Improvements in the Means of and Apparatus for the Extraction of Metals from their Ores; Particularly in the Treatment of "Blue Stone" and similar Complex Ores and for Electro and for electrolytically refining copper and for the manufacture of sulphuric acid by electrolytic action
Year: 1885

page_text: Improvements in the Means of and Apparatus for the Extraction
of Metals from their Ores; Particularly in the Treatment of
"Blue Stone" and similar Complex Ores and for
Electro
We WILLIAM ELMORE and ALEXANDER STANLEY ELMORE, both of 359 Clapham
Road, in the county of Surrey, Electro-chemical Engineers and HENRY BARRETT
of Mineval, Dulwich, in the county of Surrey, Manufacturer do hereby declare
the nature of this invention to be as follows:-
This invention has for its object improvements. in the means of and apparatus
for the extraction of metals from their ores; particularly in the treatment of
Blue Stone and similar complex ores, and for electrolytically refining copper
and for the manufacture of sulphuric acid by electrolytic action.
"
"
According to our invention in dealing with complex ores such as for instance
"Blue stone" and the like, which contain in varying quantities zinc, lead, copper,
silver, gold, iron, sulphur and gangue we proceed as follows:-
The finely ground ores from which the metals are to be extracted are charged
into an improved reverberatory furnace which we work in combination with a
fune condensing chamber and electrolytic apparatus for the manufacture of
sulphuric acid by electrolytic action as hereinafter described. The finely ground
ore is "let down" upon the hearth of the furnace before referred to, to which
there is free access of air, the furnace being at a temperature not exceeding a dull
red heat which is gradually raised to a bright red heat after the charge has been
completed-and so maintained until the zinc and copper contents have been
sufficiently oxydized; when the calcination is completed the ore is withdrawn
from the furnace and while still hot is transferred to the tubs of a mechanical
stirrer or agitator where it is by the action of the stirrers brought into intimate
contact with the water, dilute acid or other solvent to be used for the solution of
the zinc or for the solution of the zinc and copper together, or for the solution of
other metals the ore may contain either separately or together.
The solution obtained from the washing of the ore is then treated as follows:-
When the solution contains zinc, copper, iron and some silver it is run into
settling tanks where it is allowed to thoroughly settle; from thence it is run into
I Price G

page_text: .
a tank which contains netallic zinc which metallic zinc will go into solution
replacing the copper and silver, the copper and silver being precipitated in a
metallic or semi-inetallic state from the solution containing the zinc, the mixed
copper and silver being collected, washed, dried, melted and cast into convenient
form and size for use as anode or positive plates in a subsequent electrolytic
process for the separation of the copper from the silver contained as hereinafter
described.
The solution after this precipitating operation is, if not too highly charged with
iron run direct into electrolytic decomposition tanks for the purpose of depositing
the zinc. If the solution contains an objectionable quantity of iron such solution
before being run into the electrolytic depositing tanks, should be mixed with or
run over or through a sufficient quantity of carbonate of line to precipitate the
iron. It will be found advantageous during this operation to blow or force air or
steam through the solution to assist the precipitation of the iron.
of
When the copper, iron and silver have thus been eliminated we pass a current
of electricity from a Dynamo Electric machine or other suitable source
electricity through such solution containing the zinc, using lead or other insoluble
or practically insoluble material as anodes or positive plates and thin sheet zinc or
other suitable material as cathodes or negative plates, upon which a certain
quantity of metallic zinc is deposited at the cathode or negative plates and a
proportionate quantity of sulphuric acid is liberated at the anode or positivo plate;
this quantity of sulphuric acid which is liberated acts detrimentally by increasing
the back electromotive force from the tanks and by making the deposited zinc
spongy thereby making the zine difficult to melt. To overcome these difficulties
we proceed as follows-The electrolytic decomposition tanks are fitted with inlet
and outlet pipes, the inlet pipes entering at the bottoms of the tanks and the
outlet pipes being fitted to the tops of the tanks. As there is a continuous
deposition of zinc and consequently à continuous liberation of free sulphuric acid
going on. so long as the current of electricity is maintained, we provide for the
removal of the free sulphuric acid by keeping up a continuous supply of fresh
solution-neutral or nearly so-from the mechanical stirrers and passing this
neutral or nearly neutral solution into the bottom of the clectrolytic decomposition
tanks and as the molecules of solution which have been deprived of their zinc and
consequently have become more highly charged with free sulphuric acid are
lighter than those molecules which have not been deprived of their zinc rise to the
top of the tank and as the heavy neutral or nearly neutral solution is passed into
the bottoms of the tanks the lighter solution containing the largest quantity of
free sulphuric acid is run off at the tops of the tanks and so back to the stirrers to
be mixed with the ore and so be neutralized or nearly so by the free sulphuric
acid combining with the zinc oxide contained in the calcined ore forming sulphate
of zinc.
Of course the neutral or nearly neutral solution coming from the stirrers to
replace the solution which has become highly charged with free sulphuric acid as
before mentioned will dissolve more or less copper, iron and silver each time it is
passed over or mixed with the ore therefore it must when necessary be passed
through the same cycle of operations to eliminate these impurities as before
described. The apparatus for accomplishing this is conveniently arranged when
possible so that the solution will flow from one set of tanks or apparatus to the
next set by gravitation or it may be pumped, syphoned or forced from one set of
tanks or apparatus to the next set.
The calcined ore which has now been freed or practically freed from its zinc,
copper and part of its iron and silver is thrown upon a filter or slope so that
the solution held in the mass of ore may drain out and when the greater quantity
of this solution is drained out, the mass of ore may be washed with water pro
ducing a weak solution of sulphate of zinc which weak solution may be evaporated
to the necessary strength by a suitably arranged evaporating apparatus made so as
to utilize the waste heat from the calcining or other furnaces.

page_text: The residue of the ore containing lead, silver and gold from the above operations
is dried and smelted for lead which lead carries all the remaining silver and the
gold with it; this argentiferous and auriferous lead may be either treated electro-
lytically or by the Pattinson or other well known process for the separation of the
silver and gold from the lead.
When calcining the ore for the purpose of oxydizing the metals and producing
sulphuric acid we proceed as follows:-
The fume or fumes obtained from calcining the ore are cooled and introduced
with a sufficient quantity of steam into a fume condensing chamber of suitable
dimensions and constructed of suitable materials to resist the action of sulphuric
acid, such fume condensing chamber being fitted with suitable combs or plates of
platinum or other suitable metal (and connected by properly insulated wires to an.
electrical machine) arranged with a space between each pair of plates or combs so
that there may be free access of the mixture of steam and fume to all points or
surfaces of the plates or combs, such plates or combs to be properly insulated by
electrical non, conductors. Upon a current of electricity being discharged from one
set of plates or combs to the other set, ozone, ozonized air or ozonized oxygen is
formed such ozone, ozonized air or ozonized oxygen, acting as a powerful oxidizing
agent which in the presence of moisture oxidizes the sulphurous anhydrid or the
sulphurous acid gas into sulphuric acid and owing to the temperature of the fume
condensing chamber not being sufficiently high to volatilize such sulphuric acid it
is condensed and may be collected for concentration, distillation or for any purpose
for which sulphuric acid is used.
In the process of precipitating by zinc the copper and silver from the liquors
obtained from washing the ore by the use of mechanical stirrers hereinbefore
described we obtain a mass of copper in a metallic or semi-metallic state mixed:
with more or less silver in a more or less spongy state, this mass is to be washed-
preferably through a suitable sieve-with water for the purpose of removing any
particles of metallic zinc to which it may be adhering; the mixture of finely
divided copper and silver is then either filtered off from the supernatant liquor or
allowed to settle and the supernatant liquor decanted, it is then dried, melted and.
cast into suitable form and size to be used as positive plates or anodes in an
improved electrolytic process for the separation of the copper from the silver-In
carrying this into effect we proceed as follows:-
We prepare an improved electrolytic decomposition tank of suitable dimensions
having a porous compartment or porous cell, that is a part or parts of the tank is
or are separated from the other part or parts of the tank by a material of a
sufficient degree of porosity such for instance as.
.biscuit ware, asbestos, thin wood
or the like; this porous cell or compartment we provide with an outlet pipe at or
near the bottom suitably arranged so that the level of the liquor with which the,
porous cell is to be filled may be under control, this may be obtained by bending
the outlet pipe up outside the tank and then having a piece of pipe of smaller
diameter to slide inside the larger outlet pipe to act as an adjustable overflow
taking proper precautions to prevent the leakage of the liquor at the point at
which the small pipe enters the large one; by this means that is by raising or
lowering the small pipe the level of the liquor in the porous cell will be under
control; we then proceed to fill the porous cell. and the outer cell of the electro-
lytic decomposition tank with a solution of cuprous chloride in hydrochloric acid
or a solution of cuprous chloride in sodium chloride or a solution of cuprous
chloride in sodium chloride and hydrochloric acid. We then arrange the outlet
pipe from the porous cell so that the level of the liquor in the porous cell shall be
about one inch lower than the level of the liquor in the outer cell of the tank.
the outer cell there is to be fitted a supply pipe from a reservoir tank through
which pipe a constant supply of liquor is maintained in the outer cell, thence
through the porous partition to the inside of the porous cell. We then hang in
the porous cell a plate or other convenient form of copper to be treated, to act as
an anode, and in 'the outer cell we hang a thin sheet of copper to act as a cathode
To

page_text: we now connect the anode to the positive pole of a dynamo electric machine or
other suitable source of electricity and we connect the cathode to the negative pole
of the same source of electricity and pass a current from the anode through the
solution and porous partition to the cathode. This will have the effect of causing
a deposit of metallic copper at the cathode and cause the solution of a proportionate
quantity of the metal or metals at the anode and it will be found that not only
the copper but also the silver of the anode will go into solution as there is a
constant flow of liquor which has been to a greater or less degree deprived of its
copper in the outer cell to the inside of the porous cell there to be charged with
the metal or metals of the anode.
The solution which has been charged in the porous cell with the metal or metals
of the anode is to be run through the outlet pipe of the porous cell thence through
the small sliding pipe enclosed in it as before described into tanks for the purpose
of being treated as follows:-
When a sufficient quantity of this solution has been collected a sample is to be
taken and the quantity of silver accurately estimated and from the result of such
estimation calculation is to be made to determine the quantity of iodide of
potassium or other precipitant of silver to be added to the solution to precipitate
the whole of the silver contained in the total quantity of solution under treat-
ment; the precipitate is allowed to settle and the supernatant liquor is returned to
the reservoir tank to be again run into the outer cell of the electrolytic decom-
position tank there to be deprived of part of its copper and thence to the inside of
the porous cell to be recharged with copper and silver which silver is to be
precipitated as before described; the object of this is to ensure a continuous
recovery of the silver and copper from the anodes thereby reducing the capital
locked up in the stock, it has also the object of reducing the cost of depositing the
copper, as we deposit from a solution of a cuprous salt and can by the use of such
solution deposit just twice the quantity of copper by a given current than can be
deposited from a solution of, a cupric salt; and by the use of such a solution that
is a solvent for the silver in the anode as well as the copper, we obviate the
necessity of the frequent stoppage of the plant necessary under the old plan of
working with a solution of cupric sulphate to collect the residues containing the
precious metal.
We wish it to be clearly understood that we do not confine ourselves to the use
of this part of our invention for the separation of the copper and silver contained
in the precipitate obtained by working complex ores or "blue-stone"; we may
use any. copper as anode containing gold or silver or not as the case may be.
For the electro-deposition of the zinc and copper we prefer to use dynamo
electric machines manufactured under patents granted to William Elmore, No. 3565,
dated September 4th, 1879, No. 3S32, dated September 22nd, 1880 respectively and
to Shackleton. Hallett, No. 2573, dated 31st May 1882, which are specially con-
structed and adapted for such purpose, but we do not confine ourselves to the use
of such machines.

page_text: "Blue Stone" and similar Complex Ores, and for Electro-
lytically Refining Copper and for the Manufacture of Sulphuric
Acid by Electrolytic Action.
We WILLIAM ELMORE and ALEXANDER STANLEY ELMORE, both of 359 Clapham
Road, in the county of Surrey, Electro-chemical Engineers and HENRY BARRETT,
of Mineval, Dulwich, in the county of Surrey, Manufacturer, 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 has for its object improvements in the means of and apparatus
for the extraction of metals from their ores;. particularly in the treatment of
"Blue stone" and similar complex ores and for electrolytically refining copper and
for the manufacture of sulphuric acid by electrolytic action.
According to our invention in dealing with complex ores such as for instance
"Blue stone" and the like, which contain in varying quantities zinc, lead, copper,
silver, gold, iron, sulphur and gangue we proceed as follows:
The finely ground ores from which the metals are to be extracted are charged
into a reverberatory furnace which we work in combination with a fume condensing
chamber and electrolytic apparatus for the manufacture of sulphuric acid by
electrolytic action as hereinafter described. The finely ground ore is "let down "
upon the hearth of the furnace before referred to, to which there is free access of
air, the furnace being at a temperature not exceeding a dull red heat which is
gradually raised to a bright red heat after the charge has been completed and so
maintained until the zinc and copper contents have been sufficiently oxydized;
when the calcination is completed the ore is withdrawn from the furnace and while
still hot is transferred to the tubs of a mechanical stirrer or agitator where it is by
the action of the stirrers brought into intimate contact with the water, dilute acid
or other solvent to be used for the solution of the zinc or for the solution of the
zinc and copper together, or for the solution of other metals the ore may contain
either separately or together.
.
The solution obtained from the washing of the ore is then treated as follows:-
When the solution contains zinc, copper, iron and some silver it is run into
settling tanks where it is allowed to thoroughly settle; from thence it is run into
a tank which contains metallic zinc which metallic zinc will go into solution
replacing the copper and silver, the copper and silver being precipitated in a
metallic or semi-metallic state from the solution containing the zinc, the mixed
copper and silver being collected, washed, dried, melted and cast into convenient
form and size for use as anode or positive plates in a subsequent electrolytic
process for the separation of the copper from the silver contained as hereinafter
described.
The solution after this precipitating operation is, if not too highly charged with
iron run direct into electrolytic decomposition tanks for the purpose of depositing
the zinc. If the solution contains an objectionable quantity of iron such solution
before being run into the electrolytic depositing tanks, should be mixed with or-

page_text: run over or through a sufficient quantity of carbonate of lime to precipitate the.
iron. It will be found advantageous during this operation to blow or force air or
steam through the solution to assist the precipitation of the iron.
When the copper, iron and silver have thus been eliminated and the solution run
into the tanks we pass a current of electricity from a dynamo electric machine or
other suitable source of electricity through such solution containing the zinc, (using
lead or other insoluble or practically insoluble material as anodes or positive plates
and thin sheet zinc or other suitable material as cathodes or negative plates) upon
which a certain quantity of metallic zinc is deposited at the. cathode or negative
plates and a proportionate quantity of sulphuric acid is liberated at the anode or
positive plate; this quantity of sulphuric acid which is liberated acts detrimentally
by increasing the back electromotive force from the tanks and by making the
deposited zinc spongy thereby making the zinc difficult to melt. To overcome
these difficulties we proceed as follows:-The electrolytic decomposition tanks are
fitted with inlet and outlet pipes, the inlet pipes entering at the bottoms of the
tanks and the outlet pipes being fitted to the tops of the tanks. As there is
a continuous deposition of zine and consequently a continuous liberation of free
sulphuric acid going on so long as the current of electricity is maintained we
provide for the removal of the free sulphuric acid by keeping up a continuous
supply of fresh solution-neutral or nearly so from the mechanical stirrers and
passing this neutral or nearly neutral solution into the bottom of the electrolytic
decomposition tanks and as the molecules of solution which have been deprived of
their zinc and consequently have become more highly charged with free sulphuric
acid are lighter than those molecules which have not been deprived of their zinc
they rise to the top of the tank and as the heavy neutral or nearly neutral solution
is passed into the bottoms of the tanks the lighter solution containing the largest
quantity of free sulphuric acid is run off at the tops of the tanks and so back to
the stirrers to be mixed with the ore and so be neutralized or nearly so by the free
sulphuric acid combining with the zinc oxide contained in the calcined ore forming
sulphate of zinc.
Of course the neutral or nearly neutral solution coming from the stirrers to
replace the solution which has become highly charged with free sulphuric acid as
before mentioned will dissolve more or less copper, iron and silver each time it is
passed over or mixed with the ore therefore it must when necessary be passed
though the. samo cycle of operations to eliminate these impurities as before
described. The apparatus for accomplishing this is conveniently arranged when
possible so that the solution will flow from one set of tanks or apparatus to the
next set by gravitation or it may be pumped, syphoned or forced from one set of
tanks or apparatus to the next set.
The calcined ore which has now been freed or practically freed from its zinc,
copper and part of its iron and silver is thrown upon a filter or slope, so that the
solution held in the mass of ore may drain out and when the greater quantity of
this solution is drained out, the mass of ore may be washed with water producing a
weak solution of sulphate of zine which weak solution may be evaporated to the
necessary strength by a suitably arranged evaporating apparatus made so as to
utilize the waste heat from the calcining or other furnaces.
The residue of the ore containing lead, silver and gold from the above operations
is dried and smelted for lead which lead carries all the remaining silver and
the gold with it; this argentiferous and auriferous lead may be either treated
electrolytically or by the Pattinson or other well known process for the separation
of the silver and gold from the lead.
When calcining the ore for the purpose of oxydizing the metals and producing
sulphuric acid we proceed as follows:-
The fume or fumes obtained from calcining the ore are cooled and introduced
with a sufficient quantity of steam into a fume condensing chamber of suitable
dimensions and constructed of suitable materials to resist the action of sulphuric
acid such fume condensing chamber being fitted with suitable combs or plates of

page_text: platinum or other suitable metal (and connected by properly insulated wires to an
electrical machine) arranged with a space between each pair of plates or combs so
that there may be free access of the mixture of steam and fume to all points
or surfaces of the plates or combs such plates or combs to be properly insulated by
electrical non-conductors. Upon a current of electricity being discharged from one
set of plates or combs to the other set, ozone, ozonized air or ozonized oxygen is
formed such ozone, ozonized air or ozonized oxygen acting as a powerful oxidizing
agent which in the presence of moisture oxidizes the sulphurous anhydrid or the
sulphurous acid gas into sulphuric acid and owing to the temperature of the fume
condensing chamber not being sufficiently high to vaporize such sulphuric acid it is
condensed and may be collected for concentration, distillation or for any purpose
for which sulphuric acid is used.
In the process of precipitating by zinc the copper and silver from the liquors
obtained from washing the ore by the use of mechanical stirrers herein before
described we obtain a mass of copper in a metallic or semi-metallic state mixed
with more or less silver in a more or less spongy state, this mass is to be washed
preferably through a suitable sieve with water for the purpose of removing any
particles of metallic zinc to which it may be adhering; the mixture of finely
divided copper and silver is then either filtered off from the supernatant liquid or
allowed to sottle and the supernatant liquor decanted; it is then dried, melted and
cast into suitable form and size to be used as positive plates or anodes in an
improved electrolytic process for the separation of the copper from the silver. In
carrying this into effect we proceed as follows:-
We prepare an improved electrolytic decomposition tank of suitable dimensions
having a porous compartment or porous cell, that is a part or parts of the tank is
or are separated from the other part or parts of the tank by a material of a
sufficient degree of porosity such for instance as biscuit ware, asbestos, thin wood
or the like; this porous cell or compartment we provide with an outlet pipe at or
near the bottom suitably arranged so that the level of the liquor with which the
porous cell is to be filled may be under control, this may be obtained by bending
the outlet pipe up outside the tank and then having a piece of pipe of smaller
diameter to slide inside the larger outlet pipe to act as an adjustable overflow,
taking proper precautions to prevent the leakage of the liquor at the point at
which the small pipe enters the large one; by this means that is by raising or
lowering the small pipe the level of the liquor in the porous.cell will be under
control; we then proceed to fill the porous cell and the outer cell of the electrolytic
decomposition tank with a solution of cupreous chloride in hydrochloric acid or a
solution of cupreous chloride in sodium chloride or a solution of cupreous chloride
in sodium chloride and hydrochloric acid. We then arrange the outlet pipe
from the porous cell so that the level of the liquor in the porous cell shall be
about one inch lower than the level of the liquor in the outer cell of the tank:
To the outer cell there is to be fitted a supply pipe from a reservoir tank
through which pipe a constant supply of liquor is maintained in the outer cell,
thence through the porous partition to the inside of the porous cell. We then
haug in the porous cell a plate or other convenient forin of argentiferous or
auriferous or argentiferous aud auriferous "copper" to be treated, to act as an
anode and in the outer cell we hang a thin sheet of copper to act as a cathode; we
now connect the anode to the positive pole of a dynamo electric machine or other
suitable source of electricity and we connect the cathode to the negative pole of
the same source of electricity and pass a current from the anode through the
solution and porous partition to the cathode. This will have the effect of causing
a deposit of metallic copper at the cathode and cause the solution of a proportionate
quantity of the metal or metals at the anode and it will be found that not only the
copper but also the silvor of the anode will go into solution as there is a constant
flow of liquor which has been to a greater or less degree deprived of its copper in
the outer cell to the inside of the porous cell there to be charged with the metal or
metals of the anode.

page_text: The solution which has been charged in the porous cell with the metal or metals
of the anode is to be run through the outlet pipe of the porous cell thence through
the small sliding pipe enclosed in it as before described into tanks for the purpose
of being treated as follows:-
When a sufficient quantity of this solution has been collected a sample is to be
taken and the quantity of silver accurately estimated and from the result of such
estimation calculation is to be made to determine the quantity of iodide of potas
sium or other precipitant of silver to be added to the solution to precipitate the
whole of the silver contained in the total quantity of solution under treatment; the
precipitate is allowed to settle and the supernatant liquor is returned to the reser-
voir tank to be again run into the outer cell of the electrolytic decomposition tank
there to be deprived of part of its copper and thence to the inside of the porous
cell to be recharged with copper and silver which silver is to be precipitated as
before described; the object of this is to ensure a continuous recovery of the silver
and copper from the anodes thereby reducing the capital locked up in the stock, it
has also the object of reducing the cost of depositing the copper, as we deposit from
a solution of a cupreous salt and can by the use of such solution deposit just twice
the quantity of copper by a given current than can be deposited from a solution of
a cupric salt; and by the use of such a solution that is a solvent for the silver in
the anode as well as the copper, we obviate the necessity of the frequent stoppage
of the plant necessary under the old plan of working with a solution of cupric
sulphate to collect the residues containing the precious metal.
We wish it to be clearly understood that we do not confine ourselves to the
use of this part of our invention for the separation of the copper and silver con-
tained in the precipitate obtained by working complex ores or "blue-stone"; we
may use any copper as anode containing silver or gold or not as the case may be.
For the electro-deposition of the zinc and copper we prefer to use dynamo electric
machines manufactured under patents granted to William Elmore, No. 3565, dated
September 4th 1879, No. 3832, dated September 22nd 1880 respectively and to
Shackleton Hallett, No. 2573 dated 31st May 1882 which are specially constructed
and adapted for such purpose, but we do not confine ourselves to the use of such
machines.
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,―
1. The combination process for the treatment of "Blue-stone" and similar
complex ores substantially as set forth.
2. The use of a solution of cupreous chloride in sodium chloride or a solution of
cupreous chloride in hydrochloric acid or a solution of cupreous chloride in sodium
chloride and hydrochloric acid for the purpose of electrolytically treating argenti-
ferous or auriferous or argentiferous and auriferous copper substantially as set forth.
3. The porous cell in combination with an adjustable overflow for the purpose
set forth substantially as described.
4. The reverberatory furnace in combination with the fume condensing chamber
for the manufacture of sulphuric acid substantially as set forth.
Unted the 24th day of October 1886
Dated the 24th day of October 1886
"
G. F. REDFERN,
4, South Street, Finsbury, London,
Agent for the Applicants.
G. F. REDFERN,
4, South Street, Finsbury, London,
Agent for the Applicants.