Year: 1886

page_text: Date of Application, 23rd Mar., 1886
Complete Left, 23rd Dec., 1886.
Complete Accepted, 1st Feb., 1887.
We, EDWARD ARTHUR, and EDWARD MORTIMER ARTHUR, both of Avon House,
Twerton-on-Avon, in the County of Somerset, Gentlemen, do hereby declare the
nature of this invention to be as follows:—
This invention consists in treating with sulphuric acid diluted with water such liquids as
contain in solution chloride of calcium, whereby the chloride of calcium is precipitated
in the form of crystallized sulphate of calcium.
The liquid in which the chloride of calcium is held is run into tanks or reservoirs,
and to it is then added sulphuric acid diluted with water.
An approximate proportion of about five parts of sulphuric acid and water to about
four parts of such a liquid as the by-product resulting from certain processes for
manufacturing soda will give useful results, but it is to be understood that the
proportions will vary according to the nature of the liquid and the quantity of chloride
of calcium held therein. The degree of dilution of the sulphuric acid may be approxi-
mately stated at from 90 to 95 per cent of water.
W. LLOYD WISE,
46, Lincoln's Inn Fields, London, W.C.,
Agent for the Applicants.

page_text: COMPLETE SPECIFICATION.
An Improved Process for Obtaining Crystallized Sulphate of
Calcium.
We, EDWARD ARTHUR, and EDWARD MORTIMER ARTHUR, both of Avon House,
Twerton-on-Avon, in the county of Somerset, gentlemen, do hereby declare the nature
of this invention, 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 treating with sulphuric acid, diluted with water, waste
liquid resulting from any process of manufacture of soda involving the use of ammonia
and thus to precipitate as sulphate of calcium the chloride of calcium which such liquids
contain in solution.
The waste liquid which results from the process of manufacture of soda known as the
"Solvay" process is a suitable liquid for treatment according to this invention for
obtaining sulphate of calcium but, as before stated, the invention is applicable to
treating the waste liquid containing chloride of calcium, resulting from any process of
manufacture of soda which involves the employment of ammonia.
Sulphate of calcium is known commercially as "pearl hardening" and is employed
in the manufacture of writing paper, as is well understood.
In carrying this invention into effect the liquid in which the chloride of calcium is
held is run into tanks or reservoirs and to it is then added the diluted sulphuric acid
when precipitation immediately commences.
The proportion of water used in diluting the sulphuric acid may be stated at
from 90 to 97 per cent, and the proportion which the acid so diluted bears to the
liquid to be treated may be stated at about five parts of diluted acid to four parts of
the said liquid.
Such proportions are approximate proportions, and it is to be understood that they will
vary according to the nature of the liquid to be treated and the quantity of chloride of
calcium held in solution therein.
By the process in which this invention consists, sulphate of calcium or "pearl
hardening" is economically obtained.
:-
Having now particularly described and ascertained the nature of this invention,
and in what manner the same is to be performed, we declare that what we claim is :-
Obtaining sulphate of calcium or "
pearl hardening" by treating with sulphuric
acid diluted with water the waste liquid or by-product resulting from the manufacture
of soda by any process involving the use of ammonia, for precipitation of the chloride
of calcium held in solution in such liquid, substantially as hereinbefore described.
W. LLOYD WISE,
46, Lincoln's Inn Fields, London, W.C.,
Agent for the Applicants.