An Improved Process for Extracting Precious Metals from their Ores.
Year: 1894

page_text: Date of Application, 26th Sept., 1894
Complete Specification Left, 26th June, 1895-Accepted. 21st Sept.. 1895
PROVISIONAL SPECIFICATION.
An Improved Process for Extracting Precious Metals from their Ores.
I, ALFRED EDWARD MORGANS of Broad Street House, Old Broad Street,
London, E.C., Mining Engineer, do hereby declare the nature of this invention
to be as follows:-
The object of this invention is to extract the gold and silver from the ores
containing the same in a more simple and satisfactory manner than heretofore.
The invention is applicable to all kinds of ores, those known as refractory, and
containing the sulphides of the baser metals being calcined and oxidised previous to
treatment.
This, however, is only necessary when these sulphides are present in large
quantities.
The invention consists in the treatment of ores containing precious metals with
chloride of cyanogen or chlorocyanogen, and, in carrying out this invention, I first
crush the ore, preferably dry, and I then place the finely powdered ore in a vat
with a false bottom, and introduce a weak solution of cyanide of potassium, and, by
stirring, cause the ore to become thoroughly mixed with the liquid. I then intro-
duce to the bottom of the vat, chlorine gas, and this, bubbling up through the
liquid, becomes couverted into chloride of cyanogen or chlorocyanogen, which has
a most powerful effect on the ore,-completely dissolving out all the gold and silver
therein.
The ore is recovered from the solution in any convenient manner.
The treatment of the crushed ore may be effected directly with a solution of
chlorocyanogen in water of a strength equal to 16th per cent., or stronger, as
desired, the recovery of the precious metals taking place in any convenient
manner.
Dated this 26th day of September 1894.
NEWTON & SON,
Agents for the Applicant.
COMPLETE SPECIFICATION.
An Improved Process for Extracting Precious Metals from their Ores.
I ALFRED EDWARD MORGANS of Broad Street House, Old Broad Street,
London, E.C., Mining 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 :-
The object of this invention is to extract the gold, silver, and other precious.
metals from the ores containing the same, in a more simple, economical, and
satisfactory manner than heretofore.
The invention is applicable to all kinds of ores, whether easy of treatment or
refractory. If of the latter kind, when their refractory qualities arise from their
chemical or mechanical combination with the sulphides or other chemical forms of
the baser metals, or from their own peculiar chemical or mechanical characteristics,
[Price 8d l

page_text: a previous roasting, to oxidize the sulphides and change their other chemical or
physical characteristics, is desirable.
This, however, is generally only necessary when the sulphide or other chemical
combinations exist in large quantities.
The invention consists in the treatment of the ores containing the precious metals
with chloride of cyanogen, or chloro-cyanogen, in a gaseous or liquid state.
In carrying out this invention, the ore is first crushed, either dry or wet (preferably
the former) to a degree of fineness sufficient to expose the particles of the precious
metals to the action of the solvent.
The solvent in the form of a solution is generally preferred, and this treatment
may be carried out as follows-
The powdered ore containing the precious metals is placed in a vat or tank, and
is covered with a solution of cyanide of potassium. Chlorine gas is then passed into
the vat, either under a false bottom, or in any other way, until the chloro cyanogen is
formed. The ore is allowed to remain in the solution until the precious metals are
completely dissolved. The solution is then drawn off, and the precious metals are
recovered in any convenient manner.
The percentage of chloro-cyanogen in solution varies with the nature of the
ore and the time given for dissolving. It has been found that solutions of
from th to th of one per cent. give perfect results on some ores, but a weaker
or stronger solution, even up to one half of one per cent., may be advisable or
necessary on certain classes of ores.
The solvent solution may also be prepared by passing chlorine gas into a
solution of cyanide of potassium, until the cyanide elements of the cyanide of
potassium are converted into chloride of cyanogen or chloro cyanogen. The
resulting solution is then poured over the crushed ore, and allowed to stand
for sufficient time to dissolve out the precious metals. The solution is then
drawn off, as before stated, and the precious metals are recovered in any convenient
manner.
It will be obvious that the solvent (chlorocyanogen) may be prepared in many
other ways; thus a cyanide of potassium solution may be poured on chloride of
lime or other compound containing chlorine, and which will give it off freely
on the addition of water. Other forms of apparatus or plant may also be
desirable or necessary, according to the physical and chemical characteristics of the
ores to be treated, and the agitation of the ore or solution may be sometimes
necessary.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, I would here
remark that I make no claim for the preparation of chloro-cyanogen, nor for
any apparatus, as these forms no part of my present invention, but what I do
claim is
The improved process for extracting precious metals from their ores, which
consists in the use, as the solvent, of chloride of cyanogen or chlorocyanogen of a
strength not exceeding one half of one per cent., as herein set forth.
Dated this o6th dox of Tu 1905
NEWTON & SON,
Agents for the Applicant.