IM- PROVEMENTS IN THE MANUFACTURE OF SODA AND POTASSA
Year: 1867

page_text: LETTERS PATENT to James Hargreaves, of Appleton-within-Widnes, in
the County of Lancaster, Analytical Chemist, for the Invention of "IM-
PROVEMENTS IN THE MANUFACTURE OF SODA AND POTASSA."
Sealed the 12th June 1868, and dated the 14th December 1867.
PROVISIONAL SPECIFICATION left by the said James Hargreaves at
the Office of the Commissioners of Patents, with his Petition, on the
14th December 1867.
I, JAMES HARGREAVES, of Appleton-within-Widnes, in the County of
Lancaster, Analytical Chemist, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN THE MANUFACTURE OF SODA AND POTASSA," to be
as follows:
When soda is made by what is commonly known as Leblanc's process coal
is used to reduce the sulphate of soda. The impurities in the coal, which
consist principally of pyrites, aluminous shale, and other materials containing
silica and alumina in large proportions, act injuriously in the manufacture.
Pyrites, by communicating oxide of iron, and by assisting in the formation of
sulphide of sodium, damages the soda produced and renders it unfit for many
purposes, and aluminous shale and the other materials containing silica and
alumina cause great loss of soda by assisting to form insoluble compounds of
soda.
The object of my Invention is to produce soda and potassa of uniformly
good and of better qualities than have been obtainable hitherto. This I

page_text: accomplish by using coal free from the impurities above mentioned. To effect
the separation of the said impurities I wash the coal as it comes from
the mine, and preferably small coal, in a liquid bath, the liquid of such
specific gravity that the coal will float therein, whilst the impurities, they
being of higher specific gravity, will sink to the bottom. The coal is "tipped
into the liquid, is agitated by a rake or other means, and is then skimmed off
in the pure state. I prefer to use as the liquid bath a solution of sulphate of
soda or of sulphide of sodium when the pure coal is to be used in the manu-
facture of soda. The said pure coal I mix with sulphate of soda and limestone
either in a wet or dry state, to make "black ash." When the pure coal is to
be used in the manufacture of potassa, I prefer to uso a liquid bath of
a solution of sulphate of potassa or sulphide of potassium; in other respects
I proceed in the same manner as in making soda.
It will be obvious that my improvements are applicable to the reduction of
sulphate of soda when used in the manufacture of glass.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said James Hargreaves in the Great Seal Patent Office on the
12th June 1868.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
HARGREAVES, of Appleton-within-Widnes, in the County of Lancaster,
Analytical Chemist, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fourteenth day of December, in the year of our
Lord One thousand eight hundred and sixty-seven, in the thirty-first year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said James Hargreaves, Her special license that I, the said
James Hargreaves, my executors; administrators, and assigns, or such
others as I, the said James Hargreaves, 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 THE MANUFACTURE OF SODA AND POTASSA,"
upon the condition (amongst others) that I, the said James Hargreaves,
my executors or administrators, by an instrument in writing under my,
or their; or one of their hands and seals, should particularly describe and

page_text: ascertain the nature of the said Invention, and in what manner the samo
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 James Hargreaves, 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 :-
When soda is made by what is commonly known as Leblanc's process coal
is used to reduce the sulphate of soda. The impurities in the coal, which
consist principally of pyrites, aluminous shale, and other materials containing
silica and alumina in large proportions, act injuriously in the manufacture.
Pyrites by communicating oxide of iron and by assisting in the formation of
sulphide of sodium damages the soda produced and renders it unfit for
many purposes, and aluminous shale and the other materials containing
silica and alumina cause great loss of soda by assisting to form insoluble
compounds of soda.
66
The object of my Invention is to produce soda and potassa of uniformly
good and of better qualities than have been obtainable hitherto, This I
accomplish by using coal free from the impurities above mentioned. To effect
the separation of the said impurities I wash the coal as it comes from the
mine, and preferably small coal, in a liquid bath, the liquid being of such
specific gravity that the coal will float therein whilst the impurities,
they being of bigher specific gravity, will sink to the bottom. The coal is
tipped" into the liquid, is agitated by a rake or other means, and is then
skimmed off in the pure state. I use as the liquid bath a solution of sulphate
of soda or of sulphide of sodium, when the pure coal is to be used in the
manufacture of soda. The said pure coal I mix with sulphate of soda and
limestone either in a wet or dry state to make "black ash." When the pure
coal is to be used in the manufacture of potassa, I use a liquid bath of a
solution of sulphate of potassa or sulphide of potassium; in other rospects I
proceed in the same manner as in making soda.
:
It will be obvious that my improvements are applicable to the coal used
in the reduction of sulphate of soda when used in the manufacture of
glass.
Having now described the nature of my said Invention, and the manner
in which the same is to be carried into effect, I would have it distinctly
understood that what I claim in the manufacture of soda and potassa is,
the use or employment of solutions of sulphates of soda and potassa an:i

page_text: sulphides of sodium and potassium to separate shale, pyrites, and other
impurities from the coal used for reducing sulphate of soda in the process
known as Leblanc's process or other process substantially the sanie, and for
the manufacturo of glass as hercin set forth.
In witness whereof, I, the said James Hargreaves, have hereunto set my
hand and seal, this Fifth day of June, in the year of our Lord
One thousand eight hundred and sixty-eight.
In the presence of
SAMUEL TENNANT,
Accountant & Clerk,
Darlington.
Too³. R. REED,
Darlington.
JAMES HARGREAVES. (L.B.)