Improvements in Treating Hydrochloric Acid to obtain Chlorine; Using the said Chlorine in the Manufacture of Bleaching Powder, and in Apparatus Employed.
Year: 1886

page_text: Date of Application, 27th Apr., 1886.
Complete Left, 26th Jan., 1887.
Complete Accepted, 1st Mar., 1887.
Improvements in Treating Hydrochloric Acid to obtain Chlorine;
Using the said Chlorine in the Manufacture of Bleaching
Powder, and in Apparatus Employed.
We JAMES HARGREAVES, Chemist, THOMAS ROBINSON, Iron Founder, and Jons
HARGREAVES Chemist, all of Victoria Road, Widnes in the County of Lancaster; ilo
hereby declare the nature of this invention to be as follows :-
In utilizing the hydrochloric acid evolved from the action of sulphurous acid air and
aqucous vapour upon chloride of sodium by the direct process we convert it whilst hot
directly into chlorine by passing the hot hydrochloric acid gas through the well known
Deacon Hurter apparatus, in which we increase the rate of decomposition of hydro-
chloric acid by mixing a small quantity of chloride, of copper vapour, with, the
hydrochloric acid gas before it enters, the decomposer: or we convert the hydrochloric
acid gas directly into chlorine by and with the means described in our patent No. 5681
of the present year for, the treatment of pyrites in which the copper and other valuable
metals contained in the pyrites are made directly soluble, using the burnt pyrites
contained in the burner as a decomposer. The chloride of copper volatilized along
with the chlorine gas can be readily recovered as hereinafter described.
We convert the chlorine into bleaching powder as hereinafter described. The
apparatus we use for the absorption of the chlorine by means of lime is similar to
the one described in our patent No. 5001 of the year 1876 for the manufacture
of bleaching powder; although in consequence of a large amount of inert gases the
dilute chlorine gas alone will not give very strong bleaching powder this deficiency
in the strength of bleaching powder we overcome by passing the weak chlorine into
the chamber for the purpose of being absorbed by the lime at a distance of several
shelves from the bottom of the chamber and allow sufficient sirong chlorine which may
be obtained as hereinafter described to enter the space over the bottom shelf from which
point to the shelf where the weak chlorine enters the chamber the unfinished bleaching
powder is constantly stirred and exposed to an atinosphere of strong chlorine until
bleaching powder of high strength is obtained.

page_text: Or for increasing the strength of the bleaching powder obtained from dilute chlorine
a second mechanical bleaching powder chamber may be used in which the bleaching
powder made by dilute chlorine in the first chamber is brought in contact with strong
chlorine, in either case any unabsorbed strong chlorine is passed to the shelf in which
the dilute chlorine enters and is mixed therewith and absorbed by the lime. The
chlorine is aspirated through the said mechanical bleaching powder chamber by any
convenient means, so that a slight vacuum is always maintained in the chamber, and
any escape of chlorine conveyed to a chimney. Although the chlorine inade from the
hydrochloric acid gas above referred to in the Deacon Hurter apparatus will be dilute,
it will be found to be practically free from carbonic acid the presence of which has
been found to be so objectionable in chlorine by the Deacon Hurter process.
The strong bleaching powder on the bottom shelf is caused to fall by means of
scrapers into an airtight box, trough or other convenient receptacle lying beneath the
mechanical bleaching powder chamber from which it is conveyed directly by an
archimedian screw or other mechanical means to casks where it is automatically
pressed or shaken in the cask so as to increase the quantity of bleaching powder
contained in the cask and also to prevent the loss of chlorine.
When it is desired to facilitate the use of bleaching powder by the consumer we take
bleaching powder, preferably as it passes from the mechanical bleaching powder chamber
and press the bleaching powder into solid bricks cakes or other convenient shape.
We construct the bleaching powder chamber of cast iron, and varnish or otherwise
cover the cast iron in the interior of the chamber by some substance to prevent the
action of chlorine upon the iron.
We obtain strong chlorine to be used for the purpose herein before described by
absorbing a separate portion of the dilute chlorine obtained as hereinbefore described.
by means of milk of lime by any of the well known methods; the liquor is settled
sediment of lime reused, and the soloution of chloride of lime thus obtained run into
stills & heated, acidulated by the weak hydrochloric acid condensed in the chlorine
purifier, and the strong chlorine conveyed to the mechanical bleaching powder chamber
as hereinbefore described. By the same method if desired, all the dilute chlorine may
be obtained as strong chlorine. Any chloride of copper volatalised in the decomposer
used in the Deacon Hurter process is condensed with the hydrochloric acid in the wet
chlorine purifier. After the said condensed hydrochloric acid has been used for
acidifying the soloution of bleaching powder, the volatalised chloride of copper will be
found in the chloride of calcium soloution from which it is precipitated & recovered
by adding a slight excess of bleach liquor or by other suitable means.
A separate and comparatively small mechanical bleaching powder chamber as herein-
before described, and containing powdered lime or bleaching powder is used for
purifying the dilute chlorine coming from the chlorine wet, purifier, before the chlorine
enters the chamber for the manufacture of bleaching powder. Any chlorine absorbed
by the lime in the mechanical purifier is recovered as hereinbefore described for
obtaining strong from weak chlorine.

page_text: Improvements in Treating Hydrochloric Acid to obtain Chlorine,
Using the said Chlorine in the Manufacture of Bleaching
Powder, and in Apparatus Employed.
We JAMES HARGREAVES of Peel House Lane, Farnworth Chemist, THOMAS
ROBINSON of Hope House Farnworth Iron Founder and JOHN HARGREAVES of Albert
Road Widnes Chemist, all in the county of Lancaster 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:-
In using the hydrochloric acid evolved from the action of sulphuric acid air and
aqueous vapour upon chloride of sodium by the direct process.
We decompose the hydrochloric acid gas whilst hot, by passing it through the well
known Deacon Hurter apparatus in which we increase the rate of decomposition by
mixing a small quanty of chloride of copper vapour, with the hydrochloric acid gas
before it enters the decomposer, or we convert the hydrochloric acid gas directly into
chlorine by and with the means described in our Patent 5681 of the present year, for
the treatment of pyrites in which the copper and other valuable metals contained in
the pyrites, are made directly soluble, using the burnt pyrites contained in the burners
as a decomposer.
The volatilized chloride of copper passing along with the chlorine gas can be readily
recovered, as hereinafter described.
The
We absorb the chlorine and form bleaching powder as hereinafter described.
apparatus we use for the absorption of the chlorine by means of lime is similar to the
one described in our Patent number 5001 of the year 1876 for the manufacture of
bleaching powder. In consequence of a large amount of inert gases, the dilute
chlorine gas alone will not give very strong bleaching powder; this deficiency in the
strength of bleaching powder we overcome by passing the weak chlorine into the
chamber, for the purpose of being absorbed by the lime, at a distance of several shelves
from the bottom of the chamber and allow sufficient strong chlorine-which inay be
obtained as hereinafter described, to enter the space over the bottom shelf, from which
point to the shelf where the weak chlorine enters the chamber the unfinished bleaching
powder is constantly stirred and exposed to an atmosphere of strong chlorine, until
bleaching powder of high strength is obtained.
Or, for increasing the strength of the bleaching powder obtained from dilute chlorine,
a second mechanical bleaching powder chamber may be used, in which the bleaching
powder made by the dilute chlorine in the first chainber, is brought into contact with
strong chlorine in the second chamber. In either case any unabsorbed strong chlorinė
is passed to the shelf in which the dilute chlorine enters and is mixed therewith and
absorbed by the lime.
The chlorine is aspirated through the said mechanical bleaching powder chamber,

page_text: by any convenient means, but so that a slight vacuum is maintained in the chamber
and any escape of chlorine conveyed to a chimney.
Although the chlorine made from the hydrochloric acid gas above referred to, when
decomposed in the Deacon Hurter apparatus, will be dilute, it will be found to be when
treated by the method hereinafter described, practically free from carbonic acid, the
presence of which has been found to be so objectionable in chlorine, made by the
Deacon Hurter process.
The strong bleaching powder on the bottom shelf of the mechanical chamber, is
caused to fall by means of scrapers, into an airtight box, trough, or, other convenient
receptacle, lying beneath the mechanical bleaching powder chamber, from which it is
conveyed directly by an archimedian screw, or other mechanical means, from the
bottom of the mechanical chamber into casks, where it is automatically pressed, or
shaken in the cask, so as to increase the quantity of bleaching powder contained in the
cask and also to prevent the loss of chlorine. When it is desired to further increase
these advantages and to facilitate the use of bleaching powder by the consumer, we
take bleaching powder, preferably as it passes from the bleaching powder chamber
and press and thereby consolidate the bleaching powder into solid bricks, cakes, or,
other convenient shape..
We construct the bleaching powder chamber of cast iron and varnish, or otherwise
cover the cast iron in the interior of the chamber, by some substance to prevent the
action of the chlorine upon the iron. Coal tar, bitumen, asphalt, and like coating
agents are suitable.
We obtain strong chlorine to be used for the purpose hereinbefore described, by
absorbing a separate portion of the dilute chlorine obtained as hereinbefore described
by means of milk of lime, by any of the well known methods, the liquor is settled and
the sediment of lime reused, and the solution of chloride of lime, or niagnesia, thus
obtained, run into stills, acidulated by the hydrochloric acid condensed in the chlorine
wet purifier, & heated, and the strong chlorine conveyed to the mechanical bleaching
powder chamber as herein before described.
By the same methods if desired, all the dilute chlorine may be obtained as strong
chlorine.
Any volatilized chloride of copper from the decomposer, used in the Deacon Hurter
process, or, by the method of jointly obtaining chlorine from hydrochloric acid gas
and rendering soluble the valuable metals contained in pyrites, as hereinbefore
described, is condensed along with hydrochloric acid in the wet purifier.
After the condensed hydrochloric acid has been used for acidifying the solution of
bleaching powder, the volatilized chloride of copper will be found in the solution from
which it may be precipitated and recovered, by adding a slight excess of bleach liquor,
or, by other suitable means.
A separate and comparatively small mechanical bleaching powder chamber, as herein-
before described and containing powdered lime, or bleaching powder, may be used
for purifying the dilute chlorine, coming from the chlorine wet purifier; before the
chlorine enters the chamber for the manufacture of bleaching powder. Any chlorine
absorbed by the lime; in the mechanical purifier is recovered as herein described for
obtaining strong from weak chlorine.
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:
1st. Introducing chloride of copper vapour along with hot hydrochloric acid gas into
the decomposer for the purpose substantially as described.
2nd. Passing an excess of hydrochloric acid gas flirough burnt pyrites thereby
rendering soluble the valuable metals and whilst doing so under such excess converting
hydrochloric acid into chlorine substantially as herein before described.
3rd. Recovering the volatilized chloride of copper condensed along with the hydro-
chloric acid, substantially as described.

page_text: 4th. Employing strong and weak chlorine obtained as described in a mechanical
bleaching powder chamber or chambers.
5th. Whilst maintaining a partial vacuum in the mechanical bleaching powder
chamber, by an aspirator, removing by the same means any unabsorbed chlorine,
substantially as described.
6th. Passing bleaching powder from a mechanical converting chamber by an
archimedian screw, or like means to casks or packages, shaken for compressing such
bleaching powder, substantially as described.
7th. Subjecting bleaching powder to pressure to form it into cakes, bricks or
the like.
8th. Constructing bleaching powder chambers of cast iron and coating the interior
surfaces of such chambers with protecting agents to prevent corrosion, substantially as
described.
1
9th. Obtaining strong and weak chlorine as described and employing the same in
the manufacture of bleaching powder substantially as described.
10th. Purifying weak chlorine, by means of bleaching powder or lime and recovering
the remaining chlorine contained in the purifying agent, substantially as described.