Improvements in Obtaining Chlorine from Hydrochloric Acid or Chlorides and in Regenerating Peroxide of Manganese which is Used in the Process.
Year: 1888

page_text: Date of Application, 13th July, 1888
Complete Specification Left, 12th Apr., 1889
Complete Specification Accepted, 1st June, 1889
Improvements in Obtaining Chlorine from Hydrochloric Acid or
Chlorides and in Regenerating Peroxide of Manganese which is
Used in the Process.
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 has for its object the obtaining of chlorine in an improved and
economical manner, and the regenerating of peroxide of manganese which we use in
the process.
In carrying out our Invention according to one modification we treat a chloride in
the usual way with sulphuric acid, preferring to employ continuous mechanical furnaces
of the muffle type in which the fire gases are kept separate from the hydrochloric acid
gas. The hydrochloric acid gas is passed up through a tower down through which
there drips a stream of peroxide of manganese mixed with water to the consistency of
a fluid mud, which flows from a cistern kept heated to about 212 degrees Fahrenheit
and stirrers being used to keep the consistency uniform. The tower may be of com-
paratively little height but of large horizontal section, and is by preference built of
stone flags boiled in tar, and packed with fireclay pieces also boiled in tar,
or with other suitable materials presenting large surface with small obstruction
to the downward flow of the manganese mud. A reaction takes place yielding
chlorine and steam; and the steam is condensed by passing through glass,
earthenware, or other suitable pipes, the resulting water being used in making
fresh supplies of manganese mud, whilst the cooled chlorine gas is passed on to
apparatus in which it may be absorbed in the usual manner to form bleaching powder
or bleaching liquor, or chlorates.
The muddy liquor is led from the bottom of the tower into stills into which sulphuric
acid of suitable strength, is also led, and a further quantity of chlorine is evolved by
the action of the sulphuric acid on chloride of manganese formed in the tower and on
unchanged peroxide of manganese which latter must be present in sufficient quantity.
The reaction is not quite completed in the stills, and the muddy liquor is next trans-
ferred from them to other apparatus which may consist of a pot and a furnace of the
B

page_text: muffle type working under pressure; or as we prefer, it may be a mechanical furnace
of the kind described in Walker's Patent Specification No. 9760 of 1887.
Instead of stone stills as used at present we may employ glass retorts like those used
in the continuous concentration of sulphuric acid; and with these a steady stream of
muddy liquor will flow from the tower into the uppermost of the series an equivalent
quantity of the sulphuric acid being also continuously added. The mixture will flow
regularly through the series of retorts becoming gradually concentrated whilst chlorine
and steam are given off. From the last of the retorts the muddy liquor passes to the
pot or mechanical furnace in which further concentration takes place a dry sulphate
of manganese being finally obtained and the whole or nearly the whole of the chlorine
being separated. Small quantities of hydrochloric acid and sulphuric acid pass off
with the chlorine but may be effectually disposed of by being passed into the tower
into which the original hydrochloric acid is passed.
According to a second modification the peroxide of manganese in the dry state
may be charged into the furnace pot either continuously or intermittently with
equivalent quantities of hydrochloric and sulphuric acid; or the peroxide of manganese
may be mixed with some water and be run continuously into the pot. The mixture
which should be frequently stirred, is kept in the pot until it acquires considerable
stiffness, and is then transferred to a furnace in which the decomposition is completed
and a dry sulphate of manganese is obtained.
According to a third modification chloride of manganese obtained by decomposing.
hydrochloric acid with peroxide of manganese is mixed with a further equivalent of
peroxide of manganese and with sulphuric acid, and the mixture is treated, as
herein before described in the case of the similar mixture formed after treatment in the
tower.
In treating the sulphate of manganese for its reconversion into peroxide, we dissolve
it in water, heat it, and add chalk mixed with water to neutralise any free acid and
precipitate any iron, arsenic, or other impurities. After settling and separating the
liquid we add carbonate of ammonia in either the liquid or gaseous state and thereby
precipitate carbonate of manganese, care being taken to employ a suitable temperature.
The carbonate of manganese is separated by settling and filtering or otherwise; and
the solution of sulphate of ammonia is concentrated and the salt fished out in the usual
A small quantity of sulphuric acid is by preference added during concentra-
tion to hold in solution any traces of manganese that may be present. The mother
liquor is returned periodically to the manganese precipitating tank so as to utilise any
manganese in it. To make up for loss or manganese we prefer to add in the furnace
in which the reaction is completed, the small quantity required in the form of ground
native peroxide of manganese.
manner.
The carbonato of ammonia used in the hereinbefore described process may con-
veniently be that obtained in certain processes described in a Provisional Specification
accompanying an application by us for Letters Patent to be filed at the same time as
the present application, these processes being for purifying or treating coal gas or
ammoniacal liquors obtained from coal gas, or from coke ovens, or blast furnaces, or
shale works, or otherwise. The carbonate of ammonia may also be obtained by
treating any suitable ammoniacal salt with carbonate of lime.
The carbonate of manganese may be more or less completely converted into peroxide
by well known means.
Our Invention is applicable for treating hydrochloric acid from various sources
amongst which may be mentioned chloride of calcium formed in the manufacture of
chlorates and otherwise.
Dated this Twelfth day of July 1888
EDMUND HUNT,
Applicants' Agent.

page_text: COMPLETE SPECIFICATION.
Improvements in Obtaining Chlorine from Hydrochloric Acid or
Chlorides and in Regenerating Peroxide of Manganese which is
Used in the Process.
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 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 for its object the obtaining of chlorine in an improved and
economical manner and the regenerating of peroxide of manganese which we use in
the process.
In carrying out our Invention according to one modification, we treat common salt
or other suitable chloride in the usual way with sulphuric acid, preferring to employ
continuous mechanical furnaces of the muffle type, in which the fire gases are kept
separate from the hydrochloric acid gas. The hydrochloric acid gas is passed up
through an absorbing tower down through which there flows a stream of peroxide of
manganese mixed with water to the consistency of a fluid mud, supplied from a cistern⚫
kept heated to about 212 degrees, Fahrenheit, stirrers being worked in the cistern to
keep the consistency uniform. The absorbing tower may be of the ordinary proportions,
or it may be of comparatively little height and of large horizontal section; and it is by
preference built of stone flags boiled in tar, and packed with fireclay pieces also boiled
in tar, or with other suitable materials presenting large surface with small obstruction
to the downward flow of the manganese mud, or the upward passage of the gases.
A reaction takes place in the absorbing tower yielding chlorine and steam; and the
steam is condensed by passing through glass, earthenware, or other suitable pipes, the
resulting water being used in making fresh supplies of manganese mud, whilst
the cooled chlorine gas is passed on to apparatus of a well-known kind in which it may
absorbed in the usual manner to form bleaching powder, or bleaching liquor, or
chlorates.
The muddy liquor is led from the bottom of the absorbing tower into stills into
which sulphuric acid of suitable strength is also led, and a further quantity of chlorine
is evolved by the action of the sulphuric acid on chloride of manganese formed in the
tower and on unchanged peroxide of manganese which latter must be present in
sufficient quantity.
The reaction is not quite completed in the stills, and the muddy liquor is next
transferred from them to other apparatus which may consist of a pot and a furnace of
the muflle type working under pressure; or as we prefer, it may be a mechanical
furnace of the kind described in Walker's Patent Specification No. 9760 of 1857.
Instead of stone stills as used at present we may employ glass retorts like those
used in the continuous concentration of sulphuric acid; and with these a steady
stream of muddy liquor will flow from the tower into the uppermost of the series,

page_text: an equivalent quantity of sulphuric acid being also continuously added. The mixture
will flow regularly through the series of retorts, becoming gradually concentrated,
whilst chlorine and steam are given off. From the last of the retorts the muddy
liquor passes to the pot or mechanical furnace in which further concentration takes
place, a dry sulphate of manganese being finally obtained, and the whole or nearly
the whole of the chlorine being separated. Small quantities of hydrochloric acid and
sulphuric acid pass off with the chlorine but may be effectually disposed of by being
passed into the tower into which the original hydrochloric acid is passed.
According to a second modification the peroxide of manganese in the dry state may
be charged into the furnace pot either continuously or intermittently with equivalent
quantities of hydrochloric and sulphuric acids, that is to say quantities corresponding
as nearly as practically possible to the formula 4 H Cl + 2 Mn 0, + 2 H, SO, or the
peroxide of manganese may be mixed with some water and be run continuously into
the pot. The mixture, which should be frequently stirred, is kept in the pot until it
acquires considerable stiffness, and is then transferred to a furnace in which the
decomposition is made as complete as possible, and a dry sulphate of manganese is
obtained.
According to a third modification chloride of manganese, obtained by decomposing
horic acid with peroxide of manganese, is mixed with a further equivalent of
peroxide of manganese and with sulphuric acid, and the mixture is treated as hereinbefore
described in the case of the similar mixture formed after treatment in the absorbing
tower.
In treating the sulphate of manganese for its reconversion into peroxide, we dissolve
it in water, heat it, and add chalk mixed with water, to neutralise any free acid, and
precipitate any iron, arsenic, or other impurities. After settling and separating the
liquid we add carbonate of ammonia in either the liquid or gaseous state, and thereby
precipitate carbonate of manganese, care being taken to employ a suitable temperature,
which should not exceed 80 degrees Fahrenheit. The carbonate of manganese is separated
by settling and filtering or otherwise; and the solution of sulphate of ammonia formed
is concentrated and the salt fished out in the usual manner. A small quantity of
sulphuric acid is, by preference, added during concentration to hold in solution any
traces of manganese that may be present. The mother liquor is returned periodically
to the manganese precipitating tank so as to utilise any manganese in it. To make
up for loss of manganese we prefer to add what may be required for that purpose in
the furnace in which the chlorine-evolving reaction is completed, in the form of ground
native peroxide of manganese.
The carbonate of ammonia used in the hereinbefore described process may con-
veniently be that obtained in certain processes described in our Complete Specification
No. 10186 of 1888 these processes being for purifying or treating coal gas or
ammoniacal liquors obtained from coal gas or from coke ovens, or blast furnaces, or
shale works, or otherwise. The carbonate of ammonia may also be obtained by
treating any suitable ammoniacal salt with carbonate of lime, or in any other
convenient way.
:
The carbonate of manganese may be more or less completely converted into
peroxide by well known means.
Our Invention is applicable for treating hydrochloric acid from various sources,
amongst which may be mentioned chloride of calcium, formed in the manufacture of
chlorates and otherwise.
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 :-
1. The improved combination of processes, comprising the treatment of hydrochloric
acid with peroxide of manganese and water whereby some chlorine is evolved and
chloride of manganese is formed, the treatment of the chloride of manganese along with
peroxide of manganese with sulphuric acid and stilling and furnacing the mixture to
cause the evolution of the remaining chlorine or the most of it, and the treatment..of

page_text: the sulphate of manganese formed, with carbonate of ammonia to form carbonate of
manganese to be reconverted to peroxide substantially as and for the purposes
herein before described.
2. The obtaining of chlorine from hydrochloric acid by first treating the acid with
peroxide of manganese whereby some chlorine is evolved and by secondly treating the
chloride of manganese at first formed, with sulphuric acid -sufficient unaltered or
additional peroxide of manganese being present, substantially as hereinbefore
described.
3. The obtaining of chlorine according to the modification of processes in which dry
or wet peroxide of manganese is mixed with hydrochloric acid and sulphuric acid in
a furnace pot or still, and heat applied, the mixture being subsequently transferred
to a furnace to complete the decomposition substantially as herein before described.
Dated this Eleventh day of April 1889.
EDMUND HUNT,
Applicants' Agent.