A N T I M O N Y : ITS HISTORY, CHEMISTRY, MINERALOGY ...
A N T I M O N Y : ITS HISTORY, CHEMISTRY, MINERALOGY ...
A N T I M O N Y : ITS HISTORY, CHEMISTRY, MINERALOGY ...
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118 THE METALLURGY OF ANTIMONY.<br />
sulphide on the hearth of a reverberatory furnace. After the hot<br />
ore has been charged and thoroughly rabbled, iron is added, the<br />
temperature of the furnace raised, and, when the decomposition is<br />
complete, the antimony tapped; the tap-hole is closed as soon as the<br />
iron sulphide appears. Slag is drawn through the working doors;<br />
and the increase of iron sulphide obtained during the operation is<br />
removed until the bath is reduced to its original depth. This method<br />
is said to have given good results, and has been in successful<br />
operation for more than a year.<br />
Cookson patented* in 1902 a process very similar to that of<br />
Sanderson. In fact, Cookson's and Sanderson's patents are copies of<br />
a similar patent by Herrenschmidt (No. 296,200, Jan. 16, 1900,<br />
France), shown in fig. 54.<br />
(b) Water-jacket or Blast Furnaces.—Hering has experimented<br />
with shaft furnaces for the treatment of liquation residues by the<br />
precipitation method. 'Although his experiments have not been<br />
continued, yet good results might be obtained if rich ores were<br />
treated.<br />
According to Herrenschmidt, rich ore can be treated directly in a<br />
water-jacketed furnace. Temperature = 1000° to 1100° C. Airblast<br />
=10 c. of mercury. About 12 to 14 per cent, of antimony<br />
can be recovered from the condensing chambers. Coke used = about<br />
300 kgs. per ton.<br />
(c) Converters.—According to Germot, t sulphide ore can be smelted<br />
in a converter into which air is blown. The air burns part of the<br />
sulphur of the ore, with the production of sulphurous acid and the<br />
metal itself. The operation is made continuous by the addition of<br />
more ore. The sulphurous acid produced escapes through a pipe at<br />
the upper part of the converter, together with the antimony sulphide<br />
fumes. If a current of air is made to act on these fumes, oxysulphide<br />
or antimony oxide will be produced, according to the amount of air<br />
admitted.<br />
The products of the extraction of crude antimony J are unrefined<br />
antimony and slags. The former contains many foreign elements, as<br />
shown in the analyses given in the table on p. 120.<br />
This impure antimony has to be refined. The slags obtained from<br />
* French patent No. 324,864, Sept. 30, 1902.<br />
t A. Germot, Revue des Produits Chimiques, Dec. 15, 1907. Similar to Herrenschmidt's<br />
French patent No. 333,340, June 24, 1903.<br />
t The term "crude antimony," meaning the unrefined metal, must be disinguished<br />
from the teim "antimony crude,*' which means the liquated antimony<br />
sulphide.