Improvements in the Treatment of Slimes or Tailings for the Extraction of Gold or Silver therefrom by Means of Solvents, and Apparatus for that Purpose.
Year: 1895

page_text: Date of Application, 30th Aug., 1895
Complete Specification Left, 29th May, 1896-Accepted, 30th Sept.,
1896
PROVISIONAL SPECIFICATION.
Improvements in the Treatment of Slimes or Tailings for the
Extraction of Gold or Silver therefrom by Means of Solvents,
and Apparatus for that Purpose.
I, JOHN COBELDICK, of St. Pirans, 110 Stockwell Road, in the County of London,
Engineer and Colliery Owner, do hereby declare the nature of this invention to be as
follows:-
My invention has for its object to facilitate the extraction of gold and silver from
slimes and tailings by means of solvents such as cyanide solutions and the like. It
consists in forcing such solvents in an upward direction through the slimes or tailings,
either together with or alternately with gases under pressure, by which means the
material, which owing to its compact and more or less viscous nature, resists the
passage of the solvents through it in a downward direction, is more or less opened
out or levitated by the action of the gases and is thus made to afford the solvent
ready access between its particles, this action being also assisted by capillary attraction,
so that by this means the solvent will readily be enabled to take up the gold or silver
from the material. In combination with this mode of action I also provide means for
forcing the solvent alternately in an upward and in a downward direction through the
material and for operating repeatedly on one and the same charge of material with
the same body of solvent.
"
For the above purposes I employ apparatus of the following construction.
I provide one or more vessels for containing the liquid which I will call the
receiver "and one or more receptacles containing the material to be treated, which
I will call the " vat," and I connect the receiver with the vat by means of a pump
constructed as follows. The pump, which may either be of the piston and barrel or
of the centrifugal kind, has three suction orifices, and two delivery orifices
one of
the suction openings is connected to the lower part of the receiver, a second one to
the bottom of the vat, while the third one is either open to the air, or is in communi-
cation with a gas holder, each of these openings being provided with a valve by
means of which the several communications can be regulated or cut off.
The one delivery orifice of the pump is connected to the lower part of the vat in
such a way as to cause the liquid or gas entering through the orifice to be spread
evenly over the whole area of the floor or bottom of the vat, beneath the material
contained therein. The second delivery orifice of the pump is connected by branch
pipes or passages both to the top of the vat and the top of the receiver, each of the
said discharge orifices being fitted with a suitable valve for regulating and closing
the same.
With the above described arrangement I am enabled to perform either of the
following operations.
I can draw liquid from the receiver and force it below the material contained in
the vat, or I can draw liquid from the receiver, and air from the atmospher or gas
from a gas holder and force them simultaneously below the material in the vat, or I
can draw air or gas only and force it below the material in the vat, or again I can
draw liquid from the top of the vat and force it in again at the bottom of the
vat so as to pass up through the material again, and thus cause the same body of
liquid to circulate as often as may be required through the material in the vat. Or
again I can draw liquid from the bottom of the vat and discharge it into the top of

page_text: the receiver; or I can draw liquid from the bottom of the vat and discharge it into
the top, or into the receiver.
I can also treat one and the same charge of slimes or tailings with consecutive
charges of solvent, or I can employ one and the same charge of solvent for treating
several consecutive charges of slimes.
The vat and receiver are connected at top by overflow passages, so that according
as the solvent is drawn from the receiver and forced into the vat, or the converse, it
will overflow from the vat into the receiver or the converse.
Dated this 30th day of August 1895.
ABEL & IMRAY,
Agents for the Applicant.
Improvements in the Treatment of Slimes or Tailings for the
Extraction of Gold or Silver therefrom by Means of Solvents,
and Apparatus for that Purpose.
I, JOHN COBELDICK, of St. Pirans, 110 Stockwell Road, in the County of London,
Engineer and Colliery Owner, 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 :-
Distributed over the gold producing areas of the world, lying waste are millons of
tons of the more finely crushed tailings, and slimes, as well as river-borne and sea
shore sands all more or less rich in gold-that cannot be successfully treated on a
commercial scale by either of the known methods at present in use, and therefore the
millions sterling value of the gold contained therein together with the outlay in
mining and milling expended upon them are lost to the world, and this waste of
valuable material-and the resultant loss of wealth-is rapidly accumulating wherever
gold mining operations are carried on.
My invention has for its object to facilitate the extraction of gold and silver from
these slimes and tailings by means of solvents such as cyanide solutions and the like.
It consists in forcing by means of apparatus such as is hereinafter deseribed, such
solvents in an upward direction through the slimes or tailings, either together with or
alternately with air gases or vapour under pressure, by which means the material,
which owing to its compact and more or less viscous nature, resists the passage of the
solvents through it in a downward direction, is more or less opened out or levitated
by the action of the air gases or vapour and is thus made to afford the solvent ready
access between its particles, this action being also assisted by capillary attraction, so
that by this means the solvent will readily be enabled to take up the gold or silver
from the material. In combination with this mode of action I also provide means for
forcing the solvent alternately in an upward and in a downward direction through the
material and for operating repeatedly on one and the same charge of material with
the same body of solvent.
For the above purposes I employ apparatus of the following construction.
I provide one or more vessels for containing the liquid, which I will call the
"receiver," and one or more receptacles containing the material to be treated, which
I will call the "vat," and 1 connect the receiver with the vat by means of a pump
constructed as follows: The pump which may be of any known construction either
of the piston and barrel or of the centrifugal kind, has three suction orifices, and two
delivery orifices; one of the suction openings is connected to the lower part of the
receiver, a second one to the lower part of the vat, while the third one is either open
to the air, or is in communication with a gas holder, each of these openings being
provided with a valve by means of which the several communications can be regulated
or cut off.

page_text: The one delivery orifice of the pump is connected to the lower part of the vat in
such a way as to cause the liquid or gas entering through the orifice to be spread
evenly over the whole area of the floor or bottom of the vat beneath the material con-
tained therein. The second delivery orifice of the pump is connected by branch pipes
or passages both to the top of the vat and to the top of the receiver, each of the
said discharge orifices being fitted with a suitable valve for regulating and closing the
same.
With the above described arrangement I am enabled to perform either of the
following operations.
1 can draw liquid from the receiver and force it below the material contained in
the vat, or, I can draw liquid from the receiver, and air from the atmosphere, or gas
from a gas holder, and force them simultaneously below the material in the vat, or,
I can draw air or gas only and force it below the material in the vat, or again, I can
draw liquid from the top of the vat, and force it in again at the bottom of the vat,
so as to pass up through the material again, and thus cause the same body of liquid
to circulate as often as may be required through the material in the vat. Or again I
can draw liquid from the bottom of the vat and discharge it into the top of the
receiver, or,
I can draw liquid from the bottom of the vat and discharge it into the
top, or into the receiver.
I can also treat one and the same charge of slimes or tailings with consecutive
charges of solvent, or, I can employ one and the same charge of solvent for treating
several consecutive charges of slimes.
The vat and receiver are connected at top by overflow passages, so that, according
as the solvent is drawn from the receiver and forced into the vat, it will overflow from
the vat into the receiver.
The accompanying drawing shews by way of example one arrangement of apparatus
for carrying out my said invention on a moderate scale by means of a single pump.
E is a vat containing the slimes or other material to be treated. F is the receiver
for containing the solution with which the material is treated, the vat and receiver
being either open as shewn, or closed; G is the gas holder or casing containing the
gas or vapour to be forced through the slimes together with the air, such holder being
charged in any suitable known manner. The vat E is connected to the suction of a
force-pump (not shewn) at D' and to the delivery at D2, by means of pipes B' and B³,
which pipes are connected on the one hand to a delivery pipe H at top by
branches B and B*, and to the receptacle G by branches B³ and B.
The vat E is also connected by a pipe D with the receiver F, which pipe is connected
to pipe B by branch B' and to vessel G by branch D³.
To draw solution from the receiver I and force it into the lower part of the vat E.
valves B. 6, 10, 3 are opened and all the others are closed.
To draw solution from the top of the vat and force it in again at the bottom of the
vat, valves 1, 11, 5, 11, 3, are opened and all the others are closed.
To draw from the lower part of the vat, and deliver into the top of vat, valves 3, 4,
5, 9, 14, 1 are opened, and all others are closed, to deliver into the receiver instead of
into the vat, valve 15 is opened and valve 14 is closed.
To draw air from the atmosphere and force it into the lower part of the vat,
valves C. 10, 3, are opened and all others closed.
To draw air from the atmosphere and force it into the gas holder G, valves C. 8,
are opened and all others are closed.
To draw gas or vapour from the gas holder G and force it into the lower part of
the vat, valves 7, 5, 10, 3 are opened and all others are closed.
To permit the gas or vapour to pass automatically into lower part of the vat,
either alone or commingled with solution, valves 12, 2 are opened and all others are
closed.
To cause the solution to flow into the vat by gravity and by capillary attraction,
valves B, 13, 2, are opened, & all others are closed.
To cause the solution to flow into the vat by gravity while air or gas is being

page_text: forced into the lower part of the vat & through the mass lying therein, valves B, 13, 2,
and C, 10, 3, are opened, and all others are closed.
A A A are "dirt traps." The arrows indicate the direction in which the matter
flows through the pipes.
It is to be understood that the pipes B' B2 and H communicate by branches with
the vat E at any desired number of points in addition to the communication shewn in
order to distribute the solution, air or gas forced in as uniformly as possible over the
entire mass of slimes and tailings.
My above described method and apparatus may be applied with any existing plant
(large or small) suited for the extracting of gold &c. by solvents, but in cases where a
large daily output of material bas to be treated, I use more than one pump in order
to perform each of the several parts of the combined operations simultaneously, so as
to shorten the time occupied in treating a given quantity of material.
It is to he understood that in addition to the above described apparatus I employ-
when any particular material renders it advisable or necessary, any of the existing
mechanical appliances for preparing the tailings and slimes for treatment by my
method such as artificial drying, removing stones and other foreign substances
therefrom, minute subdividing of any lumps contained in the mass, and for evenly
distributing it over the whole area, while being filled into the vat preparatory for
treatment. Also any known mechanical press, or hydro-extractor for subsequent
recovery of the residual solution from argilaceous slimes, but those appliances form
no essential part of my method, and I do not claim the use of them, or either of them,
as a part of this my invention.
The following are some of the advantages obtained by the use of my method and
apparatus viz. :-
(a) The repeated passing of one and the same charge of solution through one
given charge of material, or, through consecutive charges of material, in a continuous,
or a reversible current of flow under pressure until complete saturation is effected,
permits a smaller quantity of solution being used to obtain the greatest results than
has been hitherto practicable.
() The use of a "receiver," connected in a circuit with a "vat" by apparatus as
above described, makes practicable the use of the smaller, and the separated quantity
of solution, which being small in quantity, and being separated from the common
stock of solution, may be modified as to chemical composition, strength, and tem-
perature, during the process of treating any given charge, or kind of material, and
thereby greater practical results can be obtained from the use of the smaller quantity
of chemicals.
This
(c) The forcing upwards and downwards in variable alternations either separately
or commingled, of air, gas, or vapour, and solvent solution, through the material
during its treatment, induces and maintains capillary attraction, and also causes such a
levitation of the mass as to ensure a rapid and complete saturation of the same.
levitation and capillary attraction combinedly, is of especial efficacy in any process
for the extraction of gold, silver, or other precious metals, and substances from
"slimes" by solvent solutions.
(d) The rapid withdrawal of the solution from the charge of material at the
completion of its treatment, and the delivery of the same into the receiver, is made
practicable by the use of apparatus such as above described. The passing of air, gas,
or vapour under controllable pressure through the charge during the withdrawal,
contributes greatly to the rapidity and completeness of that part of the process.
(e) The washing or scouring of the charge of material by forcing through either
plain water, or a cleaning solution (after the process of extracting the gold etc., has
been completed), and the keeping such plain water, or cleaning solution separate from
the general bulk of solvent solutions, will permit the practical recovery of a valuable
quantity of chemicals, and gold, that have hitherto been lost by being put on the
waste heap along with the damp tailings and slimes, and will bring practical results
at the mines into nearer correspondence to laboratory results than has hitherto been
attainable.

page_text: Having now particularly described and ascertained the nature of my said inven-.
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. The method of forcing and circulating, by means of apparatus substantially as
herein described, solvent solution, air, gas, vapour, and cleansing solutions, in a
continuous and reciprocative circuit of movement through a given mass of slimes or
tailings to be treated for the extraction of gold or other precious substances therefrom
by solvents, either separately or mixed, substantially as herein set forth.
2. Apparatus for inducing capillary attraction, and for producing the upward flow,
reversible flow, and the circuitous flow of liquids and air vapour or gases through a
given mass of slimes or tailings in either direction, controllable at the will of an
operator, such apparatus being arranged and operating substantially as described.
herein with reference to the accompanying drawing.
Dated this 29th day of May 1896.
ABEL & IMRAY,
Agents for the Applicant..