IMPROVEMENTS IN OBTAINING AND RELATING TO SODA AND POTASH AND THEIR SALTS, ALSO SULPHURIC ACID AND CHLORINE
Year: 1879

page_text: LETTERS PATENT to Joseph Townsend, of Glasgow, in the County of Lanark,
North Britain, Manufacturing Chemist, for the Invention of "IMPROVEMENTS
IN OBTAINING AND RELATING TO SODA AND POTASH AND THEIR SALTS, ALSO
SULPHURIC ACID AND CHLORINE."
Sealed the 28th October 1879, and dated the 30th April 1879.
PROVISIONAL SPECIFICATION left by the said Joseph Townsend at the
Office of the Commissioners of Patents on the 30th April 1879.
JOSEPH TOWNSEND, of Glasgow, in the County of Lanark, North Britain, Manu-
facturing Chemist. "IMPROVEMENTS IN OBTAINING AND RELATING TO SODA AND
POTASH AND THEIR SALTS, ALSO SULPHURIC ACID AND CHLORINE."
This Invention comprises improved processes wherein salts of magnesia and silica
are advantageously employed in obtaining soda and potash and their salts, also
sulphuric acid and chlorine.
By a first process about 100 pounds sulphate of magnesia and about 97 pounds
chloride of sodium are intimately mixed and by preference dried so as to be in a porous
condition, and are put in a retort or other suitable vessel, and heated to a tempera-
ture of about 700 degrees Fahrenheit. Steam, which may be superheated, is passed
through or in contact with the heated mixture, and causes hydrochloric acid to be
driven off, which acid may be collected and utilized in any known way, there
remains as the result of the reaction sulphate of soda and magnesia.
By a second process about 100 pounds sulphate of magnesia and about 124 pounds
chloride of potassium are treated as in the first process, and yield hydrochloric
acid, sulphate of potash, and magnesia.
Mixtures of soda and potash salts may be treated as in the first and second
processes.
By a third process about 100 pounds sulphate of magnesia, about 97 pounds chloride
of sodium, and about 50 pounds silica are first treated as in the first process, and
after the hydrochloric acid has been driven off the remaining materials are by pre-
ference placed in a fireclay retort or vessel, and strongly heated, whereupon sulphuric
acid will be driven off, and may be collected and utilized in any known way.
Magnesia and silicate of soda are left as the result of the reaction.

page_text: By a fourth process about 100 pounds sulphate of magnesia, about 124 pounds
chloride of potassium, and about 50 pounds silica are treated as in the third process,
and yield hydrochloric acid, sulphuric acid, magnesia, and silicate of potash.
Mixtures of soda and potash salts may be treated as in the third aud fourth
processes.
A fifth process is the same as the third, but with the silica increased to about
100 pounds; and a sixth process is the same as the fourth, but with the silica
increased to about 100 pounds, the results being to forin silicate of magnesia instead
of magnesia in the two processes.
In a seventh process a solution of chloride of magnesium of a strength of from
80 to 100 degrees Twaddell has a small quantity of oxide of manganese well mixed
with it, about ten parts per centum of the oxide being sufficient when the mixture
is properly agitated. Air, by preference heated, is passed through or in contact
with the mixture, and causes chlorine to be given off, which chlorine can be utilized
in any known way. The solution may be heated in any convenient way to a
temperature of at least 240 degrees Fahrenheit, but by preference the heat is applied
by means of the heated air. The process is facilitated by adding from 25 to 50
per centum of chloride of calcium, as it keeps the magnesia and manganese in a
better condition for being acted on.
The salts of soda and potash obtained as herein before described may be converted
into other salts of soda and potash, or into caustic soda and potash by well known
processes, the lowness of their cost rendering them economically advantageous for
those purposes. Sulphuric acid and chlorine are also by the process hereinbefore
described obtained at a comparatively very low cost.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Joseph Townsend in the Great Seal Patent Office on the 29th
October 1879.
JOSEPH TOWNSEND, of Glasgow, in the County of Lanark, North Britain, Manu-
facturing Chemist. "IMPROVEMENTS IN OBTAINING AND RELATING TO SODA AND
POTASH AND THEIR SALTS, ALSO SULPHURIC ACID AND CHLORINE."
My said Invention comprises improved processes wherein salts of magnesia, silica,
and salts of alumina are advantageously employed in obtaining soda and potash
and their salts, sulphuric acid and chlorine.
By a first process about 100 pounds sulphate of magnesia and about 97 pounds
chloride of sodium are intimately mixed, and by preferenco dried so as to be in a
porous coudition, and are put in a retort or other suitable vessel, and heated to a
temperature of about 700 degrees Fahrenheit. Steam, which is by preference, super-
heated, is passed through or in contact with the heated mixture, and causes
hydrochloric acid to be driven off, which acid may be collected and utilized in any
known way.
There remains as the result of the reaction sulphate of soda and
magnesia.
By a second process 100 pounds sulphate of magnesia and about 124 pounds
chloride of potassium are treated as in the first process, and yield hydrochloric acid,
sulphate of potash, and magnesia.

page_text: Mixtures of soda and potash salts may be treated as in the first and second
processes.
By a third process about 100 pounds sulphate of magnesia, about 971 pounds
chloride of sodium, and about 50 pounds silica are intimately mixed, and by pre-
ference dried so as to be in a porous condition, and are put by preference in a muffle
furnace and heated to a temperature of 1000 to 1500 degrees Fahrenheit, care being
taken that the mass does not become so much fused as to lose its porous condition.
The heated porous mass may be further treated in the muffle furnace; it is however
by preference transferred to vertical fireclay retorts, and then the heat being main-
tained atmospheric air, by preference heated, is passed through or in contact with
the mass, aid causes the evolution of chlorine, which is to be collected and utilized
in any suitable known way. The residue consists of sulphate of soda and silicate
of magnesia.
A compound or mixture of silica and alumina can be used instead of the silica,
and in that case the residue will consist of silicate and aluminate of magnesia and
sulphate of soda.
By a fourth process about 100 pounds sulphate of magnesia, about 124 pounds
chloride of potassium, and about 50 pounds silica (or a compound or mixture of
silica and alumina) are treated as in the third process, and yield chlorine, sulphate
of potash, and silicate of magnesia, or silicate and aluminate of magnesia.
Mixtures of soda and potash salts may be treated as in the third and fourth
processes.
By a fifth process the same materials and quantities as in the third process are
treated as in the first process, and after the hydrochloric acid has been driven off
the remaining materials are by preference placed in a fireclay retort or vessel, and
strongly heated, whereupon sulphuric acid will be driven off, and may be collected
and utilized in any known way. Magnesia and silicate of soda are left as the
result of the reaction.
A sixth process is designed for the treatment and utilisation of natural substances
or compounds, such as that known as kainite, and the composition of which is about
the following, namely:-
Sulphoto of natash
06.00

page_text: · from 80 to 100 degrees Twaddell has a small quantity of oxide of manganese well
mixed with it, about ten parts per centum of the oxide being sufficient when the
mixture is kept thoroughly agitated. Air, by preference heated, is passed through
or in contact with the mixture, and causes chlorine to be given off, which chlorine
can be collected and utilised in any known way. The solution may be heated in
any convenient way to a temperature of at least 240 degrees Fahrenheit, but by
preference the heat is applied by means of the heated air. The process is facilitated
by adding from 25 to 50 parts per centum of chloride of calcium, as it keeps the
magnesia and manganese in a better condition for being acted on.
This process
may be made to yield chlorine continuously by continually adding hydrochloric
acid in proportion as the chloride of magnesium becomes decomposed, and the
chlorine is in this way obtained very economically.
The salts of soda and potash obtained as herein before described may be converted
into other salts of soda and potash, or into caustic soda and potash by well known
processes, the lowness of their cost rendering them economically advantageous for
those purposes.
Having thus particularly described my said Invention, and the manner of per-
forming the same, I bave to state that I do not restrict myself to the precise details
hereinbefore described, but that what I believe to be novel and original and claim
as the Invention secured to me by and in terms of the hereinbefore in part recited
Letters Patent is,-
1. The employment of sulphate of magnesia with the aid of steam to act on
chloride of sodium in order to separate hydrochloric acid, and form magnesia and
sulphate of soda, as hereinbefore described.
2. The employment of sulphate of magnesia with the aid of steam to act on
chloride of potassium in order to separate hydrochloric acid and form magnesia and
sulphate of potash, as herein before described.
3. The employment of sulphate of magnesia and silica, or a compound of silica
and alumina, with the aid of air and heat to act on chloride of sodium in order to
separate chlorine and form sulphate of soda and silicate, or silicate and aluminate
of magnesia, as herein before described.
:
4. The employment of sulphate of magnesia and silica, or a compound of silica
and alumina, with the aid of air and heat to act on chloride of potassium in order
to separate chlorine and form sulphate of potash and silicate, or silicate and aluminte
of magnesia, as herein before described.
5. The obtaining of sulphuric acid by the process herein before described as the
fifth.
6. The treatment and utilisation of kainite and similar compounds by acting
thereon with silica, or a compound of silica and alumina, aided by heat and steam
or air, so as to obtain hydrochloric acid, or chlorine and sulphates of soda and
potash, and silicate or silicate and aluminate of magnesia, as hereinbefore described.
7. The obtaining of chlorine by causing air with the aid of heat to act on a
solution of chloride of magnesium agitated with a small proportion of oxide of
manganese, as herein before described.
In witness whereof, I, the said Joseph Townsend, have hereunto set my hand
and seal, this Twenty-eighth day of October, in the year of our Lord
One thousand eight hundred and seventy-nine.