IMPROVEMENTS IN THE SEPARATION OF GOLD AND OTHER METALS " FROM THEIR ORES
Year: 1883

page_text: LETTERS PATENT to Annie Eliza Scott of N° 3 Harrington Mansions Queen's
Gate South Kensington for an Invention of "IMPROVEMENTS IN THE
PROVISIONAL SPECIFICATION left by the said Annie Eliza Scott at the
Office of the Commissioners of Patents on the 20th February 1883.
ANNIE ELIZA SCOTT of N° 3 Harrington Mansions Queen's Gate South
Kensington. IMPROVEMENTS IN THE SEPARATION OF GOLD AND OTHER METALS
"
FROM THEIR ORES."
This Invention has for its object the separation of metals from their ores by the
electrolysis of sea water or soluble chlorides.
In a receptacle of proper dimensions I place a porous vessel (preferably wood)
containing the crushed ore, in this description I will take gold, in this porous cell
with the crushed ore is placed a well amalgamated plate of zinc joined by a wire of
silver, aluminium or platinum, to a carbon plate placed in the outer vessel. Sea
water or water impregnated with chloride of sodium, or any soluble chloride used
is then poured into both vessels, a small quantity of sulphuric or hydrochloric acid
added, and a film of benzine poured over the top of the fluid.
The gold is dissolved by the liberated chlorine, passes through the porous cell to
the main body of the liquid, this when thoroughly saturated is drawn off, evaporated
to ignition in covered vessels "to save any volatile metal." The evaporated salţ
is a mixed mud brown color and white. For the other elements the gold has so
little affinity apart from the electrical action that at 250° it is all changed into
the insoluble oxide, this can be extracted by adding water and filtering, and the
same salt can be used again for the process.
This process can be used for electro plating direct from the ore.
be precipitated from the liquid by metallic iron or the sulphate.
The gold may
In some cases I place a platinum plate in the porous cell leaving the zinc and
carbon plates in the outer vessel the wire continuing from the zinc to the carbon
plate and from the carbon to the platinum. If palladium be present in the ore it
will be deposited upon the platinum plate.
It is advisable that the large vessel should be so formed that any deposit of gold
salt should settle in one spot that it may be more easily removed.
Silicious ores may most advantageously be treated by this method.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Annie Eliza Scott in the Great Seal Patent Office on the
18th August 1883.
ANNIE ELIZA SCOTT of N° 3 Harrington Mansions Queen's Gate South
Kensington " IMPROVEMENTS IN THE SEPARATION OF GOLD AND OTHER METALS
FROM THEIR ORES
""
This Invention has for its object the separation of metals from their ores or
other substances in the form of salta. This I effect by the electrolysis of sea water,
chloride of sodium, or any soluble chloride, and by the reduction of the salts so
obtained to the metallic state by the most suitable and economical methods.
By electrolysis I here intend any process by which the elements of sea water
chloride of sodium or any soluble chloride, are split up or separated into their
elements; chlorine and the base, during the reaction.
These elements may hereafter return to their normal state or be irrevocably
separated as the case may be.
I do not confine myself to one method of electrolysis but use any metallic or
other substance to assist in reducing the ore as shall be most applicable to the
separation of the particles of the ore under treatment.
Sea water by its own electrical action will dissolve many ores or substances, some
of the metals contained therein acting the part of electrodes, and so dissolving the
remainder, these remain undissolved until the last, when the electrical action has
ceased, the solution can be drained off evaporated to dryness and the metals
contained therein reduced to a regulus by flux, or the solution can be allowed to
crystallize or the metals can be separated by the most suitable reagents, ammonia
or the potassium carbonate will be found the most useful, in this case magnesia,
lime, etc which are usually found in solution in sea water will be precipitated, the
residual liquor can then be evaporated forming caustic soda and the chlorides of
potassium and sodium.
The best method of carrying out this part of the process is to have the sea
water or inland salt water put into reservoirs or tanks containing the ore or
substance, these tanks should be lined with glazed tiles or any substance not acted
upon by the liquid, the sea water is covered with film of benzoline and left exposed
to the action of the atmosphere being occasionally stirred, from one to three weeks
will generally be necessary for saturation, the liquid can then be drawn off and
carbonate of potassium added, care must be used as an excess of the precipitant
may redissolve some of the salts, these are allowed to settle, the liquid drawn off,
'evaporated, and allowed to crystallize out, any metallic salts in solution not
precipitated by the carbonate of potassium will be found at the bottom of the tank
as oxides after the chloride of potassium has crystallized out, and can be reduced to a
regulus by a flux, the mixed carbonates must be separated by suitable reagents or
reduced to a regulus by flux.
The carbonates of sodium, potassium etc may be formed as a bye product, and
found crystallized round the sides of the tank above the fluid caused by the
electrolysis of the benzoline.
The following are examples of the way in which I prefer to carry out my
Invention

page_text: The gold ore must first be finely powdered, chloride of sodium or sea water
being added during the process, this is then put into a porous vessel preferably
membrane, parchment paper, felt or very thin porous wood, which will act as a
dialyser, placed in a tank as before described sloping slightly to one end in which
there should be an opening to draw off the fluid and deposited salts. With the
gold ore is placed a block of carbon to which is joined a well amalgamated plate of
zinc (which is placed in the outer vessel or tank) by an aluminium wire or strip of
metal, the sea water or chloride of sodium solution is poured into both the inner or
porous vessel and the outer tank, a small quantity of acid preferably sulphuric or
hydrochloric is added and the surface covered with benzoline.
When the liquid is thoroughly saturated with metallic salts it is to be drawn off
filtered from insoluble salts and either precipitated by sulphuretted hydrogen (as all
metals contained in the ore are in solution) or sulphate of iron, or the solution can
be evaporated when a brown muddy salt will be obtained which contains the
insoluble oxides of gold etc these can be extracted by adding water and filtering.
The salts can be reduced to a regulus by any of the ordinary methods. Other
metals contained in the salt solution can be precipitated by carbonate of potash and
the condensed liquid allowed to crystallize into its salts.
The solution in the porous vessel containing the silica etc is to be poured off,
filtered, and treated in the same way as above, fresh sea water chloride of sodium
or whatever soluble chloride has been used again poured over the ore, and the
process continued until the ore is perfectly exhausted, palladium, platinum, etc, will
be precipitated with the gold. Silver, and lead, will remain with the matrix as
insoluble chlorides and can be extracted by melting lead with the residuum. Any
undissolved gold pieces left in the matrix may be washed out in the usual way.
The metallic deposit must be washed from the carbon and zinc plates or scraped
off, and thrown on a filter and the wash water treated with the rest of the solution
with sulphuretted hydrogen.
The operation can also be performed without the aid of the porous cell, in which
case however the metallic salts are again precipitated with the ore if allowed to
remain too long in solution, they are also reduced on the zinc and carbon plates.
With some ores the following process answers best, soluble chloride of mercury

page_text: is mixed with the ore in the dry powder, this is placed in the porous cell and
a platinum plate placed in the cell a platinum wire or strip of the metal joineḍ
to the above and terminating in another platinum plate dipping into mercury
placed in the outer tank water is poured into both porous cell and tank the
action sets in at once, a metallic film is usually deposited, the mercury becomes
amalgamated and the salts are deposited in the outer tank, when the water is
saturated it is to be filtered and precipitated by sulphuretted hydrogen, and the
amalgam pressed through wash leather and treated in the usual way, the fluid
mercury and fresh water added, and the action continued until the ore is exhausted,
the chloride of mercury should be mixed with the ore and allowed to remain for a
few days under cover in a dry place before working.
Some ores are more difficultly acted upon than others, it is then advisable to
use a third element in the following manner-The zinc is placed at one side of
the tank and the coke or carbon at the other, joined by the aluminium wire or
strip of metal, from the carbon plate proceeds a second wire which should be
platinum and terminate in a plate of platinum placed with the ore in the porous
vessel.
The ore must be loosely placed in the porous vessel and be slightly moved
occasionally if necessary.
It is to be understood that all metals are dissolved by this process, the metals
having the greatest affinity for chloride of sodium are first acted upon such as
vanadium, niobium etc, then those separately having the greatest affinity for
chlorine, or sodium, so that it will be readily understood that the second or third
solutions from the same ore, may contain most of the metal which it is being
worked for. I claim time to determine the actual rotation in which each metal
or metalloid is extracted from the ore.
My process is specially applicable for the treatment of substances hitherto
known as carbon, viz, graphite, coal, coke, ashes, sout etc, from which I obtain
valuable products, namely metallic salts which vary according to the locality from
which the said substances are obtained.
After finely pulverising the substance to be acted upon, chloride of sodium in
solution is poured over it and two plates of amalgamated zinc or other metal joined
by a wire placed in the tank at each end, a film of benzoline poured on the surface,
the whole is stirred and allowed to remain in action until the solution is saturated
with metal, it can then be tested for alumina, chromium, cerium etc, when all has
been extrated [sic] by this treatment, acetic acid is to be added to the solution
instead of the benzoline this dissolves other salts namely, manganese, nickel etc.
The tank above described can be used, the quantity of ore used at each time is
immaterial but should not be at such a depth as to be difficultly stirred, fresh
solutions must be always added until the ore is exhausted.
The pans
with dialyser or filter on the top made of like material as the tank
should be placed upon moveable stands to facilitate the drawing off of the solution
from the tank.
The solution should be composed of one pound of chloride of sodium to four
gallons of water and a quarter of a pound of acid added.
In witness whereof 1 the said Annie Eliza Scott have hereunto set my hand
and seal this eighteenth day of August in the year of our Lord One thousand eight
hundred and eighty three.