IMPROVEMENTS IN THE MANUFACTURE OF SULPHATE OF ALUMINA
Year: 1880

page_text: LETTERS PATENT to Benjamin Edward Reina Newlands, of East Ham,
in the County of Essex, for an Invention of "IMPROVEMENTS IN THE
MANUFACTURE OF SULPHATE OF ALUMINA."
PROVISIONAL SPECIFICATION left by the said Benjamin Edward Reina
Newlands at the Office of the Commissioners of Patents on the 17th December
1880.
BENJAMIN EDWARD REINA NEWLANDS, of East Ham, in the County of Essex.
"IMPROVEMENTS IN THE MANUFACTURE OF SULPHATE OF ALUMINA."
The object of this Invention is the removal of the greater part of the free
sulphuric acid, and also a considerable part of the iron with which the ordinary
sulphate of alumina is almost invariably contaminated.
For this purpose I evaporate a solution of sulphate of alumina containing more
or less impurities to such a degree (say, 35° Beaume, or thereabouts, at the boiling
point), that it will partially solidify on cooling, forming a magma or mass of
crystals; or I add a small quantity of water to solid sulphate of alumina and incor-
porate the two together so as to produce a magma. This magma I submit to
pressure in a filter-press worked by hydraulic or other power, or I place it in an
apparatus in which it is exposed to atmospheric pressure with or without exhaustion,
and so obtain cakes of sulphate of alumina containing almost no free acid and only
a very small amount of iron. Instead of using a press the magma may be dried in
a centrifugal machine lined by preference with flannel, and thus a nearly pure salt
may be obtained.
After having separated a considerable portion of the sulphate of alumina by
means of a filter press or otherwise, as above described, the residual mother liquor
is concentrated by heat till it is sufficiently strong to give a magma of crystals on
cooling, and this second magma is submitted to pressure as before, and yields a
tolerably pure sulphate of alumina. The same operation may be repeated, and the
impure mother liquor finally left yields a sulphate of alumina containing a con-
siderable amount of iron which may be used for the purification of sewage or for
Prins J1

page_text: any other purpose for which sulphate of alumina is required, and in which the
presence of iron is not objectionable.
In carrying out my Invention, instead of using ordinary sulphate of alumina I
sometimes employ a mixture of this compound with silica, such as the well known
alum-cake.
Before evaporating the solution of sulphate of alumina or mixing the impure
sulphate of alumina with water, or at the time of so doing I sometimes add to it a
small quantity of hydrochloric acid or of a soluble chloride, such as chloride of
aluminium, capable of forming chloride of iron by double decomposition with the
sulphate of iron present. This addition renders the iron more easily removable.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Benjamin Edward Reina Newlands in the Great Seal Patent Office
on the 26th May 1881.
BENJAMIN EDWARD REINA NEWLANDS, of East Ham, in the County of Essex.
"IMPROVEMENTS IN THE MANUFACTURE OF SULPHATE OF ALUMINA."
My said Invention relates to the separation or removal from impure sulphate of
alumina of the greater part of the free sulphuric acid, and also of a considerable
part of the soluble salts of iron with which the ordinary sulphate of alumina is
almost invariably contaminated.
In carrying out my said Invention I evaporate a solution of sulphate of alumina
containing more or less impurities to such a degree (say, 35° Beaume, or thereabouts,
at the boiling point), so that it will partially solidify on cooling, forming a magma
or mass of crystals; or I add a small quantity of water to solid sulphate of
alumina, and incorporate the two together so as to produce a magma, or I dissolve
the solid sulphate of alumina or alum cake in sufficient hot water so as to produce
after filtration and cooling a magma. This magma I place in bags, and subject
the same to pressure in a hydraulic or other press, or I submit it to pressure in a
filter-press worked by hydraulic or other power; or I place it in an apparatus, in
which it is exposed to atmospheric pressure with or without exhaustion, and so
obtain cakes of sulphate of alumina almost free from acid, and only containing a
very small amount of iron.
After having separated a considerable portion of the sulphate of alumina by the
means herein before described the residual mother liquor is concentrated by heat
until it is sufficiently strong to give a magma of crystals on cooling, and this second
magma is submitted to pressure, as before mentioned, and will then be found to
yield a tolerably pure sulphate of alumina.
The same operation may be repeated, and the impure mother liquor finally left
yields a sulphate of alumina containing a considerable amount of iron, which may
be used for the purification of sewage or for any other purpose for which sulphate
of alumina is required, and in which the presence of iron is not objectionable.

page_text: In carrying my Invention into effect, instead of using ordinary sulphate of
alumina I sometimes employ a mixture of this compound with silica, such as the
well known alum cake.
Before evaporating the solution of sulphate of alumina or mixing the impure
sulphate of alumina with water, or at the time of so doing I sometimes add to it
a small quantity of hydrochloric acid, or of a suitable soluble chloride, such as
chloride of aluminium, capable of forming chloride of iron, by double decomposition
with the sulphate of iron present. This addition renders the iron more easily
removable.
Having now described and particularly ascertained the nature of my said
Invention, and the manner in which the same is or may be used or carried into
effect, I would observe in conclusion that what I consider to be novel and original,
and therefore claim as the Invention secured to me by the hereinbefore in part
recited Letters Patent is,-
The manufacture of sulphate of alumina from impure sulphate of alumina
magma by submitting the same to pressure, in order that the greater portion of
the free sulphuric acid and of the soluble salts of iron contained therein may be
removed therefrom, substantially in the manner herein before described.
In witness whereof, I, the said Benjamin Edward Reina Newlands, have
to this my Specification set my hand and seal, this Twenty sixth day of
May, One thousand eight hundred and eighty one.