Improvements in Treating Copper Matte.
Year: 1898

page_text: Date of Application, 17th May, 1898-Accepted, 23rd July, 1898
COMPLETE SPECIFICATION.
Improvements in Treating Copper Matte.
I, JAMES COLQUHOUN, of Clifton, in the County of Graham and Territory of
Arizona, United States of America, Mining Engineer, 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:-
This invention relates to reducing copper ore and its object is to improve the
method of treating the matte produced by the smelting furnace.
In the modern method of converting copper matte into the so-called Bessemer
copper, the usual steps are as follows:
First, the smelting of the raw ores in cupola or reverberatory furnaces for the
production of copper matte containing about 50 per cent. copper.
Second, the copper matte together with the slag from the furnace is allowed to
flow from the smelting furnace into a large settling pot (usually about four feet
deep and about twelve feet in diameter) the copper matte being caught in the
settling pot while the slag is allowed to flow over and away from the top of the
said settling pot. When the matte is required, it is tapped from the bottom of
the settling pot, and allowed to flow into a ladle which when filled with copper
matte to the required height, is hoisted to the converter and tilted so that the said
matte is poured into the converter where it is converted into metallic or so-called
Bessemer copper.
Third, in place of (2) and more generally, the matte, instead of being caught in
settlers, is dumped on the ground and allowed to become cool, when it is broken
up in pieces and hoisted to a smelting furnace in which it is smelted as required
by the converter.
copper converter lined
or
Fourth, the molten matte handled by either of the methods described
(2) and (3) is poured into દી
with quartz
other silicious material and air is blown through it under pressure until the iron
is fluxed into slag and the sulphur has been expelled, when metallic copper
remains and is poured into suitable moulds.
Fifth, my improvement consists in dispensing with methods (2) and (3) which
are objectionable on the following grounds: Method (2). The settler can only
be used on furnaces having very large capacities: it interferes with the proper
working of the smelting furnace by making it impossible for the workmen to
work with any degree of comfort in the presence of such a mass of molten material:
it has no control over the heat of the matte, there being no provision for heating
the matte in the event of its becoming chilled, as it does occasionally: it does not
permit of any alteration in the grade of the matte, a very essential point for the
economical working of the converters; and it is liable to spring leaks and cause
great loss and trouble.
Method (3) is objectionable on the ground that it is too expensive, the cold
matte costing nearly as much to remelt it as would the smelting of an equal
quantity of raw ore.
My invention consists in using a separate heated receptacle, preferably a rever-

page_text: beratory furnace of the ordinary type, to receive the molten matte from the smelting
furnace, and store it until it is required by the converter.
The reverberatory
furnace may be so placed that when only one smelting furnace is used, the matte
may be tapped directly into the reverberatory. Where a number of smelting
furnaces are used, the matte may be conveyed in pots or cars from each furnace
and dumped into the reverberatory.
The advantages of my invention are as follows:
1. If the matte is not of the required temperature it can be easily and cheaply
brought to that temperature.
2. If the matte is too low in grade, its grade can be easily raised by the addition
of higher grade mattes, of oxide ores, or by any of the other usual methods.
3. If the matte is too high in grade, its grade can be reduced by the addition
of iron pyrites or by an addition of lower grade matte.
4. The slags made in converting the copper matte carry a considerable per-
centages of copper, varying from one and a half to five per cent. By the ordinary
method they are either remelted or thrown away. By my method, I simply pour
them into the aforesaid reverberatory furnace, exposing them to the action of said
furnace, whereby they are rendered practically free of their copper and may be
skimmed off as waste slags.
To sum up briefly, the reverberatory furnace, used in this manner in the process
of bessemerizing copper, serves, (1) as an agent to control the temperature of the
copper matte (2) as an agent to control the grade of the copper matte: (3) as an
agent to clean the slags produced in the converter or in any other way.
I am aware that a reverberatory furnace has long been used for melting copper
ores and that matte is taken from said furnace to be bessemerized, just as is done
from a cupola smelting furnace; but it will be observed that I use it not for smelt-
ing ores, but for distinctly different purposes, as before specified.
As far as my knowledge goes, a reverberatory furnace has never been used for
the purposes mentioned in connection with bessemerizing or for any other purpose.
I am also aware that a reverberatory furnace has been used as an adjunct to a
cupola furnace, and that the coarse ore can be smelted in the cupola
and the resulting metal and slag conveyed into the reverberatory,
where it is mixed with fine ores and the smelting is continued to
produce metallic copper. The object of this proposed method ig to
avoid the loss of flue dust which occurs when fine ores are smelted in a cupola.
But this is not the purpose or mode of operation of my invention. In the first
place I smelt all my ore, coarse or fine, in the blast furnace. I do not attempt
to obtain greater speed in my furnace by screening out the fine ore and treating
it in a reverberatory furnace, nor do I attempt to save flue dust, or to make
metallic copper in the reverberatory furnace. No slag flows from my blast furnace
into the reverberatory furnace. I simply take the matte produced in the blast
furnace, dump it into the reverberatory, store it there, alter its grade if necessary,
and use it while there for removing the copper contained in the slags from the
Bessemer process.
In the accompanying drawings,
Figure 1 is a plan view of a copper reducing plant embodying my improvement.
Figure 2 is an elevation of the same.
The blast furnaces A may be of any suitable construction and any number may
be used. They are conveniently located with reference to the reverberatory
furnace B, which has a stack B¹ and is protected by a shed B. The reverberatory
has an opening b into which the molten matte from the cupolas A can be dumped
and a spout 61 through which the matte can be drawn from the reverberatory
into a ladle C mounted on a car C¹. The track c on which the car runs leads to a
shed D in which is an overhead electric crane E by means of which the ladle can
be conveyed to the converters F.
The drawings are more or less diagrammatic, and do not attempt to show all
the details of such a plant. Nor is it necessary that the arrangement shown should

page_text: always be followed. It is given merely as an illustration of one way to carry out
the invention.
The process may be briefly described as follows: The raw ore is smelted in the
blast furnace. The matte, composed of copper, iron and sulphur, is tapped into
pots and dumped into the reverberatory furnace. Here it is kept molten, and
its temperature and grade regulated. When desired it is tapped into the ladle, which
is run over the converter shed, hoisted by the crane, and its contents dumped into a
converter. Air is blown through the molten mass until the iron is slagged off,
the sulphur eliminated, and nothing but metallic copper remains, which is then
poured into ingot moulds.
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:-
1. As an improvement in the art of reducing copper by the Bessemer process,
drawing off the molten matte from the blast furnace, keeping it in a molten
condition by an independent controllable source of heat, and altering its grade by
the addition of suitable agents, substantially as described.
2. As an improvement in the art of reducing copper by the Bessemer process,
storing the matte in a reverberatory furnace, and adding slags from the con-
verter in order to clean them, substantially as described.
3. In apparatus for reducing copper by the Bessemer process, the combination
with a blast furnace and a converter, of a receptacle for the matte from the blast
furnace, and a separate furnace for maintaining and regulating the temperature
of the contents of said receptacle, substantially as described.
4. In apparatus for reducing copper by the Bessemer process, the combination
with a blast furnace and a converter, of a reverberatory furnace to receive the
molten matte from the blast furnace and store it until required by the converter,
substantially as described.
1000