A N T I M O N Y : ITS HISTORY, CHEMISTRY, MINERALOGY ...

124 THE METALLURGY OF ANTIMONY.
The following analyses refer to material from the mine La Lucette;
the quantities are those yielded per ton:—
Antimony, kilos .
Gold, grammes .
Waste ground by
Crushing
Mill.
10'9
6
Ball
Mill.
9*5
5
Concentrates
from "Waste.
Sample Sample
II.
1141
34
97*5
214
Mixed
Materials.
14*6
1
Tailings.
6-1
traces
(b) The Treatment of the Concentrates.—They are lixiviated in
agitators with a solution of sodium sulphide. The sulphide of
antimony is dissolved as double sulphide of antimony and sodium,
and the gold is left in the residues.
The liquor thus obtained is heated with the sulphurous acid coming
direct from the roasting of pyritic ores or of the sulphide of antimony,
obtained in the same process from a previous treatment. The antimony
sulphide thus precipitated has a red colour. The gold residue can bo
treated in a reverberatory furnace in the presence of litharge. The
gold can be extracted by cupellation or by oxidation with nitrate of soda.
The process is profitable with an ore containing:—
Antimony, 4 per cent., or 40 kilos per ton.
Gold, 12 grms. per ton.
The profit is 21 frs. per ton, after subtracting the expenses. One
ton of ore may cost only 6 frs. This result has boon obtained at
Genest (Mayenne); France.
Lyte proposes to roast antimony-bearing lead, silver, and copper
ores in the presence of chlorides, to condense the antimony vapour
in a solution of salt, and to precipitate the metal by iron or zinc.
This process requires complicated condensing apparatus.
The Utah Antimony Company, of Garfield Co., Utah, has been able
to obtain a concentrate containing 65 per cent, antimony from ore
containing only 11 per cent, of that metal. The mill is capable of
producing 10 tons of concentrate per day.
III. EXTRACTION BY ELECTROLYTIC METHODS.*
It has been proposed to treat poor sulphide antimony ores, and the
residue from the liquation of richer ores, with solutions of alkali-
* Electric Smelting and Refining of Dr W. Borchors, translated \)y W. G.
McMillan, pp. 476-487 ; London, C. Griffin & Co., 1904.