An Improved Method or Process for the Treatment of the Ores of Nickel and Cobalt.
Year: 1894

page_text: Date of Application, 11th June, 1894
Complete Specification Left, 2nd Apr., 1895-Accepted, 8th June, 1895
PROVISIONAL SPECIFICATION.
An Improved Method or Process for the Treatment of the Ores of
Nickel and Cobalt.
I, Dr. CARL HOEPFNER, Chemical Electrician, of Giessen, in the Empire
of Germany, do hereby declare the nature of this invention to be as
follows:-
The present application relates to a process having for its object to render more
economical the treatment of the ores of nickel and cobalt, containing these
metals in the state of oxide, carbonate or silicate, especially the ores of New
Caledonia.
My process consists in mixing these ores with ores or mattes, containing in the
state of sulphuret, copper, silver or other precious metals, and in smelting the
whole.
The cupreous matte thus produced is then treated by the wet process according
to my process which I have already specified in prior Patents viz. Nos. 4626
of 1888, 18080 of 1890, 18,900 of 1892 and 22,030 of 1891.
The metals are then extracted and separated by electrolysis.
According to my process the solution of the metals is effected by means of cupric
chloride CuCl which dissolves the sulphurets and which itself is reduced to a
cupreous state Cu³CI.
This solution of cupreous chloride CuCl is decomposed by electrolysis in a bath
having a diaphragm between the electrodes; the copper becomes separated from
the solution and is deposited on the cathodes, then this solution is freed from the
iron and from all those metals which are more negative than nickel and cobalt,
finally these latter are precipitated either electrolytically or chemically.
D LT 1904
DR. CARL HOEPFNER,
By Harris & Mills,
23, Southampton Buildings, London, W.C., Agents.
COMPLETE SPECIFICATION.
An Improved Method or Process for the Treatment of the Ores of
Nickel and Cobalt.
I, Dr. CARL HOEPFNER, of Giessen in the Empire of Germany, Chemical
Electrician, 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 present application relates to a process having for its object to render more
economical the treatment of the ores of nickel and cobalt containing these
metals in the state of oxide carbonate or silicate, especially the ores of New
Caledonia.
My process consists in mixing these nickel and cobalt ores with ores or mattes
containing, in the state of sulphuret, copper, silver or other valuable metals and in
smelting the whole.

page_text: i
Latter ores containing besides sulphur a great proportion of iron and having in
most cases a basic nature on account of its amount of lime or calcareous matters
cause therefore by means of their iron or basic matter the conversion of the silica
of the nickeliferous or cobaltiferous ores into slag, so as to cause the nickel and
cobalt to combine with sulphurets of other metals and to prevent the former from
entering the slag.
If nickeliferous or cobaltiferous materials or mixtures containing silica are
smelted alone, the nickel and cobalt are liable to form with the silica a nickeliferous
or cobaltiferous slag. If however such materials or mixtures further contain
ferriferous combinations or calcareous matter and sulphurets of metals the iron and
the oxide of calcium is more liable than nickel or cobalt to form with the silica a
slag and the nickel or cobalt are more liable to combine with the metallic
sulphurets so that firstly the iron and the lime combines with the suitable
quantities of silica being present; if the quantity of ferriferous combinations and
of CaO is quite sufficient to convert the whole quantity of silica into slag, no silica
remains to convert nickel or cobalt into slag and therefore by employing a sufficient
quantity of such material containing sulphurets the nickel and cobalt is prevented
from entering the slag. The relative proportions of the nickeliferous or cobalti-
ferous materials and of the material containing the sulphurets mentioned are
therefore to be chosen in such a manner that the ferriferous combinations and the
calcareous matter contained in the latter materials are quite sufficient to scorify
the silica contained in the nickeliferous or cobaltiferous ores. These relative
proportions can easily be stated either by experiences in previously trying such
melting together with small quantities or by firstly stating by analysis the
composition of the nickeliferous or cobaltiferous material as well as of the material
containing the sulphuret and then by choosing the proportions so as to have in the
mixture for one molecule or 60 parts by weight of SiO, (silica) about one atom or
56 parts by weight of iron whereby, if calcareous matters also be present, 1 atom
or 56 parts by weight of iron can be replaced by 1 molecule or 56 parts by weight
of CaO. If for instance the nickeliferous or cobaltiferous material contains
40% SiO, and the material to be mixed therewith being free from silica con-
tains 38% iron (partly as FeS) and 38% CaO, it is advantageous to mix 10 parts
by weight of the first material with 5 parts by weight of the latter. Anyhow it is
advantageous to produce a matte containing about 60-70% of valuable metals
(Cu+Ni+ Co + Sn + Pb ..) and about 10% of iron and to have besides a
slag, which is easily fusible. The molecular composition of the slug is of course
influenced by the presence or absence of ferric silicates as well as the presence or
· absence of alumina.
The best fusible slag would contain for instance:
56 parts of silica SiO,
30 parts of CaO
14 parts of Al,O,
but smelters use preferably. slags of a more basic character in order to save the
furnace which often do not allow except of a more basic slag.
Therefore my process diminishes or prevents the losses of nickel or cobalt. In
fact without my said process a large amount of nickel or cobalt would be scorified
by the silica of its ore, as such ores contain up to 50% SiO. It is furthermore
very advantageous to smelt the nickeliferous or cobaltiferous ores, having a great
amount of silica SiO), together with the said cupriferous ores or mattes, because the
latter contain a large amount of sulphide of iron and eventually calcareous matter,
.which scorify with silica, thereby producing a matte, the latter in view of the
scorification of the ferriferous and calcareous matters of the ores containing the
sulphurets of copper, nickel and cobalt and other valuable metals in a more
concentrated form. Thus it is possible to obtain by the first smelting a matte
containing up to 60% of valuable metals.
Hitberto for the purpose of obtaining pure nickel, it has been thought to be

page_text: The
absurd to add copper ores to pure Caledonian nickel ores: my process however
consists in this absurd combination of copper ores with nickel or cobalt ores.
result is that the losses as well as the smelting cost of both copper and nickel are
diminished whilst the manufacture of pure copper and nickel is facilitated.
My said process is furthermore of great commercial advantage for the reason,
that the considerable amount of copper in such matte in fact facilitates the
electrolytical extraction of nickel by the aid of the cuprous chloride process,
as described for instance in former Letters Patent No. 4626 1888 and
No. 18900°.
Like cupriferons ores, also silver ores which may also contain lead as well as
auriferous pyrites act in a similar manner.
The matte produced as above described contains besides' copper all metals
of the materials melted together: nickel, cobalt and the other valuable or
precious metals.
Such matte can then be treated by a wet process or electrolytically in order to
extract the said metals. For this purpose it is advantageous to employ the
processes of Dr. Hoepfner, as described in the Specification of former Letters
Patent No. 6736, 1884, No. 4626, 1888, No. 18080, 1890 No. 18900, 1892,
No. 22030, 1891, thereby treating such matte practically in a powdered state
with a solution of cupric chloride CuCl, which dissolves the sulphurets and is
thereby converted into cuprous chloride, held in solution by means of suitable
solvents.
This solution of cuprous chloride Cu,Cl, may be treated by means of the process
described in Letters Patent No. 4626, 1888 and No. 18900, 1892. Part of the
cuprous solution is suitably converted into a cupric one electrolytically at the
anodes or chemically by means of a current of air or oxygen in the presence of an
acid, such as hydrochloric acid, or by means of chlorine gas, so as to be again
employed for the lixiviation of fresh portions of matte and to enable its continuous
extraction. The other part of the cuprous solution is treated so as to extract one
after another the metals dissolved therein.
For the employment of the process conforming to my Letters Patent No. 18080,
1890 it is necessary to roast the matte with or without common salt.
The iron accumulating in the solution may be eliminated or its accumulation
avoided as described in the said Letters Patent or by means of the process described
in the Specification of Letters Patent No. 22030, 1891.
Preferably the cupreous solution, obtained from the matte or part of the same as
before mentioned, is treated according to my process, described in No. 4626, 1888
and No. 22030, 1891 and electrolyzed, for which electrolysis a bath is practically
employed with insoluble anodes and a diaphragm between the electrodes. Part of
the solution is thus purified and freed from silver and copper and the residual
solution so treated as to produce a pure nickel or cobalt.
For this purpose the solution is freed from iron and all metals more electro-
negative than nickel and cobalt and then preferably subjected to electrolysis.
Thus pure nickel and cobalt is deposited whilst chlorine is set free.
The latter can conveniently be used for different purposes viz. for extracting gold
as well as for reconverting Cu,Cl, into CuCl, (cuprous chloride into cupric
chloride) for the sake of a continuous extraction of mattes or minerals.
The said residual nickel and cobalt solutions can of course also be utilized for
electroplating as well as for the production of oxides of nickel and cobalt.
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 treatment of ores, containing nickel or cobalt in the state of oxides,
carbonates or silicates especially of the ores of New Caledonia, consisting in mixing
these ores with ores or mattes containing sulphurets of copper, silver, gold or other
valuable metals and in smelting a matte from the whole for the purpose of obtaining

page_text: a matte containing besides nickel or cobalt several metals from which matte the
nickel or cobalt as well as the accompanying metals such as copper and silver, can
be economically recuperated separately.
2. The treatment of ores containing nickel or cobalt in the state of oxides,
carbonates or silicates especially of the ores of New Caledonia consisting in mixing
these ores with ores or mattes containing sulphurets of copper, silver, gold or other
valuable metals and in smelting a matte from the whole from which matte thus
produced the valuable metals are again separated by some wet or electrolytic or
other process.
3. The treatment of the matte obtained according to Claim 1 by the processes,
described in Letters Patent No. 4626, 1888, No. 18080, 1890, No. 18900, 1892,
No. 22030, 1891 whereby the extraction of nickel and other metals takes place by
means of cupric chloride CuCl, which is converted into cuprous chloride Cu,Cl, and
then for the continuous extraction partially reconverted into cupric chloride
electrolytically or by the action of oxygen or of chlorine.
4. The treatment of the solutions of nickel chloride or cobalt chloride and
cuprous chloride obtained from the matte produced according to Claim 1, by means
of the processes described in Letters Patent No. 4626, 1888, No. 18900, 1892 or
by roasting in combination with the process described in Letters Patent No. 18080,
1890, such treatment consisting in freeing, the whole or a part of them from copper,
then purifying the same from all metals more electronegative than nickel or cobalt
and finally extracting wholly or partially also the nickel and cobalt.
5. The treatment of solutions of chloride or nickel or cobalt from the described
matte during the process as characterized in Claim 4, such treatment consisting in
electrolyzing the said solutions with insoluble anodes and utilizing the chlorine
thus set free or part of it for extracting new portions of metals or for reconverting
cuprous chloride into cupric chloride or for extracting the gold and other residual
metals from the residue.
Dated this 2nd dow of a 1905
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.