AN IMPROVED PROCESS FOR THE DECOMPOSITION OF CERTAIN SALTS OF SODA AND SALTS OF POTASH
Year: 1880

page_text: LETTERS PATENT to Charles Humfrey, Manufacturing Chemist, of 27, Hough
Green, Chester, in the County of Chester, for an Invention of "AN IMPROVED
PROCESS FOR THE DECOMPOSITION OF CERTAIN SALTS OF SODA AND SALTS
OF POTASH,"
PROVISIONAL SPECIFICATION left by the said Charles Humfrey at the
Office of the Cominissioners of Patents on the 11th May 1880.
CHARLES HUMFREY, Manufacturing Chemist, of 27, Hough Green, Chester, in the
County of Chester. "AN IMPROVED PROCESS FOR THE DECOMPOSITION OF
CERTAIN SALTS OF SODA AND SALTS OF POTASH."
If sulphurous acid gas, either alone or mixed with the products of combustion, is
led through or into or over a solution of aluminate of soda or aluminate of potash,
sulphite of soda or sulphite of potash is formed, and alumina is precipitated, which
can be removed by a filter press. If an excess of gas be used sulphite of alumina
will be formed soluble in a further excess of sulphurous acid gas.
If sulphurous acid gas is passed through or into or over a solution of tri-sodic
(or tri-potassic) phosphate decomposition ensues, sulphite of soda (or sulphite of
potash) being formned together with hydro-disodic (or hydro-dipotassic) phosphate.
Or if the sulphurous acid gas be led through a mixture of aluminate of soda and
tri-sodic phosphate, alumina will be precipitated and the tri-sodic phosphate will
be reduced to hydro-disodic phosphate, while sulphite of soda is formed, and a
corresponding action will take place if salts of potash are substituted for salts
of soda.
Mixtures of sodic and potassic phosphates, or of these with the corresponding
aluminates, are decomposed in the same manner.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Charles Humfrey in the Great Seal Patent Office on the 10th
November 1880.
"
CHARLES HUMFREY, Manufacturing Chemist, of 27, Hough Green, Chester, in the
County of Chester. 'AN IMPROVED PROCESS FOR THE DECOMPOSITION OF
CERTAIN SALTS OF SODA AND SALTS OF POTASH."
If sulphurous acid gas, either alone or mixed with the products of combustion, is
led through or into or over a solution of aluminate of soda or aluminate of potash,
sulphite of soda or sulphite of potash is formed, and alumina is precipitated,
which can be removed by a filter press. If an excess of gas be used sulphite of
alumina will be formed soluble in a further excess of sulphurous acid gas.
If sulphuric acid gas is passed through or into or over a solution of tri-sodic
(or tri-potassic) phosphate decomposition ensues, sulphite of soda (or sulphite of
potash) being formed together with hydro-disodic (or hydro-dipotassic) phosphate.
Or if the sulphurous acid gas be led through a mixture of aluminate of soda and
tri-sodic phosphate, alumina will be precipitated and the tri-sodic phosphate will
be reduced to hydro-disodic phosphate, while sulphite of soda is forined, and a
corresponding action will take place if salts of potash are substituted for salts
of soda.
Mixtures of sodic and potassic phosphates, or of these with the corresponding
aluminates are decomposed in the same manner.
Having now described the nature of my said Invention and in what manner the
same is to be performed, I declare that I claim,—
The use of sulphurous acid gas for the precipitation of alumina from solutions of
aluminate of soda or potash, and for the reduction of tri-sodie (or tri-potassic)
phosphate into hydro-disodic (or hydro-dipotassic) phosphate and sodic sulphite.
In witness whereof, I, the said Charles Humfrey, have hereunto set my hand
and seal, this Ninth day of November, in the year of our Lord One thousand
eight hundred and eighty.
CHARLES HUMFKEY. (L.S.)