Mr. Jas. J. Shedlock, with the assistance of Mr. T. Denny, of
Australia, has constructed on behalf of the Metallurgical Syndicate,
of 105 Gresham House, London, an apparatus on a commercial scale,
which, it is said, effects at the smallest expense, and with the best
economical results, the entire separation of metals from their ores.
In treating ores by this process, the stone is crushed in the usual
way, either by rolls or stamps, the crushed ore being conveyed into an
apparatus, where each atom is subjected to the action of gases under
pressure, whereby the whole of the sulphur and other materials which
render the ore refractory are separated. The ore is then conveyed into
a vessel containing an absorbing fluid metal, so constructed that
every particle of the ore is brought into contact with the metal. For
the production of reducing gases, steam and air are passed through
highly heated materials, having an affinity for oxygen, and the gases
so produced are utilized for raising the ore to a high temperature. By
this means the sulphur and other metalloids and base metals are
volatilized and eliminated, and the gold in the ore is then in such a
condition as to alloy itself or become amalgamated with the fluid
metal with which it is brought into close contact. The tailings
passing off, worthless, are conveyed to the dump.
The apparatus in the background is that in which the steam is
generated, and which, in combination with the due proportion of
atmospheric air, is first superheated in passing through the hearth or
bed on which the fire is supported. The superheated steam and air
under pressure are then forced through the fire, which is
automatically maintained at a considerable depth, by which means the
products of combustion are mainly hydrogen and carbonic oxide. These
gases are then conveyed by means of the main and branch pipes to the
cylindrical apparatus in the foreground, into which the ore to be
acted upon is driven under pressure by means of the gases, which,
being ignited, raise the ore to a high temperature. The ore is
maintained in a state of violent agitation. Each particle being kept
separate from its fellows is consequently very rapidly acted upon by
the gases. The ore freed from its refractory constituents is then fed
into a vessel containing the fluid metal, in which each particle of
ore is separated from the others, and being acted upon by the fluid
metal is absorbed into it, the tailings or refuse passing off freed
from any gold which may have been in the ore.
[Illustration: APPARATUS FOR THE TREATMENT OF REFRACTORY ORES.]
Quantities of refractory ores treated by this process are said to have
demonstrated that the whole of the gold in the ore is extracted. The
successful outcome of these trials is stated to have resulted in the
Anglo-French Exploration Co. acquiring the right to work the process
on the various gold fields of South Africa. It is anticipated that the
process will thus be immediately brought to a test by means of
apparatus erected on the gold fields under circumstances and
conditions of absolute practical work. As is well known, gold-bearing
ores in South Africa which are below the water line are, by reason of
the presence of sulphur, extremely difficult to deal with, and are
consequently of small commercial value. The gold in these ores, it is
maintained, will, by the new process, be extracted and saved, and make
all the difference between successful and unsuccessful mining in that
country.
It will have been seen that the peculiar and essential features of the
invention consist in subjecting every particle of the ore under
treatment to the process in all its stages instead of in bulk, thereby
insuring that no portion shall escape being acted upon by the gases
and the absorbing metal. This is done automatically and in a very
rapid manner. It is stated that this method of treatment is applicable
to all ores, the most refractory being readily reducible by its means.
The advantages claimed for this process are: simplicity of the
apparatus, it being practically automatic; that every particle of the
ore is separately acted upon in a rapid and efficient manner; that the
apparatus is adaptable to existing milling plants; and that there is
an absence of elaborate and expensive plant and of the refinements of
electrical or chemical science. These advantages imply that the work
can be done so economically as to commend the new process to the
favorable consideration of all who are interested in mines or mining
property.--_Iron._
* * * * *