Improvements in Extracting Gold from Ores."
Year: 1897

page_text: Date of Application, 22nd Jan., 1897
Complete Specification Left, 11th Oct., 1897-Accepted, 11th Dec., 1897
PROVISIONAL SPECIFICATION.
66
Improvements in Extracting Gold from Ores."
I, CARL WICHMANN, of the London and Hamburg Gold Recovery Company
Limited, of 22 Austin Friars, in the City of London, Merchant, do hereby declare
the nature of this invention to be as follows:-
This invention relates to a process for extracting gold from ores, chiefly those
of a refractory kind, which cannot be successfully treated by ordinary processes.
The process which forms the subject of the present invention consists of several
successive steps of operation as follow:
:-
The ore is first crushed, it may be by a stone breaker or by that and a roller,
to particles of such size that they can be thoroughly dried. After drying the
material is farther crushed so that it will pass through a sieve having preferably
about 20 to 30 meshes per inch. It is then graded into three classes:-
it:-
1. Coarse part, with the larger grains of gold and of the minerals accompanying
-
2. Middle sized part with smaller grains of gold and mineral:--
3. Dust with fly gold and the finest particles of mineral.
The product of class 1 may be directly subjected to amalgamation for extracting
the gold, but generally it is preferable to heat or roast it in the first place so as to
disintegrate or volatilise more or less of the mineral which covers or carries the
gold, and then to extract the gold by amalgamation, and eventually supplemented
by leaching if necessary.
The product of class 2 has its gold dissolved out by potassium cyanide or other
solvent, the solution containing the gold being separated by percolation and after-
wards treated in any known manner for deposit of the gold.
The product of class 3 is converted into a sludge by a solution containing enough
solvent to dissolve the contained gold.
This sludge is agitated in rotating cylinders or in vessels provided with rotating
agitators or by air or in any other suitable manner.
After agitating sufficiently to ensure solution of the gold, the sluage is allowed
to settle and the solution containing the gold is decanted off. Or, instead of
allowing the sludge to settle, which occupies a considerable time, I separate the
solution by filter pressing, and effect deposit of the gold from the solution in any
known manner.
Dated this 22nd day of January 1897.
"Improvements in Extracting
I, CARL WICHMANN, of the London and Hamburg Gold Recovery Company
Limited, of 22 Austin Friars, in the City of London, Merchant, do hereby declare

page_text: 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 a process for extracting gold from ores, chiefly those
of a refractory kind, which cannot be successfully treated by ordinary processes.
The process which forms the subject of the present invention consists of several
successive steps of operation as follow:-
The ore is first crushed, it may be by a stone breaker or by that and a roller,
to particles of such size that they can be thoroughly dried. After drying, the
material is farther crushed so that it will pass through a sieve having preferably
about 20 to 30 meshes per inch. It is then graded into three classes: -
1. Coarse part, with the larger grains of gold and of the minerals accompanying
it:-
2. Middle sized part with smaller grains of gold and mineral:-
3. Dust with fly gold and the finest particles of mineral.
The product of class 1 may be directly subjected to amalgamation for extracting
the gold, but generally it is preferable to heat or roast it in the first place so as to
disintegrate or volatilise more or less of the mineral which covers or carrics the
gold, and then to extract the gold by amalgamation, and eventually supplemented
by leaching if necessary.
The product of class 2 has its gold dissolved out by potassium cyanide or other
solvent, the solution containing the gold being separated by percolation and after-
wards treated in any known manner for deposit of the gold.
The product of class 3 is converted into a sludge by a solution containing enough
solvent to dissolve the contained gold.
This sludge is agitated in rotating cylinders or in vessels provided with rotating
agitators or by air or in any other suitable manner.
After agitating sufficiently to ensure solution of the gold, the sludge is allowed
to settle and the solution containing the gold is decanted off. Or, instead of
allowing the sludge to settle, which occupies a considerable time, I separate the
solution by filter pressing, and effect deposit of the gold from the solution in any
known manner.
Having now particularly described and ascertained the nature of this invention
and in what manner the same is to be performed, I declare that what I claim is :-
The herein described process for extraction of gold from ores more or less refrac-
tory by crushing, drying, farther reducing and separating the ore into three grades
or classes, subjecting the coarsest product of the first class to amalgamation sup-
plemented by leaching and to previous heating and roasting when necessary, treat-
ing the middle sized product of the second class with solvent for the gold, convert-
ing the finest product of the third class into sludge, by adding solvent solution,
agitating and separating the solution by decanting after settlement or by filtering,
and depositing the gold from the solutions obtained by the treatment of the second
and third class products.
Dated this 5th day of October 1907