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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128 THE METALLURGY OF ANTIMONY.<br />
sodium sulphide solution and then boiled repeatedly with water;<br />
they are then allowed to pass through o into the filter p, where<br />
they are washed again with hot water. The wash-waters collected<br />
in the holder q are used again for washing other residues. Such a<br />
plant can extract 6 to 8 cwts. of antimony from its ores containing<br />
less than 10 per cent, of the metal in twelve hours.<br />
Figs. 57 and 58 show the arrangement of the electrolytic baths on<br />
a large scale. A are the anodes, K the cathodes, which are hung in<br />
iron baths. The cathodes are of sheet-iron and bolted on to the<br />
rails T, and rest directly upon the rim of the baths, so that the<br />
baths also serve as cathodes. The anodes are plates of lead suspended<br />
FIG. 58.<br />
from iron rails, resting upon the positive leads, which are isolated by<br />
resting on the wooden bars J. The electrolyte is fod through the<br />
three-way cock D under the bath, since it becomes less dense as the<br />
antimony is removed. The outlet is through G by means of the<br />
rubber pipes S into the next bath. In order to effect an oven distribution<br />
of the incoming electrolyte, a plate, V, is riveted upon and along<br />
the bottom of the bath; over this plate is another ono, U, which<br />
is so attached that there is a little space between the two, the two<br />
thus forming a channel.<br />
With concentrated solutions electrolysis may be commenced with<br />
a current of 100 to 150 amperes per square metre (0'064 to 0*1<br />
ampere per square inch), which may gradually be reduced to 40 or 45