An Improved Process for the Treatment of Metalliferous Ores and Products.
Year: 1895

page_text: The Print is in accordance with the Original Specification as it stands after
Amendment (under Section 18 of the Patents, &c. Act, 1883) as allowed by
the decision of the Chief Examiner of the 8th day of September 1897.
Date of Application, 3rd Aug., 1895
Complete Specification Left, 4th May, 1896-Accepted, 3rd Nov.,
1896
PROVISIONAL SPECIFICATION.
An Improved Process for the Treatment of Metalliferous Ores and
Products.
I, EDGAR ARTHUR ASHCROFT, of Willyama Works, Globe Works, Grays, in
the County of Essex, Electrical Engineer, do hereby declare the nature of this
invention to be as follows -
is invention relates to the combined electrolytic and leaching treatment of
zinc-bearing ores and products in conjunction with copper and iron bearing ores
and products.
My improved process is carried out in a manner and with apparatus very similar
to my former process, as described in detail in the Specification of previous Letters
Patent dated the 18th day of July 1894, No. 13,850 and in my Application for
Letters Patent dated the 13th day of July 1895 and numbered 13,534; and the
improved process herein described can best be explained and understood by reading
the specifications referred to in conjunction with the following.
The essential improvements now made consist in working in conjunction with
the zinc-bearing ores and products other ores and products especially products
containing copper and iron such as are obtained from iron and copper pyrites or
sulphide ores by means of the preliminary furnace treatment almost universally
employed in the treatment of such ores These products z. copper and iron
mattes, regulus, or crude copper, can by the method under review be employed as
a substitute for a portion of the raw material required in my process above referied
to and, in such employment, while economizing the treatment of the other ones
are themselves cheaply treated for the recovery of their valuable constitutents.
In carrying this improved process into effect, I operate in a similar manner and
with similar apparatus as in the former patented process with the exception that I
substitute for the iron anodes either entirely or partially anodes consisting of the
iron and copper bearing mattes, regulus, or crude metal above mentioned. The
metals in this material may bear various proportions to each other which pro-
portions will be determined by economical considerations.
In operating with anodes of this description, the anodes are dissolved, gold,
silver, sulphur, and other constitutents of the original material are set free in solid
form, while iron or copper or both are imparted to the solution in amounts
depending in their proportions on the composition of the anodes. The products of
the electrolysis of the anodes are absorbed as in the formerly patented process and
pure zinc may be deposited at the cathode from a regenerated solution as before or
if preferred mixtares of copper and zinc, or copper and zinc and iron, or copper
and iron, or zinc and iron, may be obtained at the cathode, the proportions of such

page_text: mixtures being determined by the proportions of the metals in solution and the
strength of the current. The copper thus imparted to the solution may be removed
therefrom and ferrous salts, contained in another batch of the solution simul-
taneously raised to the ferric state by electrolysis in vats having insoluble anodes
and copper cathodes separated by diaphragms. The copper, thus produced is
refined copper and the ferric salt solution is regenerated leaching solution for
leaching zinc-bearing ores.
In certain cases it may be preferred to take the whole or a part of the copper
out of the solution by the simple contact of metallic iron (known as the cementa-
tion method) in which case an equivalent of iron is dissolved for the copper pre-
cipitated, in other cases copper may be deposited at the cathode and metallic iron
anodes dissolved and the superabundant electromotive force then developed may
be usefully employed to aid the operation of depositing zinc by connecting such
vats in the same electrical circuit as the vats wherein the zinc is deposited. In
cases where pure zinc is to be deposited it will be necessary to employ diaphragms
as formerly described, but in certain cases where products of convenient composi-
tion are being operated upon a diaphragm may be dispensed with and the pro-
portion of the different metallic salts in solution maintained sufficiently constant
to ensure a uniform product riz.:-an alloy of the different metals of a uniform
composition.
It is unnecessary to more minutely describe the methods herein explained as
they will be readily understood by any person properly versed in the art to which
they appertain on reference to the former patents referred to.
Dated this 3rd day of August 1895.
A M. & WM. CLARK,
53, Chancery Lane, London, Chartered Patent Agents.
An Improved Process for the Treatment of Metalliferous Ores and
Products.
I, EDGAR ARTHUR ASHCROFT formerly of Willyama Works, Globe Works,
Grays, in the County of Essex and at present of 34 Queen Street, Melbourne,
Victoria, Australia, Electrical 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:―
This invention relates to the treatment of ores and products containing copper
and iron in conjunction with the combined leaching and electrolytic treatment of
ores and products containing zinc.
My improved process is carried out in a manner and with apparatus very similar
to my former process, as described in detail in another application for Letters
l'atent dated 13th July 1895 No 13534.
The essential improvements now made consist in working in conjunction with
the zinc-bearing ores and products other ores and products especially products
containing copper and iron such as are obtained from iron and copper pyrites or
sulphide ores by means of the preliminary furnace treatment almost universally
employed in the treatment of such ores. These products viz.:-copper and iron
mattes, regulus, or crude copper, can by the method under review be employed as
a substitute for a portion of the iron anodes required in my process above referred
to, and, in such employment, while effecting an economy in the treatment of the
zinc-bearing ores. are themselves cheaply treated for the recovery of their valuable
constituents.

page_text: In carrying this improved process into effect I operate in a similar manner and
with similar apparatus and with the same solutions as in the former patented
process with the exception that I substitute for the iron anodes (either entirely or
partially) anodes consisting of the ion and copper bearing mattes, regulus, or
crude metal above mentioned. The metals in this material may occur in various
proportions to each other but it is immaterial for the purpose of this invention
what those proportions are except in so far as may be determined by economical
considerations.
The
In operating with anodes of this description the gold, silver, and sulphur, of the
ancde are set free in solid form, while ion and copper are impaited to the
solution in amounts depending on the composition of the anodes Whilst the
products of the electrolysis of the anodes are being dissolved as in the formerly
patented process pure zinc is being deposited at the cathode as before.
copper imparted to the solution in the anode chamber may be subsequently
removed therefiom by electrolysis and ferous salts contained in the same solution
may in such electrolysis be also raised to the ferric state, the electrolysis being
performed in vats having insoluble anodes and copper cathodes separated by
diaphragms. In such electrolysis, the solution, after the copper has been deposited
on the copper cathode, is led into the anode compartment where the oxidation of
the dissolved ferrous salts into ferric salts proceeds. The copper thus produced is
refined copper and the ferric salt solution is regenerated leaching solution suitable
for leaching zinc-bearing ores. The process hereinafter described in full with
reference to Figures 1, 2 and 3 of the accompanying drawings will be best under-
stood by the following preliminary description of the electrolytic part of the
operation, with reference to the diagram Figure 4 The solution containing salts
of zinc, practically pure, is led into the vats A and B (Figure 4 of the drawings)
which are duplicated, coming into the cathode compartments K. The zinc is
patially deposited in the cathode chambers. The solution then passes into the
anode chamber H. The anodes are copper mattes and consequently copper and
ferrous salts become added to the solution. The solution is then led into the
cathode chambers of another vat C where the copper is taken out as refined metal.
Hence the solution, containing only zinc and ferrous salts, passes to the anode
chamber of the same vat C where, in contact with carbon anodes M, its iron con-
tent becomes oxidized to the ferric state. Three vats are shown diagrammatically
in senes, so that the quantities of metal are correctly proportioned for cyclic
working in connection with the leaching process. If the matte contain more than
the best proportion of iron, part of the liquid from the cathode chamber K of C,
when freed from copper, is led into the anode chamber of a similar subsidiary
vat with carbon anodes where the ferrous salt is oxidized in the anode chamber.
The cathode chamber of this subsidiary vat is fed with pure zinc solution from
which zinc is deposited on the zinc cathode. The solution from the cathode
chamber of this subsidiary vat is then added to the anode solutions in A and B.
If, on the other hand, the matte contain too much copper, a subsidiary vat is
interpolafed between C and A and B with iron anodes and copper cathodes and no
diaphragm. Copper is thus deposited and iron goes into solution. Merely
treating the liquid with metallic iron may suffice The pipes d, d, e shewn in the
diagram connect the anode and cathode compartments in each vat.
It will be seen that cathodes of other conducting materials than copper may be
used 11 desired.
In certain cases it may be preferred to take the whole or a part of the copper out
of the solution by the simple contact of metallic iron (known as the cementation
method) in which case an equivalent of iron is dissolved for the copper precipi-
tated; in other cases copper may be deposited at the cathode whilst metallic iron
anodes become dissolved, and the superabundant electromotive force then developed
may be usefully employed to aid the operation of depositing zinc by connecting
such vats in the same electrical-circuit as the rats wherein the zinc is deposited.
In cases where pure zinc is to be deposited it will be necessary to employ dia-

page_text: phragms but in certain cases where products of convenient composition are being
operated upon a diaphragm may be dispensed with; and the proportion of the
different metallic salts in solution may be maintained sufficiently constant to
ensure a uniform product z.: an alloy of the different metals of a uniform
composition.
It is unnecessary to more minutely describe the methods herein explained as
they will be readily understood by any person properly versed in the art to which
they appertain, on reference to the former patent referred to but to facilitate
reference I here incorporate certain portions of the previous specification.
The operation of leaching the zinc bearing ore or product is the same as before,
that is to say-
The oie, if it contain zine salphide, is first subjected to an oxidizing roast
whereby the zine sulphide is converted, as far as possible, to neutral or basic zinc
sulphate and zinc oxide, any lead sulphide contained also undergoing oxidation
more or less completely In the case of ores or products containing zinc only, in
the form of oxide, such roasting will be unnecessary.
The ore or product having been ground to extreme fineness (which may be done
either before or after roasting) is then subjected in properly proportioned quantity
to the action of a leaching solution containing ferric salt, as hereinafter specified,
the reaction between the finely ground ore or product and the solution being
promoted by maintaining the same in a constant state of agitation by stirring or
otherwise, this operation being continued for from half an hour to two hours, and
the proportional quantity of ore and solution being so calculated, that the reaction
with all the iron salt in the solution will be complete when so much zinc has been
extracted from the ore that the residue left is of good composition for subsequent
smelting. For instance with ores containing 30% of zinc, probably some 5%
allowed to main in the residue. on account of the higher cost of total
extraction
The solution, after being separated from the residues, may contain a small
quantity of silver, gold, copper, antimony, arsenic, manganese, alumina, silica,
and other foreign matters taken from the ore, also a small quantity of iron in the
form of soluble ferric hydrate, which foreign matters I prefer to remove by well
known means before subjecting the solution to electrolysis
The solution having been brought to the condition indicated, is now to be
treated in the electro-depositing plant where zinc is recovered and the solution is
recharged with ferric salts so as to render it fit for use again in the above
described operation of leaching.
The electro-depositing apparatus consists essentially of a number of depositing
vats provided with anodes of copper and iron and suitable cathodes (preferably
zinc pates) and a number of similar vats having anodes of insoluble material,
such as carbon, the total depositing capacity of the plates in the iron-anode vats
being about twice that of the carbon-anode vats Diaphragms of porous material
are placed between the anode and the cathode plates so as to divide each vat into
a number of separate cells permitting the passage of the current without allowing
the intermingling of the liquids.
The form and arrangement of the depositing vats is not material, but one
arrangement which I have found suitable is shewn in the accompanying drawings.
Any suitable number of such sets of apparatus may be employed and the connec-
tion and arrangement of the same may be varied to suit particular conditions and
requirements.
Figure 1 is a section of a leaching vat with stirrers.
Figure 2 shews the arrangement of electro-depositing vats in a cascade and the
reservoirs.
Figure 3 is a general plan of the electrolysis plant.
The electro-depositing vats are arranged in such a manner, and with such pipe
and trough connections between them, that a continual circulation of solution. in
three separate stages of progress is maintained in the system, the liquids being

page_text: preferably circulated at sufficient speed to ensure a brisk and continual motion
at every part of the plates.
The depositing apparatus consists of a series of any number of electrolysis
vatsa', A2, A3, A4, A5, A6, A7, A8, Aº, preferably arranged as shewn in Figures 2
and, and a number of reservoirs B1, B2, B3, B4, B5, 13. Each of the vats is
divided by diaphragms C of filter-cloth, or other suitable material, into a number
of compartments each of which has an inlet pipe D entering near the bottom
and an outlet pipe E discharging near the top.
Each of the vats A1, A2, A3, A4, A5, A6, contains three copper and iron anodes H
and two metallic cathodes K, while each of the vats A7, A8, A³, contains three
carbon anodes M and two metallic cathodes K. The electrical connections may
be made in any suitable manner, all the plates in the same vat being connected
in parallel and the plates of successive vats being connected in series.
The reservoir B¹, has a number of exit pipes which discharge into the inlets of
the cathode compartments of the three upper vats A¹, A4, and A7. The outlet
pipes of these compartments discharge into the inlets of the cathode compartments
of the vats A2, A³ and A8 The outlet pipes of these compartments discharge into
the inlets of the cathode compartments of the vats A³, A and Aº, and the outlet
of these compartments discharge into the reservoir B. The reservoir B³, has
a number of exit pipes which discharge into the inlets of the anode compartments
of the vats A¹ and A. The outlet pipes of these compartments discharge into the
inlets of the anode compartments of the next vats A2 and A³
The outlet pipes
of these compartments discharge into the anode compartments of the vats A³
and A, and the outlet pipes of these compartments discharge into the reservoir B*.
the reservoir has exit pipes which discharge into the inlets of the carbon anode
compartments of the vat A7. The outlet pipes of these compartments discharge
into the inlets of the carbon anode compartments of the vat A8. The outlet pipes
of these compartments discharge into the inlets of the carbon anode compartments
of the vat Aº, and the outlet pipes of these compartments discharge into the
reservoir Bº.
For the above described operations one of several solutions of different, though
analogous, compositions may be employed according to varying circumstances."
No. 1. Zinc chloride mixed with sodium, potassium, magnesium, or ammonium
sulphate
No. 2. Zinc chloride, mixed with sodium, potassium, magnesium, or ammonium
chloride.
No 3. Zinc sulphate mixed with sodium, potassium, magnesium, or ammonium
sulphate
The ferric salt required in each of the above solutions, in order to effect the
solution of the zinc is generated in the electro depositing plant as hereinbefore
described.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, 1 declare that what I
claim is: 1
1. The improved process whereby a solution containing copper and iron is
obtained electrolytically by employing an anode consisting of the products result-
ing from the preliminary furnace treatment of products or ores containing copper
and iron, as the anode of a zinc depositing vat, substantially as described.
2. The improved process whereby from a solution obtained by the process
claimed in the first claim hereof, the copper is deposited and the dissolved iron
simultaneously raised to the ferric state by the use, in an electrolytic vat, of
copper or other cathodes in conjunction with carbon or other insoluble anodes,
substantially as described.
3. The improved process consisting in including in one and the same electrical
circuit, vats in which the electro-deposition of zinc is proceeding, and vats provided
with anodes of metallic iron and cathodes of metallic copper or other metal in

page_text: which copper is being electrolytically deposited from a solution obtained by the
process claimed in the first claim, substantially as described.
4. The method of preparing from copper mattes containing iron, a solution of
a fenic salt for use as a leaching solution while the other metal of the matte, vz.:
copper, is being deposited, substantially as described.
ad this 2nd day of Nov 1906
5
A. M. & WM. CLARK,
53, Chancery Lane, London, Chartered Patent Agents.
A. M. & WM. CLARK,
53, Chancery Lane, London, Chartered Patent Agents.