IMPROVEMENTS IN THE PRODUCTION OF CHLORINE AND HYPOCHLORITES
Year: 1871

page_text: LETTERS PATENT to Thomas James Smith, of the Firm of Robertson,
Brooman, and Company, of 166, Fleet Street, in the City of
London, Patent Agents, for the Invention of “IMPROVEMENTS IN
THE PRODUCTION OF CHLORINE AND HYPOCHLORITES."-A communication.
Sealed the 16th February 1872, and dated the 25th August 1871.
PROVISIONAL SPECIFICATION left by the said Thomas James Smith
at the Office of the Commissioners of Patents, with his Petition, on
the 25th August 1871.
I, THOMAS JAMES SMITH, of the Firm of Robertson, Brooman, and
Company, of 166, Fleet Street, in the City of London, Patent Agents,
do hereby declare the nature of the said Invention for "IMPROVEMENTS
IN THE PRODUCTION OF CHLORINE AND HYPOCHLORITES," to be as follows:-
The processes hitherto employed to produce chlorine continuously
by means of oxygen or of air and hydrochloric acid in presence of
certain metallic peroxides or dehydrating salts have never given prac-
tically valuable results, because the excess of oxygen or air and nitrogen

page_text: of this chlorine or its combination with the alkalies and alkalino-terrous
bodies intended to produce hypochlorites suitable to be practically used
for bleaching.
The object of this Invention is while wholly or partly utilizing the
hydrochloric acid employed to generate pure chlorine in an isolated
state which can combine without waste with the alkaline or alkalino-
terrous bodies in the form of decolorizing chlorides.
For this object the Inventor has discovered two methods.
First Method. In a retort heated to a deep red containing peroxido
of manganese, or a mixture of peroxide of manganese and lime, a current
of hydrochloric acid is caused to pass; chlorine and steam are produced
and disengaged, and there remains in the retort non-decomposed peroxide
of manganese and chloride of manganese, or a mixture of peroxide of
manganese, chloride of manganese, and chloride of calcium. The chlorine
is collected in the water or led away into a chamber for the production of
.dry hypochlorites. Over the mixture remaining in the retort and at the
same temperature a current of air or oxygen is caused to pass, which in
the presence of peroxyde of manganese decomposes at once the chloride of
manganese alone, or the chlorides of manganese and calcium regenerated
from the sesquioxide of manganese alone into sesquioxide of manganese
mixed with lime and sets at liberty the chlorine contained in the
chlorides. This chlorine mixed with air and azote or oxygen is led into
vats containing a mixture of lime and protoxide of manganese which has
been previously produced by the decomposition of chloride of manganese
by an excess of lime, the soluble chloride of calcium produced in this
reaction having been previously run off. In presence of the oxygen of
the air and of the chlorine it produces immediately sesquioxide of
manganese and hypochlorite of lime, which in reacting upon the sesqui-
oxide produces finally the hydrate of peroxide of manganese and chlorido
of calcium. The excess of lime remaining having no longer to act upon
the sesquioxide remains in the state of hypochlorite of lime. Upon
this mixture, composed of hydrate of peroxide of manganese, chloride of
calcium, and hypochlorite of lime, liquid hydrochloric acid is made to
react in the ordinary manner. Chlorine is at once disengaged by the
reaction of this acid upon the one hand upon the hydrate of peroxide
of manganese, and on the other upon the hypochlorite of lime. This

page_text: chlorine is led into the chamber for the production of hypochlorites. After
this reaction it remains in the vats of the chlorides of manganese and
calcium. Upon the chlorides of manganese and calcium an excess of
lime is caused again to act, which reproduces the mixture of protoxide
of manganese, chloride of calcium, and lime already referred to. The
chloride of calcium which is soluble is then run off, and there remains
in the insoluble state a mixture of protoxide of manganese and lime
which will serve for other similar operations by repassing under the
action of chlorine and air to the state of hydrate of peroxide of man-
ganese, chloride of calcium, and hypochlorite of liquid lime.
It therefore follows, 1st, that by the reaction of gaseous hydrochloric
acid, air, and oxygen in retorts heated to redness containing peroxide of
manganese or a mixture of peroxide of manganese and lime, a first
quantity of pure chlorine is produced, which is led away into condensing
3 chambers and for the production of dry hypochlorites; 2nd, that by the
decomposition by means of air or oxygen of the chloride of manganese
alone or the chlorides of manganese and lime contained in the said.
retorts, gaseous compounds are produced containing at once oxygen and
chlorine. These compounds in their passage across the vats containing
the protoxides of manganese and liquid hypochlorites of lime produce
pure chlorine by the action of liquid hydrochloric acid, which chlorine in
its turn is led into the chambers for the production of dry hypochlorites.
Instead of the mixture of protoxide of manganese and lime in excess,
upon which the chlorine as above said mixed with air and oxygen is
caused to pass just as it comes from the retorts, a milk of lime may be
employed which is transformed into hypochlorite of lime. This hypo-
chlorite as well as the mixture of hydrate of peroxide of manganese
and hypochlorito of lime treated by liquid hydrochloric acid regenerates
pure chlorine suitable to be taken to the chambers for the production
of dry hypochlorites.
:
The chloride of calcium remaining from the above described operation
is collected in vessels wherein carbonate of magnesia or magnesia and
carbonic. acid are caused to react simultaneously, carbonate of lime and
chloride of magnesium are produced. This distilled chloride of mag-
nesium regenerates the hydrochloric acid, which is again employed for
the production of a fresh quantity of chlorine. The magnesia remaining
serves again for another operation.

page_text: Thus the ensemble of the reactions which constitute this process will
be perceived, 1st, the oxides of manganese serving for the production
of chlorine are ceaselessly regenerated; 2ndly, the hydrochloric acid
is entirely utilized for the production of chlorine; 3rdly, all the chlorine
generated is in a pure state, and consequently proper for the production &
of dry hypochlorites.
T
Second Method.--This method only differs from the one just described
in that instead of lime magnesia is directly substituted; the chlorides
of magnesium produced being without transformation and by distillation
alone capable of re-engendering hydrochloric acid.
Such are the two methods which characterise this Invention, the
object of which is the production without waste from oxides of man-
ganese and hydrochloric acid of pure chlorine and consequently of dry
hypochlorites by means of the reactions described.
1
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Thomas James Smith in the Great Scal Patent
Office on the 24th February 1872.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
JAMES SMITH, of the Firm of Robertson, Brooman, and Company,
of 166, Fleet Street, in the City of London, Patent Agents, send
greeting.
•
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-fifth day of August, 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 Thomas James Smith, Her special
licence that I, the said Thomas James Smith, my executors, admi-
nistrators, and assigns, or such others as I, the said Thomas James
Smith, my executors, administrators, and assigns, should at any time
agree with, and no others, from time to time and at all times there-
after 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 THE PRODUCTION OF CHLORINE AND HYPOCHLORITES,"
(a communication to me from abroad by Cyprien Marie Tessié du

page_text: Motay, of Paris, France,) upon the condition (amongst others) that I,
the said Thomas James Smith, 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 Thomas James Smith, do hereby
declare the nature of the said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in and
by the following statement thereof, that is to say :-
The processes hitherto employed to produce chlorine continuously
by means of oxygen or of air and hydrochloric acid in the presence
of certain metallic peroxides or dehydrating salts have never given
practically valuable results, because the excess of oxygen or air and
nitrogen mixed with the chlorine generated partly prevents the con-
densation of this chlorine or its combination with the alkalies and
alkalino-terrous bodies intended to produce hypochlorites suitable for
practical use in bleaching.
The object of this Invention is while wholly or partly utilizing the
hydrochloric acid employed to generate pure chlorine in an isolated
state which can combine without waste with the alkaline or alkalino-
terrous bodies in the form of decolorizing chlorides.
For this object the Inventor has discovered two methods.
First Method. Into a retort heated to a deep red containing peroxide
of manganese or a mixture of peroxide of manganese and lime a current
of hydrochloric acid is caused to pass; chlorine and steam are produced
and disengaged, and there remains in the retort non-decomposed peroxide
of manganese and chloride of manganese, or a mixture of peroxide of
manganese, chloride of manganese, and chloride of calcium. The chlorine
is collected in the water or led away into a chamber for the production of
dry hypochlorites. Over the mixture remaining in the retort and at the
same temperature a current of air or oxygen is caused to pass, which in
the presence of peroxide of manganese decomposes at once the chloride of
manganese alone or the chlorides of manganese and calcium regenerated
from the sesquioxide of manganese alone into sesquioxide of manganese
mixed with lime, and sets at liberty the chlorine contained in the chlorides.

page_text: This chlorine mixed with air and azote or oxygen is led into vats con-
taining a mixture of lime and protoxide of manganese which has been
previously produced by the decomposition of chloride of manganese by
an excess of lime, the soluble chloride of calcium produced in this
reaction having been previously run off. In presence of the oxygen of
the air and of the chlorine it produces immediately sesquioxide of
manganese and hypochlorite of lime, which in reacting upon the sesqui-
oxide produces finally the hydrate of peroxide of manganese and chloride
of calcium. The excess of lime remaining having no longer to act
upon the sesquioxide remains in the state of hypochlorite of lime. Upon
this mixture composed of hydrate of peroxide of manganese, chloride of
calcium, and hypochlorite of lime, liquid hydrochloric acid is made to
react in the ordinary manner. Chlorine is at once disengaged by the
reaction of this acid upon the one hand upon the hydrate of peroxide.
of manganese and on the other upon the hypochlorite of lime. This ]
chlorine is led into the chamber for the production of hypochlorites.
After this reaction it remains in the vats of the chlorides of manganese
and calcium. Upon the chlorides of manganese and calcium an excess
of lime is caused again to act, which reproduces the mixture of
pretoxide of manganese, chloride of calcium, and lime already referred
to. The chloride of calcium which is soluble is then run off, and there
remains in the insoluble state a mixture of protoxide of manganese and
lime, which will serve for other similar operations by repassing under
the action of chlorine and air to the state of hydrate of peroxide of
manganese, chloride of calcium, and hypochlorite of liquid lime.
It therefore follows, 1st, that by the reaction of gaseous hydrochloric
acid upon air and oxygen in retorts heated to redness containing per-
oxide of manganese of a mixture of peroxide of manganese and lime
a first quantity of pure chlorine is produced, which is led away into
condensing chambers and for the production of dry hypochlorites; a
2ndly, that by the decomposition by means of air or oxygen of the
chloride of manganese alone or the chlorides of manganese and lime
contained in the said retorts gaseous compounds are produced containing
at once oxygen and chlorine. These compounds in their passage across
the vats containing the protoxide of manganese and liquid hypochlorites a
of lime produce pure chlorine by the action of liquid hydrochloric acid,
which chlorine in its turn is led into the chambers for the production of
dry hypochlorites. Instead of the mixture of protoxide of manganese
and lime in excess upon which the chlorine as above said mixed with air

page_text: and oxygen is caused to pass just as it comes from the retorts a milk of
lime may be employed which is transformed into hypochlorite of lime.
This bypochlorite as well as the mixture of hydrate of peroxide of
manganese and hypochlorite of lime treated by liquid hydrochloric acid
regenerates pure chlorine suitable to be taken to the chambers for the
production of dry hypochlorites.
The chloride of calcium remaining from the above described operation
is collected in vessels wherein carbonate of magnesia or magnesia and
carbonic acid are caused to react simultaneously, carbonate of limo and
chloride of magnesium are produced. This distilled chloride of mag-
nesium regenerates the hydrochloric acid, which is again employed for
the production of a fresh quantity of chlorine. The magnesia remaining
serves again for another operation.
Thus the reactions which constitute the process are shortly as
follows:-1st, the oxides of manganese serving for the production of
chlorine are ceaselessly regenerated; 2ndly, the hydrochloric acid is
utilised completely for the production of chlorine; 3rdly, all the chlorine
generated is in a pure state and consequently proper for the production
of dry hypochlorites.
Second Method. This method only differs from the one just described
in that instead of lime magnesia is substituted, the chlorides of
magnesium produced being without transformation and capable of
re-engendering hydrochloric acid by simple distillation.
Such are the two methods which characterize this Invention, the
object of which is the production without waste from oxides of man-
ganese and hydrochloric acid of pure chlorine and consequently of dry
hypochlorites by means of the reactions described.
In witness whereof, I, the said Thomas James Smith, have herc-
unto set my hand and seal, this Twenty-third day of February, in
the year of our Lord One thousand eight hundred and seventy-
two