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

THE METALLURGY OF ANTIMONY. '13
The mineral is introduced into the muffles through doors, /, which
are closed" during the roasting.
The muffles are not in communication with one another ; each
muffle has an opening through, e, into a chamber, c/, which communicates,
through an opening, o, with a channel, h, connected with the
condensing chambers, •?'. The circulation of the vapour is obtained
by means of a ventilator,,;, placed immediately after the last chamber
of condensation. The remaining gas, after passing through k, is
washed by a water-shower in I, and then passes into the basins, m.
The Miniere e Fonderie d'antimonie Sociuta Anonima, Genoa, Italy,
one of the principal antimony smelters, patented in 1907 the following
process* :—
In other processes the oxide produced is generally condensed either
in long flues, or on baffles, or in large condensation chambers. In
many cases the volatile matter is mixed with water in the ventilators,
after which the oxido is separated out by decantation. The condensation
in these cases is not always complete, and the object of the
present invention is to prevent any loss of the oxide by filtering
through cotton, linen, or any other fabric that will arrest the oxide contained
in the smoke.
In order to prevent the carbonisation of the tissues used, it is
necessary to cool them to about 100°. If the oxide-containing fumes
have too high a temperature, they must be cooled by passing them
through chambers or metallic tubes more or less surrounded by water.
Care must be taken not to allow the oxide at its early stage to come
into contact with any water, as the presence of water would destroy
the permeability of the tissue and lead to the formation of sulphurous
acid. In order to overcome the resistance to the draught, offered by
the tissues used, it is necessary to use ventilators.
Figs. 33, 34, 35, 36 represent cooling and condensing chambers;
figs. 37, 38, 39, 40, filtering chambers.
Fig. 33 is a cross-section of fig. 34. The walls and foundations of
these chambers are of masonry, stone-concrete, or sheet-iron. The
roof is always bordered lengthwise by L-shaped plates, 2, so
as to serve as evaporating basins for the water flowing over the
roof. The condensed oxido falls into the sacks, 3, from which it
can bo discharged. Figs. 35, 36 show another form of condensing
chambers, fig. 35 being a cross-section ; the channels are arranged
in chicanes, 5, with openings, 4, for the discharge of the condensed
oxide.
Fig. 37 represents a cross-section, and fig. 38 a longitudinal section,
* French patent No. 381,517, Sept. 4, 1907.