. more from Mr. McCutcheon. T h e first material contained a little indium a n d zinc a n d a trace of calcium, as determined spectroscopically b y Dr. K. Burns a t t h e Bureau of Standards. T h e second lot is of similar composition, presumably. An a s yet incompleted test b y one of us (H.) indicates a n indium content probably of less t h a n one per cent. The metal or alloy is a liquid resembling mercury in appearance, b u t it wets glass a n d porcelain a n d a d heres so tenacicusly t h a t if agitated in a glass vial t h e contents can he seen only as a coating oh t h e walls. This latter proper Iy is not in evidence if t h e metal is covered with hydrcchloric or sulfuric acid. Although gallium melts at about 3 0 ° , i t is said t o remain liquid far below this temperature, indefinitely unless inoculated with solid gallium. Inquiry of Mr. K u r t Stock, Superintendent of t h e Bartlesville Zinc Company, brought out some exceedingly interesting information, as shown b y t h e following extracts from his letter of reply, dated October 2 1 , 1 9 1 j: “His attention [Mr. McCutcheon’s] was drawn to peculiar beads and drops, in appearance like mercury, which seemed t o sweat out of zinc-lead dross plates after these had been exposed to the weather for a time. Mr. McCutcheon, with the help of his two assistants, made a great number of tests, proving the material to be an alloy of gallium and indium with small amounts of zinc * * * * * 7,
“Your hope that a new source of supply for both metals has been opened up, with the prospect of continued manufacture, is not shared by me, as the conditions leading to the concentration of gallium and indium are very unusual and are based on the abnormal state of the spelter market. You are aware that the
present demand for high-grade spelter has led zinc smelters to the practice of redistillation, and i t is the final leady residue from such continued redistillation that carries gallium in noticeable quantities * * * *. We are not at all sure which of the large variety of ores is responsible. Gallium is not found in all dross and where it is found it does not occur continuously
* * * * * *
*,I9
“That the amount in the original ores must be extremely small can well be realized when you consider that the residue from the continued distillation of about IZ,OOO lbs. of spelter weighs about 60 lbs., and represents our raw material from which we can obtain a few grams of the alloys. However, we have at present about 45,tons of dross on hand, which we suspect carries gallium.”
“A very interesting feature is that both gallium and indium are volatile a t the temperature prevailing in our ore furnaces, where a maximum of 1350’ C. is reached for only a few hours, hut they resist distillation if kept for three weeks and longer at
the temperature at which we operate our redistilling furnaces, namely about 1000’C.”
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“Please be assured that we shall leave nothing untried to save these rare metals, but do not get impatient if results are not forthcoming for a while * * * “You may use this very general information any way you desire.” It will be of interest t o determine if this metal, hitherto such a rarity, possesses qualities of value in itself or when combined in small amounts with other metals, and E i it has such, whether their importance will justify continued production after the price of spelter falls. So far as known t o us, t h e only uses for gallium t h a t have been so far suggested are in alloy with aluminum as cathode material in metal vapor lamps‘ a n d for t h e production of optical mirrors. T h e fact t h a t i t wets quartz would seem t o negative t h e suggestion t h a t i t might be suitable in quartz thermometer tubes for measuring temperatures too high for glass instruments. The authors would gladly receive further suggestions. Also of interest is t h e particular source of this gallium, Mr. Stock assures us t h a t i t comes from domestic ores, probably from certain as yet undetermined ones of Joplin. I t s presence has been reported in t h e past in a number of domestic blendes, including one from Joplin. A very recent statement from Mr. Stock is t o t h e effect t h a t t h e dross produced of late shows no gallium a n d t h a t t h e amount of gallium a t first thought t o be available will not come up t o expectations: “ I a m more convinced t h a n ever t h a t gallium will remain a rarity and t h a t a commercial production is out of the question.” Since t h e foregoing was written, spectroscopic tests have been made a t t h e Bureau of Standards b y Dr. K. Burns upon seven samples of zinc ore kindly supplied by, Mr. S. M. Rodgers of t h e American Steel a n d Wire Company. Germanium was also included in t h e metals looked for. The data concerning t h e precise sources of some of t h e ores tested are unfortunately meager, particularly with respect t o Nos. 2, 4 a n d 7 , b u t t h e presumption is strong t h a t No. 4 came from t h e Joplin district. Of special interest is t h e fact t h a t this ore showed more of both gallium a n d germanium t h a n a n y of’ t h e others. The tests obtained b y Dr. Burns follow, accompanied b y his comments : *.I’
SPECTROSCOPIC TESTSOF ZINC ORES Xo. KINDA N D SOURCE OF ORE 1 Sulfide-Sunset, Idaho.. . .
2 3
4 5 6 7
Germanium Moderate Not found Weak Strong , Absent Moderate ~. . . . . , Very weak
.. . . . . . . . . . . . . Sulfide-Australia.. . . . Sulfide-Frisco, Idaho Sulfide-Missouri.. . Carbonate-Monarch, Leadville. . . . . . . . . Carbonate-Doctor Mine, Almont, Colo .... ,,
Gallium Moderate Moderate Moderate Strong Moderate Not found Rather weak
... . “By means of the carbon arc the spectrum was examined in the region 2800 A to 3600 A. Large amounts of iron were present in all these samples. This makes the determination of indium by our method not very accurate, as the most sensitive lines of indium coincide either with carbon lines or with iron lines. I t is certain, however, that indium is not present in these ores in quantities approaching one-tenth of the gallium Found in ores marked ‘moderate.’” BUREAUOF STANDARDS, W A S H I N G T O N , D. c. Carbonate-Utah,
1
Nevada..
~
T.W. Vogel. Zentvalblatt, 1910, I, 703. German patent.
