IMPROVEMENTS IN THE TREATMENT OF NATURAL PHOSPHATES OF ALUMINA FOR THE PURPOSE OF OBTAINING SULPHATE OF ALUMINA AND PHOSPHORIC ACID OR COMPOUNDS THEREOF.
Year: 1871

page_text: LETTERS PATENT to John Berger Spence and Peter Dunn, of Man-.
chester, in the County of Lancaster, Merchants, for the Invention
of "IMPROVEMENTS IN THE TREATMENT OF NATURAL PHOSPHATES OF ALUMINA
FOR THE PURPOSE OF OBTAINING SULPHATE OF ALUMINA AND PHOSPHORIC ACID
OR COMPOUNDS THEREOF.'
"
Sealed the 5th December 1871, and dated the 15th June 1871.
PROVISIONAL SPECIFICATION left by the said John Berger Spence
and Peter Dunn at the Office of the Commissioners of Patents, with
their Petition, on the 15th June 1871.
We, JOHN BERGER SPENCE and PETER DUNN, of Manchester, in the
County of Lancaster, Merchants, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN THE TREATMENT OF NATURAL PHOSPHATES
OF ALUMINA FOR THE PURPOSE OF OBTAINING SULPHATE OF ALUMINA AND PHOSPHORIC
ACID OR COMPOUNDS THEREOF," to be as follows:-
Our Invention consists in a decomposition of natural phosphates of
alumina whereby we obtain sulphate of alumina and also phosphoric

page_text: .
acid or compounds thereof, which afford valuable fertilizing agents or
may be used for other known purposes.
In carrying out our Invention we take natural phosphate of alumina
and having broken it (if necessary) into small pieces, place it in a
leaden or other suitable vessel and pour sulphuric acid thereon, the
quantity of which acid to a given weight of the mineral will vary
according to the quality of the said mineral. The result is the formation
of sulphate of alumina and also phosphoric acid, which may be used
as before-mentioned.
The above process may be varied by substituting alkaline sulphates :
or sulphurous acid for the sulphuric acid, but in this case sulphite of
alumina will be produced which changes however into the sulphate on
exposure to air.
The combined products may be separated by operations adopted in
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John Berger Spence and Peter Dunn in the Great
Seal Patent Office on the 15th December 1871.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, JOHN
BERGER SPENCE and PETER DUNN, of Manchester, in the County of
Lancaster, Merchants, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Fifteenth day of June, in the year
of our Lord One thousand eight hundred and seventy-one, in the thirty-
fourth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto us, the said John Berger Spence and Peter Dunn,
Her special licence that we, the said John Berger Spence and Peter
Dunn, our executors, administrators, and assigns, or such others as
we, the said John Berger Spence and Peter Dunn, 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

page_text: "
THE TREATMENT OF NATURAL PHOSPHATES OF ALUMINA FOR THE PURPOSE OF
OBTAINING SULPHATE OF ALUMINA AND PHOSPHORIC ACID OR COMPOUNDS THEREOF,"
upon the condition (amongst others) that we, the said John Berger
Spence and Peter Dunn, our executors or administrators, by an instru-
inent in writing under our 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 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 John Berger Spence on behalf of
myself and of the said Peter Dunn, 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 Invention consists in a decomposition of natural phosphates of
alumina whereby we obtain sulphate of alumina and also phosphoric
acid or compounds thereof which afford valuable fertilizing agents, or
may be used for other known purposes.*
In carrying out our Invention we take the natural phosphate of
alumina, and having broken it (if necessary) into small pieces place
it in a leaden or other suitable vessel and pour sulphuric acid thereon
in the proportions of about twelve hundredweight of sulphuric acid to
one ton of phosphate of alumina, but the proportion of sulphuric acid
may be increased or decreased according to the per-centage of alumina
contained in the phosphate of alumina. After digestion for a few hours
the result will be the formation of sulphate of alumina and phosphoric
acid, and in order to separate the alumina from the acid we introduce.
ammoniacal water or the products distilled therefrom until the alumina
is precipitated. This substance can then be obtained by running off the
supernatant liquor from the precipitated alumina. We then add sul-
phuric acid to the precipitate in about equal proportions when sulphate
of alumina will be formed. The phosphoric acid thus set free from the
alumina may be collected and obtained or combined with any desired
base so as to form salts by any of the known processes for so doing.
The above process may be varied by substituting alkaline sulphates
or sulphurous acid for the sulphuric acid, but in this case sulphite of

page_text: •
alumina will be produced, which will, however, be converted into
the sulphate by exposure to air, so that it may take up the required
proportion of oxygen.
The process may be varied by the use of soda or potash or their
carbonates in the place of ammonia.
Having now described our Invention and the manner of carrying the
same into effect, we claim as the Invention secured to us by Letters
Patent, as aforesaid, the process herein set forth for the manufacture
of sulphate of alumina and phosphate salts from the natural phosphates
.of alumina.
In witness whereof, I, the said John Berger Spence, have hereunto
set my hand and seal, the Fifteenth day of December, in the
year of our Lord One thousand eight hundred and seventy-one.