IMPROVEMENTS IN THE PRODUCTION OF SULPHATE OF ALUMINA, TO BE USED IN THE FLUID STATE, OR TO BE RENDERED INTO THE SOLID CONDITION, KNOWN COMMERCIALLY AS CAKE ALUM
Year: 1855

page_text: LETTERS PATENT to Peter Spence, of Pendleton, in the County of
Lancaster, Manufacturing Chemist, for the Invention of "IMPROVEMENTS
IN THE PRODUCTION OF SULPHATE OF ALUMINA, TO BE USED IN THE FLUID
STATE, OR TO BE RENDERED INTO THE SOLID CONDITION, KNOWN COMMERCIALLY AS
CAKE ALUM
"
Sealed the 11th April 1856, and dated the 11th October 1855.
PROVISIONAL SPECIFICATION left by the said Peter Spence at the
Office of the Commissioners of Patents, with his Petition, on the 11th
October 1855.
I, the said PETER SPENCE, of Pendleton, in the County of Lancaster,
Manufacturing Chemist, do, hereby declare the nature of the said Invention
for "IMPROVEMENTS IN THE PRODUCTION OF SULPHATE OF ALUMINA, TO BE USED IN
THE FLUID STATE, OR TO BE RENDERED INTO THE SOLID CONDITION, KNOWN COMMER-
CIALLY AS CAKE ALUM," to be as follows:-
My Invention consists in the application of granite in a partial state of
disintegration, as now found in a natural condition, and sometimes used in
the earthenware manufacture. The substance I allude to consists, therefore,
of aluminous powder and numerous small portions of undecomposed rock, the
mechanical arrangement of which is such as to render the mass pervious
to the fluids required for the purpose of my Invention. The material

page_text: in fragments is first calcined, and then placed in a suitable vessel to which
muriatic acid is admitted; this removes any iron that may be present; after
which it is treated with sulphuric acid, kept at a proper degree of heat; the
liquor then run off is sulphate of alumina, which' may be used by calico
printers or others in that state, or it may be concentrated and brought into the 5
form of "cake alum."
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Peter Spence in the Great Seal Patent Office on the
11th April 1856.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, PETER
SPENCE, of Pendleton, in the County of Lancaster, Manufacturing Chemist,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Eleventh day of October, in the year of our Lord
One thousand eight hundred and fifty-five, in the nineteenth year of Her.
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Peter Spence, Her especial license that I, the said Peter Spence,
my executors, administrators, 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 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 PRO-
DUCTION OF SULPHATE OF ALUMINA, TO BE USED IN THE FLUID STATE, OR 'TO BE
RENDERED INTO THE SOLID CONDITION, KNOWN COMMERCIALLY AS 'CAKE' ALUM,"" upon
the condition (amongst others) that I, the said Peter Spence, by an instru-
ment in writing under my hand and seal, 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 Peter Spence, do hereby declare the
nature of my said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement (that is to say):-
My Invention consists in the application and treatment of granite in a
.

page_text: partial state of disintegration, as found in a natural condition, and some-
times used in the earthenware manufacture. The materials I prefer are those
kinds of decomposing.granite cor rock in which the felspar constituent is
in a state of 'decomposition, and appears as a concrete clay powder, held
together: by theiquartz crystals, and is not easily washed out by water; when
theidisintegration has proceeded so far that the powder floats out and makes
water milky; it does not so well suit! my purpose. The substance I allude to
is sometimes called china clay, and is found in great abundance in various
pärts of Cornwall; and may exist: in other localities. Ins selecting the said
decomposing rock I also choose that which contains the smallest amount of
iron; I have obtained it with about one half per cent. of that metal, and, by
preference, such amount should not be exceeded. In manufacturing sulphate
of alumina from the above materials I proceed as follows:-I first break it by'
any ordinary means into pieces about the size of small-beans, avoiding as much
as possible the reducing it to powder. When thus broken I place it upon a.
false bottom in an ordinary iron vessel lined with lead; and set in-brickwork,
with a fire-place beneath. A convenient depth for this vessel, will be found to
be about three feet. The false bottom upon which the material is placed may
be made of fire clay tiles, supported at the junctions by bricks, by which
means sufficient interstices will be gained for percolation, and a space of about
three inches beneath will be left. The quantity of material I place within the
vessel at a charge occupies about two feet in-depth, and the first operation is
to extract as far as possible the iron contained therein. Several equivalent
methods may be adopted for effecting this; 'the following I have found to
answer: I take water which has been impregnated by any well-known means
with sulphurous acid gas, so as to contain double its volume, and I add to such
water one per cent. of sulphuric acid of commerce, the water and acid being
thoroughly mixed. I now cover the material with the said fluid, and allow it
to remain thereon twenty-four hours, by which time I find it will have dissolved
a considerable portion of the iron. If the extract seems to have proceeded
satisfactorily, which may be ascertained by testing in a general way by prus-
siate of potash, I now run off the whole of the liquid, and cover the material
with pure water, which after standing on it for five or six hours is also run off.
I now take sulphuric acid diluted until it stands at eighty of Twaddle's hydro-
meter, 1-4 specific gravity; heat is then applied and the liquid brought up to
at least two hundred and forty degrees Fahrenheit, and kept at that or not
lower until the sulphuric acid is sufficiently saturated with alumina; this will
generally be effected by the boiling being continued from thirty-six to forty-
eight hours. The solution is then run off into stone or leaden coolers, as in the

page_text: ordinary manufacture of sulphate of alumina, and it will concrete into a solid
body, constituting the usual article of commerce; if, however, it be made by
the user, it may be applied in the liquid state. to any purpose to which sulphate
of, alumina in solution, is applicable. Previously, to the adaptation of another
charge of material, water may be, admitted to, the vessel, and after: standing
a sufficient time run off for diluting the acid employed in the next operation.
Having thus described, and ascertained the nature of my said Invention, and
the manner in which the same is to be performed, I desire it to be understood
that I do not limit myself to the construction of apparatus or precise details
of. operation above described; that which I claim as secured to me under the
above in part recited Letters Patent being,-
Firstly, the use of the materials above described for the purposes of obtaining
sulphate of alumina, to be used in the fluid state, or in. the solid condition,
known commercially as cake alum.
Secondly, treating the materials,, substantially as above described, for the
purpose of extracting iron.
In witness whereof, I, the said Peter Spence, have hereunto set my
hand and seal, this Tenth day of April, in the year of our Lord One
thousand eight hundred and fifty-six.
PETER SPENCE. (L.S.)