IMPROVEMENTS IN THE MANUFACTURE AND TREATMENT OF COPPER AND OF ALLOYS OF COPPER
Year: 1880

page_text: LETTERS PATENT to John Henry Johnson, of 47, Lincoln's Inn Fields, in the
County of Middlesex, Gentleman, for an Invention of "IMPROVEMENTS IN
THE MANUFACTURE AND TREATMENT OF COPPER AND OF ALLOYS OF COPPER."
A communication from abroad by Pierre Manhes, of Paris, in the Republic of
T
PROVISIONAL SPECIFICATION left by the said John Henry Johnson at the
Office of the Commissioners of Patents on the 3rd August 1880.
JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex,
Gentleman. "IMPROVEMENTS IN THE MANUFACTURE AND TREATMENT OF COPPER
AND OF ALLOYS OF COPPER." A communication from abroad by Pierre Manhes,
of Paris, in the Republic of France.
This Invention relates to improvements in the manufacture of copper from its
ores and other cupreous substances, and it has for its object reducing the cost of
treating sulphurous copper ores, by enabling the series of alternate roastings and
fusions which are involved by the systems of treatment heretofore employed to
be dispensed with, and is also applicable to the treatment of other sulphurous and
non sulphurous cupreous materials, it being however necessary to render the said
non-sulphurous materials sulphurous before submitting them to the improved
treatment.
The said improved treatment is based upon chemical reactions of the same
nature as are produced in the treatment of cast iron by the well known Bessemer
process, and it is preferred to employ for the purposes of this Invention a Bessemer
converter, such as is ordinarily employed for the treatment of iron, but the operation
may however be effected in the bed of any suitable furnace.
In carrying out this Invention when applied to the treatment of sulphurous
copper ores, for example, the ore is reduced or melted without submitting it to a
preliminary roasting process. This reduction may be effected in any suitable
melting furnace, but it is preferred to employ a cupola or half bigh blast furnace
for this purpose, and it has for its object the elimination of the earthy gangues by
the formation of slag or cinder, and concentrating the metallic parts into a matt
rn

page_text: more or less rich in copper, but also containing iron and a large proportion of
sulphur.
The liquid matt thus obtained is run direct from the melting furnace into the
converter, which is previously heated to the requisite temperature, and the
manipulation of the converter, the admission and pressure of the blast of air, are
regulated and conducted in the same manner as when cast iron is treated by the
Bessemer process.
The air passing through the matt quickly produces a great elevation of
temperature by the combustion of the sulphur in the first place, and afterwards
of the iron and other metals which are more readily oxidised than copper.
The oxidising action becomes more effective as it takes place throughout the
entire mass of the fused matt; the sulphur is eliminated by the rapid generation
of sulphurous acid, together with the other volatile substances present, such as
arsenic, antimony, and the like; iron which is rapidly burnt and oxidised becomes
converted into silicate on coming in contact with the earthy substances forming
the lining of the converter, with the assistance if required of silicious fluxes, and a
scoriæ is formed which floats upon the surface of the fused metal and is removed
in the usual manner.
This operation, which lasts for a short time only, is known to be completed when
the sulphurous vapours have entirely disappeared, and a sample taken from the
converter indicates that the product consisting of crude copper is sufficiently
purified to enable it to be refined in the usual manner.
After removing the scoriæ the crude copper thus obtained is refined, as hereinafter
described, or is moulded into blocks or conducted directly to a suitable refining
furnace previously heated, in order to obviate the necessity for remelting the
metal.
The scoris removed from the converter still contain copper in the state of oxide
and grains, and the portions which after sifting are found to be too rich to be
discarded are treated in a subsequent operation in the converter, or are melted
separately in a cupola furnace with suitable fluxes, in order to produce black
copper, whilst the oxide of iron in the scoriæ is available as a flux in the fusion of
ores and other quartzose substances.
Oxidised, carbonated, and other cupreous ores and materials may be advan-
tageously treated according to this Invention, as well as sulphurous copper ores,
matts, regulus, and the like, by previously converting them into matts by fusion
and sulphurisation.
One of the advantages of the improved process is that it enables copper of very
good quality to be obtained even from materials which, when treated by the
ordinary processes, only yield very inferior description of copper, such, for example,
as the grey coppers, arsenical or antimoniacal ores, and the like, as it will be readily
understood that the elevated temperature and the powerful oxidising action that
takes place in the converter are eminently favourable to the elimination of arsenic
and antimony.
When treating matts containing a large proportion of iron, the earthy lining of
the converter is liable to be rapidly destroyed by the corrosive action of the
'scoriæ produced and occasion serious accidents; it is therefore advisable to construct
the lining with basic materials, such as lime, magnesia, and the like but in this
case it is necessary to introduce a suitable proportion of a silicious flux into the
matt in the converter in order to scorify the oxides produced.
In order to convert the cupreous matt directly into refined copper ready for
hammering, rolling, or other like operations, the matt is first converted into crude
copper, as herein before described, and after the scoriæ floating on the surface of the
metal has been removed, a sample is taken out and broken in order to ascertain
the chemical condition of the metal by an inspection of the fracture. When the
fracture being reddish, purple, and granular, indicates that the copper holds a
certain proportion of protoxide, it may be concluded that the foreign matter is

page_text: completely eliminated, and that the reduction of the protoxide in order to render
the metal malleable may be proceeded with, as hereinafter described.
When on the other hand the metal does not present the indications of pure
copper, it is necessary to repeat the process of oxidation until it is brought to the
desired degree of purity; for this purpose air is again blown into the converter,
and the progress of the oxidation being watched by taking samples a few minutes
will suffice to remove all the remaining impurities from the copper.
In case the last remaining foreign substances are not of a nature fitted to support
the inter molecular combustion, the copper will immediately set or solidify on
contact with the air blown into the converter. In order to prevent the copper
from setting from this cause a small quantity of pulverized sulphur is introduced
along with the blast and is burnt in the mass of metal, so as to maintain the
requisite degree of heat, being subsequently eliminated in the form of sulphurous
acid; this sulphur does not interfere materially with the oxidation of the other
metallic substances, as there is always a considerable excess of oxygen in the blast.
Carbon dust may be employed in lieu of the sulphur, but the latter
account of the reducing action of the carbon.
preferable on
In order to render the copper malleable by reducing the protoxide with which
it is impregnated, the scum is removed and a few shovelsful of wood charcoal in
small pieces are thrown in at the mouth of the converter so as to cover the metal,
after which a considerable quantity of wood charcoal in the form of powder is
blown in along with the blast; this charcoal not only exercises a powerful
reducing action, but also serves to raise the temperance considerably, and to
maintain the metal at the proper degree of heat until the whole of it is run out of
the vessel. The progress of the reduction is watched by taking samples, and when
the copper, although not malleable, commences to present a closer grain and paler
colour, the converter is again placed in the horizontal position and the blast
stopped, after which the refining is completed in the same manner as in an ordinary
furnace by means of a pole of green wood.
This novel mode of refining is applicable to the treatment of all descriptions of
crude copper, it being simply necessary to fuse the metal in any suitable furnace
in order to run it into the converter in a fluid condition.
Bronze, brass, old tinned copper, and crude copper which contain neither
sulphur nor iron, may also be refined according to this Invention by adding
sulphur to them before the operation, or by introducing pulverised sulphur or
carbon along with the blast.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Henry Johnson in the Great Seal Patent Office on the 29th
January 1881.
JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex,
Gentleman. "IMPROVEMENTS IN THE MANUFACTURE AND TREATMENT OF COPPER
AND OF ALLOYS OF COPPER." A communication from abroad by Pierre Manhes,
of Paris, in the Republic of France.
This Invention relates, first, to a process which has for its special object to
cheapen and facilitate the treatment of sulphurized copper ores by suppressing the
repeated roasting and fusions which take place in the processes which are actually
in use; it may also be applied, with advantage, to the treatment of all other
materials containing copper after they have been sulphurized.
The process is based upon chemical reactions of the same kind as those which
take place when pig-iron is treated by the "Bessemer" process, and though the
operation can be carried on in any kind of furnace or retort I prefer to employ the
"Bessemer" converter as used in the metallurgy of iron.
Taking as an example the treatment of sulphurous copper ores, I proceed as
follows, that is to say :-
Without any preliminary roasting the ore is submitted to simple smelting in any
suitable furnace, but preferably in a cupola-furnace or a half-high furnace. This
smelting has for its object to eliminate the earthy matters by forming a dross or
scorire, and concentrating the metallic parts into a matte, which is more or less rich
in copper, but always contains iron and much sulphur.
The molten metal is run directly from the smelting furnace into the converter,
which must be previously heated. The manipulation of the converter, the manner
of introducing the blast and its pressure, are regulated and conducted as usual
in the treatment of pig-iron by the "Bessemer process, and need not now be
described.
"
The passage of the blast through the molten matte immediately causes a con-
siderable rise in the temperature by reason of the combustion, first, of the sulphur,
and then of the iron and other metals which oxidize more readily than copper;
the oxidation will increase in energy as it extends throughout the mass of the
molten matte; the elimination of the sulphur is attended by a violent liberation of
sulphurous acid, and a similar netion takes place with regard to the arsenic,
antimony, and other volatile substances. The rapidly burnt or oxidized iron is
transformed into silicate by contact with the earthy matters which exist in the
lining of the converter, this transformation being assisted, if necessary, by the
addition of silicious fluxes, consequently a scoria is formed which floats on the
molten metal, and which is removed by the ordinary methods.
The above described operation requires but little time, the product thereof is
crude copper which may be treated by the ordinary refining processes; the completion
of the said operation is indicated by the almost entire disappearance of the
sulphurous vapors, when a sample taken from the converter shews that the crude
copper is sufficiently purified to be fined without difficulty.
After the scoria has been removed the crude copper may be run into ingots;
or it may be more advantageously run directly into a previously heated fining
furnace if the refining is to be effected at once, thereby obviating the necessity of
remelting.
The scoriæ from the converter always contain copper in the form of oxide and of
slag-cobs; they are therefore sorted, and those which are too rich to be thrown
away are either again treated in a subsequent operation, or they are melted
separately to make black copper.

page_text: By this process I can very economically treat, not only sulphurous copper-ores,
mattes, copper-regulus, and the like, but also mineral and other matters (which may
be oxidized, carbonized, or the like) containing copper, and these I first transform
into crude copper by simple sulphurous fusion.
very
As I have above stated the scorise of the converter always contain copper, and it
is desirable to cause them to undergo a fusion with suitable fluxes in the cupola
furnace; by this operation black copper is obtained and also dross, which
poor and fit only to be thrown away, and as the scoriæ of the converter are always
very rich in oxide of iron they may, with advantage, be used as fluxes for ores and
quartzy matters.
Another advantage of my process is that it allows the obtention of copper of very
good quality from materials which, by ordinary processes, yield but very inferior
copper, such, for instance, as grey copper ores, arsenical or antimonial ores, and the
like. The high temperature and the energetic oxidising action produced in the
converter are eminently favorable to the elimination of arsenic and antimony.
When mattes containing a great proportion of iron are treated the scoriæ
produced would exert a very energetic corrosive action upon the ordinary earthy
lining of the converter, which would thus be quickly destroyed, and serious
accidents might result therefrom. It is, in such cases, advisable to make the lining
of the converter with some basic material, such as lime, magnesia, or the like, and
I add to the matte in the converter a convenient proportion of some silicious flux
which is capable of scorifying the oxides which are produced.
According to my Invention I can, by a single rapid and inexpensive operation,
effect the transformation of the copper matte into refined copper, ready to be
laminated, rolled, hammered, or otherwise worked.
This object I effect in the following manner, that is to say:-
When the operation above described, whereby the matte of copper is transformed
into crude copper, is finished, the converter is tilted and the scoria which float on
the metal are run off or removed by means of a rake, and when the surface of the
copper is cleared, a sample is taken by means of a small ladle and broken in the
vice, so that by examining the fracture the chemical condition of the copper may
be ascertained. When the reddish-violet coarsely granulated fracture indicates
that the copper in fusion contains a certain proportion of protoxide, it will be
certain that the complete elimination of foreign matters has been accomplished, and
it is then only necessary to reduce the protoxide, as hereinafter explained. If, on
the contrary, the copper does not give this indication, it has to be submitted to a
fresh oxidation to bring it to the requisite degree of purity. To this end the blast
in the converter, which is returned to its vertical position, is started again, the
progress of oxidation is watched by taking further samples, and a few minutes are
sufficient to free the copper from its last impurities.
It may occur that the last matters to be eliminated are not of a nature to serve
as fuel for the intermolecular combustion, without which the copper would at once
solidify or set in contact with the blast. To avoid this difficulty I introduce into
the converter a small quantity of powdered sulphur which is carried in by the
blast. This sulphur burning in the mass of the metal is sufficient for maintaining
the requisite heat, and it is eliminated as sulphurous acid, and does not in any
noticeable degree impair the oxidation of the other metallic materials, as the oxygen
of the air is always in excess. I have also tried the use of pulverised charcoal
for keeping up the combustion, with good results; but sulphur is preferable, as it
is free from the reducing action which is always caused by coal.
The copper being now made sufficiently pure it is only necessary to render it
malleable by reducing the protoxide with which it is impregnated. To effect this
object, the bath having again been skimmed, a few shovels-full of charcoal in pieces
are thrown into the converter through its throat so as to cover the surface of the
metal; then the blast is caused to carry into the converter a considerable quantity
of pulverized charcoal. The latter not only exerts an energetic reducing activity,
but also serves to heighten the temperature to the degree requisite for maintaining

page_text: the copper sufficiently heated to the end of the operation; the progress of the
reduction is watched and ascertained by means of samples taken from the
converter.
When the reduction has made considerable progress, and the copper, without
being malleable, begins to take a closer or finer grain, and a paler color, the
converter is brought into a horizontal position, the blast is stopped, and the fining
is finished, as in an ordinary furnace, by means of a rod of green wood; this latter
operation is quickly effected, and the copper easily maintains its temperature
during the time required for the same.
When the copper is completely refined the converter is tilted to pour the copper
either directly into ingot moulds, or into ladles, by means of which it is distributed
to the ingot-moulds.
The above is the operation of refining by the "Bessemer" converter; the
advantages it offers are considerable; it occupies but little time, and thus allows
considerable quantities of copper to be quickly refined; it always yields copper of
good quality, and is effected without the use of special or expensive fuel. This
manner of refining is distinct from the treatment of the crude copper; it may be
applied directly for refining all kinds of crude metallic copper melted in any kind
of furnace, and introduced in a molten state into the converter.
metallic copper, more or less impure, this process will give economical results far
superior to those obtained by the methods of refining hitherto in use.
With crude
With a previous addition of sulphur, or by introducing pulverized sulphur or
carbon with the blast, bronze, brass, and other kinds of crude copper which contain
neither sulphur nor iron can be refined.
When matters rich in copper are treated according to the above described refining
process the operation is performed in a few minutes. The combustion of the sulphur
and of the iron contained in the ore is sufficient to maintain the requisite tempe-
rature. This is not the case, however, when poor mattes are treated, when black
copper is refined in the converter, or when crude copper is to be fined; I therefore
modify my process by the introduction of some substance capable of serving as
intermolecular fuel. Good results are obtained by introducing with the blast
sulphur or coal-dust, but this expedient cannot be employed without practical
difficulties.
Experiments have therefore been made with other substances, and the following
have been found very effectual, viz., manganese, silica, and phosphorus, which
serve as reagents for maintaining during the whole of the operation that high
temperature without which the fused matters in the converter would not remain
in a sufficiently fluid condition, and their treatment would be ineffectual.
The combustion of manganese produces a higher and steadier temperature than
that of sulphur and iron, and its use is therefore always advantageous, even for the
treatment of rich ores, as an excess of heat need never be feared.
Nevertheless when, by reason of the poverty or unsuitableness of the matters to
be treated, the operation in the converter requires some time, the temperature
produced by the combustion of manganese is insufficient except when the quantity
used is excessive, and then the oxide of manganese which is produced would render
the dross or scoriæ pasty, thereby impairing the progress of the operation; in this
case recourse must be had to silica or phosphorus. The temperature produced by
the combustion of silica or of phosphorus is exceedingly high, and is amply sufficient
for the completion of the operation. The quantity in which these reagents are
to be used must necessarily vary according to the nature of the materials to be
treated, but it is very slight, and a few thousandth parts are almost always
sufficient.
The reagents, manganese, silica, and phosphorus may be incorporated with the
materials to be treated in various ways. They may be introduced in their natural
state and in small quantities into the molten materials, but this manner of usage
is expensive when applied to manganese and silica, and is perilous when applied
to phosphorus. If it is desired to fuse a matte of black copper, or minerals

page_text: containing the saine, these materials may be mixed with compounds of manganese,
of silica, or of phosphorus. But it will be found most economical in practice to
employ cast iron rich in manganese, in silica, or in phosphorus, such as spiegeleisen,
ferro-manganese, or ferro-silicate, phosphorus, cast-iron, and the like. The quantity
to be employed varies according to the richness of cast-iron in the reagents, but it
is very sinall, a few hundredths being always sufficient. Moreover, in addition to
its economy the use of such cast-iron offers the advantage of introducing iron and
carbon, which increase the elements of intermolecular combustion. This cast iron
can be added during the fusion of the materials to be treated, but it is preferable
to melt it separately and to pour the same into the converter afterwards, either at
the beginning of the operation, or, preferably, when the temperature beginning to
fall renders the presence of a reagent indispensable.
Although silica and phosphorus cause the same elevation of temperature the use
of phosphorus is preferable. The combinations with silica, which are easily reduced,
are rare and highly silicious cast-iron, such as silicate of iron, is very expensive,
whilst numerous combinations with phosphorus which are easily reduced are found
with which true iron-phosphates can be manufactured at a low price for use as
reagents.
Phosphorus is therefore preferable to manganese, or silica to the former, because
it will produce a higher temperature to the latter, because its use is easier, and more
economical.
The use of the three reagents above indicated offers another considerable
advantage, viz., that of dispensing with the previous sulphurization for treating
non-sulphuric materials, black copper-ores, for example. In fact black copper-ore
containing manganese, and especially silica or phosphorus, is very suitable for
treatment in the converter, the temperature remains high, and the separation of
the copper is complete in a few minutes.
In the Bessemer converter or other apparatus used for practising my Invention
it is desirable not to lower the temperature of the metallic copper, which by degrees,
as it is produced, sinks to the bottom of the apparatus, and contains no more
combustible elements. Therefore the tuyeres should open into the converter at
a height level with the place to be occupied by the copper which is to be pro-
duced, so that this metal when it collects need not be further subjected to the
blast.
Having thus fully described the said Invention as communicated to me by my
foreign correspondent, and the manner of performing the same, I wish it understood
that I claim,―
First. The process, characterized by the suppression of all preliminary roasting
of the sulphurous ores, and by great facility of operating with all sulphurized matters
containing copper, and based essentially upon the combustion and oxidation of the
sulphur and the iron by the forced passage of air (preferably heated air) under
pressure through the matte of molten copper in a "Bessemer" converter or analogous
apparatus, or in any suitable furnace, all substantially as and for the purposes set
forth.
Second. The processes of refining copper in a "Bessemer "converter, substantially
as above set forth.
In witness whereof, I, the said John Henry Johnson, have hereunto set
my hand and seal, this Twenty eighth day of January, in the year of
Our Lord One thousand eight hundred and eighty one