Improvements in connection with Obtaining Chlorine and in Utilising Calcium Chloride and other Bye-products.
Year: 1890

page_text: Date of Application, 12th Apr., 1890
Complete Specification Left, 8th Jan., 1891-Accepted, 28th Feb., 1891
PROVISIONAL SPECIFICATION.
Improvements in connection with Obtaining Chlorine and in Utilising
Calcium Chloride and other Bye-products.
We, ARCHIBALD CAMPBELL, of 42 Whittaker Road, Upton Park, in the
County of Essex, and WILLIAM BOYD, of 6, Broompark Terrace, Glasgow, in the
County of Lanark, North Britain, Technical Chemists, do hereby declare the nature
of this invention to be as follows, that is to say :-
Our said invention has principally for its object to further improve and cheapen
the cycles of processes for obtaining chlorine various modifications of which are
described in the Specifications of Patents Nos. 10187 of 1888, 18,056 of 1888,
18,921 of 1888, 881 of 1889, 3407 of 1889, and 16630 of 1889. Our present
improvements are also applicable in other known processes for obtaining chlorine;
and in carrying it out we utilise calcium chloride obtained as a bye product in such
processes or in other chemical manufactures.
In an ordinary series of processes for obtaining chlorine common salt is treated
with sulphuric acid yielding hydrochloric acid and sulphate of soda; and the latter
owing to its relatively large proportion and diminished value has become to some
extent a bye product. The hydrochloric acid is by means of peroxide of manganese
made to yield chlorine and manganese chloride, the larger part of the chlorine of
the acid being combined with the manganese: In processes described in the earlier
Specifications hereinbefore referred to or in some of them operations are employed
with the view of separating all or nearly all the remaining chlorine, a part of the
operations for effecting this consisting in treating the chloride of manganese with
sulphuric acid, thereby yielding chlorine and manganese sulphate. Various pro-
cesses are described for reconverting the manganese salts formed into peroxide for
reuse; and when operating on a large scale it is convenient and economical to
vary the processes or series of processes as applied to different portions of the
materials.
When calcium chloride is formed in any part of the processes, or when it is con-
veniently obtainable otherwise, we proceed to utilise it for the obtainment of
chlorine and calcium sulphate by treating it with sulphate of soda, thereby also
utilising a part of this last named salt so superabundantly formed in the primary
treatment of common salt as hereinbefore indicated. A solution of the sulphate of
soda is rendered neutral by any convenient alkali or alkaline earth, and after settling
and separation from precipitated matters is mixed with the calcium chloride. The
reaction is accelerated by heat and takes place rapidly, yielding an extremely pure
calcium sulphate which is precipitated and common salt. The calcium sulphate is
separated, washed, dried and prepared for use or for sale in any suitable known way;
and the solution of common salt is evaporated and treated like the original salt for
the obtainment of its chlorine. As the solution is not strong it will be convenient
to utilise it in forming along with rock salt a solution of the strength usually
employed when rock salt is used.
When convenient or economical sulphate of potash may be employed instead of
sulphate of soda.
Dated this Eleventh day of April 1890.
EDMUND HUNT,
Applicants' Agent.

page_text: Improvements in connection with Obtaining Chlorine and in Utilising
Calcium Chloride and other Bye-products.
We, ARCHIBALD CAMPBELL, of 42, Whittaker Road, Upton Park, in the
County of Essex, and WILLIAM BOYD, of 6, Broompark Terrace, Glasgow, in
the County of Lanark, North Britain, Technical Chemists, 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, that is
to say :-
Our said invention has principally for its object to further improve and cheapen
the cycles of processes for obtaining chlorine various modifications of which are
described in the Specifications of Patents Nos. 10,187 of 1888, 18,056 of 1888,
18,921 of 1888, 881 of 1889, 3,407 of 1889, and 16,630 of 1889. Our present
improvements are also applicable in other known processes for obtaining chlorine;
and in carrying it out we utilise calcium chloride obtained as a bye product in such
processes or in other chemical manufactures.
In an ordinary series of processes for obtaining chlorine common salt is treated
with sulphuric acid yielding hydrochloric acid and sulphate of soda; and the latter
owing to its relatively large production and diminished value has become to some
extent a bye product. The hydrochloric acid is by means of peroxide of manganese
-made to yield chlorine and manganese chloride, the larger part of the chlorine of
the acid being combined with the manganese. In processes described in the earlier
Specifications herein before referred to or in some of them operations are employed
with the view of separating all or nearly all the remaining chlorine, a part of the
operations for effecting this consisting in treating the chloride of manganese with
sulphuric acid, thereby yielding chlorine and manganese sulphate. Various pro-
cesses are described for reconverting the manganese salts formed into peroxide for
reuse; and when operating on a large scale it is convenient and economical, to
vary the processes or series of processes as applied to different portions of the
materials.
When calcium chloride is formed in any part of the processes, or when it is con-
veniently obtainable otherwise, as for example, in what is known as the ammonia-
soda process, we proceed to utilise it for the obtainment of chlorine and calcium
sulphate by treating it with sulphate of soda thereby also utilising a part of this
last named salt so superabundantly formed in the primary treatment of common
salt as hercinbefore indicated. A. solution of the sulphate of soda is rendered
neutral by any convenient alkali or alkaline earth, and after settling and separation
from precipitated matters is mixed with the calcium chloride. The reaction is
accelerated by heat and takes place rapidly, yielding an extremely pure calcium
sulphate, which is precipitated, and common salt. The calcium sulphate is
separated, washed, dried and prepared for use or for sale in any suitable known
way and the solution of common salt is evaporated and treated like the original
salt for the obtainment of its chlorine, as the solution is not strong it will be con-
venient to utilise it in forming along with rock salt a solution of the strength
usually employed when rock salt is used.
When convenient or economical sulphate of potash may be employed instead of
sulphate of soda.
Having now particularly described and ascertained the nature of our said inven-
tion, and in what manner the same is to be performed, we declare that what we
claim is :-
In processes for obtaining chloxine and in unanocras fav utilizing calsium chloride

page_text: the treatment of the calcium chloride with sulphate of soda substantially as and for
the purposes herein before described.
Dated this Seventh day of January 1891.
EDMUND HUNT,
Applicants' Agent.