IMPROVEMENTS IN THE TREATMENT OF ORES FOR THE. SEPARATION OF THE METALS THEY CONTAIN AND IN THE REDUCTION OF CERTAIN OF THE METALS AND IN APPARATUS EMPLOYED THEREFOR-
Year: 1882

page_text: LETTERS PATENT to Alexander Melville Clark of the firm of A. M and
"
W. Clark of 53, Chancery Lane, in the County of Middlesex, Patent Agents,
for an invention of IMPROVEMENTS IN THE TREATMENT OF ORES FOR THE.
SEPARATION OF THE METALS THEY CONTAIN AND IN THE REDUCTION OF
CERTAIN OF THE METALS AND IN APPARATUS EMPLOYED THEREFOR-A com-
munication from abroad by Amedée Mathurin Gabriel Sébillot of Paris,
PROVISIONAL SPECIFICATION left by the said Alexander Melville Clark
at the Office of the Commissioners of Patents on the 21st April 1882.
ALEXANDER MELVILLE CLARK of the firm of A. M and W. Clark of 53 Chancery
Lane in the County of Middlesex, Patent Agents "IMPROVEMENTS IN THE
TREATMENT OF ORES FOR THE SEPARATION OF THE METALS THEY CONTAIN AND
IN THE REDUCTION OF CERTAIN OF THE METALS AND IN APPARATUS EMPLOYED
23
THEREFOR [A communication from abroad by Amedée Mathurin Gabriel Sébillot
of Paris, France.
This Invention relates to a process and apparatus for effecting the complete
disintegration of minerals in order to separate any metals contained in the ore, and
the process consists mainly in a new method of treatment with sulphuric acid as
hereafter described.
I am aware that sulphuric acid has been used before to some extent for
metallurgical purposes but has generally failed to answer on account of the slowness
of its action, the cost of labor and the wear and tear of apparatus.
In the process or method of treatment of this Invention the sulphuric acid is
used in a concentrated form, with the application of sufficient heat to boil and
distil it, whereby the ores are obtained in the form of matts containing the metals
as sulphates, that is to say in a condition suitable for effecting the separation of
the metals by lixiviation and simple chemical operations.
The process involves three successive steps or operations vic 1st preparation of
the ores 2nd conversion into sulphates; 3rd. separation of the metals.

page_text: Preparation of the ores. This merely consists in pulverizing very finely, except
in the case of sulphurets which are distilled in retorts so as to eliminate the excess
of sulphur and reduce the bisulphide of iron to monosulphide which is readily
attacked by sulphuric acid.
Conversion into sulphate. This operation together with the furnace wherein it
is effected constitute the most important features of the Invention and they will be
described with reference to the accompanying drawings in which figures 1 and 2
represent a sectional elevation and plan and figure 3a cross section on a larger
scale of the apparatus which I term a converter. It consists of a long furnace
heated like a muffle, forming a long gallery of uniform sectional area filled with a
series of trucks capable of containing the mixture of ore and sulphuric acid, and
resting on rails along which they are capable of being moved at intervals for the
purpose of removing one truck at a time from one end when the contents are
dried off, and of adding another truck containing fresh mixture at the other end
of the series. A, B, is the furnace closed at the end by sliding doors M, N. C the
grate. D the chimney and E the trucks. The flames from the grate escape
through the interval between the arch Fand the muffle G which is here represented
as made of cast iron but may be constructed of bricks of proper shape and
materials. At intervals corresponding to the positions of the trucks the muffle is
provided with pipes H to convey the fumes to a condenser K made of lead where
the excess of sulphuric acid is condensed whilst the sulphurous acid passes on
through pipes I to a lead chamber J which is here roughly represented only in
outline but which would-be-constructed according to the latest improvements in
the manufacture of sulphuric acid: The-trucks, containing the mixture-of-ore-and-
sulphuric acid, are constructed of cast iron pans L mounted on wheels, the shape
of the pan or body of the truck being the same as that of the muffe, and the
sides and ends being as close as possible to the surface of the muffle so as to leavo
-a-small interval only sufficient for the admission of the necessary quantity of air
to convert the sulphurous acid into sulphuric acid. Thus the excess of sulphuric
acid used is recovered and that passing off in the form of sulphurous acid is
reconstituted in the lead chamber in which fresh sulphuric acid is also produced in
the ordinary way-by-the-combustion of sulphur or pyrites, in order to compensate
for loss.
The operation is as follows:-Suppose the furnace to contain the proper number
of trucks-say five or more-and that No. is just beginning to be heated
and the others are in successive stages of progress according to the time they have
been in the furnace and the progressive increase of heat from B to A, up to No 1
which is nearly dry. As soon as No 1 is thoroughly dry it must be removed and
the whole series of trucks moved along towards A to make room for another truck
containing a freshly made mixture of ore and sulphuric acid, which is added to the
series at the end B. The doors M N which were temporarily opened for this
purpose are again closed and the operation which has not been interrupted
continues to go on without intermission.
The converted oro contained in the truck which has been withdrawn is then
lixiviated in a set of tanks and the chemical operations are proceeded with, which
it is unnecessary to describe as they are simple and vary according to the character
of the orc.
The solutions will generally contain the soluble sulphates of base metals-such as
the sulphates of zinc and iron-whereas the silver, gold and sulphate of lead, if that
metal be present will remain in the insoluble residue. The copper will for the
most part remain unattacked and if any has been dissolved it is convenient to
precipitate it by means of iron in the tanks themselves so as to have in the residue
silver, copper and gold
These residues are treated again as purified ore, in the same way, and then all
the silver and copper come into solution, and the gold free in the final residue is
recovered by amalgamation
It then remains to treat the sulphates of the base metals iron and zinc. These

page_text: solutions are evaporated and yield matts of vitriol from which the sulphuric acid is
distilled off and collected.
Pure oxides either of iron or of zinc, sometimes of both, remain and a very
important result of the process is that by distillation in large retorts, the oxides aro
obtained in large cakes which harden by the heat and form an artificial ore which
is pure and porous and fit for the extraction of metals which operation is conducted
in the following way forming an integral part of the process as applied to the new
form in which those oxides are obtained.
In consequence of the porosity of the oxides I employ a reducing furnace in
which the oxides are reduced to the metallic state by the action of carbonic oxide.
This reducing furnace is represented in vertical section in figure 4 O is a round
or rectangular shaft containing the. oxides in lumps filled in at the door P from
time to time, the reduced oxides being withdrawn at the bottom through the
doorway Q. The current of carbonic oxide is generated in the furnace R which is
deep enough to produce only carbonic oxide and is charged through the aperture S
the door T being only occasionally opened. The current of carbonic oxide passes
through a flue which encircles the shaft and enters therein through the openings v
and escape through the chimney V. The oxides are thus reduced at a low
temperature by a continuous operation and are therefore converted into spongy
metal retaining a small amount of carbon, and instead of yielding cast iron as
would be the case in an ordinary blast furnace they are in a proper condition to
yield steel at once and of very good quality ns the oxides are chemically pure
When the oxides contain only iron a common cupola furnace capable of producing
a very high temperature is used but it frequently happens that a mixture of oxide
of zine and oxide of iron is produced in which case the furnace is altered as hereafter
described aud shown in figure 5. The cupola furnace is closed at top the charges
of spongy iron and fuel being introduced by means of a bell X. The gases escapo at
Y carrying zine vapors which it is intended to remove and collect. The openings Y
being at a proper height to keep the zinc in the form of vapor the whole of the
guses are conveyed through the pipe Z first to a cast iron kettle W kept at a
temperature sufficient to keep the zinc in a molten state, and afterwards to a
condensing chamber W₁ constructed of masonry in which the fumes are condensed
and may be collected at intervals. The molten zinc is run off at the hole u by;
removing the plug b.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Alexander Melville Clark in the Great Seal Patent Office on
the 21st October 1882.
ALEXANDER MELVILLE CLARK of the firm of A. M. and W. Clark of 53 Chancery
"IMPROVEMENTS IN THE
Lane in the County of Middlesex Patent Agents.
TREATMENT OF ORES FOR THE SEPARATION OF THE METALS THEY CONTAIN, AND
IN THE REDUCTION OF CERTAIN OF THE METALS, AND IN APPARATUS EMPLOYED
THEREFOR." A communication from abroad by Amedée Mathurin Gabriel Sébillot
of Paris, France.
This Invention relates to a process and apparatus for effecting the complete
disintegration of minerals in order to separate any metals contained in the ore, and
the process consists mainly in a new method of treatment with sulphuric acid as
hereafter described. I am aware that sulphuric acid has been used before to some
extent for metallurgical purposes, but has generally failed to answer on account of
-the slowness of its action, the cost of labor, and the wear and tear of apparatus.
In-the-process_or_method of treatment-of-this-Invention, the sulphuric acid is
used in a concentrated form with the application-of-sufficient. hent to boil and
distil it, whereby the ores are obtained in the form of matts containing the metals
as sulphates, that is to say, in a condition suitable for effecting the separation of
the metals by lixiviation and simple chemical operations. The process involves
threo-successive-steps.or operations, viz (1) Preparation of the ores; (2) Conversion
into sulphates; (3) Separation of the metals.
Preparation of the Ores. This-merely consists in pulverising very finely, except
in the case of sulphurets which are calcined in retorts so as to eliminate the excess
of sulphur and reduce the bisulphide-of-iron_to_monosulphide which is readily
attacked by sulphuric acid.
Conversion into Sulphate. This operation together with the furnace wherein it
is effected constitute the next important features of the Invention, and they will
be described with reference to the accompanying drawings, in which Figures
and 2 represent a sectional elevation and plan, and Figure 3 a cross section on a
larger scale of the apparatus which 1 term a converter. It consists of a long
furnace heated like a muflle, forming a long gallery of uniform sectional area fillerl
with a series of trucks capable of containing the mixture of ore and sulphuric acid,
and resting on rails along which they are capable of being moved at intervals for
the purpose of removing one truck at a time from one end when the contents are
dried off, and of adding another truck containing fresh mixture at the other end
of the series. A B is the furnace closed at the end by sliding doors M N, C the
grate, D the chimney, and E the trucks. The flames from the grate escape through
the interval between the arch F and the muffle G which is hero represented as
made of cast iron but may be constructed of bricks of proper shape and materials.
At intervals corresponding to the positions of the trucks, the muffle is provided
with pipes H to convey the fumes to a condenser K made of lead where the excess
of sulphuric acid is condensed whilst the sulphurous acid passes on through pipes I
to a lead chainber J which is here roughly represented only in outline, but which
would be constructed according to the latest improvements in the manufacture of
sulphuric acid. The trucks containing the mixture of ore and sulphuric acid are
constructed of cast iron pans L mounted on wheels, the shape of the pan or body
of the truck being the same as that of the muffle, and the sides and ends being as
close as possible to the surface of the muffle so as to leave a small interval only
sufficient for the admission of the necessary quantity of air to convert the

page_text: sulphurous acid into sulphuric acid. Thus the excess of sulphuric acid used is
recovered, and that passing off in the form of sulphurous acid, is reconstituted in
the lead chamber in which fresh sulphuric acid is also produced in the ordinary
way by the combustion of sulphur or pyrites, in order to compensate for loss.
The operation is as follows:-Suppose the furnace to contain the proper number
of trucks say five or more, and that No. 5 is just beginning to be heated and the
others are in successive stages of progress according to the time they have been in
the furnace and the progressive increase of heat from B to A, up to No 1 which is
nearly dry. As soon as No 1 is thoroughly dry, it must be removed and the
whole series of trucks moved along towards A to make room for another truck
containing a freshly made mixture of ore and sulphuric acid which is added to the
series at the end B. The doors M N which were temporarily opened for this
purpose are again closed and the operation which has not been interrupted,
continues to go on without intermission.
The converted ore contained in the truck which has been withdrawn, is then
lixiviated in a set of tanks and the chemical operations which it is unnecessary to
describe as they are simple and vary according to the character of the ore, are
proceeded with.
The solutions will generally contain the soluble sulphates of base metals, such as
the sulphates of zinc and iron, whereas the silver, gold, and sulphate of lead, if
that metal be present, will remain in the insoluble residue. The copper will for
the most part romain unattacked, and if any has been dissolved, it is convenient to
precipitate it by means of iron in the tanks themselves so as to have in the
residue silver, copper, and gold.
These residues are treated again as purified ore in the same way and then all
the silver and copper come into solution, and the gold free in the final residue is
recovered by amalgamation.
It then remains to treat the sulphates of the base metals iron and zinc. Theso
solutions are evaporated and yield inatts of vitriol from which the sulphuric acid is
distilled off and collected
Pure oxides either of iron or of zinc, sometimes of both, remain and a very
important result of the process is that by distillation in large retorts the oxides
are obtained in large cakes which harden by the heat and form an artificial ore
which is pure and porous and fit for the extraction of metals, which operation is
conducted in the following way forming an integral part of the process as applied
to the new form in which those oxides are obtained.
In consequence of the porosity of the oxides, I employ a reducing furnace in
which the oxides are reduced to the metallic state by the action of carbonic oxide.
This reducing furnace is represented in vertical section in Figure 4. U is a round
or rectangular shaft containing the oxides in lumps filled in at the door P from
time to time, the reduced oxides being withdrawn at the bottom through the door-
way Q. The current of carbonic oxide is generated in the furnace R which is
deep enough to produce only carbonic oxide and is charged through the aperture S,
the door at T being only occasionally opened. The current of carbonic oxide
passes through a flue which encircles the shaft and enters therein through the
openings O and escape through the chimney V. The oxides are thus reduced at a
low temperature by a continuous operation and are therefore converted into spongy
metal retaining a small amount of carbon and instead of yielding cast iron as
would be the case in an ordinary blast furnace, they are in a proper condition to
yield steel at once, and of very good quality as the oxides are chemically pure.
When the oxides contain only iron, a common cupola furnace capable of
producing a very high temperature is used, but it frequently happens that a
mixture of oxide of zinc and oxide of iron is produced, in which case the furnace
is altered as hereafter described and shown in Figure 5. The cupola furnace is
closed at top, the charges of spongy iron and fuel being introduced by means of a
bell X. The gases escape at Y carrying zinc vapors which it is intended to
remove and collect. The openings Y being at a proper height to keep the zinc in

page_text: the form of vapor, the whole of the gases are conveyed through the pipe Z first to
a cast iron kettle W kept at a temperature sufficient to keep the zinc in à molten
state, and afterwards to a condensing chamber W constructed of masonry in
which the fumes are condensed and may be collected at intervals. The molten
zinc is run off at the hole a by removing the plug b.
Having described the nature of the said Invention and the manner of performing
the same, I declare that what I claim as the Invention to be protected by the
herein before in part recited Letters Patent is.
1st. The herein described process having for its object the complete disintegration
of minerals in order to obtain the metals contained in the ore in a separate state,
the said process being based on the employment of concentrated sulphuric acid
brought to such a temperature as will boil and distil the same.
2nd. The herein described process consisting in the following steps or
operations: (1) preparation of the ore by pulverising, (2) conversion into
sulphates, and (3) separation of the metals, the whole substantially as specified.
3rd. The apparatus for effecting the conversion of the ore into sulphates and
recovering the sulphurous and sulphuric acid gases, constructed substantially as
described and shown in the drawings.
4th. Reducing the oxide of iron by a continuous operation in a furnace
constructed substantially as described, and the production by subsequent smelting,
of steel as specified.
5th. The furnace for the treatment of the mixture of oxide of zinc and of iron
to separate-the-zinc-from-the-iron,-constructed as described.
In witness whereof T the said Alexander Melville-Clark-have.bercunto
set my hand and seal this nineteenth day of October, A.D. 1882.