Improvements in Obtaining Chlorine.
Year: 1888

page_text: Date of Application, 11th Dec., 1888
Complete Specification Left, 7th Sept., 1889-Accepted, 19th Oct., 1889
PROVISIONAL SPECIFICATION.
Improvements in Obtaining Chlorine.
We, ARCHIBALD CAMPBELL, of 42 Whittaker Road, Upton Park, in the County of
Essex, Chemist, and WILLIAM BOYD, of 90 Regent Terrace, Stirling Road, Glasgow,
in the County of Lanark, Chemist, do hereby declare the nature of this Invention to be
as follows, that is to say :-
Our said Invention comprises improved modifications of the processes described in
the Provisional Specification lodged with our Application for Letters Patent,
numbered 10,187 of 1888.
By our present Invention we operate on hydrochloric acid obtained in any suitable
known way, but instead of having such acid absorbed in simple water or in water
containing peroxide of manganese, we have it absorbed in a solution of sulphate of
manganese, after the successive operations have been set agoing so as to produce
sulphate of manganese. The solution of sulphate of manganese may have peroxide
of manganese mixed with it, before, during, or subsequently to the absorption of
hydrochloric acid.
The quantity of peroxide of manganese used is such as is sufficient not only to cause
the evolution of about half the chlorine as in the ordinary process, but also, with the
aid of sulphuric acid which is added at this stage, to cause the evolution of a further
large proportion of chlorine. Sulphate of manganese is principally forined instead of
chloride of manganese as in the ordinary process, and it is the sulphate of manganese
which is thus formed or a portion of it, the solution of which is used for absorbing
fresh quantities of hydrochloric acid.
In this improved modification of our process we do not require to dry and furnace
the residues from the chlorine stills as described in our earlier Provisional Specification
bereinbefore referred to, but we avoid loss of any material quantity of hydrochloric
acid or chlorine by continually returning the still residues or a large portion of them
to the hydrochloric-acid absorption apparatus, either as they leave the stils or after
neutralisation. We prefer to neutralise the still residues to allow of ordinary pumps
being used with them, the neutralisation being done principaily with recovered.
peroxide of manganese, whilst carbonate of lime may be used occasionally for the
purpose of separating impurities such as iron and arsenic.
-
As quantities of peroxide of manganese are continually being added in the apparatus
it is necessary to withdraw corresponding quantities of the sulphate of manganese and
matters mixed with it, and such withdrawal may be effected by transferring to an
evaporating pan, heated preferably by surface or reverberatory heat, such portions of
the neutralised solutions as are unduly accumulating. The sulphate of manganeso
salts out, the chloride, being more soluble, remaining to the last. The salts formed are.
fished out or drawn out "soft and the liquor drained from them is returned either to
the hydrochloric-acid absorption apparatus or to the neutralising well. The separated
sulphate of manganese is dissolved and treated, with carbonate of ammonia and the
resulting carbonate of manganese is converted into peroxide by known means.
"
Dated this Tenth day of December 1888.
EDMUND
HUNT,
.
Applicants Agent.

page_text: in the County of Lanark, Chemist, 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 comprises improved modifications of the processes described in
the Specification of our Patent, No. 10.187 of 1888.
By our present Invention we operate on hydrochloric acid obtained in any suitable
known way, but instead of having such acid absorbed in simple water. or in water
containing peroxide of manganese, we have it absorbed in a solution of sulphate of
manganese, after the successive operations have been set agoing so as to produce
sulphate of manganese. The solution of sulphate of manganese may have peroxide of
manganese mixed with it before, during, or subsequently to the absorption of hydro-
chloric acid.
The quantity of peroxide of manganese used is such as is sufficient not only to cause
the evolution of about one third the clilorine as in the ordinary process, but also, with
the aid of sulphuric acid which is added. at this stage, to cause the evolution of a
further large proportion of chlorine. Sulphate of manganese is principally formed
instead of chloride of manganese formed in the ordinary process; and it is the
sulphate of manganese which is thus formed, or a portion of it, the solution of which
is used for absorbing fresh quantities. of hydrochloric acid.
In this improved modification of our process we do not require to dry and furnace
the residues from the chlorine stills as described in our said earlier Specification herein-
before referred to, but we avoid loss of any material quantity of hydrochloric acid or
chlorine by continually returning the still residues or a large portion of them to the
hydrochloric acid absorption apparatus, either as they leave the stills or after neutrali-
sation. We prefer to neutralise the still residues to allow of ordinary pumps being
used with them, the neutralisation being done, principally with recovered peroxide of
manganese, whilst carbonate of lime may be used occasionally for the purpose of
separating impurities such as iron and arsenic.
As quantities of peroxide of manganese are continually being added in the apparatus
it is necessary to withdraw corresponding quantities of the sulphate of manganese, and
matters mixed with it, and such withdrawal may be effected by transferring to an
evaporating pan, heated preferably by surface or reverberatory heat, such portions of
the neutralised solutions as are unduly accumulating. The sulphate of manganese salts
out, the chloride, being more soluble remaining to the last. The salts formed aire fished
out or drawn out "soft" and the liquor drained from them is returned either to the
hydrochloric-acid absorption apparatus, or to the neutralising well. The separated
sulphate of manganese is dissolved and treated with carbonate of ainmonia and the
resulting carbonate of manganese is converted into peroxide by known means.
.
Having now particularly described and ascertained the nature of our said
Invention and in what manner the same is to be performed, we declare that what
we claim is —
;
1. In processes for obtaining chlorine from hydrochloric acid by means of peroxide
of manganese and sulphuric acid, the employment of the solution containg sulphate
of manganese formed in the processes, for absorbing the hydrochloric acid, such
solution being used alone.or-with-fresh peroxide of manganese added to it substantially
as bereinbefore described.
:
. .
2. The separating of sulphate of nanganese from the solutions circulating through
the apparatus by evaporating portions of such solutions and fishing out the crystallised
salt for the purpose of recouverting it into peroxide of manganese substantially as
bereinbefore described.
Dated this-Sixth day of September 1889
EDMUND HUNT,
Applicants' Agent.