IMPROVEMENTS IN THE TREATMENT OF SOLUTIONS CONTAINING METALS AND SODA AND OTHER SALTS FOR EFFECTING THE SEPARATION OF THE SAME
Year: 1874

page_text: LËTTERS PATENT to George James Snelus, Manager of Iron and Steel
Works, Workington, in the County of Cumberland, for the Inven-
tion of "IMPROVEMENTS IN THE TREATMENT OF SOLUTIONS CONTAINING
METALS AND SODA AND OTHER SALTS FOR EFFECTING THE SEPARATION OF THE
SAME."
Scaled the 27th April 1875, and dated the 2nd November 1874.
PROVISIONAL SPECIFICATION left by the said George James Snclus
at the Office of the Commissioners of Patents, with his Petition, on
the 2nd November 1874.
I, GEORGE JAMES SNELUS, Manager of Iron and Steel Works,
Workington, in the County of Cumberland, do hereby declare the nature
of the said Invention for "IMPROVEMENTS IN THE TREATMENT OF SOLUTIONS
CONTAINING METALS AND SODA AND OTHER SALTS FOR EFFECTING THE SEPARATION
OF THE SAME," to be as follows:-
In extracting copper by wet processes solutions are obtained con-
taining besides copper silver and gold. When these metals are present
in the ore and when the ore has been calcined with common salt, the
solutions contain besides these metals sulphate of soda. These solutions
are ordinarily digested on metallic iron for the precipitation of the

page_text: copper, and the resulting solutions are run to waste. In this method of
treatment the silver and gold are precipitated with the copper, and the
sulphate of soda is lost. The silver and gold usually bear such a small
proportion to the precipitated copper, that any special operation for their
separation from it would be unprofitable.
According to my Invention I separate from the aforesaid solutions,
the precious metals with a fractional part of the copper before pro-
ceeding to the complete precipitation of the latter metal, and separate
the sulphate of soda in marketable purity after the precipitation of the
copper. The separation of the silver and gold is effected by iron in a
fine state of division, such as the well known spongy iron ground to
powder added gradually to the solutions whilst they are kept violently
agitated. By these means the silver and gold are precipitated in much
larger proportion than the copper, for example I have found that with
solutions containing 2000 grains of copper and 1 grains of silver per
gallon, 80 per cent. of the silver was precipitated in precipitating 10 per
cent. of the copper.
For the gradual addition of iron to the solutions and their simul-
taneous agitation, I employ a blast of air which carries with it the
powdered iron, and by which both of the above objects are effected. It
is not necessary nor is it a part of my Invention to reduce the proto-
chloride of copper to subchloride, although some proportion may be so
reduced in precipitating the fractional proportion of copper to be
separated with the silver and gold.
After allowing the precipated metals to subside the solution is run off
and the copper completely precipitated. When the solutions have been
obtained from ores calcined with common salt and contain sulphate of
soda, I evaporate after the precipitation of the copper by blowing into
them heated air or the products of combustion from a closed furnace
or cupola with or without excess of air, whilst their bulk is kept up
by the addition of fresh quantities of the solution, until they become so
concentrated that the sulphate of soda salts out.
By continuing to evaporate and to add fresh quantities of solution, a
large proportion of the sulphate of soda of marketable purity or such as
can be readily purified for the market may be separated, whilst almost
the whole of the chlorides remain in solution and may be drained off in
the ordinary manner.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Georgo James Snclus in the Great Seal Patent
Office on the 30th April 1875.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GEORGE
JAMES SNELUS, Manager of Iron and Steel Works, Workington, in the
County of Cumberland, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Second day of November, in the year
of our Lord One thousand eight hundred and seventy-four, in the
thirty-eighth year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto me, the said George James Snelus, Her
special licence that I, the said George James Snelus, my executors,
administrators, and assigns, or such others as I, the said George James
Snelus, my executors, administrators, and assigns, should at any time
agree with, and no others, from time to time and at all times there-
after during the term therein expressed, should and lawfully might
make, use, exercise, and vend, within the United Kingdom of Great
Britain and Ireland, the Channel Islands, and Isle of Man, an Inven-
tion for "IMPROVEMENTS IN THE TREATMENT OF THE SOLUTIONS CONTAIΝΙΝΗ
METALS AND SODA AND OTHER SALTS FOR EFFECTING THE SEPARATION OF THE
SAME," upon the condition (amongst others) that I, the said George
James Snelus, my executors or administrators, by an instrument in
writing under my, or their, or one of their hands and seals, should
particularly describe and ascertain the nature of the said Invention,
and in what manncı the same was to be performed, and cause the
same to be filed in the Great Seal Patent Office within six calendar
months next and immediately after the date of the said Letters
Patent.
NOW KNOW YE, that I, the said George James Snelus, do hereby
declare the nature of my said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in and
by the following statement:-
In extracting copper by wet processes solutions are obtained
containing not only copper, but also silver and gold when these metals
are present in the ore, and when the ore has been calcined with common
salt the solutions contain besides these metals sulphate of soda. These

page_text: solutions are ordinarily digested on metallic iron for the precipitation
of the copper, and the resulting solutions are run to waste. By this
method of treatment the silver and gold are precipitated with the
copper, and the sulphate of soda is lost. The silver and gold usually
bear such a small proportion to the precipitated copper that any special
operation for their separation from it would be unprofitable.
According to my Invention I separate from the aforesaid solutions the
precious metals with a fractional part of the copper before procceding
to the complete precipitation of the latter metal, and separate the
sulphate of soda in marketable purity after the precipitation of the
copper. The separation of the silver and gold is effected by iron in a
fine state of division, such as the well known spongy iron ground to
powder added gradually to the solutions, whilst they are kept violently
agitated. By these means the silver and gold are precipitated in much
larger proportion than the copper, for example I have found that with
solutions containing 2000 grains of copper and 1 grain of silver per
gallon, 80 per cent. of the silver was precipitated in precipitating 10 per
cent. of the copper.
For the gradual addition of iron to the solutions and their simul-
taneous agitation I employ a blast of air which carries with it the
powdered iron, and by which both of the above objects are effected, I
have found that by running the powdered iron into the blast pipe, where
it dips into the solution from an air-tight covered vessel through a valve
formed by an india-rubber pipe and clip, it is conveniently introduced
and the proportion readily regulated.
I am aware that it has been proposed to separate silver and gold from
uch solutions as aforesaid, by means of metallic iron in fine powder
used in quantities sufficient to reduce the whole of the protochloride of
copper to subchloride, and in addition to precipitate a part of the copper
in the metallic state, but I have found that when the iron is applied in
the manner above described reduction to subchloride is not necessary,
although some proportion of the protochloride may be so reduced in
precipitating the fractional proportion of copper to be separated with the
silver and gold.
After allowing the precipitated metals to subside the solution is run
off and the copper completely precipitated. When the solutions have
been obtained from ores calcined with common salt and contain sul-

page_text: phate of soda, I evaporate such solutions after the precipation of the
copper, by passing into them the products of combustion from any
convenient furnace. The products of combustion may be forced into the
solution through one or more pipes or through a coil perforated with
small holes by means of a blowing engine supplying air to the furnace,
which must in this case be closed by such means as are adopted in iron
smelting furnaces, or they may be drawn from the furnace and forced
through the solution by means of an air blast applied in a manner
similar to that in which the steam jet is employed in ventilating mines.
The heated products of combustion passing through the solution
evaporate the same at a low temperature, and with a small expenditure
of fuel, whilst from being only in contact with the solutions they have
no action on the containing vessel. As the evaporation proceeds the
bulk of the solution is kept up by the addition of fresh quantities of
solution until it becomes so concentrated that the sulphate of soda
salts out.
By continuing to evaporate and to add fresh quantities of solution, a
large proportion of the sulphate of soda of marketable purity or such as
can be readily purified for the market, may be separated whilst almost
the whole of the chlorides remain in solution, and may be drained off in
the ordinary manner.
Having thus fully described my said Invention and the manner of
performing the same, I wish it understood that I claim,―
First. The separation of silver and gold from solutions containing
these metals, and copper with a fractional part of the latter metal by
means of iron in a finely divided condition applied as herein described.
Second. The separation of sulphate of soda from solutions containing
this salt and metals by passing through the solution the products of
combustion from a furnace or cupola, as herein described.
In witness whereof, I, the said George James Snelus, have here-
unto set my hand and seal, this Twenty-eight day of April,
in the year of our Lord One thousand eight hundred and seventy-
fen