An Improved Method of and Apparatus for Separating Liquid Containing Precious Metal from Ores Treated by Wet Processes.
Year: 1889

page_text: Date of Application, 8th Apr., 1889
Complete Specification Left, 8th Jan., 1890-Accepted, 15th Feb., 1890
PROVISIONAL SPECIFICATION.
[Communicated from abroad by THOMAS KIRKE ROSE and DONALD DENNES, both
of 22, Londoner Block, Denver, Colorado, United States of America.]
An Improved Method of and Apparatus for Separating Liquid
Containing Precious Metal from Ores Treated by Wet Processes.
I, FRANK WHITE ROSE of 73 Grove Hill Road, Denmark Park, in the County of
Surrey, Commercial Traveller, do hereby declare the nature of this invention to be
as follows:
This invention relates to the treatment of ores and to apparatus therefor, and
comprises various improvements hereinafter set forth.
According to a method hitherto considerably practised for the reduction of
auriferous and argentiferous ores the latter are treated with some reagent having a
greater affinity for the precious metal contained therein, than has or have the
element or elements that the said ores are found in combination with, and which
forms' with such precious métal a comparatively easily reducible salt or compound.
An example of this is found in any of the wet chlorination processes, wherein the
ore, for example a suitable form of auriferous ore, properly crushed or chlorinated,
is treated with chlorine directly or is mingled with reagents liberating chlorine in
its presence the chlorine displacing the elements. formerly in combination with the
gold and forming therewith the chloride of gold.
As the ore had been moistened with water, made into a pulp, this chloride of gold
is mingled with such water, held in suspension thereby, and after thorough chlorini-
zation it is necessary to remove this water and its contained chloride of gold from the
treated mass, the pulp as speedily and thoroughly as possible, an operation generally
known as leaching the ore." To this end it is sometimes usual to dump a quantity
of the chloridized ore into a suitable vat or tank connected to an exhaust apparatus
by which the liquid is drawn off or sucked from the mass so to speak.
This method has, however been found faulty.and objectionable for several reasons.
Amongst others that even with perfect mechanism the force or pressure of the
exhaust acting to draw off or suck off the water, can never be greater than the
atniospheric pressure at the place of application and as the machinery cannot be
made perfect, this forcé is rarely if ever found in practice to be greater than one
half to three fourths such atmospheric pressure, while for speedy economical and
effective work a much greater pressure is often desirable.
Moreover by the use of the exhaust finely, chlorinated and gritty particles are
often carried over from the material under treatment into the exhaust mechanism,
cutting valves and cylinders and piston packings and consequently impairing their
efficiency and necessitating frequent repairs, the latter entailing not only the cost
of labor and material therefor, but also loss of operating time and therefore of
productive capacity during the stoppages necessary for such repairs.
The main object of this invention is to obviate these defects and to provide a
method by which any degree of force or pressure may be applied to the treated ore
or pulp necessary to speedily and effectively and thoroughly remove. therefrom the
mineral bearing water and by which the danger above mentioned of particles of
ore, grit or the like being carried into the working parts of the mechanism is
avoided. The said method moreover is easily and cheaply practised and requires
but simple mechanisin and apparatus and is effective and reliable in operation.
The said invention consists in a novel method and apparatus for leaching ores
consisting essentially in enclosing them in an air tight vat or tank.and then forcing
air or other gas under pressure upon the upper or lower surface of the mass, or
TD 077

page_text: HASELTINE, LAKE & Co.,
45, Southampton, Buildings, London, Agents for the Applicant.
COMPLETE SPECIFICATION.
An Improved Method of and Apparatus for Separating Liquid
Containing Precious Metal from Ores Treated by Wet Processes.
I FRANK WHITE ROSE of 73 Grove Hill Road Denmark Hill London S.E.
do hereby declare the nature of this Invention which has been communicated to
me from abroad by Donald Dennes, Mechanical Engineer and Thomas Kirke Rose
Assayer of Denver in the County of Arapahoe in the State of Colorado United
States of America and in what manner the same is to be performed to be particularly
described and ascertained in and by the following statement:—
A method considerably practised for the reduction of auriferous and argentiferous
ores consists in treating the ore with some reagent having a greater affinity for the
precious metal contained therein than has or have the element or elements such ore
is found in combination with and which re-agent forms with such precious metal a
comparatively easily reducible salt or compound.
An example of this is found in any of the wet chlorination processes, wherein the
ore, a suitable form of auriferous ore for example properly crushed or comminuted
is treated with chlorine directly or is mingled with re-agents liberating chlorine in
its presence, the chlorine displacing the elements formerly in combination with
the gold and forming therewith the chloride of gold.
As the ore is moistened with water and made into a pulp, this chloride of gold is
mingled with such water, held in suspension thereby and after thorough chlorination
it is necessary to remove this water and its contained chloride of gold from the
treated mass or pulp as speedily and thoroughly as possible, a step commonly termed
leaching the ore. To this end a plan somewhat in vogue is to dump a quantity of
the chloridized ore into a suitable vat or tank connected to an exhaust apparatus by
which the liquid is drawn off or pulled from the mass so to speak.
Such plan is however faulty and objectionable for several reasons.
By such
exhaust method and even with absolutely perfect mechanism, the force or pressure
of the exhaust so acting to draw off the water can never be greater than the atmo-

page_text: spheric pressure at the place of application and as the machinery cannot be made
absolutely perfect in practice the force is rarely, if ever, greater than one half to
three fourths such atmospheric pressure, while for speedy economical and effective
work a much greater pressure is often desirable.
Again, by the use of the exhaust finely comminuted and gritty particles are often
carried over from the material under treatment into the exhaust mechanism, cutting
the valves and cylinders and piston packings and consequently impairing efficiency
and necessitating frequent repairs, the latter entailing not only the cost of labour
and material therefor but also loss of time, during the stoppages necessary for such
repairs.
In view of these things the object of our Invention is to furnish a method by
which any degree of force or pressure may be applied to the treated ore or pulp
necessary to speedily and effectively and thoroughly remove therefrom the mineral
bearing water and by which the injury to the mechanism from particles of ore,
grit &c. being carried there into is obviated. This improved method can be carried
out with facility and economy requiring no complicated mechanism and being
effective and reliable in operation.
In practicing our Invention the ore being first chloridized by any suitable method
therefore is placed in a vat or tank constructed to be closed or sealed after receiving
its charge so as to be air tight or as nearly so as is practicable. To the top of such
tank at some point preferably above the normal level or top line of its charge is
connected an air forcing apparatus while from its lower part a draw-off pipe leads to
a suitable receptacle. The air is then compressed upon the upper surface of the
charge or that surface of the charge facing the direction from which the air is
supplied the force of its compression driving the liquid before it until finally a blast
is established through the mass. Using compressed air any desired pressure may be
given, the column of air acting within the tank as a piston composed of mobile
particles penetrating through the interstices between the units of the mass and
driving the water therefrom, such value bearing water or solution being removed
more thoroughly and speedily than is possible by the use of an exhaust. The liquid
thus leached from the ore is then treated in any of the known ways for the precipita-
tion of the metal.
In some cases in place of using compressed air as herein before described we may
use any other fluid such as steam, water or any suitable gases by means of which
the required degree of pressure can be applied.
Figure 1 of the accompanying drawings represents an apparatus employed accord-
ing to our invention. This apparatus consists of a vat or closed vessel A constructed
with a balanced removeable lid B and provided with a perforated false bottom C
upon which rests the filtering material D retained in position by a perforated
covering E immediately beneath the mass of ore F. His an air pipe provided with
a cock and communicating with an air compresser. I is a pipe through which the
liquid forced through the filter by the action of the compressed air is discharged
from the vessel. K is a pipe provided with a cock through which water may be
introduced at the lower part of the charge occasionally or when required to lighten
up the mass or thoroughly wash the chloride of gold from the ore.
The ore is
dumped into the vessel A and the cover screwed down suitable packing being
employed to make an air tight joint. Air under suitable pressure (usually about
60 lb.) is then introduced through the pipe H and drives the water or solution
through the filtering material D as herein before described.
In dealing with ores of a thick slimy nature difficult of penetration by the air or
fluid employed to apply the pressure the process is more advantageously conducted
in two closed vats or vessels A and A' as indicated in Figure 2. The charge of ore
is dumped into the vessel A and allowed to stand until the more gritty portion has
settled at the bottom. On the surface of the ore in this vessel there is placed a
float L carrying a pipe or tube M the lower end of which communicates with the
compact slime which tends to collect at the surface as indicated at G. This pipe
is connected on the other hand with a second vessel A' by a tube so that when the

page_text: pressure acts on the materials in the vessel A the slime at the surface is forced
through the pipe M M over into the second vessel A'. The main or gritty portion
of the charge being thus freed from the slime which would otherwise interfere with
the action of the compressed air is then treated as hereinbefore described and the
slime in the second vessel A' is treated separately in a similar manner.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed I declare that what I
claim is:-
1. The method of leaching ores consisting in enclosing the material to be leached
in closed filtering vats or tanks and forcing air, steam, water or other fluid into
the said vats or tanks so as to force the solution through the filter substantially as
herein before described.
2. The apparatus consisting in the combination of the closed filtering vessels with
means for supplying air or other fluid under pressure for the purpose of acting
on the ore and driving the solution through the filtering material substantially as
herein before described with reference to Figure 1 of the accompanying drawings.
3. In leaching ores as hereinbefore set forth the combination of two vessels such
as A and A Figure 2 for the purpose of separating the slime from the more gritty
portion of the charge and treating it separately therefrom substantially as herein-
before described.
L