Improvements in and Apparatus for the Separation of Gold and Silver from Ores or Materials Containing them.
Year: 1890

page_text: Date of Application, 30th Dec., 1890
Complete Specification Left, 31st July, 1891-Accepted, 12th Sept., 1891
PROVISIONAL SPECIFICATION.
Improvements in and Apparatus for the Separation of Gold and
Silver from Ores or Materials Containing them.
I, WILLIAM DUNSMORE BOнм of 51 Avenue Road, Acton in the County of
Middlesex, Metallurgical Chemist and Engineer, do hereby declare the nature of
this invention to be as follows:-
My invention has for its object to provide means whereby gold and silver (either
or both of them) can be obtained from ores or materials containing them, very
efficiently and economically.
According to my invention I prepare a solution of chloride of sodium in water of
a density of preferably 1150, water being reckoned at 1000. I add to this a
mineral acetate such for example as acetate of calcium or acetate of barium. A
suitable proportion of such acetate is to 20 per cent. of the salt solution. I also
add oxalic acid preferably one to ten per cent. of the salt solution and further I add
cyanide of potassium preferably to-2 per cent. of the salt solution.
I place the powdered ore (which need not be previously roasted although it may
be roasted if so desired) upon a porous diaphragm in a vat having a filter at top
and provided with an inlet under the porous diaphragm and an outlet above the
filter to which I attach the delivery and suction of a circulating pump. The
solution may be first mixed in a vessel and the pump draw it therefrom and pass it
into the ore vat through the inlet under the porous diaphragm and when the pump
delivery passages and vat are fully charged with solution the communication with
the liquor vessel may be disconnected and the outlet pipe from the vat be put into
communication with the pump inlet so that a constant circulation of the solution
through the vat is obtained. This circulation is preferably such that the solution
is forced by the pump upwards through the vat.
The circulation of the solution is
continued until the precious metals are in solution and then the solution containing
the said metals is drained or drawn from the vat and is passed or forced through
an alloy of zinc and any suitable electro-positive metal such as sodium or potassium
(a suitable alloy consisting of zinc with about 2 per cent. of sodium) cut into
shavings. A trace of cadmium may be added to the alloy if desired, or the
solution may be caused to circulate continuously or at intervals through the
precipitator vessel by connecting the suction pipe of another pump to the outlet of
the ore vat and the delivery of this pump to the precipitator at its lower end if the
liquor is to be forced upward through it and the suction pipe of the ore vat pump
to its other end or a small tub with the ends of the pipes dipping into it may be
used. The solution is then passed away for re-use the precious metals having been
taken up by the alloy.
Water and such of the aforesaid chemicals as are needed to bring the solution to
normal strength are added before re-use when necessary. Water is then passed
(preferably upwards) through the ore to wash it of all remaining traces of
chemicals and metal and this water may be passed through the alloy vessel to
obtain the metal. This water, or the richer portion of it may be used as the water
to add to the solution as aforesaid and the remainder after it leaves the alloy vessel
may be run off.
I
The aforesaid operations are repeated with each charge of ore.
I
may employ electricity to facilitate the extraction of the metals in which case
may use an annode say of carbon at the bottom of the vat below the porous
diaphragm and supply coil and a cathode above the filter at the upper part of the
vat which cathode may be of mercury, copper, iron or platinum or other suitable
metal or alloy of metals or substance, the gold and silver being deposited onto the

page_text: cathode whilst the annode facilitates the solution of the precious metals contained
in the ore.
Dated this 30th day of December 1890.
J. H. JOHNSON & Co.,
47, Lincoln's Inn Fields, Agerts.
COMPLETE SPECIFICATION.
Improvements in and Apparatus for the Separation of Gold and
Silver from Ores or Materials Containing them.
I, WILLIAM DUNSMORE BOHм of 51 Avenue Road, Acton in the County of
Middlesex Metallurgical Chemist and Engineer, 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 has for its object to provide means whereby gold and silver (either
or both of them) can be obtained from ores or materials containing them very
efficiently and economically.
According to my invention I prepare a solution of chloride of sodium in water
of a density of preferably 1.150, water being reckoned at 1000. I add to this a
mineral acetate such for example as acetate of calcium or acetate of barium or
acetate of sodium. A suitable proportion of such acetate is to 20 per cent. of the
salt solution. I also add oxalic acid preferably in the proportion of one to
ten per cent. of the salt solution and further I add cyanide of potassium preferably
in the proportion of to 2 per cent. of the salt solution.
I will describe the invention with reference to the accompanying drawing which
shews an arrangement of apparatus suitable for use in carrying out my invention
although I do not limit myself to the precise form of apparatus shewn.
I place the powdered ore (which need not be previously roasted although it may
be roasted if so desired) upon a porous diaphragm a having a suitable filtering
medium such as sacking above it in a vat A having a filter a² at top and provided
with an inlet b under the porous diaphragm a and an outlet c above the filter a² to
which inlet and outlet respectively I attach the delivery and suction of a circulating
pump D. The vat A is closed by a cover A2 which may be secured by bolts and
nuts a so that it holds the filter a² in position and allows of its being readily
removed when required. The solution may be first mixed in a vessel such as is
shewn at E and the pump draws it therefrom by the pipe (which for the time
being is put in communication with the suction of the pump D by the three way
cock g and passes it at greater than atmospheric pressure into the ore vat A through
the inlet communicating with the perforated coil 62 under the porous diaphragm a
and when the pump delivery passages and vat are fully charged with solution the
communication with the liquor vessel E may be closed and the outlet pipe from the
vat be put into communication with the pump inlet by operating the three way
cock g so that a constant circulation of the solution through the vat is obtained.
This circulation is preferably such that the solution is forced by the pump upwards
through the porous diaphragm a then through the ore in the vat and then through
the filter a². The circulation of the solution is continued until the precious metals
are in solution and then the solution containing the said metals is drained or drawn
from the vat and is passed or forced through a precipitator shewn at H containing"
an alloy of zinc with any suitable electro-positive metal (such as sodium or
potassium) cut into shavings. A suitable alloy consists of zinc with about 2 per
cent. of sodium and a trace of cadmium may be added to the alloy if desired. The
precipitator as shewn consists of perforated trays with rims which when placed
together form a closed vessel the series of trays being held together by the saddle
piece I and screw i. The solution drawn or drained from the vat A may be passed
or allowed to pass by the pipe j into the vessel J and thence be pumped up through
the precipitator H or the said solution may be caused to circulate continuously or

page_text: at intervals through the precipitator by connecting the suction pipe of a pump to
the outlet of the ore vat and the delivery of the said pump to the precipitator at
its lower end if the liquor is to be forced upward through it. The solution is
passed away from the precipitator H by the pipe for reuse the precious metals
having been taken up by the alloy from which it may be obtained in any suitable
or well known way.
Water and such of the aforesaid chemicals as are needed to
bring the solution to normal strength are added before reuse when necessary.
Water is then passed (preferably upwards) through the ore in the vat A to wash
it of all remaining traces of chemicals and metal and this water may be passed or
allowed to percolate by means of the pipe e¹ through the precipitator H to obtain
the metal. This water or the richer portion of it may be used as the water to add
to the solution as aforesaid and the remainder after it leaves the precipitator may
or if the solution be allowed
be run away to any suitable place by the pipe
to percolate through. The aforesaid operations are repeated with each charge
of ore.
I
I may employ electricity to facilitate the extraction of the metals, in which case
may use an anode say of carbon at the bottom of the vat as shewn at K below the
porous diaphragm a and supply coil 2 and a cathode as shewn at L above the
filter a² which cathode may be of mercury copper iron or platinum or other suitable
metal or alloy of metals or substance the gold and silver being deposited onto the
cathode whilst the anode facilitates the solution of the precious metals contained in
the ore.
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 :-
1st. The process for the separation of gold or silver or both from ores or
materials containing them by circulating through the ore or material in the
leaching-vat a solution such as described by an arrangement of apparatus substan-
tially as hereinbefore described and shewn in the accompanying drawings with or
without the arrangement for employing electricity whilst leaching.
2nd. For the separation of gold or silver or both from ores or materials con-
taining them the employment of a leaching solution of or containing chloride of
sodium, a mineral acetate (such as acetate of calcium or acetate of barium or acetate
of sodium) oxalic acid and cyanide of potassium.
3rd. The obtainment of gold or silver or both from a solution thereof by passing
the solution through shavings of an alloy of zinc with an electro-positive metal
such as sodium or potassium.
4th. For the purpose described the arrangement and combination of parts
constituting the apparatus hereinbefore described and illustrated in the accom-
panying drawings.
J. H. JOHNSON & Co.,
Agents.