IMPROVEMENTS IN OBTAINING SILVER AND GOLD FROM Cupreous PYRITES
Year: 1871

page_text: LETTERS PATENT to William Wright, of Mostyn, in the County of
Flint, for the Invention of "IMPROVEMENTS IN OBTAINING SILVER AND
GOLD FROM Cupreous PYRITES."
Sealed the 5th September 1871, and dated the 28th March 1871.
PROVISIONAL SPECIFICATION left by the said William Wright at
the Office of the Commissioners of Patents, with his Petition, on
the 28th March 1871.
I, WILLIAM WRIGHT, of Mostyn, in the County of Flint, do hereby
declare the nature of the said Invention for "IMPROVEMENTS IN OBTAINING
SILVER AND GOLD FROM CUPREOUS PYRITES," to be as follows:-
: -
This Invention has for its object improvements in obtaining silver
and gold from cupreous pyrites. In the treatment of cupreous pyrites
it is at present usual to roast it with salt, and a solution is thus obtained
containing copper, silver, and gold. From this solution it has been
before attempted to precipitate the silver and gold in a metallic state by
means of metallic copper, but heretofore without much success, as in

page_text: the product the silver and gold have borne but a very small proportion
to the metallic copper remaining undisolved.
I overcome this difficulty and obtain a very rich product by using
the metallic copper in a very finely divided state and by separating the
sub-chloride of copper produced in the operation by dissolving it in
brine.
The process is conducted in the following manner :-The solution from
the roasted pyrites is run into a tank; the finely divided copper in
suitable quantity is added to it, and the solution is agitated; then it is
allowed to subside and the metallic particles go down together with
some of the sub-chloride of copper.
For convenience I use two settling tanks. The solution having
deposited all the metallic particles, but having some sub-chloride of
copper in suspension, is then run into a tank in which the copper in
solution and suspension is precipitated from it as metallic copper by
means of scrap iron in the usual way. The operation is repeated in the
first tank until a sufficient quantity of precipitate is obtained, and this
is then removed and boiled with brine, and the residue will consist
mainly of metallic copper, silver, and gold, which will be found to be
rich enough to be at once sold, or it may be roasted until all the copper
is converted into black oxide; this will then dissolve in sulphuric acid,
leaving the silver and gold not acted upon, and they may then be melted
and run into ingots and sold. The brine, after use, is run into a tank
with scrap iron and so the copper is precipitated from it. Afterwards it
is used to boil another charge of precipitate, and so on.
I can conveniently obtain the copper in a suitably divided form by
precipitating it by means of iron from a solution which is kept constantly
agitated during the process of precipitation.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said William Wright in the Great Seal Patent Office 30
on the 28th September 1871.

page_text: WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-eighth day of March, in the
year of our Lord One thousand eight hundred and seventy-one, in the
thirty-fourth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said William Wright, Her special license
that I, the said William Wright, my executors, administrators, and
assigns, or such others as I, the said William Wright, my executors,
administrators, and assigns, should at any time agree with, and no others,
from time to time and at all times thereafter 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 Invention for "IMPROVEMENTS IN OBTAINING
SILVER AND GOLD FROM CUPREOUS PYRITES," upon the condition (amongst
others) that I, the said William Wright, 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 manner 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 William Wright, do hereby declare
the nature of the said Invention, and in what manner the same is to
be performed, to be particularly described and ascertained in and by the
following statement thereof, that is to say:-
This Invention has for its object improvements in obtaining silver
and gold from cupreous pyrites. In the treatment of cupreous pyrites
it is at present usual to roast it with salt, and a solution is thus obtained
containing the copper, silver, and gold. From this solution it has been
before attempted to precipitate the silver and gold in a metallic state by
means of metallic copper, but heretofore without much success, as in
the product the silver and gold have borne but a very small proportion
to the metallic copper remaining undissolved.
According to my Invention I overcome this difficulty and obtain a
very rich product by using the metallic copper in a very finely divided
state and by separating the sub-chloride of copper produced in the
operation by dissolving it in brine.
-The
I prefer to conduct the process in the following manner:-
solution from the roasted pyrites is run into a tank, hereafter called

page_text: No. 1, containing a quantity of sub-chloride of copper with which it is
well mixed and then allowed to settle, and it will be found to have
precipitated a certain portion of the silver. The solution is then blown
up into tank No. 2, and the finely divided copper in suitable quantity
is added to it and well agitated, then it is allowed to subside and the
metallic particles go down together with some of the sub-chloride of
copper and chloride of silver.
For convenience I use two settling tanks. The solution having
deposited all the metallic particles, but having some sub-chloride of
copper in suspension, is then run into a tank in which the copper in
solution and suspension is precipitated from it as metallic copper by
means of scrap iron in the usual way. As soon as a sufficient quantity
of sub-chloride is deposited in the settler it is tapped off into No. 1
tank and used for saturating the solution, as previously described. The
operation is repeated, and as soon as a sufficient quantity of precipitate
is obtained in No. 2 tank it is boiled with brine, and the residue will
consist mainly of metallic copper, silver, and gold, which will be found
to be rich enough to be at once sold, or it may be roasted until all the
copper is converted into black oxide; this will then dissolve in sulphuric.
acid, leaving the silver and gold not acted upon, and they may be then
melted and run into ingots and sold. The brine solution containing the
chloride of silver and sub-chloride of copper is treated with very fine
copper to precipitate the silver, and then run into another tank con-
taining iron to make fine copper.
charge, and so on.
Afterwards it is used to boil another
I can conveniently obtain the copper in a suitably divided form by
precipitating it by means of iron from a solution which is kept constantly
agitated during the process of precipitation.
In witness whereof, I, the said William Wright, have hereunto
set my hand and seal, this Twenty-sixth day of September, in
the year of our Lord One thousand cight hundred and seventy-
one.
WILLIAM WRIGHT. (L.S.)