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

104 THE METALLURGY OF ANTIMONY.
Figs. 48, 49, 50, and 51 show another type of the same furnace.
The dust obtained from the condensing chambers contains up to
50 per cent, of antimony. The charge for this furnace consists of
400 to 500 lbs. of roasted ore, oxidised ores, and flue dust, 90 to 110
FIG. 46.—Scale=3^.
lbs. of a flux consisting of salt, smaller quantities of soda, and sometimes
a small quantity of Glauber salt, 65 to 75 lbs. of ground charcoal,
and 220 to 330 lbs. of slag from previous charges, the slag containing
principally common salt.
The furnace is first charged with the fluxes and is then fired; about
FIG. 47.—Section A B. Scale -
an hour after their charging the liquefied fluxes will remain in a state
of tranquil fusion. The other ingredients are then charged in
portions of about 44 lbs. at intervals of fifteen minutes, and are well
stirred. The scum produced after each charge is drawn off through
the working door. The furnace is strongly fired after the last charge.