IMPROVEMENTS IN TREATING ALUMINOUS SUBSTANCES AND IN APPARATUS EMPLOYED THEREFOR, THE SAME BEING IN PART APPLICABLE FOR THE MANUFACTURE OF SULPHATE OF IRON
Year: 1877

page_text: LETTERS PATENT to John Howison, of Hurlet, in the County of Renfrew,
North Britain, for the Invention of "IMPROVEMENTS IN TREATING ALUMINOUS
SUBSTANCES AND IN APPARATUS EMPLOYED THEREFOR, THE SAME BEING
IN PART APPLICABLE FOR THE MANUFACTURE OF SULPHATE OF IRON."
.
Sealed the 27th April 1877, and dated the 24th February 1877.
PROVISIONAL SPECIFICATION left by the said John Howison at the
Office of the Commissioners of Patents on the 24th February 1877.
" IM-
. JOHN HOWISON, of Hurlet, in the County of Renfrew, North Britain.
PROVEMENTS IN TREATING ALUMINOUS SUBSTANCES AND IN APPARATUS EMPLOYED
THEREFOR, THE SAME BEING IN PART APPLICABLE FOR THE MANUFACTURE OF
SULPHATE OF IRON."
The first part of this Invention consists in calcining aluminous shales or fire-clay
in heaps or in draw or flare kilns provided with a pipe leading from the bottom to
some distance up into the centre of the kiln, so that air or steam can be admitted
up into the body or mass of the material for the purpose of assisting or retarding
the calcination. Should there not be sufficient carbonaceous matter present to effect
good calcination, some may be added. The aluminous shales or fire-clays after
being calcined are ground into a fine powder, and it is preferred to use burr stones
for the grinding operation. Any desired quantity of the pulverised material is then
charged into a tank or cistern, which may be heated by steam, superheated or not
by hot water or by fire. Sulphuric acid (either heated or cold) is then added to the
material in the tank or cistern, which, acting upon the aluminous material, converts
it into sulphate of alumina; or the acid may be charged into the tank or cistern
before the aluminous material is charged into it. The mixture of aluminous
material and sulphurice acid, after remaining for a sufficient length of time to
allow of complete reduction to sulphate of alumina, may be lexiviated and con-
centrated in the heated cistern or churn herein-after described.
The second part of this Invention relates to an improved apparatus to be employed
in the manufacture of alum or sulphate of alumina from aluminous minerals, and of
sulphate of iron from manufactured protoxide or peroxide of iron. This part of

page_text: the Invention consists in applying for the lexiviation and concentration a vessel or
churn consisting of an inside casing of iron, which is made circular or of any other
suitable form, and lined with lead or other equivalent material.. Around this inside
casing an outer casing or jacket of iron is placed so as to leave a sufficient space
between it and the inside casing for the steam or hot water to circulate through.
When hot water is employed, a fire-grate. is situated below the outer casing, and
a safety valve is placed either on the top or side of the apparatus. A steam trap is
also placed at the bottom of the outer casing to let off the water of condensation
when the heat necessary for the lexiviation and concentration of the materials is
obtained by the use of steam.
The supply of steam or of hot water to the annular space between the jackets is
capable of being so regulated that the slimy particles (caused by the digestion of the
aluminous earths (in the manufacture of alum or sulphate of alumina), and the
reduction of iron or its protoxide or peroxide (in the manufacture of sulphate of
iron) will settle down thoroughly before any crystallization or solidification takes
place, whereby the said crystallization or solidification is rendered very clean.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Howison in the Great Seal Patent Office on the 18th August
1877.
JOHN HOWISON, of Hurlet, in the County, of Renfrew, North Britain.
"IM-
PROVEMENTS IN TREATING ALUMINOUS SUBSTANCES, AND IN APPARATUS EMPLOYED
THEREFOR, THE SAME BEING IN PART APPLICABLE FOR THE MANUFACTURE OF
SULPHATE OF IRON."
The first part of my said Invention consists in calcining aluminous shales or fire-clay
in heaps or in draw or flare kilns provided with a pipe leading from the bottom to
some distance up into the centre of the kiln, so that air or steam can be admitted
up into the body or mass of the material for the purpose of assisting or retarding
the calcination. Should there not be sufficient carbonaceous matter present to effect
good calcination, some may be added. The aluminous shales or fire-clays after
being calcined are ground into a fine powder, and it is preferred to use burr stones
for the grinding operation. Any desired quantity of the pulverised material is then
charged into a tank or cistern, which may be heated by steam, superheated or not
by hot water or by fire. Sulphuric acid (either heated or cold) is then added to the
material in the tank or cistern, which acting upon the aluminous material, converts
it into sulphate of alumina; or the acid may be charged into the tank or cistern
before the aluminous material is charged into it. The mixture of aluminous
material and sulphuric acid, after remaining for a sufficient length of time to allow
of complete reduction to sulphate of alumina, may be lixiviated and concentrated
in the heated cistern or churn herein-after described.
The second part of this Invention relates to an improved apparatus to be
employed in the manufacture of alum or sulphate of alumina from aluminous
minerals, and of sulphate of iron from manufactured protoxide or peroxide of iron.
This part of the Invention consists in applying for the lixiviation and concentration
a vessel or churn consisting of an inside casing of iron, which is made circular or of
any other suitable form, and lined with lead or other equivalent material. Around
this inside casing an outer casing or jacket of iron is placed, so as to leave a
sufficient space between it and the inside casing for the steam or hot water to
circulate through.
When hot water is employed, a fire-grate is situated below the outer casing, and
a safety valve is placed either on the top or side of the apparatus. A steam trap is
also placed at the bottom of the outer casing to let off the water of condensation

page_text: when the heat necessary for the lixiviation and concentration of the materials is
obtained by the use of steam.
The supply of steam or of hot water to the annular space between the jacket is
capable of being so regulated that the slimy particles caused by the digestion of the
aluminous earths (in the manufacture of alum or sulphate of alumina, and the
reduction of iron or its protoxide or peroxide (in the manufacture of sulphate of
iron) will settle down thoroughly before any crystallization or solidification takes
place, whereby the said crystallization or solidification is rendered very clean.
Having now described and particularly ascertained the nature of my said
Invention, and the system, mode, or manner in or under which the same is or may
be used or practically 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 herein-before in part recited Letters Patent is,-
First. The pipe led from the bottom to some distance up into the centre of heaps
of aluminous shales or fire-clay, or draw or flare kilns, for the purpose of admitting
air or steam into the body or mass whilst being calcined, and for the purpose of
assisting or retarding the calcination, as herein-before described.
Second. The double cased vessel or churn for the lixiviation or concentration of
sulphate of alumina or sulphate of iron, and heated by hot water or steam, as
herein-before described.
In witness whereof, I, the said John Howison, have hereunto set my hand
and seal, this Twenty-first day of June, in the year of our Lord, One
thousand eight hundred and seventy-seven.