Improvements in the Manufacture of Potassium Sulphites.
Year: 1885

page_text: Improvements in the Manufacture of Potassium Sulphites.
We ARTHUR BOAKE and FREDERICK GEORGE ADAIR ROBERTS of The Warton
Road, Stratford, in the County of Essex, Manufacturing Chemnists, do hereby
declare the nature of our invention for IMPROVEMENTS IN THE MANUFACTURE OF
POTASSIUM SULPHITES to be as follows:-
This Invention consists in the manufacture of a new Bi-sulphite of Potassium
which differs from the ordinary Bi-sulphite or that heretofore in use, in being
unchangeable in the air or nearly so, in crystallizing freely and which we dis-
tinguish by the name of Meta or Iso Anhydro Bisulphite of Potassium.
We procure this salt by treating hydrate or carbonate of potassium either in a
dry state or in solution, or a mixture of potassium sulphate and calcium hydrate
in suspension or solution in water, at a boiling temperature with sulphurous acid,
this latter being prepared by any of the ordinary methods.
We take either of the above mentioned compounds, and place them in a suitable
vessel provided with boiling water, also an agitator or stirring apparatus, and we
maintain the boiling temperature during the whole time we pass in sulphurous
acid till the whole of the base is converted into bi-sulphite, and the solution has
attained a specific gravity of 92 Twaddell or thereabouts.
The solution having the aforesaid gravity of 92 Twaddell is run off into
crystallizing vessels and crystallized in the usual way, the mother liquor is drawn
off when the temperature of the liquor has fallen to 30° Centigrade, and returned
to the generating vessel to be again treated with more base and sulphurous acid.
JOHN HAYES,
27, Leadenhall Street, E.O.,
Agent for Patentees.

page_text: We, ARTHUR BOAKE and FREDERICK GEORGE ADAIR ROBERTS, of The Clonskeagh
Works, Warton Road Stratford, in the County of Essex, Manufacturing Chemists,
do hereby declare the nature of our invention for "IMPROVEMENTS IN THE MANU-
FACTURE OF POTASSIUM SULPHITES," and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement:
This Invention consists in the manufacture of a new bisulphite of Potassium
which differs from the ordinary Bisulphite or that heretofore in use, in being
unchangeable in the air, or nearly so, in crystallizing freely, and which we dis-
tinguish by the name of meta or Iso-Anhydro Bisulphite of Potassium.
We procure this salt by treating hydrate carbonate or bi-carbonate of potassium
either in a dry state, or in solution, or a mixture of potassium sulphate and calcium
hydrate in suspension or solution in water, at a boiling temperature with sulphurous
acid, this latter being prepared by any of the ordinary methods.
We take either of the above mentioned compounds, and we place them in a
suitable vessel provided with boiling water, and also with an agitator or stirring
apparatus, and we maintain the temperature at or near 100 degrees Centigrade, at
the same time passing in sulphurous acid till the whole of the base is converted
into bi-sulphite, and the solution has attained a specific gravity of 92 Twaddell or
thereabouts.
The solution having the aforesaid gravity of 92 Twaddell or thereabouts is run
off into crystallizing vessels, and crystallized in the usual way, the mother liquor
is drawn off when the temperature of the liquor has fallen to about 30 degrees
Centigrade and returned to the generating vessel to be again treated with more
base and sulphurous acid as above described.
Having now particularly described and ascertained the nature of our said
Invention & in what manner the same is to be performed, we declare that what
we claim is
"Certain Improvements in the manufacture of potassium sulphites as above set
forth."