Ores or other Compounds.
Year: 1886

page_text: Date of Application, 17th Sept., 1886.
Complete Left, 14th June, 1887.
Complete Accepted, 15th July, 1887.
from Ores or other Compounds.
We, JOHN STEWART MAC ARTHUR, of 15 Princes Street, Pollokshields, in the
County of Renfrew, North Britain, Analytical Chemist, ROBERT WARDROP
FORREST, M.D., and WILLIAM FORREST, M.B., both of 319 Crown Street, Glasgow,
in the County of Lanark, North Britain, and GEORGE MORTON, of 104 West George
Street, Glasgow, aforesaid, Stockbroker, do hereby declare the nature of this
Invention to be as follows, that is to say :-
This Invention has principally for its object the obtaining of gold from ores or
other compounds but it is also applicable for obtaining silver and other noble metals
from such compounds and it comprises an improved process which whilst applicable
to various ores and compounds is effectual with ores or compounds from which gold
or other noble metals have hitherto not been easily obtainable.
In carrying out the Invention the ore or compound, in a powdered state, is treated
with a solution containing chlorine, bromine, or iodine, or a mixture of these
substances, together with a salt or substance which will not to any material extent
absorb chlorine, bromine, or iodine nor precipitate gold from solution, and which will
prevent base metals and pyrites or mundic from dissolving. For this purpose the
following salts may be used; namely, arsenites, arsenates, antimonites, antimonates,
borates, biborates, bromides, hypobromites, carbonates, bicarbonates, chromate, bichro-
mates, acetates, chlorites, hypochlorites, ferrates, manganates, permanganates, phos-
phates, silicates, stannates, tungstales, uranates, and any others acting similarly
towards the ingredients of the ore or compound.
The powdered ore or compound is kept well stirred in the solution, which may be
of various strengths, a strength approaching saturation being preferred, until all the
gold and silver is considered to have been sufficiently acted on, the operation being
conducted in a wooden vessel or in a vessel made of or lined with a material not
acted on by the solution or substances contained therein. The solution is then drawn
--.

page_text: off and the gold and silver are precipitated from it by any suitable one of the well
known processes.
For the purposes of the Invention when chlorine is used, it is by preference
employed in a liquefied condition due to compression, and it is injected by means of its
own expansive force into the liquid containing the ores or compounds and salts.
Bromine or iodine may be added in the uncombined state, or a bromide or iodide
may be added to the solution and the bromine or iodine be set free in the solution by
subsequently adding hypochlorite of calcium and an acid or other suitable chemical
agent or agents known to be capable of doing so.
The solubility of the chlorine, bromine, and iodine in the liquid may be advan-
tageously increased by adding a suitable salt such as a chloride, bromide, or iodide,
or by adding glycerin or alcohol; and in some cases especially when using chlorine
it may be advantageous to conduct the operation in a closed vessel and under
pressure. It is better to conduct the operation in darkness or in a subdued light.
The chlorine, bromine, and iodine may be recovered by well known chemical
processes after the gold and silver have been separated, and can be used over again.
Dated this Sixteenth day of September 1886.
EDMUND HUNT,
Applicants' Agent.

page_text: Improvements in Obtaining Gold, Silver, and other Noble Metals
from Ores or other Compounds.
We, JOHN STEWART MAC ARTHUR, of 15 Princes Street, Pollokshields, in the
County of Renfrew, North Britain, Analytical Chemist, ROBERT WARDROP
FORREST, M.D., and WILLIAM FORREST, M.B., both of 319 Crown Street, Glasgow,
in the County of Lanark, North Britain, and GEORGE MORTON of 104 West George
Street, Glasgow, aforesaid, Stockbroker, 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, that is to say:-
This Invention has principally for its object the obtaining of gold, from ores or
other compounds, but it is also applicable for obtaining silver and other noble metals
from such compounds; and it comprises an improved process which whilst applicable
to various ores and compounds is effectual with ores or compounds from which gold
or other noble metals have hitherto not been easily obtainable.
In carrying out the Invention the ore or compound in a powdered state, is treated
with a solution containing chlorine, bromine, or iodine, or a mixture of these sub-
stances, together with a salt or substance which which not to any material extent
absorb chlorine, bromine, or iodine, nor precipitate gold from solution, and which
will prevent base metals and pyrites or mundic from dissolving. For this purpose
the following salts may be used; namely:-arsenates, antimonates, borates, biborates,
hypobromites, carbonates, bicarbonates, chromates, bichromates, acetates, hypochlorites,
ferrates, manganates, permanganates, phosphates, silicates, stannates, tungstates,
uranates, and any others acting similarly towards the ingredients of the ore or
compound. In practice we use the particular salt or salts which we find to be most
convenient and economical.
When using some salts, as for instance biborate of soda (or borax) we prefer to
have the solution of a strength approaching saturation; but with other salts, as for
instance hypochlorite of soda, about one fourth of the strength of a saturated solution ;
the strength of the solution may however be varied, but the best or most convenient
strengths for each particular ore or compound can be easily ascertainable by
practical trial.
The solution is charged with chlorine, bromine, or iodine, either directly or
indirectly in any convenient way; and generally but not necessarily to saturation.
A quantity of the powdered auriferous ore is placed in a tank or other suitable vessel,
and the solution is added until the ore is at least covered. We have found that a
quantity of solution equal to about twice the bulk of the ore treated is generally
requisite and convenient. The ore and solution are allowed to remain in contact and
being stirred if necessary until the gold and silver if present are considered to be
dissolved to the extent to be reasonably expected, the operator using any well known
test for ascertaining this if he finds it necessary. The tank or vessel should be of

page_text: wood or made of or lined with a material not acted on by the solution or substances
contained therein. The solution is drawn off and the gold and silver are precipitated
from it by any suitable one of the well known processes; whilst the chlorine, bromine,
or iodine may be recovered for further use.
For the purposes of the Invention when chlorine is used it may be employed in a
liquefied condition due to compression; and it may be injected by means of its own
expansive force into the liquid containing the ores or compounds and salts. Bromine
or iodine may be added in the uncombined state or a chloride, bromide, or iodide may
be added to the solution, and the chlorine, bromine, or iodine be set free in the solution
by subsequently adding hypochlorite of calcium and an acid or other suitable agent
or agents known to be capable of doing so.
The solubility of the chlorine, bromine or iodine in the liquid may be modified by
adding a suitable salt such as a chloride, perchloride, bromide, perbromide, iodide, or
periodide, or by adding glycerin or alcohol; and in some cases especially when
using chlorine it may be advantageous to conduct the operation in a closed vessel
and under pressure.
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 :-
The improved process for obtaining gold, silver, and other noble metals from ores
or compounds, and consisting in treating the ores or compounds in a powdered
condition with chlorine, bromine, or iodine, in a solution also containing salts such as
those hereinbefore specified which will not to any material extent absorb the chlorine,
bromine, or iodine, nor precipitate gold from solution, but will prevent base metals
and pyrites or mundic from dissolving, the process being conducted substantially as
hereinbefore described.