Improvements in connection with the Elimination of Arsenio from Metallic Copper.
Year: 1896

page_text: Date of Application, 13th Aug., 1896
Complete Specification Leit, 11th May, 1897--Accepted, 7th Aug., 1897
PROVISIONAL SPECIFICATION
Improvements in connection with the Elimination of Arsenio from
Metallic Copper.
We, BENJAMIN THOMAS of 4, Bryn Terrace, Llanelly, Copper Refiner, and
JOHN WALTER THOMAS of 3, Lakefield Place, Llanelly, Copper Smelter, do hereby
declare the nature of this invention to be as follows:-
Our improved method of eliminating arsenic from metallic copper we carry out in
or in about the following manner. For the treatment of copper containing an excess of
arsenic, a flux may be used composed of lime and soda ash in suitable proportions, and
this is employed in the following manner. The above flux is to be thrown upon the
molten copper in the refining furnace and stirred rapidly in, at the same time a
current of air is admitted at the side of the furnace by a suitable pipe (preferably an
ordinary gas pipe covered with silicia clay bound round with copper wire to secure it
and dried or baked before using. The pipe leads from a receiver connected with a
compressor supplying air at about 35 to 40 lbs per square inch. (This pipe should be
led from a receiver and not direct from the compressor). This pipe passing through
the side of the Furnace must be placed in the copper at about six inches below the
surface, when it will be found to cause a constant and decided spraying of the copper
in the furnace, and result in a rapid elimination of the arsenic partly by volatilization
and partly into the lime slag. The process must be conducted with the ordinary
heat required for the keeping of the copper in a fluid state and the use of flux and air
until the required amount of arsenic is separated from the copper. The slag resulting
from this process will be found to be easily reduced by means of any coarse sulphide
of copper, (ore or regulus) giving a "sharp slag" containing about one per cent. of
copper. It will be found that the combined use of the above flux and forced
atmospheric air will decrease the cost of production by fully fifty per cent. The copper
when purified by the above methods will be found to be improved in its toughness
and can be easily worked up to give a copper produce of 99-75 per cent.
The above process of throwing the flux upon the molten copper can be performed
by a machine, the advantages being a still more rapid elimination of the arsenic, a
poorer slag (containing less oxide of copper) and the furnace (refining) used being less
attacked. This process will give as great a saving as seventy five per cent. and these
savings are calculated on the results of practical test on many hundreds of tons of
copper coutaining arsenic. The machine just referred to comprises a steam boiler
capable of bearing a pressure of forty pounds per square inch of air. Running
through the boiler is a screw worked by a steam or other motor. A pipe leads
from the boiler into the furnace as above mentioned. There is a partition at one
end of the boiler into which the air is blown and the screw brings the line and
soda ash from the boiler into or through this partition into the pipe leading from
the bottom to the pipe. The boiler is filled with the composition before commencing

page_text: the operation and screwed down tightly, the air let into the partition and the screw
set in motion by the engine, and in this way the air and composition are easily
passed through into the pipe.
Dated this 10th day of August 1806
HUGHES & YOUNG,
23, Coleman Street, London, E.C., Agents for the Applicants.
COMPLETE SPECIFICATION.
Improvements in connection with the Elimination of Arsenic from
Metallic Copper.
We, BENJAMIN THOMAS, of 4, Bryn Terrace, Llanelly, Copper Refiner, and
JOHN WALTER THOMAS, of 3, Lakefield Place, Llanelly, Copper Sinelter, 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:-
Our improved method of eliminatng arsenic from metallic copper consists
essentially in the use of a suitable flux (or suitable fluxes) and a stream (or streams)
of compressed air. Any oxidizing fluxes with slaked lime may be used, and the
compressed air may be hot or cold and it is intended to use the flux or fluxes and the
compressed air simultaneously. In carrying the new process into effect, we proceed in
or in about the following manner. Compressed atinospheric air at a pressure of not
less than 30 lb. (preferably from 35, to 40 lb.) per square inch is conveyed from a
receiver and not direct from the compressor to the side of a reverbaratory furnace, by
means of gas or iron piping of suitable diameter (say " or 1").
This piping we
prepare with a good coating of plastic silicious material, such as silicia clay, well
bound with copper wire, the whole being dried and baked before use. The covered
pipe is led into the molten copper about three or four inches below the surface. While
this supplying of air to the copper is taking place, the fluxes can be rabbled on the
face of the copper at the front door of the furnace in suitable quantities, the usual
amount being about 1. to 1. cwt. to the charge of 10. or 12. tons of copper. The
application of the air causes a constant and decided spraying of the copper in the
furnace and results in a rapid elimination of the arsenic partly by volatalization
and partly into the slag. When the slag has become fairly fluid upon the copper it
can be skimmed off into a moveable pot, and the process continued until the arsenic
is eliminated, care being taken that the air is continuously kept up at the proper
pressure during the whole operation. The process must be conducted at the ordinary
heat required for keeping copper in a fluid state and the use of flux and air must be
continued until the required amount of arsenic is separated from the copper. The
slag resulting from this process will be found to be easily reduced by means of any
coarse sulphide of copper (ore or regulus), the result being a "sharp" slag containing
about one per cent of copper. It will be found that the combined use of flux and
forced atmospheric air will decrease the cost of eliminating the arsenic from the copper
by fully fifty per cent. The copper when purified by this process, will be found to be
improved in its toughness, and can easily be worked up to give a copper produce of
99-75 per cent. It is also to be remarked that if the arsenical copper under treatment
contains any bismuth, it will be found that our new process materially improves the
tough quality of the copper.
As regards the fluxes usable in our process, either soda ash; nitrate of soda; or a

page_text: good black oxide of copper may be employed. Soda ash is preferable as being a cheap
flux and more advantageous as regards the quality and quantity of slag produced by
the process. The soda ash slag is easily reduced of its copper contents by the
addition of a small amount of anthracite small coal. The slag (Silicate of soda, iron
and copper) contains from 0.8 to 1% of copper and can be easily cleaned in the ore
smelting process to about 0-25% of copper. A suitable mixture containing this flux
is three parts by weight of lime and one part by weight of soda ash, used at the rate
of four barrows (of 1. cwt. each) of the lime and soda ash per hour to a charge of
10. to 14. tons of copper under treatment, and this proportion is continued until the
elimination is complete, or reaches the stage required by the manufacturer. The
nitrate of soda produces a rich slag when used with slaked lime and is not so easily
reduced to permit of a poor slag for the ore smelting process, i.e. without the aid of
copper sulphides or pyrities. The cost of the flux (NaNO3) is also a decided
disadvantage. A suitable mixture containing this flux, is three parts by weight of
lime and one part by weight of the nitrate of soda, used in the saine ratio as the
soda ash, and for an equivalent period. Although a good black oxide of copper can
be used for the extraction of arsenic by this process, nevertheless, great care must be
exercised in providing a dust chamber, as a portion of the flux (CuO) is carried away.
A good proportion to use is eighty pounds of oxide of copper to 196 pounds of lime.
In result, the use of oxides in place of soda ash or nitrate of soda, comes to practically
the same thing as regards the elimination of the arsenic, but the slag is richer in
copper.
Our improved process can also be conducted in a machine specially arranged for the
purpose,
and illustrated by Figs. 1. and 2. of the accompanying drawing, the former
being a longitudinal section, and the latter a cross section. The use of the machine
obviates rabbling in the fluxes through the front door of the furnace. In the machine
process the flux composition is made fine and thoroughly mixed by passing through
a sieve, and is then placed in the boiler a, having the partition 6 forming the air
compartment c and dividing the air from the fluxes. The flux is moved from a to c
by a worm or other conveyor d, propelled by an engine or other motor by means of
the driving wheel e and gearing f. The fluxes are then passed down by pressure into
the funnel g and thence by pipe h to the furnace. The air for c is delivered by pipe i
connected to the compressor. The process can thus be continuous; the slag resulting
from the use of the fluxes being easily taken off the face of the copper while the
machine is in motion. This however need only be done when the operator finds the
slag to be in a suitable condition, and with care in the manipulation, the slag can be
made to contain only a very small amount of copper.
As the copper treated becomes purified by the extraction of the arsenic, the slag
becomes fluid and should be thoroughly skimmed off, so as to allow the action of the
air and flux to be completely accomplished, and also to prevent the sides of the
furnace (silicia) being attacked.
The refining of the copper is conducted exactly as in the case of any other copper,
one feature only is noticed in the use of soda ash, and that is the copper becomes
"fine" i.e. tough pitch very easily.
Compared with the ordinary process of rabbling in the flux or fluxes at the front
door of a reverberatory furnace and the older method of "slagging" in the refinery or
roaster furnaces, our new process lessens the cost by fully fifty per cent., besides
having the advantage of permitting the treatment of ten or fourteen tons of arsenical
copper in a refinery in twelve hours, the copper containing 1. or 1.25% of arsenic,
and the result being copper of not less than 99.50. and only a trace of arsenic.
As the above machine can be varied in shape, disposition and proportion of parts,
without departure from the essential features, we do not confine ourselves to precisely
what is shewn in the drawings.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we

page_text: 1. For the elimination of arsenic from metallic copper the simultaneous use of a
flux or of fluxes and a stream or of streams of hot or cold compressed air, the flux or
fluxes being rabbled in at the front door of a reverbaratory furnace and the compressed
air being supplied to, and below the surface of, the molten copper, the whole
substantially as described in the above specification.
2. For the elimination of arsenic from metallic copper, the delivery to the molten
copper of a stream or of streams of compressed air carrying with it or them the flux
or fluxes to be used, the whole substantially as described in the above specification
with reference to Figs. 1. and 2. of the accompanying drawings.
3. For carrying into effect the modification which is the subject matter of the
preceeding Claim 2, the use of a machine consisting essentially of a boiler containing
the flux or fluxes, a chamber communicating with an air compressor, and a conveyer
for transferring the flux or fluxes from the boiler to a funnel shaped entrance to a
pipe leading to the furnace, through which pipe the flux or fluxes is or are carried
with and by the air from the above mentioned chamber, the whole substantially as
.described in the above specification, and exemplified in the accompanying drawings.
4. The use of soda ash with or without lime, for the elimination of arsenic from
metallic copper substantially in the manner or manners set forth in the above
specification.
5. For the elimination of arsenic from metallic copper, the use of compressed air,
substantially in the manner or manners set forth in the above specification.
Did the 10th day of May 1807
HUGHES & YOUNG,
23, Coleman Street, London, E.C., Agents for Applicants.
HUGHES & YOUNG,
23, Coleman Street, London, E.C., Agents for Applicants.