Improvements in the Treatment of Copper Precipitates.
Year: 1889

page_text: Date of Application, 11th Jan., 1889.
Complete Specification Left, 28th Aug., 1889-Accepted, 28th Sept., 1889
PROVISIONAL SPECIFICATION.
Improvements in the Treatment of Copper Precipitates.
I GEORGE GATHERAL of Heathfield Hebburn on Tyne in the County of Durham
Chemist do hereby declare the nature of this Invention to be as follows:-
¡My Invention relates to the treatment of copper precipitates containing arsenic.
According to my Invention I add to the copper precipitates to be treated. iron or
copper pyrites and I calcine the mixture in a chamber furnace or, retort which is
closed.. A large proportion of the arsenic is thereby volatilized and the arsenious,
acid given off may be condensed in any suitable way.
The mixture after the period of close calcination may be further calcinod (but with
access of air) to a degree to suit the smelting operations or mixtures of furnace.
material.
The product of the aforesaid treatment can then be smelted in the usual or any
suitable way.
COMPLETE SPECIFICATION.
Improvements in the Treatment of Copper Precipitates.
I GEORGE GATHERAL of Heathfield Hebburn on Tyne in the County of Durham
Chemist 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 the treatment of copper precipitates containing arsenic.
According to my Invention I add to the copper precipitates to be treated iron
pyrites or copper pyrites and I calcine the mixture in a chamber furnace or retort
which is closed. A large proportion of the arsenic is thereby volatilized and the
arsenious acid given off may be condensed in any suitable way.
The mixture after the period of close calcination may be further calcined (but with
access of air) to a degree to suit the smelting operations or mixtures of furnace
material.
The product of the aforesaid treatment can then be smelted in the usual or any
suitable way.
And in order that my said Invention may be fully understood I shall now proceed
more particularly to describe the same.
I take copper precipitates from mines or other places and containing arsenical com-
pounds and recognised as the more impure because of the presence of these compounds
and I mix with the said precipitates in a mill a quantity of iron pyrites or copper
pyrites in proportions variable according to, the composition of the precipitates to be
operated upon.
For instance to precipitates containing 6 to 8 per cent. of arsenic and 30 per cent.
of copper I have found from 25 to 30 per cent. "pyrites smalls" to be sufficient for
the elimination of most of the arsenic present but as the quantity of pyrites necessary
must depend upon the composition of the precipitates I do not bind myself to this
proportion but use less or more, as may be found necessary from the composition of
the precipitates to be operated upon.
This mixture of precipitate and pyrites I next calcine in
the air as much as possible and working the charge very
evolved may be condensed in flues in the usual manner.
ΓΙ
a close furnace, excluding
little.. The arsenious acid
When on testing with an

page_text: iron rod I find little or no arsenious acid is being driven off. When this stage has
been reached 1 work the charge frequently and with a free admission of air so as to
oxidize as much as possible the sulpbides still left in the charge, and when the
quantity of these has been reduced, to suit the requirements of the smelting operations
for the time being, the charge is drawn and the calcined mixture smelted according to
any of the usual methods common to copper works.
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 1
claim is.―
1st. The treatment of copper precipitates by adding thereto iron pyrites or copper
pyrites and calcining the mixture in a close furnace chamber or retort substantially as
hereinbefore described.
2nd: The treatment of copper precipitates by adding thereto iron pyrites or
copper pyrites and calcining the mixture in a close furnace chamber or retort and
after all or most of the arsenious acid has been driven off working the charge with
free admission of air all substantially as hereinbefore described.
Dated this 27th day of August 1889.
GEORGE GATHERAL.