Improvements in or relating to the Treatment of Ores and the Pre- cipitation of Precious Metals from their Cyanide Solutions,
Year: 1898

page_text: Date of Application, 8th Dec., 1898
Complete Specification Left, 28th Aug, 1899-Accepted, 28th Oct., 1899
PARATORADITIVATION.
Improvements in or relating to the Treatment of Ores and the Pre-
cipitation of Precious Metals from their Cyanide Solutions,
We, FREDERICK WILLIAM MARTINO, Manufacturer, of 107, Montgomery Road,
Sharrow, Sheffield, in the County of York, and FREDERIC STUBBS, Engineer, of
Edgegate," Osborne Road, Sheffield, in the County of York, do hereby declare
the nature of this invention to be as follows:-
66
This invention relates to the treatment of ores of the precious metals and
tailings formed from their treatment and the precipitation of precious metals
from their cyanide solutions, its object being to set "free" the precious metal
prior to its extraction when it is in the "occluded" state and also to obviate
the necessity for the use of zinc in precipitating precious metals from their
cyanide solutions. A further object is to separate silver from gold when the
two metals are present in the same solution in the form of cyanides.
The essential feature of this invention is the employment of calcium carbide
and acetylene in the treatment of precious metals.
Acetylene or a mixture of acetylene and oxygen may be passed through a
cyanide solution containing gold, or calcium carbide may be added to the liquid,
thus producing nascent acetylene. The gold is precipitated, but silver, if present,
remains in the solution and may consequently be readily separated; the process
is found to be quicker and cleaner if oxygen be passed through the solution.
When the precious metals are in the "occluded" state, that is to say, when
they are combined with or intimately enclosed in the metalloids or the baser
metals, the ore is finely divided and thoroughly mixed in a dry state with calcium
carbide. The mixture is then moistened the result being that acetylene is
generated accompanied by considerable heat. By the action of the acetylene,
hydrides of the metalloids or baser metals are formed, leaving the precious
metal in the "free" state. The free precious metal may be treated in any con-
venient way, preferably, the coarser metal is separated by washing and the finer
particles dissolved in a cyanide solution which is then subjected to the action of
acetylene as herein before described.
This treatment of the finely divided ore with calcium carbide is also applicable
to siliceous of quartzy ores or tailings, where minute particles of the precious
metal are enclosed in a casing of silica. The casing is opened up by the action
of the carbide leaving the gold exposed so that it may be acted upon by any
desired solvent.
Heat from any outside source may if desired be applied during any of the
stages constituting this improved process.
TOAL
1000

page_text: Improvements in or relating to the Treatment of Ores and the Pre-
cipitation of Precious Metals from their Cyanide Solutions...
We, FREDERICK WILLIAM MARTINO, Manufacturer, of 107, Montgomery Road,
Sharrow, Sheffield, in the County of York, and FREDERIC STUBBS, Engineer, of
"Edgegate," Osborne Road, Sheffield, in the County of York, 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:-
This invention relates to the treatment of ores of the precious metals and
tailings formed from their treatment and to the precipitation of precious metals
from their cyanide solutions, its object being to set free" the precious metal
prior to its extraction when it is in the "occluded" state and also to obviate
the necessity for the use of zinc in precipitating precious metals from their
cyanide solutions.
"
The essential feature of this invention is the employment of acetylene or
calcium carbide in the treatment of precious metals.
Acetylene is passed through a cyanide solution containing the precious metal,
say gold, or calcium carbide may be added to the liquid thus producing nascent.
acetylene, in either case the gold is precipitated. When acetylene is passed
through the cyanide solution its action is found to be promoted by also passing
atmospheric air through the liquid.
When the precious metals are in the "occluded" state, that is to say, when
they are combined with or intimately enclosed in the metalloids-sulphur,
selenium, tellurium, phosphorus, silicon, fluorine, etc.-or the baser metals, such
as arsenic and antimony, the ore is finely divided and thoroughly mixed in a
dry state with calcium carbide. The mixture is then moistened, the result being
that acetylene is generated, accompanied by considerable heat. By the action of
the acetylene, hydrides of the metalloids, or baser metals are formed, leaving the
precious metal in the "free" state. The free precious metal may be treated in
any convenient way, preferably the coarser metal is separated by washing, and
the finer particles dissolved in a cyanide solution, which is then subjected to the
action of acetylene as herein before described.
This treatment of the finely divided ore with calcium carbide is also applicable
to siliceous or quartzy ores or tailings, where minute particles of the precious
metal are enclosed in a casing of silica. The casing is opened up by the action
of the carbide leaving the gold exposed so that it may be acted upon by any
desired solvent.
Heat from any outside source may, if desired, be applied during any of the
stages constituting this improved process; for instance the cyanide solution
may be heated before, or during the treatment, by passing steam through pipes
immersed in it, or the vessels containing the solution may be steam jacketed.
Again the intimate mixture of ore and calcium carbide, either before or after
moistening, may be heated in any convenient form of furnace, such heating
being found to accelerate the process.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that what
we claim is:-
1. In the treatment of ores or tailings containing the precious metals the
employment of acetylene.
2. In the precipitation of the precious metals from their cyanide solutions tho
employment of acetylene.

page_text: 3. In the precipitation of the precious metals from their cyanide solutions
the employment of acetylene and atmospheric air.
4. The precipitation of the precious metals by the addition of calcium carbide
to their cyanide solutions.
5. The treatment of ores or tailings containing the precious metals by finely
dividing the ore, mixing it with calcium carbide and moistening the mixture
substantially as described.
FREDERICK WILLIAM MARTINO.
FREDERIC STUBBS,
Boult & Wade.
Agents for the Applicants.