IMPROVEMENTS IN REFINING COPPER
Year: 1867

page_text: LETTERS PATENT to Alexander Melville Clark, of 58, Chancery Lane, in
the County of Middlesex, for the Invention of "IMPROVEMENTS IN REFINING
COPPER." A communication from abroad by Frédéric Le Clerc, Doctor
PROVISIONAL SPECIFICATION left by the said Alexander Melville Clark
at the Office of the Commissioners of Patents, with his Petition, on the
15th November 1867.
I, ALEXANDER MELVILLE CLARK, of 53, Chancery Lane, in the County of
Middlesex, do hereby declare the nature of the said Invention for "IMPROVE
MENTS IN REFINING COPPER," to be as follows:-
This Invention relates to an improved process of refining copper. Black
copper in a more or less impure condition is subjected to the action of heat
in a reverberatory furnace as in ordinary, and immediately the metallic masses
have reached a sufficiently high temperature to begin to soften, water is pro-
jected on the heated metallic mass in the form of very fine jets or small rain,
until the complete fusion of the metal is obtained when the supply of water
is stayed. Supposing the coppery masses subjected to the action of heat
contain copper, iron, sulphur, arsenic, antimony, lead, or tin, under the
influence of the high temperature, the water on coming in contact is decom-
posed and forms sulphuretted, arseniated, or antimoniated hydrogen which

page_text: disengages; the oxygen acts on the copper, iron, or other fixed metals and
forms oxides, which derive silica from the sides of the furnace and pass into
the form of scoria. I would also add that a small amount of sulphuric,
arsenious, and antimonious acid is produced, which disengages in the form
of vapor. Immediately the copper is completely fused I place a tube of
refractory clay in the metallic bath, the diameter of which tube is propor-
tionate to the quantity of copper forming the bath. This being done, I project
a large amount of atmospheric air through the tube, when an extremely active
reaction is produced, and the refining is operated in a very short time, often in
a few minutes only when the copper to be refined is not very impure. The
air may be introduced into the midst of the copper bath in various ways, but
the most practical mode I find is to pass it through the tube before mentioned
at the centre of the roof of the furnace. This tube may be readily raised out
of the bath when it is not required to introduce air, and it always remains at
a sufficiently high temperature to prevent its breaking, as it would do were it
subject to sudden variation of temperature. It is essential that the treatment
should extend beyond the period of oxidation, and when the metal on exami-
nation is found to be of a deep or brick red color the refining is complete,
after which the metal is treated exactly as in ordinary.
Theory. The bath of metallic copper, although much purer than at the
commencement of the operation, still contains sulphur, arsenic, antimony, and
iron. Under the influence of the air introduced into the bath an excessively
active oxidation takes place whereby the sulphurous, arsenious, and antimo-
nious acids are disengaged, oxides of copper and iron being also produced in
the form of scoria. Combinations of oxisulphuret of copper and antimony are
also obtained more or less arseniated. An important point to be noted, which is
also well known, is that by exceeding the oxidation, which may be readily
done, a large quantity of oxide of copper may be obtained which has the
property of giving up its oxygen to foreign matters, and in this manner
conduces to the reduction of the copper.
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 14th May 1868.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ALEXANDER
MELVILLE CLARK, of 53, Chancery Lane, in the County of Middlesex, send
greeting

page_text: WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters:
l'atent, bearing date the Fifteenth day of November, in the year of our
Lord One thousand eight hundred and sixty-seven, in the thirty-first year.
of Her reign, did, for Herself, Her heirs and successors, give and grant.
unto me, the said Alexander Melville Clark, Her special licence that I, the
said Alexander Melville Clark, my executors, administrators, and assigns, or;
such others as I, the said Alexander Melville Clark, my executors, adminis-
trators, 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 In-
vention for "IMPROVEMENTS IN REFINING COPPER," a communication 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
Alexander Melville Clark, my executors or administrators, by an instrument
in writing under my, or their, or one of their hands and seals, should par-
ticularly 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 Alexander Melville Clark, do hereby
declare the nature of the said Invention, and in what manner the same iş
to be performed, to be particularly described and ascertained in and by the
following statement (that is to say) :-
This Invention relates to an improved process of refining copper. Black
copper in a more or less impure condition is subjected to the action of heat in
a reverberatory furnace as in ordinary, and immediately it has reached a suffi-
ciently high temperature to begin to soften, water is projected on the heated
metallic mass in the form of very fine jets or small rain until the complete
fusion of the metal is obtained, when the supply of water is stayed. Supposing
the cupreous mass subjected to the action of heat contain copper, iron,
sulphur, arsenic, antimony, lead, or tin under the influence of the high tem-
perature the water on coming in contact is decomposed and forms sulphuretted,
arseniated, or antimoniated hydrogen which disengages; the oxygen acts on
the copper, iron, and other fixed metals and forms oxides which derive silica
from the sides of the furnace and pass into the form of scoria. I would also
add that a small amount of sulphuric, arsenious, and antimonious acid is
produced which disengages in the form of vapor. Immediately the copper is
completely fused I place a tube of refractory elay in the metallic bath, the

page_text: diameter of which tube is proportionate to the quantity of copper forming the
bath. This being done I project a large amount of atmospheric air through
the tube when an extremely active reaction is produced, and the refining is
operated in a very short time, often in a few minutes only when the copper
to be refined is not very impure. The air may be introduced into the midst
of the copper bath in various ways, but the most practical mode I find is to
pass it through the tube before mentioned at the centre of the roof of the
furnace. This tube may be readily raised out of the bath when it is not
required to introduce air, and it always remains at a sufficiently high tem-
perature to prevent its breaking, as it would do were it subject to sudden
variations of temperature. It is essential that the treatment should extend
beyond the period of oxidation, and when the metal on examination is found
to be of a deep or brick red color the refining is complete, after which the
metal is treated exactly as in ordinary.
Theory. The bath of metallic copper, although much purer than at the
commencement of the operation, still contains sulphur, arsenic, antimony, and
iron. Under the influence of the air introduced into the bath excessive oxida,
tion takes place whereby the sulphurous, arsenious, and antimonious acids are
disengaged, oxides of copper and iron being also produced in the form of
scoria. Combinations of oxisulphuret of copper and antimony are also
obtained more or less arseniated. An important point to be noted, which is
also well known, is that by extending the oxidation, which may be readily
done, a large quantity of oxide of copper may be obtained, which has the
property of giving up its oxygen to foreign matters and in this manner
conduces to the reduction of the copper. The production of the protoxide of
copper in superabundant quantity necessarily causes a considerable loss of
copper, which combine under the form of complex silicate of iron and oxysul-
phuret of antimony, more or less arsenical, formed by the influence of the air
insufflated into the metallic bath. For this reason, when after having
introduced the air, as before described, the metal assumes a deep brick red
color, I take the precaution to add to the bath a mixture of from two to five
per cent. of charcoal and lime, or charcoal and limestone, and well stir them.
In this manner I obtain the complete reduction of the silicate, as above
mentioned, all loss of copper is thus entirely prevented. Immediately
following the action of this mixture the refining process is proceeded with
as in ordinary.
Having described the nature of this Invention, and the manner of performing
the same, I declare that what I claim as the Invention to be protected by the
berein-before in part recited Letters Patent is,-

page_text: 1st. The application of air insufflated into the bath of copper for effecting
the expeditious refining of copper, as herein-before described.
2ndly, I claim the reduction of the silicate of copper by the aid of a
mixture of lime and charcoal or of limestone and charcoal, as before
described.
In witness whereof, I, the said Alexander Melville Clark, have hereunto
set my hand and seal, this Fourteenth day of May, in the year of our
Lord One thousand eight hundred and sixty-eight.
A. M. CLARK. (L.B.)