IMPROVEMENTS IN TREATMENT OF PYRITES AND IN OBTAINING PRODUCTS THEREFROM
Year: 1869

page_text: LETTERS PATENT to James Hargreaves, of Widnes, in the County of
Lancaster, Analytical Chemist, and Thomas Robinson, of the same
Place, Lion Founder, for the Invention of "IMPROVEMENTS IN
TREATMENT OF PYRITES AND IN OBTAINING PRODUCTS THEREFROM"
Sealed the 29th April 1870, and dated the 1st November 1869.
PROVISIONAL SPECIFICATION left by the said James Hargreaves and
Thomas Robinson at the Office of the Commissioners of Patents,
with their Petition, on the 1st November 1869.
We, JAMES HARGREAVES, of Widnes, in the County of Lancaster,
Analytical Chemist, and THOMAS ROBINSON, of the same Place, Iron
Founder, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN THE TREATMENT OF PYRITES AND IN OBTAINING PRODUCTS
THEREFROM." to be as follows:-
Our Invention consists in passing a current or currents of heated
atmospheric air and water vapour together through a layer or layers of
broken, crushed, or powdered pyrites, so as to convert sulpludes of iron
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page_text: and copper into sulphates; the said sulphates, or either of them, are then
separated by lixiviation or other suitable means. The soluble sulphates
are treated by any of the well known and suitable means to render them
available, and when burnt pyrites is the material operated upon we
obtain a residue of oxide of iron, which is available in the manufacture
of iron
The method by which we prefer to carry our said Invention into effect
is as follows The said pyrites, which may be either raw or the burnt
pyntes (such as is produced in the manufacture of sulphuric acid), is
placed in a vat with a perforated bottom, and by means of a jet of steam
at a high pressure a current of air either of the ordinary temperature or
superheated is forced through the layer or layers of pyrites.
Another method by which we may carry our said Invention into effect
1s to draw or force a current of heated and moistened air through the
said layer or layers of pyrites, or we pass heated air alone through the
said layer or layers of pyrites, and moisten or wet the said mass of
pyrites with water. When we wish to form sulphate of soda we add
chloride of sodium to the mass of pyrites before it is acted upon by the
curient of moist and heated air. The solution obtained by lixiviation is
boiled to dryness and heated to redness to expel hydrochloric acid. The
oxide of iron is separated by dissolving out the sulphate of soda, and
used as a pigment for glass polishing or for other purposes.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said James llai greaves and Thomas Robinson in the
Great Seal l'atent Office on the 29th April 1870.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, JAMES
ПTARGREAVES, of Widnes, in the County of Lancaster, Analytical Chemist,
and THOMAS ROBINSON, of the same Place, lion Founder, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by He
Letters Patent, bearing date the First day of November, in the year
of our Lord One thousand eight hundred and sixty-nine, in the thirty-
third year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto us, the said James Hargreaves and Thomas
Robinson, Her special license that we, the said James Hargreaves and
Thomas Robinson, our executors, administrators, and assigns, or such

page_text: others as we, the said James Hargreaves and Thomas Robinson, our
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 THE TREATMENT OF PYRITES AND IN OBTAINING PRODUCTS THEREFROM," upon
the condition (amongst others) that we, the said James Hargreaves and
Thomas Robinson, our executors or administrators, by an instrument
in writing under our, or their, or one of our or 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 l'atent Office within six
calendar months next and immediately after the date of the said Letters
Patent.
NOW KNOW YE, that we, the said James Hargreaves and Thomas
Robinson, do hereby declare the nature of our 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 writing, that is to
say:-
Our Invention consists in passing a current or currents of heated
atmospheric air and water vapour together through a layer or layers of
broken, crushed, or powdered pyrites, so as to convert the sulphides of
Iron and copper, or either of them, into sulphates; the said soluble
sulphates, or either of them, are separated by lixiviation, and then
treated by any known means to render the said sulphates, or either of
them, available. When burnt pyrites is the material to be operated
upon we convert the remaining sulphides of copper and iron, or either of
them, into soluble sulphates in the manner herein set forth; and after
separating the said sulphate or sulphates, or either of them, the
residue of oxide of iron is available in the manufacture of iron and for
other purposes.
The method by which we prefer to carry our said Invention into effect
is as follows:-The said pyrites, which may be either raw pyrites or
burnt pyrites (such, for instance, as is produced when sulphuric acid is
made by the combustion of pyrites), is placed in a vat or other suitable
vessel with a perforated bottom, and by means of a jet of steam at a high
pressure, or by means of air pumps, fans, or other suitable means, a

page_text: current of air either of the ordinary temperature or superheated is forced
through the said layer or layers of pyrites.
Another method by which we may carry our said Invention into effect
is to draw or force a current of heated and moistened air, or air mixed
with water vapour, through the said layer or layers of pyrites, or we pass
heated air alone through the said layer or layers of pyrites, and moisten
or wet the said mass of pyrites with water When we wish to form
sulphate of soda we add chloride of sodium to the mass of pyrites in the
proportion of about 4 parts of chloride of sodium to every one part of
sulphur contained in the pyrites before the said mass of pyrites is acted
upon by the current of moist and heated air. After being acted upon by
the said moist and heated air the said mass of pyrites and the products
of the decomposition of chloride of sodium are lixiviated, and the
sulphate of soda together with soluble salts of iron and copper removed
in solution. The solution of sulphate of soda aforesaid is then con-
centrated to dryness and heated to redness, or to a sufficient temperature
to expel hydrochloric acid and render the salts of iron insoluble.
salts of copper are present we previous to heating the said sulphate of
soda precipitate the copper either as metal or as sulphide by means now
well known. The oxide of iron which remains after the separation of
the sulphate of soda may be used as a pigment for grinding glass or in
the manufacture of iron.
If
When water vapour is used with air of the ordinary temperatures the
chemical action is very slow; we therefore prefer to use air superheated
to about 500 to 700 degrees of Fahrenheit's thermometer, and when we
use superheated air we make the vats or other vessels of fire-brick or of
other suitable substances. When superheated air is used rapid com-
bustion of the pyrites is induced, and a great proportion of the sulphur
is carried off in the form of sulphurous acid when no chloride of sodium
is present, but when chloride of sodium is present in the proportions
afore-mentioned along with excess of ait sulphuric acid is formed, by
which the chloride of sodium is decomposed and sulphate of soda is
formed, while hydrochloric acid is liberated. We condense the hydio-
chloric acid formed as aforesaid in condensing towers or by other suitable
means.
In practice we prefer to use heated air moistened with about ten
per cent. of water vapour, but we do not confine ourselves, as will be
obvious from the foregoing description, to that proportion.

page_text: Having now described the nature of our said Invention, and par-
ticularized the same in such manner that others will be enabled to carry
our improvements into beneficial operation, we desire to state that we
do not confine ourselves to any particular mode of heating the air, nor
of obtaining water vapour, nor of passing air through the broken,
crushed, or powdered pyrites; what we do claim is, forcing, drawing, or
passing a curient of air and water vapour, either cold or superheated,
through broken, crushed, or powdered pyrites, or a mixture of pyrites
and chloride of sodium, substantially in the manner and for the purposes
set forth.
In witness whereof, I, the said James Hargreaves, have hereunto
set my hand and seal, this Twenty-eighth day of April, in the
year of our Loid One thousand eight hundred and seventy.
Witness to the signature of the
said James Hargreaves,
CHARLES ROBINSON.
JAMES HARGREAVES. (L.S.)