IMPROVEMENTS IN THE PRODUCTION OF SULPHATE OF POTASH FOR THE MANUFACTURE OF ALUM
Year: 1869

page_text: LETTERS PATENT to Peter Spence, of Newton Heath, Manchester, in
the County of Lancaster, Manufacturing Chemist, for the Invention
of "IMPROVEMENTS IN THE PRODUCTION OF SULPHATE OF POTASH FOR THE
MANUFACTURE OF ALUM."
Scaled the 13th July 1869, and dated the 15th January 1869.
PROVISIONAL SPECIFICATION left by the said Peter Spence at the
Office of the Commissioners of Patents, with his Petition, on the
15th January 1869.
I, PETER SPENCE, of Newton Heath, Manchester, in the County of
Lancaster, Manufacturing Ohemist, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN THE PRODUCTION OF SULPHATE OF POTASK
FOR THE MANUFACTURE OF ALUM," to be as follows:-
My Invention consists in a method of converting the muriate of
potash of commerce into sulphate of potash so as to be suitable for the

page_text: manufacture of alum when it is produced by digesting or boiling shale
or other aluminous matters with sulphuric acid, as, for example,
according to that process for which Letters Patent were granted to me,
bearing date 27th Nov. 1845, No. 10,970.
My present Invention is carried out by taking the muriate of potash
and heating it with an excess which I prefer to be considerable of
sulphuric acid until the muriatic acid is driven off. The solution, which
now contains sulphate of potash and free sulphuric acid, I run into
vessels where shale or other aluminous matters are being or are to be
boiled with sulphuric acid, and the free acid in the aforesaid solution
then becomes available for combining with alumina, and the sulphate
of potash enters into combination with the solution of sulphate of
alumina to form alum as is well known.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Peter Spence in the Great Seal Patent Office on
the 15th July 1869.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, PETER
SPENCE, of Newton Heath, Manchester, in the County of Lancaster,
Manufacturing Chemist, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent, bearing date the Fifteenth day of January, 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 me, the said Peter Spence, Her
special license that I, the said Peter Spence, my executors, adminis-
trators, and assigns, or such others as I, the said Peter Spence,
my executors, administrators, and assigns, should at any time
agree with, and no others, from time to time and at all times thero-
after 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
Luvention for "IMPROVEMENTS IN THE PRODUCTION OF SULPHATE OF POTASH
FOR THE MANUFACTURE OF ALUM," upon the condition, amongst others, that

page_text: and seal, should particularly describe and ascertain the nature of the
Invention, and in what manner the same was to be performed, and
cause the same to be filed in the Great Seal Patent Office under six
calendar months next and immediately after the date of the said Letters
Patent.
NOW KNOW YE, that I, the said Peter Spence, 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, that is to say :-
My Invention consists in a method of converting muriate of potash of
commerce into sulphate of potash so as to be suitable for the manu-
facture of alum when it is produced by digesting or boiling shale or
other aluminous matters with sulphuric acid, as, for example, according
to that process for which Letters Patent were granted to me, bearing
date Twenty-seventh November One thousand eight hundred and forty-
five, No. 10,970.
My present Invention is carried out by taking the muriate of potash
and heating it with an oxcess of sulphuric acid, and I prefer that this
excess should be about 50 per cent. above its combining quantity. The
boiling or heating I conduct in a vessel similar to that which is used
in the manufacture of chlorine from hydrochloric acid and peroxido of
manganese, the heating medium being a jet or jets of steam, and the
operation is continued from three to five hours, or until the whole of the
muriatic acid is driven off. The resulting solution, which now contains
sulphate of potash and free sulphuric acid, I run into vessels whero
shale or other aluminous matters are being or are to be boiled with
sulphuric acid, and the free acid in the said solution becomes availablo
for combining with alumina, and the sulphate of potash enters into
combination with the solution of sulphate of alumina to form' alum as is
well known.
Having thus described and ascertained the nature of my said Inven-
tion, and the manner in which the same is to be performed, I desire it
to be understood that I claim as secured to me under the above in part
recited Letters Patent and for the purpose above set forth, the conversion

page_text: of muriate of potash into sulphate of potash by boiling or heating it with
excess of sulphuric acid.
In witness whereof, I, the said Peter Spence, have hereunto set
my hand and scal, the Fourteenth day of July, in the year of our
Lord One thousand eight hundred and sixty-nine.