antimony - Sciencemadness.org
antimony - Sciencemadness.org
antimony - Sciencemadness.org
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106 THE METALLURGY OF'ANTIMONY.<br />
Altogether, the process occupies from four to six hours. The combined<br />
action of the charcoal and soda is to separate the <strong>antimony</strong> from its<br />
oxygen and sulphur compounds, while the gangue is slagged by the<br />
soda, and the foreign metals, if present, are carried into the slag as<br />
sulphides by the action of the sulphide of soda resulting from the<br />
reduction of the Glauber salt by the charcoal. The influence of the<br />
salt added is like that of the Glauber salt and soda, acting as a flux<br />
and as a cover, and in addition carrying the foreign metals present<br />
into the slag as chlorides.<br />
The fuel consumption is 5-6 cwts. per charge, and the loss amounts<br />
to 14 or 15 per cent.<br />
It must be borne in mind that the metal drawn off from the<br />
tapping-hole must be covered over with the slag during its cooling in<br />
FIG. 51.—Front view.<br />
the tapping-pot. When solid, the regulus ie freed from its slag by<br />
hammering.<br />
The following figures were obtained from the working of 830<br />
charges as practised at Siena:—<br />
368,838 lbs. of roasted ore.<br />
268,918<br />
12,641<br />
88,628<br />
38,205<br />
4,409<br />
>t<br />
a<br />
>»<br />
sea salt.<br />
soda ash.<br />
Glauber salt.<br />
slag from previous charges.<br />
iron slag.<br />
The <strong>antimony</strong> obtained weighed 113,573 lbs.<br />
In New Brunswick the l eduction and the refining are carried out<br />
consecutively in the same operation. The furnace dimensions are :<br />
diameter, 8 feet 6 inches; the depth in the centre is 1 foot 6 inches ;<br />
the beds are built of fire-clay and are concave,