Improvements in Precipitating and Collecting Metals from Solutions Containing them.
Year: 1892

page_text: Date of Application, 16th Feb., 1892
Complete Specification Left, 18th Nov., 1892-Accepted, 16th Feb., 1893
PROVISIONAL SPECIFICATION.
Improvements in Precipitating and Collecting Metals from Solutions
Containing them.
A communication by BERNARD CHARLES MOLLOY, Member of Parliament,
Barrister-at-Law, of the Middle Temple, London, temporarily residing in
Johannesburg, South African Republic.
I ALFRED GEORGE BROOKES of 55 & 56 Chancery Lane in the County of
London, Chartered Patent Agent do hereby declare the nature of this invention to
be as follows :-
This invention consists in a new method of precipitating and collecting gold and
other metals from solutions containing these metals such as bromide, chloride and
cyanide solutions.
In some cases these solutions are acid, but under the action of this process these
solutions are rendered neutral and alkaline so that the solutions are, or, become
alkaline solutions of the metals which are soluble in alkaline solution.
The application of this process may be carried out in apparatus of many forms of
construction and under many and differing conditions depending on the character of
the work required to be done.
The following example will however explain the nature of the process and how it
may be carried out.
Take a tray or tank constructed of wood, cement or other suitable material and
of a size as may be necessary.
Cover, or partially cover, the bottom of the tank with mercury. On this mercury
will rest the solution from which the metals are to be precipitated. This mercury
is then charged electrolytically with ammonium, sodium, potassium or other alkaline
metal which is then amalgamated by the mercury. These alkaline metals or the
amalgams of these metals when they come to the surface of the mercury and in
contact with the water of the solution, decompose the water, the alkaline metal
combining with the oxygen of the water to form an alkaline oxide, and so rendering
the solution alkaline if not previously so and the hydrogen of the decomposed water
is at the same time evolved in a nascent state from the surface of the mercury in
contact with and against the solution from which the metal in solution, say the gold,
is to be precipitated and collected.
Under this action the metals in solution, such as gold will be precipitated and
absorbed by the mercury from which it can be released in the ordinary manner by
the action of heat.
In the above described case the charging of the mercury with the alkaline metal
has been effected electrolytically by the electrolysis of say an alkaline salt of the
alkaline metal used in a porous vessel in contact with a mercury cathode or other
convenient method.
Another though much less advantageous method is the mechanical addition to
the mercury, of potassium or other alkaline metal or amalgam of the same when the
nascent hydrogen with an equivalent of the alkaline oxide will be produced.
These are some methods by which the process may be carried out, but there are
others, as is evident, which may be employed.
In carrying out this process a solution of bromine, chlorine or cyanogen may be
used to dissolve the gold and other metals from their compounds and then the process
here described may be used to precipitate and collect the metals.
It is evident that generation of nascent hydrogen in contact with an alkaline

page_text: solution of metals soluble in such solution may be obtained by other means though
not detailed here.
Dated the 16th day of February 1892.
WM. BROOKES & SON,
55 & 56, Chancery Lane, London, Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Precipitating and Collecting Metals from Solutions
Containing them.
A communication by BERNARD CHARLES MOLLOY, Member of Parliament,
Barrister-at-Law, of the Middle Temple, London, temporarily residing in
Johannesburg, South African Republic.
I ALFRED GEORGE BROOKES of 55 and 56 Chancery Lane in the County
of London, Chartered Patent Agent 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 consists in a new method of precipitating and collecting the gold
and other metals from the solutions containing these metals, such as bromide,
chloride and cyanide solutions, when such are employed for dissolving out the
precious metals from compounds containing the same.
In some cases these solutions are acid, but under the action of this process these
solutions are rendered neutral and alkaline, so that the solutions are, or become,
alkaline solutions of the metals, which are soluble in alkaline solutions.
The application of this process may be carried out in apparatus of many forms of
construction, and under many and differing conditions depending on the character
of the work required to be done.
The following example of the treatment of a gold bearing compound, will how-
ever explain the nature of the process, and how it may be carried out.
When
The crushed ore is treated, say, with a solution of cyanide of potassium, the
quantity and saturation being in proportion to the work to be done.
the solvent solution is sufficiently charged then the precipitation of the gold, the
regeneration of this solvent, and the collection of the gold is effected as follows:-
Take a tray, or tank, constructed of wood, cement or other suitable material, and
of a size as may be necessary. Cover, or partially cover the bottom of the tank
with mercury.
On this mercury will rest, or pass over the solution from which the metals are to
be precipitated. This mercury is then charged electrolytically with ammonium,
sodium, potassium, or other alkaline metal. These alkaline metals, when they come
to the surface of the mercury and in contact with the water of the solution, (now
containing gold) decompose the water, the alkaline metal combining with the
oxygen of the decomposed water to form an alkaline oxide, rendering the solution
alkaline, if not previously so, and the hydrogen of the decomposed water is at the
same time evolved in a nascent state from the surface of the mercury in contact
with and against the solution from which the metal in solution, (say the gold) is to
be precipitated and collected. While the current continues to pass the required
nascent hydrogen and oxide will be produced and act on the solution containing
the gold.
Under this action the metals in solution, such as gold, will be precipitated and
absorbed by the mercury from which it can be released in the ordinary manner by
the action of heat.
In the above described case, the charging of the mercury with the alkaline metal,
has been effected electrolytically by the electrolysis of, say, an alkaline salt of the
alkaline metal used in a porous vessel in contact with the mercury (cathode), or
other convenient method.

page_text: or compounds by means of a suitable solvent for said metals, an electrolyte of the
alkaline metals, a current of electricity, a mercury cathode, all substantially as set
forth.
7. The employment of bromine, chlorine, iodine, and cyanogen, or their com-
pounds, as solvents for gold, or other metals, in combination with the above described
process for effecting the precipitation and collection of the gold and other metals in
solution therein, substantially as set forth.
Dated the 16th dow of Novombou 1000
WM. BROOKES & SON,
55 & 56, Chancery Lane, London, Agents for the Applicant.