IMPROVEMENTS IN THE MANUFACTURE OF CAUSTIC SODA AND CARBONATE OF SODA FROM CERTAIN ALKALINE LIQUORS AND SALTS
Year: 1859

page_text: LETTERS PATENT to William Gossage, of Widnes, in the County of Lan-
caster, Chemist, for the Invention of "IMPROVEMENTS IN THE MANUFACTURE
OF CAUSTIC SODA AND CARBONATE OF SODA FROM CERTAIN ALKALINE LIQUORS
AND SALTS."
Sealed the 27th October 1859, and dated the 2nd May 1859.
PROVISIONAL SPECIFICATION left by the said William Gossage at the
Office of the Commissioners of Patents, with his Petition, on the 2nd
May 1859.
I, WILLIAM GOSSAGE, of Widnes, in the County of Lancaster, Chemist, do
bereby declare the nature of the said Invention for "IMPROVEMENTS IN THE
MANUFACTURE OF CAUSTIC SODA AND CARBONATE OF SODA FROM CERTAIN ALKALINE
LIQUORS AND SALTS," to be as follows:-
My improvements apply to the manufacture of caustic soda and carbonate
of soda from solutions of rough soda, commonly called "black ash liquors,"
also from certain salts obtained from such "black ash liquors," and from
solution of silicate of soda.
In the Specification of an Invention of Improvements in the Manufacture
of Alkali from Common Salt," for which I obtained Letters Patent bearing
date on or about the Eighteenth day of May 1853, I have described certain
operations by means of which I obtain, carbonate of soda and caustic soda

page_text: from black ash liquors, by concentrating such black ash liquors to such an
extent that carbonate of soda becomes separated therefrom in the form of
salts, whilst caustic soda remains in solution.
In carrying into effect the said Invention, the first portions of salts which
are separated by concentration of such black ash liquors consist almost entirely
of crystals of carbonate of soda, but these crystals retain a portion of liquid
caustic soda adhering to them. I separate as much of this liquid caustic soda
from the crystals as may be conveniently practicable, either by washing as
described in my said Specification, or by other means, but such separation is
not perfect, and the presence of remaining portions of caustic soda with the
salts is objectionable.
My present Invention provides for the conversion of such remaining por-
tions of caustic soda into carbonate of soda, and I effect such conversion by
exposing the salts so obtained to carbonic acid gas, or by mixing such salts
with bicarbonate of soda or sesquicarbonate of soda previously to the salts
being dried.
The second portions of salts separated from black ash liquors by concentra-
tion are obtained in the state of very small crystals, and these consequently
retain a large proportion of liquid caustic soda mixed with them, which it is
difficult to separate by washing. I effect such separation as much as may be
conveniently practicable, and I then treat such salts in the manner I have
described for the treatment of the first portions of salts, and I thereby convert
caustic soda into carbonate of soda previously to such salts being dried. Or,
in place of converting such caustic soda (contained in the second portions of
salts obtained from black ash liquors) into carbonate of soda, I dissolve such
salts in water, and I treat the solution with lime, so as to produce an addi-
tional quantity of caustic soda, and I treat the liquors (so obtained) by
concentration, and obtain salts and liquid caustic soda therefrom in a manner
similar to that which is described in my said former Specification. The salts
thus obtained usually contain a large proportion of sulphate of soda, and I
cause such salts to be fluxed with small coal and lime, and thereby convert
sulphate of soda into carbonate of soda.
To obtain caustic soda or carbonate of soda from liquid silicate of soda, I
cause such liquid to be boiled with caustic lime or carbonate of lime, and I
thereby cause silicate of soda to become decomposed, producing caustic soda
or carbonate of soda (as the case may be), and silicate of lime.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Gossage in the Great Seal Patent Office on the
2nd November 1859.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
GOSSAGE, of Widnes, in the County of Lancaster, Chemist, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Second day of May, in the year of our Lord One
thousand eight hundred and fifty-nine, in the twenty-second year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
William Gossage, Her special license, that I, the said William Gossage,
my executors, administrators, and assigns, or such others as I, the said
William Gossage, 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 MANUFACTURE OF CAUSTIC SODA AND CARBONATE OF SODA FROM CERTAIN ALKA-
LINE LIQUORS AND SALTS," upon the condition (amongst others) that I, the said
William Gossage, by an instrument 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 imme-
diately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said William Gossage, 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 improvements apply to the manufacture of caustic soda and carbonate
of soda from solutions of rough soda, commonly called "black ash liquors,"
also from certain salts obtained from such "black ash liquors," and the
production of caustic soda from solution of soluble glass.
In the Specification of an Invention for improvements in the manufacture
of alkali from common salt, for which Invention I obtained Letters Patent
bearing date on or about the Eighteenth day of May 1853, I have described
certain operations by means of which I obtain carbonate of soda and caustic
soda from black ash liquors, by concentrating such liquors to such an extent
that carbonate of soda becomes separated therefrom in the form of salts, whilst
caustic soda remains in solution.

page_text: In carrying into effect the said Invention, the first portions of salts which
are separated by concentration of such liquors, consist almost entirely of crystals
of carbonate of soda, but these crystals retain a portion of liquid caustic soda
adhering to them. I seperate as much of this liquid caustic soda from the
crystals as may be conveniently practicable, either by washing as described in
my said Specification, or by other means, but such saparation is not perfect,
and the presence of remaining portions of caustic soda with such crystals is
objectionable.
My present Invention provides for the conversion of such remaining portions
of caustic soda into carbonate of soda.
In effecting this part of my Invention I cause the crystals obtained from
black ash liquors, as herein-before mentioned, to be exposed to carbonic acid
gas, by placing such crystals in layers upon shelves or floors contained in a
chamber constructed, by preference, of bricks set in hydraulic cement, and
having a doorway for the introduction and withdrawal of such crystals. I
generate carbonic acid gas by any well-known means, and I introduce such
gas into the said chamber containing crystals, and I provide an escape opening
from such chamber, so that I can cause a current of carbonic acid gas to pass
through the same. I continue the supply of gas into such chamber until I
find that the whole or nearly the whole of the caustic soda previously present
with such crystals of carbonate of soda has become converted into carbonate of
soda; I then withdraw such crystals, and by roasting I convert these into
dry carbonate of soda, or I apply them to the manufacture of ordinary soda
crystals.
The second portions of salts which are separated from black ash liquors by
continuing the process of concentrating such liquors after the first portions of
salts have been withdrawn are obtained in the state of very small crystals, and
these consequently retain a large proportion of liquid caustic soda mixed with
them, which it is difficult to separate therefrom by washing. I effect such
separation as much as may be conveniently practicable, and I then treat such
crystals in the manner I have herein-before described for the treatment of the
first portions of crystals obtained by the concentration of black ash liquors,
and I thereby convert caustic soda present with such crystals into carbonate
of soda previously to such crystals being roasted for the production of dry
carbonate of soda.
In effecting that part of my Invention which relates to the obtainment of
caustic soda from certain salts obtained from black ash liquors, I take the
salts which I have herein-before mentioned as the second portion of salts
obtained by the concentration of black ash liquors, and which salts retain

page_text: much liquid caustic soda, and also contain sulphate of soda; I cause such salts
to be dissolved by water, and I add caustic lime to the solution. I cause the
mixture thus produced to be boiled by injection of steam, or otherwise, and I
thus convert carbonate of soda into caustic soda. I concentrate the solution
thereby obtained so as to cause salts. to be deposited therefrom, and I continue
such concentration until the greater part of the salts previously contained in
the solution have become separated therefrom, and the remaining liquid is
sufficiently charged with caustic soda to become solid on cooling. The salts
thus obtained from such solution contain much sulphate of soda, and I prefer
to subject such salts to a process of fluxing with lime and coal, so as to obtain
carbonate of soda from such sulphate of soda.
In effecting that part of my Invention which relates to the production of
caustic soda from solution of silicate of soda, I prepare soluble glass, by
fluxing clean siliceous sand with about its own weight of soda ash, containing
about fifty-four per cent. of real soda, and I cause such glass to become
dissolved by boiling it with water. I ascertain the proportionate quantity of
silicic acid contained in the solution thereby obtained, and for each 100 parts
so present I add thereto about 80 parts of caustic lime, previously slaked to a
fine powder by the addition of hot water, and I cause the mixture of solution
of soluble glass and lime to be well boiled together, and I thereby produce
caustic soda in solution and insoluble silicate of lime.
I allow the mixture to remain quiet, so that the silicate of lime may
subside, and I draw off the solution of caustic soda, which I apply to the
manufacture of soap, or to other purposes for which such solution is appli-
cable, or I cause such solution to be concentrated by evaporation of water
therefrom, until it becomes sufficiently strong to yield solid caustic soda on
cooling.
I have herein-before particularly described and ascertained in what manner
my said Invention of "Improvements in the Manufacture of Caustic Soda and
Carbonate of Soda from certain Alkaline Liquors and Salts may be per-
formed, but I do not confine myself in performing the same to the precise
details herein before described, as these may be varied to some extent without
deviating from the nature of my said Invention.
I claim as my Invention, secured to me by the herein-before in part recited
Letters Patent,-
Firstly, the manufacture of carbonate of soda from caustic soda contained in
or mixed with salts obtained by the concentration of black ash liquors (as
herein-before mentioned), by exposing such salts mixed with caustic soda to
carbonic acid gas.

page_text: Secondly, the manufacture of caustic soda from such salts obtained by the
concentration of black ash liquors (as herein-before mentioned), by boiling
such salts with water and caustic lime.
Thirdly, the manufacture of caustic soda by boiling solution of soluble glass
(obtained as herein-before mentioned), with caustic lime, so as to produce
silicate of lime and caustic soda.
In witness whereof, I, the said William Gossage, have hereunto set my
hand and seal, this First day of November, in the year of our Lord
1850
WILL. (L.S.) GOSSAGE.