IMPROVEMENTS IN TREAT
Year: 1871

page_text: LETTERS PATENT to James Hargreaves, of Widnes, in the County of
Lancaster, Chemist, for the Invention of "IMPROVEMENTS IN TREAT-
זvansmiAה ntagזסחn Turnחיימ) מה המזמהstartitm ay
"
PROVISIONAL SPECIFICATION left by the said James Hargreaves at
the Office of the Commissioners of Patents, with his Petition, on
the 25th November 1871.
I, JAMES HARGREAVES, of Widnes, in the County of Lancaster,
3 Chemist, do hereby declare the nature of the said Invention for “Im-
PROVEMENTS IN TREATING DILUTE CHLORINE TO SEPARATE IMPURITIES THERE-
FROM," to be as follows:-
The object of my Invention is to separate impurities, such for
instance as acids and metallic salts from dilute or impure chlorine so
as to obtain such chlorine in a condition fit for use in the manufacture
of bleaching powder and for other purposes.

page_text: To effect the said object I proceed as follows:-
First. When chlorine is mixed with hydrochloric or sulphuric acid, or
with chlorides such as those of iron and copper, I cause the said mixture
to rise through milk of lime, or a mixture of powdered magnesia and
water, or I cause it to pass through a tower containing pieces of lime or
magnesia. Hypochlorite of lime or magnesia is formed at first, but is
afterwards decomposed by the sulphuric or hydrochloric acids present in
succeeding portions of dilute or impure chlorine, and the free chlorine
which has been absorbed is subsequently given out.
Second. I pass the said dilute or impure chlorine over or through
lime in a fine state of division, which is thereby converted into an
impure bleaching powder or hypochlorite of lime. The said impure
bleaching powder or hypochlorite of lime is dissolved in water, and the
insoluble materials allowed to subside. The solution is afterwards passed
into another vessel and hydrochloric acid added to it, and the evolution
of pure chlorine effected.
Third. I pass the said dilute or impure chlorine through a layer or
layers of pieces of binoxide of manganese, and thereby convert any
hydrochloric acid present into chlorine. If sulphuric acid is present
.chloride of sodium is mixed with the said binoxide of manganese.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said James Hargreaves in the Great Seal Patent
Office on the 25th May 1872.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
HARGREAVES, of Widnes, in the County of Lancaster, Chemist, send
greeting:
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-fifth day of November, in the
year of our Lord One thousand eight hundred and seventy-one, in the
thirty-fifth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said James Hargreaves, Her special
licence that I, the said James Hargreaves, my executors, adminis-
trators, and assigns, or such others as I, the said James Hargreaves,

page_text: "
my executors, administrators, and assigns, should in any time agree
with, and no others, from time to time and at all times thereafter
during the term therein expressed, should and lawfully might make,
use, exercise, and vend, within the United Kingdom of Great Britain
and Ireland, the Channel Islands, and Isle of Man, an Invention for
"IMPROVEMENTS IN TREATING DILUTE CHLORINE TO SEPARATE IMPURITIES THERE-
FROM," upon the condition (amongst others) that I, the said James
Hargreaves, my executors or administrators, by an instrument in writing
under my, or their, or one of their hands and seals, should particularly
describe and ascertain the nature of the said Invention, and in what
manner the same was to be performed, and cause the same to be filed
in the Great Seal Patent Office within six calendar months next and
immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said James Hargreaves, do hereby
declare the nature of my said 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:-
The object of my Invention is to separate impurities, such for instance
as acids and metallic salts from dilute or impure chlorine so as to obtain
such chlorine in a condition fit for use in the manufacture of bleaching
powder and for other purposes.
To effect the said object I proceed as follows:-
First. When chlorine is mixed with hydrochloric or sulphuric acid, or
with chlorides such as those of iron and copper, I cause the said mixture
to rise through milk of lime or a mixture of powdered magnesia and
water, or I cause it to pass through a tower containing pieces of lime or
magnesia. Hypochlorite of lime or magnesia is found at first, but is
afterwards decomposed by the sulphuric or hydrochloric acids present in
succeeding portions of dilute or impure chlorine, and the free chlorine
which has been absorbed is subsequently given out.
Second. I pass the said dilute or impure chlorine over or through lime
in a fine state of division, which is thereby converted into an impure
bleaching powder or hypochlorite of lime. The said impure bleaching
powder or hypochlorite of lime is dissolved in water and the insoluble
materials allowed to subside. The solution is afterwards passed into
another vessel and hydrochloric acid added to it, and the evolution of
pure chlorine effected.

page_text: I would have it understood that as regards this second part of my
Invention I do not claim the use of impure hypochlorite of lime as a
source of chlorine, but what I claim is the separation of the hypochlorite
of lime from any excess of lime and also from carbonate of lime by the
solution of the said hypochlorite of lime in water, and then causing the
evolution of pure or nearly pure chlorine by the addition of an acid,
preferably hydrochloric acid, to the solution of hypochlorite of lime for
the purpose of separating the impurities present in impure or dilute
chlorine.
Third. I pass the said dilute or impure chlorine through a layer or
layers of pieces of binoxide of manganese, and thereby convert any
hydrochloric acid present into chlorine. If sulphuric acid is present
chloride of sodium is mixed with the said binoxide of manganese. The
said binoxide of manganese may be either the natural binoxide or
artificially prepared binoxide. One of the most convenient forms of
using artificial binoxide of manganese is manganite of magnesia, which
after being saturated with the free hydrochloric acid may be restored to
its original condition by heating to dull redness in the presence of
atmospheric air.
Having now described the nature of my said Invention, and particu-
larized the same in such manner that others will be enabled to carry my
improvements into practice, I claim, treating dilute chlorine for the
purpose of separating impurities by the processes substantially as hercin.
described.
In witness whereof, I, the said James Hargreaves, have hereunto
set my hand and seal, this Twenty-second day of May, in the
year of our Lord One thousand eight hundred and seventy-
In the presence of
JAMES JOHNSON,
Liverpool.
JAMES HARGREAVES. (L.S.)