A New or Improved Process for Extracting Gold and other Metals from their Ores, especially applicable to the Treatment of Refractory Ores.
Year: 1896

page_text: Date of Application, 5th May, 1896
Complete Specification Left, 5th Feb., 1897-Accepted, 1st May, 1897
PROVISIONAL SPECIFICATION.
A New or Improved Process for Extracting Gold and other Metals
from their Ores, especially applicable to the Treatment of
Refractory Ores.
I, JANE ANN BRUCE-FRASER, of No. 113, Great Russell Street, Bedford
Square, in the County of London, Gentlewoman, do hereby declare the nature of
this invention to be as follows:-
This invention relates to a new or improved process for extracting metals from
their ores or the like and has for its object to effect the separation of the metals
from the mineral with which they may be in combination and to recover them in a
marketable form, by a simple and inexpensive process.
According to this invention, the ore is acted upon by means of nascent chlorine
generated as hereinafter described.
In carrying the invention into effect, the ore is reduced to a fine state of division
in any suitable manner and a quantity of peroxide of barium is added thereto in
the proportion of about 100 parts by weight of the pulverized ore and from
about 1 to 5 parts by weight of peroxide of barium and these materials are
thoroughly mixed by any suitable means.
This mixture is then placed in a closed vat furnished with a perforated false
bottom upon which the material is supported, whilst, in order to prevent the
perforations of the false bottom from becoming choked and to obtain a free passage
for the fluid hereinafter referred to, the false bottom is previously covered with
small branches or twigs covered with straw, or, other means may be employed for
effecting the desired object.
Hydrochloric acid is then run into the vat in sufficient quantity to cover the
pulverized material and the vat is allowed to stand for a period of about 12 hours
or more if necessary according to the nature of the ore under treatment after which
water is added to the hydrochloric acid in suitable quantity.
The liquor is then brought into intimate contact with and forced through the
pulverised material until the latter has been sufficiently washed therewith and the
fluid is then run off or decanted into other vats and treated to recover the metals
contained therein.
The liquor is first treated for copper by introducing thereinto iron preferably in
the form of scrap iron which has the effect of throwing down or precipitating any
copper contained in the solution and which may then be removed by running or
decanting the liquor into another vnt.
The liquor is next heated to drive off the excess of free chlorine.
If it be desired to recover silver therefrom, chloride of sodium is added thereto
in the necessary proportions in order to hold in solution any chloride of silver that
may have been formed by the action of the chlorine on the silver contained in the
ore, strips of copper are then introduced into the liquor in order to throw down in
a metallic form the silver which may then be recovered by decanting the liquor
into another vat.
A saturated or concentrated solution of ferrous chloride or ferrous sulphate is
ow added to the liquor which has the effect of precipitating in a metallic form

page_text: any gold held in solution and which gold may be recovered by running off the
liquor.
When employing ferrous sulphate as lastly described, the barium chloride must
be previously removed by means of sulphuric acid or a soluble sulphate, in any
known manner.
Instead of mixing with the pulverised ore or the like, peroxide of barium and
generating the chlorine by the addition of hydrochloric acid, a mixture of chloride
of sodium and peroxide of barium in the proportion of six parts by weight of the
former to four parts by weight of the latter, acted upon by dilute sulphuric acid
to free the chlorine, can be employed in lieu thereof.
It will be obvious that the process may be varied by omitting the treatment for
the precipitation of any metal that is not present in sufficient quantity to render its
recovery profitable.
By the means herein before described, the extraction of the metals is effected
inexpensively and without endangering the health of the operatives, whilst, in the
case of gold, not only is the metallic gold in the ore extracted but any that may be
present in a refractory form is also attacked and dissolved.
Dated this 5th day of May 1896.
VAUGHAN & SON,
Agents for the Applicant.
COMPLETE SPECIFICATION.
A New or Improved Process for Extracting Gold and other Metals
from their Ores, especially applicable to the Treatment of
Refractory Ores.
1, JANE ANN BRUCE-FRASER, of No. 113, Great Russell Street, Bedford
Square, in the County of London, Gentlewoman, do hereby declare the nature of
his invention and in what manner the same is to he performed to be particularly
described and ascertained in and by the following statement :-
My said invention relates to a new or improved process for extracting metals
from their ores and has for its object to effect the separation of the metals from
the minierat with which they may be in combination and to recover them in a
marketable form, by a simple and inexpensive process.
According to this invention, the ore is acted upon by means of nascent chlorine
which may be generated as hereinafter described.
In carrying the invention into effect, the ore is reduced to a fine state of division
in any suitable manner. and if desired may be roasted, and a quantity of peroxide
of barium is added thereto in the proportion of about 100 parts by weight of the
pulverized ore and from about one to five parts by weight of peroxide of barium
and these materials are thoroughly mixed by any suitable means.
This mixture is then placed in a closed vat furnished with a perforated false
bottom upon which the material is supported, whilst, in order to prevent the
perforations of the false bottom from becoming choked and to obtain a free passage
for the fluid hereinafter referred to, the false bottom is previously covered with
small branches or twigs covered with straw, or, other means may be employed for
effecting the desired object.
Hydrochloric acid is then run into the vat in sufficient quantity to cover the
pulverized material and the vat is allowed to stand for a period of about 12 hours
or more if necessary according to the nature of the ore under treatment after which
water is added to the hydrochloric acid in suitable quantity, that is to say, in such
quantity as to make an acid containing about 3 per cent. of real hydrochloric acid.

page_text: The liquor is then brought into intimate contact with the pulverized material by
stirring the latter by the aid of mechanical stirrers arranged within the vat in any
well known manner and the liquor is then passed through the pulverized material
until the whole, or nearly so, of the gold has been extracted and the fluid is then.
run or drawn off or decanted through a valve placed below the perforated false
bottom into other vats and treated to recover the metals contained therein.
The liquor is treated for copper by introducing thereinto iron preferably in the
form of scrap iron which has the effect of throwing down or precipitating any
copper contained in the solution and which may then be recovered by running or
decanting the liquor into another vat.
The liquor is next heated to drive off the excess of free chlorine.
If it be desired to recover silver from the liquor chloride of sodium is added.
thereto in the necessary proportions, say for example:-
Chloride of sodium
Solution
5%
95% by weight
"
for the purpose of holding in solution any chloride of silver that may have been
formed by the action of the chlorine on the silver contained in the ore, strips of
copper are then introduced into the liquor in order to throw down in a metallic
form the silver which may then be recovered by decanting the liquor into another
vat.
A saturated or concentrated solution of ferrous chloride or ferrous sulphate is
now added to the liquor which has the effect of precipitating in a metallic form
any gold held in solution and which gold may be recovered by running off the
liquor.
When employing ferrous sulphate as lastly described, the barium chloride must
be previously removed by means of sulphuric acid or a soluble sulphate, in any
known manner.
Instead of mixing with the pulverized ore peroxide of barium and generating the
chlorine by the addition of hydrochloric acid a mixture of chloride of sodium and
peroxide of barium in the proportion of six parts by weight of the former to four
parts by weight of the latter, acted upon by dilute sulphuric acid to free the
chlorine, can be employed in lieu thereof.
Or, the chlorine may be generated by any other suitable and well known means.
It will be obvious that the process may be varied by omitting the treatment for
the precipitation of any metal that is not present in sufficient quantity to render its
recovery profitable.
By the means hereinbefore described, the extraction of the metals is effected
inexpensively and without endangering the health of the operatives, whilst, in the
case of gold, not only is the metallic gold in the ore extracted but any that may be
present in a refractory form is also attacked and dissolved.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. The recovery of gold or other metals from their ores by submitting the same
to the action of nascent chlorine generated by any suitable means, substantially as
hereinbefore described.
2. The recovery of gold or other metals from their ores by submitting the same
to the action of nascent chlorine generated in the presence of the ore by any suitable
means, substantially as herein described.
3. The recovery of gold or other metals from their ores by steeping the same in
a bath of hydrochloric acid, or of sulphuric acid and chloride of sodium, from
which nascent chlorine is generated or released by the addition of any suitable
material which will set free the chlorine, substantially as herein described.
4. The recovery of gold or other metals from their ores by mixing the same in

page_text: suitable proportions with peroxide of barium and steeping the mass in a bath of
hydrochloric acid, substantially as herein described.
5. The recovery of gold or other metals from their ores by submitting the same
to the action of nascent chlorine in a suitable bath and precipitating the metal by
the employment of suitable means, substantially as herein described.
6. The recovery of gold or other metals from their ores by the process and
means herein before described.
Dated this 5th day of February 1897.
VAUGHAN & SON,
Agents for the Applicant.