IMPROVEMENTS IN THE 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, Ironfounder, for the Invention of "IMPROVEMENTS IN THE
TREATMENT OF PYRITES, AND IN OBTAINING PRODUCTS THEREFROM."
Sealed the 21st June 1870, and dated the 24th December 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 24th December 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 improvements consist in passing heated air, either alone or mixed
with water vapour, through or among broken, granulated, or powdered
pyrites. The said air may be heated either by passing it through or over
a fire, or by passing it through heated tubes, or by passing it over or

page_text: among bricks or other substances which have been heated, or in any
other suitable manner. When we wish to produce sulphate of soda or
sulphate of potash we add to the said pyrites chloride of sodium or
chloride of potassium previous to passing the said heated air through the
said pyrites. We do so in the proportion of one chemical equivalent
of the said chlorides, or either of them, to every chemical equivalent of
sulphur contained in the said pyrites. When we wish to use heated air
mixed with water vapour we obtain the said water vapour from a boiler
or other suitable apparatus, or we produce water vapour by the com-
bustion of hydrogen or hydrocarbons, by which we can at the same time
heat the said air. If the said pyrites contain copper or zinc soluble salts
thereof are produced, which can be separated by lixivation with water
or with dilute sulphuric acid or dilute hydrochloric acid.
Another method by which we carry our said Invention into effect is
as follows, that is to say:-We enclose the said broken, granulated, or
powdered pyrites, either alone or mixed with chloride of sodium or chloride
of potassium as aforesaid, in a retort, which said retort is heated, and the
said air or mixture of air and water vapour is or are passed through or
among the said pyrites in the said retort, by which means the said air
or mixture of air and water vapour is or are heated along with the said
pyrites.
Note. The oxygen of the atmosphere is the active oxidising agent in
the reactions which occur in the process herein-before set forth, and we
wish it to be understood that where the word "air" is used oxygen or
other gas containing and capable of evolving oxygen is also intended,
meant, and implied. We wish it to be understood that we do not
confine ourselves to the use of the said chloride of sodium or chloride
of potassium to mix with the said pyrites, so long as pyrites whether
raw or burnt is one of the substances reacted upon, substantially as
aforesaid.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said James Hargreaves and Thomas Robinson in the
Great Seal Patent Office on the 24th June 1870.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, JAMES
HARGREAVES, of Widnes, in the County of Lancaster, Analytical Chemist,
and THOMAS ROBINSON, of the same Place, Ironfounder, send greeting.

page_text: WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-fourth day of December, 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 exccutors, administrators, and assigns, or such
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 CBTAINING 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 scals,
should particularly describe and ascertain the nature of the said In-
vention, 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 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, that is to say :-
Our improvements consist in passing heated air, either alone or mixed
with water vapour, through or amongst broken, granulated, or powdered
pyrites, which said pyrites may be either raw pyrites or pyrites from
which the greater part of the sulphur has been separated in the manu-
facture of sulphuric acid, or for other purposes. When we wish to
produce sulphate of soda or sulphate of potash we add to the said pyrites
chloride of sodium or chloride of potassium previous to passing the said
heated air through or amongst the said pyrites. We add the said
chloride of sodium or chloride of potassium in the proportion of about
58.5 parts of the former or 74.5 parts of the latter to every 16 parts of
sulphur present in the said pyrites. When we wish to use heated air
-mixed with water vapour we obtain the said water vapour from a boiler

page_text: or other like apparatus, or we produce water vapour by the combustion
of hydrogen or hydrocarbons, by which means we can at the same time
heat the said air. If the said pyrites contains copper or zinc soluble
salts thereof are produced, which we separate by lixiviation or with
dilute sulpburio acid or dilute hydrochloric acid.
In carrying the foregoing part of our said Invention into effect we
place the said broken, granulated, or powdered pyrites in a suitably
shaped vessel or chamber lined with fire-brick or other suitable
substance. We find that a vessel of the form of an ordinary pyrites
burner does very well, but we do not confine ourselves to any particular
form of apparatus. We force or draw air through the mass of said
pyrites contained in the said chamber or other suitable vessel by any
suitable means, such as gas exhausters, fans, air forcing or blowing
engines, steam jets, chimney draught, or other suitable means. In
practice we find a depth of from four to six feet of the broken,
granulated, or powdered pyrites answers very well when the pyrites is
in pieces of about one inch cube. Should the pieces be smaller a less
depth will answer. For the purpose of making the said process or
treatment continuous the pyrites is fed in at the top of the vessel, and
after the combustion or oxidation of all or nearly all the sulphur by
the action of the heated air drawn off at the bottom in the form of
oxide of iron, with oxides or soluble salts of any copper or zinc
contained in the pyrites, and of sulphate of soda or sulphate of potash
should chloride of sodium or chloride of potassium have been added, as
hercin-before is set forth. We prefer to use air heated to 500° Fah*, for
raw raw pyrites, and 800° for burnt pyrites.
Another method by which we carry our said Invention into effect is
as follows, that is to say:-We enclose the said broken, granulated, or
powdered pyrites, either alone or mixed with chloride of sodium or
chloride of potassium as aforesaid, in a retort (which said retort we
prefer to place in a vertical position), though we do not confine ourselves
to any particular arrangement in that respect. The said retort is heated,
and the said air or mixture of air and water vapour is or are passed
through or amongst the said pyrites in the said retort, by which means
the said air or mixture of air and water vapour is or are heated along
with the said pyrites.
Note. The oxygen of the atmosphere is the active oxidising agent in

page_text: we wish it to be understood that where the word "air" is used oxygen
or other gas containing and capable of evolving oxygen is also intended,
meant, and implied. We also wish it to be understood that we do not
confine ourselves to the use of the said chloride of sodium or chloride
of potassium to mix with the said pyrites, so long as pyrites whether
raw or burnt is one of the substances reacted upon, substantially as
aforesaid.
And now having set forth the nature of our said Invention, and the
methods by which we carry the same into effect, we wish it to be
understood that what we claim is,-
First. The use or employment of heated air, substantially in the manner
and for the purpose set forth.
Second. The use or employment of hydrogen or of hydrocarbons to
produce water vapour, and at the same time heat the air which is passed
or forced through or amongst the said pyrites, substantially in the
manner and for the purpose set forth.
Third. The use or employment of a retort or retorts heated as aforesaid
containing pyrites which is reacted upon by air or a mixture of air
and water vapour, substantially in the manner and for the purpose set
forth.
In witness whereof, I, the said James Hargreaves, have hereunto
set my hand and seal, this Twenty-first day of June, in the year
of our Lord One thousand eight hundred and seventy.
JAMES HARGREAVES. (L.S.)
25 In the presence of
SAMUEL TAYLOR.