An improved гrocess of Treating word ores.
Year: 1897

page_text: Date of Application, 18th Sept., 1897
. Complete Specification Left, 2nd May, 1898-Accepted, 17th Sept., 1898
I, CHARLES WETHERWAX, of Best, Rensselaer County, in the State of New
York, United States of America, Manufacturer, do hereby declare the nature of
this invention to be as follows:-
My invention relates to the preliminary treatment of gold ores, and more par-
ticularly refractory gold ores, with the object of liberating the gold from its
combination or association with other elements or compounds which render the
ore difficult of treatment by ordinary reagents and to this end my invention
consists in digesting the ore under steam pressure in a solution containing water-
glass (sodium or potassium silicate) and so preparing the ore for the recovery
of the gold therefrom by usual means.
In carrying out my invention the solution is first placed in the digester and
the digester is then charged with such a quantity of pulverized ore as will be
covered by the solution, the whole being then submitted to digestion under
steam pressure of, say, 80 pounds for an hour, more or less. The duration of
the operation necessarily depends on the nature and conditions of the auriferous
mineral treated and on the amount of steam pressure employed, the period
generally varying inversely as the amount of pressure.
Dated thie 17th day of September 1897
.
A. M. & WM. CLARK,
Chartered Patent Agents, 53, Chancery Lane, London.
An improved гrocess of Treating word ores.
I, CHARLES WETHER WAX, of Best, Rensselaer County, in the State of New
York, United States of America, Manufacturer, do hereby declare the nature of
this invention and in what manner the same is to be performed to be particularly
described and ascertained in and by the following statement:.-
My invention relates to the preliminary treatment of gold ores, more particu-
larly refractory gold ores, with a view to more completely liberating the gold
from its combination or association with other elements or compounds which
render the ore difficult of treatment by the usual reagents, and so preparing the
ore for recovery of the gold therefrom by usual means.
The invention consists in digesting the ore under steam pressure in a solution
containing water-glass. In another application for Letters Patent dated 1st July
1897 No. 15,674 I have specified the conjoint use of water-glass and of caustic
Price RI

page_text: soda or potash, but since making that application I find that water-glass may
be used alone with good effect, and the object of my present application is to
secure broadly the use of water-glass for the purpose.
The average strength of the solution which may be employed is, say, about
10 ounces of sodium or potassium silicate to the gallon of water, these propor-
tions being however susceptible of variation according to the nature and condi-
tion of the ore, allowance being made in the strength of the solution when
treating ore in a wet state for the dilution of the solution by the contained
moisture. The quantity of solution used should be sufficient to cover the ore,
the whole being submitted to digestion under a steam pressure of eighty pounds
(more or less) to the square inch for an hour (more or less) the duration of the
operation necessarily depending on the nature and condition of the auriferous
mineral treated and on the amount of the steam' pressure' employed, the period
generally varying inversely as the amount of the pressure.
The operation may be performed in an apparatus such as that illustrated in
the accompanying drawing wherein A is the digester provided with an inclined
grid or apertured false bottom B and connected with a centrifugal pump C by
a system of circulation pipes; the pipes being preferably connected with the
digester below the grid B and at a point above the level of the charge of ore
but below the level of the supernatant solution, the pipes connected with the
suction and delivery of the pump being so controlled by stop cocks that a circu-
lation of the leaching solution may be maintained either in the upward or the
downward direction through the mass of ore contained in the digester.
To the bottom of the digester is connected a pipe D by which live steam at a
pressure of, say, eighty pounds (more or less) may be introduced below the false
B so as by passing up through the charge of ore to cause a circulation
of the leaching solution and bring it into intimate contact with the ore.
E is a condenser with which the upper part of the digester is connected.
The digester and its contents may be heated by an internal steam coil or by
an external steam jacket (which are not shewn but will be readily understood)
to prevent excessive weakening of the solution by the condensation of the steam
injected therein.
The digester is provided at top with a manhole F for charging in the ore
and with a valve G just above the lower part of the inclined grid B for discharg-
ing-the-contents of the digester into a sluice H, provided with ripples and other
usual means of intercepting the gold. J is a nozzle whence a jet of steam may
be directed towards the aperture G to facilitate the discharge of the solid matters,
and I is a manhole in the bottom of the digester for cleaning out the chamber
below the grid B.
The solution of water-glass may be contained in a tank K whence a pipe
leads into the upper part of the digester and terminates in a nozzle L. M is a
water tank also connected with the same nozzle, the connection in each case
being controlled by stop cocks. The nozzle L is upwardly directed in order that
the jet may be directed against the top of the digester so as to be evenly distri-
buted over the contents.
The operation is performed as follows:-The necessary quantity of solution
to cover the charge of ore is first admitted into the digester from the tank K
and then the charge of ore is introduced and the digestor closed. If the
digester is provided with a steam coil or jacket the contents are heated and
then steam is admited by pipe D, and the contents submitted to digestion for
an hour (more or less). The solution may be meanwhile circulated by the pump
although such forced circulation is not indispensable when steam is injected
below the grid B. The circulation would generally be in the upward direction
when finely crushed ore is treated and in the downward direction only when
the ore is in coarse lumps. When the operation is complete, connection is
opened with the condenser E in order to discharge and condense the fumes or
obnoxious gases evolved, and then the valve G is-opened and the contents dis-
.J.

page_text: charged onto the sluice H, the discharge being assisted by the steam jet at J
and by water from the tank M to wash out the digester and carry the solid
matters over the sluice.
Instead of steam being injected it may be generated in the digester which
would in that case be externally fired and may be placed in a vertical or hori-
zontal position.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed I declare that what
I claim is:-
1. In the treatment of gold ores for liberating the gold from its combination
or association with other elements or compounds, the process which consists in
digesting the ore under steam pressure in a solution containing water-glass
(sodium or potassium silicate) as specified.
2. The herein described process of treating gold ores, which consists in sub-
jecting the ore in a closed vessel, to the conjoint action of steam heat and pressure
and of a solution containing sodium or potassium silicate which solution is
caused to circulate through the ore substantially as specified.
Dated this 20th dow of Annil jege
A. M. & WM. CLARK,
Chartered Patent Agents, 53, Chancery Lane, London.
A. M. & WM. CLARK,
Chartered Patent Agents, 53, Chancery Lane, London.