IMPROVEMENTS IN TREATING TIN ORES, AND IN ATTARATUS FOR TREATING ORES AND MATTERS CONTAINING ARSENIC
Year: 1863

page_text: LETTERS PATENT to James Polkinghorne, of Redruth, in the County of
Cornwall, Tin Smelter, for the Invention of "IMPROVEMENTS IN TREATING
LETTERS PATENT to James Polkinghorne, of Redruth, in the County of
Cornwall, Tin Smelter, for the Invention of "IMPROVEMENTS IN TREATING
TIN ORES, AND IN ATTARATUS FOR TREATING ORES AND MATTERS CONTAINING
ARSENIC."
Sealed the 11th September 1863, and dated the 12th March 1863.
PROVISIONAL SPECIFICATION left by the said James Polkinghorne at
the Office of the Commissioners of Patents, with his Petition, on the
12th March 1863.
I, JAMES POLKINGHORNE, of Redruth, in the County of Cornwall, Tin
Smelter, do hereby declare the nature of the said Invention for "IMPROVE-
MENTS IN TREATING TIN ORES, AND IN APPARATUS FOR TREATING ORES AND MATTEES
CONTAINING ARSENIC," to be as follows:-
My Invention consists, firstly, in treating tin ores as hereafter described.
I heat tin ores with rectified concentrated or diluted sulphuric acid and
chloride of sodium, and keep them in a heated state till the whole or nearly
the whole of the iron, copper, and foreign matters and impurities are dissolved
or so reduced that they may be easily separated by washing. Four hours will
generally be sufficient, but more or less time may be allowed. The progress
of the operation may be ascertained from time to time by withdrawing a small
portion from the furnace or pan and washing it in water, and then smelting
When the ore has been sufficiently acted upon it is removed from
the furnace or pan to be washed in water to separate from it the soluble and
insoluble matters and impurities it may contain.

page_text: My Invention consists, secondly, in an improved method of smelting tin
In order to free the metal contained in the ores I mix twenty parts by
weight of the ores containing about from 60 to 72 per cent. of metal, with a
flux composed of about from four to five parts by weight of culm, and from
one-thirtieth to one-eightieth part by weight of old wrought iron, wrought-
iron borings or turnings, or tin-plate clippings, and from one to two parts
by weight of caustic soda, bicarbonate of soda, pearlash, or potash. I smelt
the mixture of ore and flux in an ordinary smelting or reverberatory furnace,
in like manner to that usually pursued for the purpose of reducing tin ores.
My Invention consists, thirdly, of an apparatus for treating ores and other
matters containing arsenic, in order to obtain arsenic therefrom. My appa-
ratus for obtaining arsenic from ores and other matters containing the same
consists of a retort placed in a furnace and surrounded by flues, with an
outlet leading from the retort into a chamber for collecting the gases. The
ores or matters are fed into the retort through doors made for the purpose, or
through shoots leading into and through the roof or upper part of the retort;
a pipe is carried through and into the upper part of the retort, through which
the arsenious gases are led into the usual poison chambers or flues.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said James Polkinghorne in the Great Seal Patent Office on the
12th September 1863.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
POLKINGHORNE, of Redruth, in the County of Cornwall, Tin Smelter, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, beaing date the Twelfth day of March, in the year of our Lord
One thousand eight hundred and sixty-three, in the twenty-sixth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said James Polkinghorne, Her special licence, that I, the said James
Polkinghorne, my executors, administrators, and assigns, or such others as I,
the said James Polkinghorne, 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 TREATING TIN ORES, AND IN APPARATUS FOR TREATING ORES

page_text: AND MATTERS CONTAINING ARSENIC," upon the condition (amongst others) that
I, the said James Polkinghorne, my executors or administrators, by an instru-
ment 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
Patent Office within six calendar months next and
immediately after the date of the said Letters Patent.
filed in the Great Seal
NOW KNOW YE, that I, the said James Polkinghorne, 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 thereof, that is to say:-
My Invention consists, firstly, in treating tin ores as hereafter described.
I treat tin ores with rectified concentrated or diluted sulphuric acid and
chloride of sodium, and keep them in a heated state till the whole or nearly
the whole of the iron, copper, and foreign matters and impurities are dissolved
or so reduced that they may be easily separated by washing. Four hours will
generally be sufficient, but more or less time may be allowed. The progress
of the operation may be ascertained from time to time by withdrawing a
small portion from the furnace or pan and washing it in water, and then
smelting the ore. When the ore has been sufficiently acted upon it is
removed from the furnace or pan to be washed in water to separate from it
the soluble and insoluble matters and impurities it may contain.
My Invention consists, secondly, in an improved method of smelting tin
ores. In order to free the metal contained in the ores I mix 20 parts by
weight of the ores containing about from 60 to 72 per cent. of metal, with a
flux composed of about from 3 to 5 parts by weight of culm, and from about
th to of a part by weight of wrought iron, wrought-iron borings or
turnings, or tinplate clippings, and from about th of a part to 2 parts by
weight of caustic soda, bicarbonate of soda, pearlash, or potash, according to the
nature of the tin ores. The exact proportions must be fixed by a competent
smelter, whose experience will readily enable him to apportion the proper doses
according to the ores operated on. I smelt the mixture of ore and flux in an
ordinary smelting or reverberatory furnace, in like manner to that usually
pursued for the purpose of reducing tin ores.
My Invention consists, thirdly, of an apparatus for treating ores and other
matters containing arsenic, in order to obtain arsenic therefrom. My appa-
ratus for obtaining arsenic from ores and other matters containing the same
consists of a furnace surrounded by flues, with an outlet leading from the
furnace into a chamber for collecting the gases. The ores or matters are fed

page_text: into the retort through doors made for the purpose, or through shoots leading
into and through the roof or upper part of the retort; a pipe is carried
through and into the upper part of the retort through which the arsenious
gases are led into the usual poison chambers or flues.
And having now described the nature of my said Invention, and in what
manner the same is to be performed, I declare that I claim,―
First, treating tin ores by the means and in manner substantially herein-
before firstly described.
Second, treating tin ores by the means and substantially in manner herein-
before secondly described.
And, third, the apparatus herein-before described for treating tin ores and
matters containing arsenic.
In witness whereof, I, the said James Polkinghorne, have hereunto set
my hand and seal, this Eleventh day of September, One thousand
eight hundred and sixty-three.
JAMES POLKINGHORNE. (L.S.)