I PROVEMENTS IN THE TREATMENT OF COPPER ORES IN THE MANUFACTURE OF COPPER
Year: 1865

page_text: LETTERS PATENT to William Clark, of 53, Chancery Lane, in the County:
of Middlesex, Engineer and Patent Agent, for the Invention of. "I
PROVEMENTS IN THE TREATMENT OF COPPER ORES IN THE MANUFACTURE OF
COPPER." A communication from abroad by Frédéric Le Clerc, Doctor
of Medicine, of 29, Boulevart St. Martin, Paris.
PROVEMENTS IN THE TREATMENT OF COPPER ORES IN THE MANUFACTURE OF
COPPER." A communication from abroad by Frédéric Le Clerc, Doctor
of Medicine, of 29, Boulevart St. Martin, Paris.
Sealed the 10th April 1866, and dated the 16th October 1865.
PROVISIONAL SPECIFICATION left by the said William Clark at the
Office of the Commissioners of Patents, with his Petition, on the 16th.
October 1865.
I, WILLIAM CLARK, of 53, Chancery Lane, in the County of Middlesex,
Engineer and Patent Agent, do hereby declare the nature of the said Inven-
tion for "IMPROVEMENTS IN THE TREATMENT OF COPPER ORES IN THE MANUFACTURE
OF COPPER," to be as follows:-
The ore is first broken into pieces and roasted in a reverberatory furnace.
The heat is slowly applied at first, to prevent the ore from adhering together,
and immediately a red heat is attained I project water over the surface of the
heated mass. The water is introduced under pressure through a narrow
opening in such manner that it falls in the form of a fine rain wherever it
may be projected. When the white vapours cease to disengage the heat is
increased, so as to effect the fusion of the mass, after which it is run off, a
"matt" of a very white color being obtained.

page_text: Secondly, the white matt is broken in pieces and roasted in a reverberatory
furnace in presence of a large amount of air; the heat is first slowly applied,
in order to prevent the fusion of the mass, and immediately a red beat is
obtained I project water in the form of a fine rain on the mineral mass, care
being taken to well stir and subdivide it with a stirrer in order that the water
shall act on the greatest possible number of points.
Immediately copper appears in a metallic state the above roasting process
is repeated until the larger pieces of matt have become transformed into
metallic copper, which is rapidly effected. The addition of from one to two
per cent. of coal in powder to the mass while at a red heat facilitates the
roasting, although it is not absolutely necessary. The condition of the
matters may be ascertained by withdrawing some of the large pieces from
the furnace and breaking them. The roasting should be continued until
these pieces indicate the presence of copper in a metallic state, at which
time the heat is increased, so as to effect the fusion of the mass, and a
mixture is added of powdered charcoal or coke, lime, or other calcareous
matter, after which the whole is well agitated and mixed as completely as
possible.
Thirdly, a considerable chemical action will now be produced in the
metallic bath. The supernatant scoria is removed by the aid of a suitable
instrument, and air admitted without delay into the interior of the metallic
bath.
After numerous experiments on a comparatively large scale I have found
that the action of steam, as previously employed, in concurrence with air is
entirely useless, as the inflation or injection of air into the bath, which may
be effected in any suitable manner, will succeed perfectly by employing a tube
of refractory clay. The enormous chemical action produced by the injection
of air into the metallic bath generally exceeds the degree of oxidation
required, for which reason recourse should be had finally to charcoal and
wood poles for stirring.
The copper is tested from time to time until the metal assumes a red tint
and the silky appearance and malleability desired, after which the melted
metal is run into suitable apparatus so arranged as not to permit of the
action of air on the metal in fusion, and having only one opening for the
introduction of the metal. In this manner copper may be produced not only
of commercial value, but suitable for rolling direct from the ore.
In the foregoing I have supposed the ore "mousaïa" of Algeria to be
employed, containing from seven to ten per cent. of pure metal; but when
treating grey copper of greater purity the metal may be obtained in a single

page_text: operation; for this purpose the raw ore is first melted and the slag removed,.
immediately on which the injection of air into. the metallic bath should
commence.
The production of copper in a chemical point of view may be reduced to
two distinct operations, viz., 1st, oxidation by the action of the water and
air; 2ndly, deoxidation by the action of charcoal.
First, as regards oxidation.-Water falling in a subdivided state on the
mineral mass at a red heat, as before described, during the roasting of the
ore, and also afterwards brought in contact with the matt heated to a high
temperature, in both cases becomes decomposed, its oxygen, acting on the
sulphur, arsenic, and antimony produces sulphurous acid, arsenious acid, and
antimonious acid, which are all disengaged, while its hydrogen unites with
the sulphur, arsenic, and antimony, and forms sulphuretted, arseniated, and
antimoniated hydrogen, which becomes disengaged. I should add that in
the presence of protoxide of copper formed there is produced a certain
quantity of silicate of alumina and of oxysulphuret of antimony more or less
charged with arsenic and copper, the silicate forming on the sides of the
furnace, and in order to destroy it I add a mixture of charcoal and lime, by
means of which the silicate of copper may be readily reduced.
Secondly, as regards deoxydation.-The air injected into the metallic bath
may produce arseniate and antimoniate of copper, and silicate of oxysulphuret
of antimony and copper, for which reason it is advisable towards the end of
the operation to employ charcoal and wood stirrers, with a view to prevent
oxidation.
The improvements herein described may be employed for the treatment of
all kinds of copper ore as well as that of grey copper, that is, to copper
pyrites and oxide of copper ore, and carbonate of copper, more or less
combined with metallic copper known under the name of corocoro.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Clark in the Great Seal Patent Office on the
14th April 1866.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
CLARK, of 53, Chancery Lane, in the County of Middlesex, Engineer and
Patent Agent, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Sixteenth day of October, in the year of our

page_text: Lord One thousand eight hundred and sixty-five, in the twenty-ninth year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said William Clark, Her special licence that I, the said William Clark,
my executors, administrators, and assigns, or such others as I, the said
William Clark, my executors, administrators, and assigns, should at any time
agree with, and no others, from time to time and at all times thereafter
during the term therein expressed, should and lawfully might make, use,
exercise, and vend, within the United Kingdom of Great Britain and Ireland,
the Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN
THE TREATMENT OF COPPER ORES IN THE MANUFACTURE OF COPPER," a com-
munication to me from abroad by Frédéric Le Clerc, Doctor of Medicine,
of 29, Boulevart St. Martin, Paris, upon the condition (amongst others)
that I, the said William Clark, my executors or administrators, by an
instrument in writing under my, or their, or one of their hands and
seals, should particularly describe and ascertain the nature of the said
Invention, and in what manner the same was to be performed, and cause
the same to be filed in the Great Seal Patent Office within six calendar
months next and immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said William Clark, do hereby declare the
nature of the said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement (that is to say) :-
The ore is first broken into pieces and roasted in a reverberatory furnace.
The heat is slowly applied at first, to prevent the ore from adhering together,
and immediately a red heat is attained I project water over the surface of the
heated mass. The water is introduced under pressure through a narrow
opening in such manner that it falls in the form of fine rain wherever it may
be projected. When the white vapours cease to disengage the heat is
increased so as to effect the fusion of the mass, after which it is run off, a
matt of a very white color being obtained.
Secondly, the white matt is broken into pieces and roasted in a reverberatory
furnace in the presence of a large amount of air; the heat is first slowly
applied in order to prevent the fusion of the mass, and immediately a red
heat is obtained I project water in the form of fine rain on the mineral mass,
care being taken to well stir and subdivide it with a stirrer, in order that the
water shall act on the greatest possible number of points.
Immediately copper appears in a metallic state the above roasting process
is repeated until the larger pieces of matt have become transformed into
metallic copper, which is rapidly effected. The addition of from one to two

page_text: per cent. of coal in powder to the mass while at a red heat facilitates the
roasting, although it is not absolutely necessary. The condition of the matters
may be ascertained by withdrawing some of the larger pieces from the furnace
and breaking them. The roasting should be continued until these pieces
indicate the presence of copper in a metallic state, at which time the heat is
increased so as to effect the fusion of the mass, and a mixture is added of
powdered charcoal, or coke, lime, or other calcareous matter, after which the
whole is well agitated and mixed as completely as possible.
Thirdly, a considerable chemical action will now be produced in the
metallic bath. The supernatant scoria is removed by the aid of a suitable
instrument, and air admitted without delay into the interior of the metallic.
bath.
After numerous experiments on a comparatively large scale I have found
that the action of steam, as previously employed, in concurrence with air is
entirely useless, as the injection of air into the bath, which may be effected in
any suitable manner, will succeed perfectly by employing a tube of refractory
clay. The enormous chemical action produced by the injection of air into the
metallic bath generally extends the degree of oxidation required, for which
reason recourse should be had finally to charcoal and wood poles for stirring.
The copper is tested from time to time until the metal assumes a red tint and
the silky appearance and malleability desired, after which the melted metal is
run into suitable apparatus so arranged as not to permit of the action of air
on the metal in fusion, and having only one opening for the introduction of
the metal. In this manner copper may be produced not only of commercial
value, but suitable for rolling direct.
In the foregoing I have supposed the ore mousaïa of Algeria to be employed
containing from seven to ten per cent. of pure metal; but when treating grey
copper of greater purity the metal may be obtained in a single operation; for
this purpose the raw ore is first melted and the slag removed, immediately on
which the injection of air into the metallic bath should commence.
. The production of copper in a chemical point of view may be reduced to
two distinct operations, viz., 1st, oxidation by the action of water and air;
2ndly, deoxidation by the action of charcoal.
First, as regards oxidation.-The water falling in a subdivided state on the
mineral mass at a red heat, as before described, during the roasting of the ore,
and also afterwards brought into contact with the matt heated to a high tem-
perature, in both cases becomes decomposed, its oxygen acting on the sulphur,
arsenic, and antimony produces sulphurous and arsenious acids, and anti-
monious acid, which are all disengaged, while its hydrogen unites with the

page_text: sulphur, arsenic, and antimony, and forms sulphuretted, arseniated, and
antimoniated hydrogen, which also becomes disengaged. I should add that
in the presence of the protoxide of copper formed there is produced a certain
quantity of silicate of alumina and of oxysulphuret of antimony more or less
charged with arsenic and copper, the silicate forming on the sides of the
furnace, and in order to destroy.it I add a mixture of charcoal and lime, by
means of which the silicate of copper may be readily reduced.
Secondly, as regards deoxydation. The air injected into the metallic bath
may produce arseniate and antimoniate of copper and silicate of oxysulphuret
of antimony and copper, for which reason it is advisable towards the end
of the operation to employ charcoal and wood stirrers, with a view to prevent
oxidation.
The improvements herein described may be employed for the treatment of
all kinds of copper ore as well as that of grey copper, that is, to copper
pyrites and oxide of copper ore and carbonate of copper, more or less combined
with metal copper, known under the name of corocoro.
Having described the nature of this Invention, and the manner of per-
forming the same, I declare that what I claim as the Invention to be protected
by the herein-before in part recited Letters Patent is,―
First, reducing the matt by the simultaneous action of air and cold water
injected in a fine shower, the matt being raised to a high temperature. The
water under the influence of the sudden transition from a low to a much
higher temperature disaggregates the fragments of matt, thus allowing the
air to penetrate to their very centre, and causing a consequent production of
arsenious, antimonious, and sulphurous acids, which are evolved in the form of
vapors. Moreover in case of matt extracted from grey copper ores the water
further exerts an action by preventing said matt from melting, which condition
has the peculiar property of immediately arresting the action of the air,
and consequently of oxidation, without which there can be no reduction of
the matt.
Secondly, the injection of air into the interior of the black impure copper
bath resulting from the roasting process. The air injected into the metallic
bath causes a rapid production of protoxide of copper, and a consequent
decomposition of sulphurets of copper, arsenic, and antimony, sulphurous acid
is also evolved and metallic copper produced. Besides the sulphurets above s
mentioned scoria forms on the furnace sides, which is composed of silicate of
alumina and oxysulphuret of antimony, more or less charged with arsenic.
Thus in a very short time copper is produced which is as pure as that
ordinarily produced in slabs or sheets. The copper thus produced contains no

page_text: sulphur, iron, lead, or tin, and retains like most sheet coppers but a small
proportion of antimony. A like result may be obtained by injecting com-
pressed air on to the surface of the metallic bath, but in this case the bath
should be cleared absolutely of scoria, the operation being effected much more
slowly than when air is injected into the bath. The air may be introduced
into the copper bath through a fire-clay tube, but the most practical means is
to convey the compressed air through a pipe placed within the furnace bridge,
and leading by branch tubes to the bottom of the metal bath.
In witness whereof, I, the said William Clark, have hereunto set my
hand and seal, this Fourteenth day of April, in the year of our Lord
One thousand eight hundred and sixty-six.
Witness,
53, Chancery Lane,
London.
W. CLARK. (L.S.)