An Improved Process, and Furnaces used therewith, for Copper Smelting and Refining.
Year: 1893

page_text: Date of Application, 14th Apr., 1893
Complete Specification Left, 15th Jan., 1894-Accepted, 14th Apr., 1894
PROVISIONAL SPECIFICATION.
An Improved Process, and Furnaces used therewith, for Copper
Smelting and Refining.
I, ALFREDO OVALLE VICUÑA of Vallenar, Province of Atacama, Chili,
South America, Landed Proprietor and Mine Owner, do hereby declare the nature
of this invention to be as follows :-
My invention relates to an improved method of smelting copper ores and to the
construction of an improved compound furnace, used therefor, consisting of a
combination of a cupola blast or reverberatory furnace with several subsidiary
hearths and auxiliary furnaces therewith, by means of which copper sulphurous
ore may be reduced to " copper bar" in one heat and by a single and continuous
operation.
The following arrangement of combined furnace has been practically worked for
many months and has been found to effect the following advantages.
1st. The cupola furnace which is part of my improved furnace, smelts with a
greater rapidity than is usual, because only soft and easily reducible ores are
treated in it, the dust and refractory silicious ores being treated in the reverberatory
hearths of my combined furnace.
2nd. The first reverberatory hearth, receiving as it does the molten charge from
the cupola, requires little additional heat from the auxiliary furnaces, to slag the
is
iron, by the addition therein of silicious ores, or to melt the dust ores, which as
well known cannot be conveniently smelted in cupola furnaces.
3rd. The addition of subsidiary hearths beyond the first hearth where the
slagging and removal of the iron takes place, enables the resulting matte to be
there desulphurized by oxidation, and refined until reduced to "copper bar," with
small addition of heat and little expenditure of time or labour.
4th. The usual operations in smelting and refining copper, of calcination, and of
the handling and moving of the calcined ore; the pulverisation of the matte, and
consequent handling and moving; the calcination of the pulverized matte in
calcining furnaces, the consequent handling and moving; and the final smelting in
refinery furnaces are avoided and saved.
**
5th. The cost of my combined furnace for the continuous process from ore to
copper bar," is much less than the cost of the usual smelting furnaces, calcining
furnaces, and refinery furnaces, usually required, and the means of transport and
handling of the ores in the usual known processes is obviated.
6th. Poor ores, which by existing processes cannot be treated at a profit, may be
smelted in my combined furnace to advantage.
7th. The heat from the cupola furnace may be utilized in my combined furnace
for the reduction of the ores to "bar copper" in my auxiliary hearths.
I first use a cupola furnace of known construction which receives the first
charge of sulphurous copper ore, and coke or other fuel, and it is provided with
the usual blast or tuyere pipes.
After the charge has been smelted in this cupola furnace, the molten charge is
discharged into the first auxiliary hearth, with the accompaniment of a considerable
amount of heat and flame.
In this first hearth, the molten matte, or copper sulphide, settles to the bottom,
the slag floating on the surface, which slag is removed in the usual way, through
the door in the front of the hearth.
This hearth has on either side a diagonal grate or furnace, which serves to
increase the heat in the hearth, or by means of flues to throw the heat into the

page_text: further hearths, when the communication below the flues, between the grates
and the hearth, has been closed, and the flues opened by dampers or other suitable
means.
In the first hearth may be added the dust ore or other material which it is not
convenient to smelt in the cupola furnace.
The secondary hearths serve to receive the discharge of the molten matte
from the first hearth, where the slag has already been removed. The outflow of
the matte from the first hearth to the secondary hearths is received by open and
curved channels.
The matte, thus freed from slag is exposed alternately in the secondary hearths
to a desulphurising and oxidising current of air, and heat, either from the first
hearth, or from the grates, or when desired by the admission of air by small doors
or air holes in the walls of the secondary hearths, and near the bridges.
Hot air tuyere pipes connected with main wind-tube of the cupola furnace may
also be fitted to these hearths. The pipes are sunk into the sides of the hearth
so that the air may be heated from the said hearth before it is discharged on to the
bath of metal to prevent the bath from being too rapidly cooled.
Before the matte gets cool and begins to redden, which cooling may have been
effected by closing the communication with the fire grates, the dampers of the flues
may be again opened to re-heat the charge in the secondary hearths, and any
remaining iron and impurities in the matte may be removed by the addition of a
silicious red ore, which will slag the remaining iron and other impurities.
The bath in the said secondary hearths may thus be alternatively re-heated and
treated with silicious ores, or oxidised by the admission of air for desulphurisation,
until the copper in a single heat from its first smelting as an ore, may be reduced
to fine "copper bars" of recognized commercial value, and with the economy as to
time, fuel, and labour, and capital outlay as hereinabove specified.
"
as refined
If desired, the ordinary poling, with timber poles may be carried out in the
secondary hearths, to bring the copper bath therein to any "pitch
copper.
Though I have described a cupola furnace with auxiliary hearths as the preferred
example of my improved furnace, my auxiliary hearths and grates and the process
of treatment hereinabove described, may be used with an ordinary reverberatory
furnace in place of the cupola; though, in such case, the copper pyrites ore must
be previously calcined before treatment in the reverberatory furnace.
Dated this 14th day of April 1893.
FELL & WILDING,
1, Queen Victoria Street, London, E.C., Agents for the Applicant.
COMPLETE SPECIFICATION.
An Improved Process, and Furnaces used therewith, for Copper
Smelting and Refining.
I, ALFREDO OVALLE VICUÑA, of Vallenar, Province of Atacama, Chile,
South America, Landed Proprietor and Mine Owner, 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 :-
My invention relates to an improved method of smelting copper ores, and to the
construction of an improved compound furnace used therefor, consisting of a com-
bination of a cupola blast or reverberatory furnace with several subsidiary hearths
and auxiliary furnaces therewith, by means of which copper sulphurous ore may be
copper bar" in one heat and by a single and continuous operation.
The following arrangement of combined furnace has been practically worked for
many months and has been found to effect the following advantages.
reduced to "

page_text: 1st. The cupola furnace which is part of my improved furnace, smelts with a
greater rapidity than is usual, because only soft and easily reducible ores are
treated in it, the dust and refractory silicious ores being treated in the reverberatory
hearths of my combined furnace.
2nd. The first reverberatory hearth receiving as it does the molten charge from
the cupola, requires little additional heat from the auxiliary furnaces to slag the
iron by the addition therein of silicious ores, or to melt the dust ores which as is
well known cannot be conveniently smelted in cupola furnaces.
3rd. The addition of subsidiary hearths beyond the first hearth where the
slagging and removal of the iron takes place, enables the resulting matte to be
there desulphurized by oxidation and refined until reduced to "
small addition of heat and little expenditure of time or labour.
copper bar" with
4th. The usual operations in smelting and refining copper, of calcination and of
the handling and moving of the calcined ore; the pulverisation of the matte and
consequent handling and moving; the calcination of the pulverized matte in
calcining furnaces, the consequent handling and moving; and the final smelting in
refinery furnaces are avoided and saved.
5th. The cost of my combined furnace for the continuous process from ore to
<< copper bar" is much less than the cost of the usual smelting furnaces, calcining
furnaces and refinery furnaces, usually required, and the means of transport and
handling of the ores in the usual known processes is obviated.
6th. Poor ores, which by existing processes cannot be treated at a profit, may be
smelted in my combined furnace to advantage.
7th. The heat from the cupola furnace, may be utilized in my combined furnace
for the reduction of the ores to "bar copper "in my auxiliary hearths.
Figure 1 is an outside elevation of my improved furnace and
Figure 2 is a sectional plan of the same.
A is a cupola furnace of known construction which receives the first charge of
sulphurous copper ore and coke or other fuel, and it is provided with the usual
blast or tuyere pipes a.
After the charge has been smelted in this cupola furnace, the molten charge is
discharged into the first auxiliary hearth with the accompaniment of a
considerable amount of heat and flame.
In this hearth B, the molten matte or copper sulphide settles to the bottom, the
slag floating on the surface, which slag is removed in the usual way, through the
door in the front of the hearth.
This hearth B has on either side a diagonal grate or furnace C, which serves to
increase the heat in the hearth B, or by means of flues D to throw the heat into
the further hearths E E, when the communication below the flues between the
grates C and the hearth B has been closed and the flues D opened by dampers d or
other suitable means.
In the hearth B may be added the dust ore or other material which it is not
convenient to smelt in the cupola furnace.
The secondary hearths E E serve to receive the discharge of the molten matte
from the first hearth B where the slag has already been removed. The outflow of
the matte from the first hearth B to the secondary hearths E is received by the
open and curved channels F.
The matte, thus freed from slag is exposed alternately in the secondary
hearths E E to a desulphurising and oxidising current of air, and heat, either from
the hearth B or from the grates C; or when desired by the admission of air by
small doors or air holes in the walls of the secondary hearths E E and near the
bridges.
Hot air tuyere pipes G connected with main wind-tube of the cupola furnace
may also be fitted to these hearths. The pipes are sunk into the sides of the
hearth at H so that the air may be heated from the said hearth before it is
discharged on to the bath of metal to prevent the bath from being too rapidly
cooled.

page_text: Before the matte gets cool and begins to redden, which cooling may have been
effected by closing the communication with the fire grates C, the dampers of the
flues D may be again opened to re-beat the charge in the secondary hearths E and
any remaining iron and impurities in the matte may be removed by the addition of
a silicious red ore which will slag the remaining iron and other impurities.
The bath in the said secondary hearths E may thus be alternatively reheated
and treated with silicious ores or oxidised by the admission of air for desulphurisa-
tion, until the copper, in a single heat, from its first smelting as an ore, may be
reduced to fine copper bars of recognized commercial value, and with the economy
as to time, fuel, labour and capital outlay, as hereinabove specified.
If desired, the ordinary "poling" with timber poles may be carried out in the
secondary hearths E E to bring the copper bath therein to any pitch as refined
copper.
Though I have described a cupola furnace with auxiliary hearths as the preferred
example of my improved furnace, my auxiliary hearths and grates and the process
of treatment hereinabove described may be used with an ordinary reverberatory
furnace in place of the cupola, though, in such case, the copper pyrites ore must be
previously calcined before treatment in the reverberatory furnace.
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 :-
1st. The process of manufacture of bar copper from sulphurous copper ore in one
heat by smelting the ore in an ordinary open cupola furnace, discharging the
molten matte into a hearth attached thereto, desulphurising the charge therein,
with the addition of silicate and dust ores; and a final alternate treatment for
further purification in two or more auxiliary hearths receiving charge from first
hearth, and auxiliary heat and air supply, substantially as described.
2nd. To carry out such a process the combination of a cupola furnace with
subsidiary hearths all connected together and to the said cupola, the subsidiary
hearths being provided with auxiliary fire grates, flues controlled by dampers, air
doors and air tubes to effect the re-heating, treatment, and desulphurising of the
first smelted product of the ore whilst still molten to produce marketable bar
copper, substantially as described.
3rd. To carry out such a process the combination of a reverberatory furnace
with subsidiary hearths all connected together, provided with auxiliary fire grates,
flues controlled by dampers, air doors and air tubes, to effect the reheating, treat-
ment and desulphurising of the first melted product of the calcined ore, whilst still
molten to produce marketable bar copper, substantially as described.
4th. The arrangement and construction of a combined furnace and hearths for
smelting and producing marketable bar copper from sulphurous ore in one
continuous operation, substantially as described and illustrated herewith.
Dated this 15th day of January 1894.
FELL & WILDING,
1, Queen Victoria Street, London, E.C., Agents for the Applicant.