IMPROVEMENTS IN THE MANUFACTURE OF CHLORINE, AND IN THE PRODUCTION OF ARTIFICIAL OXIDES
Year: 1867

page_text: LETTERS PATENT to Walter Weldon, of Park Villa, West Hill, Highgate,
in the County of Middlesex, for the Invention of "IMPROVEMENTS IN THE
MANUFACTURE OF CHLORINE, AND IN THE PRODUCTION OF ARTIFICIAL OXIDES
33
Sealed the 9th July 1867, and dated the 18th January 1867.
PROVISIONAL SPECIFICATION left by the said Walter Weldon at the
Office of the Commissioners of Patents, with his Petition, on the
18th January 1867.
I, WALTER WELDON, of Park Villa, West Hill, Highgate, in the County
of Middlesex, do hereby declare the nature of the said Invention for " Im-
PROVEMENTS IN THE MANUFACTURE OF CHLORINE, AND IN THE PRODUCTION OF
ARTIFICIAL OXIDES OF MANGANESE FOR EMPLOYMENT BOTH IN THAT AND OTHER
MANUFACTURES," to be as follows:-
In the Specification of an Invention for "Improvements in the Manufacture
of Chlorine," for which Letters Patent, numbered 1948, and dated the 26th
of July 1866, have been granted to me, I have described a novel and simple
method of transforming protoxide of manganese, obtained from chloride of

page_text: process based
upon
the said
manganese or otherwise, into sesquioxide, and a
method of converting protoxide of manganese into a higher oxide, whereby
the same manganese may be made to serve as a means of liberating chlorine
from hydrochloric acid any indefinite number of successive times, and other
important economies in the manufacture of chlorine be also effected.
My present Invention consists in certain further improvements, mainly
relating to the process described in the Specification aforesaid, but partly
applicable also to other processes, whereby I can both still further cheapen
the production of chlorine, and produce an artificial peroxide of manganese
for use, also in any other manufacture for which that compound is available.
One of the improvements comprised in my present Invention consists in
the transformation of protoxide of manganese into peroxide, and in the use
in the manufacture of chlorine, and also in that of glass, and in any other
manufacture in which such compound is of service of the artificial peroxide so
obtained. I have found that when protoxide of manganese has been converted
into sesquioxide by the method set forth in my Specification referred to above
the sesquioxide so produced may be converted into the very much more
valuable peroxide by simply further continuing the peculiar operation of
oxidation, by means of which the sesquioxide was itself formed. This
conversion of the said sesquioxide into peroxide may sometimes be facilitated
by leaving the sesquioxide at rest for a time before further continuing the
process of oxidation in question, as also by adding to the said sesquioxide,
prior to the continuance of the said operation of oxidation, a small portion of
previously formed peroxide, and likewise by first artificially heating the blast
of air by injection of which into a mixture of oxide and water or other neutral
liquid the conversion of the said oxide into a higher oxide is effected. I have,
moreover, found that in the conversion of protoxide of manganese into sesqui-
oxide by the method referred to this preliminary heating of the injected air
considerably facilitates the operation in certain states of the atmosphere, which
states I believe to have reference to the proportion of ozone contained therein.
Another of the improvements collectively constituting my present Invention
consists in dispensing, when employing for the liberation of chlorine from hydro-
chloric acid either the artificial sesquioxide of manganese obtained by the process
described in my former Specification aforesaid, or the artificial peroxide of
manganese obtained by means of the first part of my present Invention, with
the preliminary condensation of the hydrochloric acid. I have found that when
either the said sesquioxide or the said peroxide is used in a moist state it will
absorb gaseous hydrochloric acid with extreme avidity, and that therefore when
either of the said artificial oxides is used in the manufacture of chlorine the

page_text: hydrochloric acid with which it is to react may be passed into the stills in
which the reaction is to take place in the state of either hot or but partially
cooled gas, thereby saving either all or the greater part of the expense alike
of first cooling and condensing the hydrochloric acid as is always done at
present before employing it in the manufacture of chlorine, and of subsequently
heating when in the chlorine stills, the acid which having been originally
generated as a hot gas has been converted by such cooling and condensation
into a nearly cold solution of the said gas in water.
Another of the improvements forming part of my present Invention
consists in a method of recovering the chlorine contained in the chloride of
calcium or other metal which is produced when chloride of manganese is
decomposed by lime or other oxide, as is directed in my former Specification
already several times referred to. This method consists in first decomposing
the said chloride of calcium or other metal by means of carbonate of
ammonium, in then decomposing the resulting chloride of ammonium by
meaus of either oxide of zine, magnesia, or other similar oxide, and in
then decomposing the resulting chloride of zinc or other metal by heating
it either in a current of air or in a current of steam. The second of these
three operations yields free ammonia, needing only to be associated with
more carbonic acid in order to enable it to decompose another portion of
calcic or other chloride, and the final operation liberates the chlorine, either in
the free state if the chloride of zinc or other metal be heated in a current of
air, or as hydrochloric acid if it be heated in a current of steam, at the
same time reproducing in a form in which it is immediately fit for use over
again the oxide of zinc or other metal which had been employed to decompose
the chloride of ammonium; both the ammonia and the metallic oxide used
in this process can thus be employed over and over again continually.
This part of my Invention is applicable also to the chloride of ammonium
obtained by causing carbonate of ammonium to react directly upon chloride
of manganese.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Walter Weldon in the Great Seal Patent Office on the
11th July 1867.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WALTER
WELDON, of Park Villa, West Hill, Highgate, in the County of Middlesex,
send greeting.

page_text: WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Eighteenth day of January, in the year of our
Lord One thousand eight hundred and sixty-seven, in the thirtieth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said Walter Weldon, Her special licence that I, the said Walter
Weldon, my executors, administrators, and assigns, or such others as I, the
said Walter Weldon, my executors, administrators, and assigns, should at
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 Britain Great
and Ireland, the Channel Islands, and Isle of Man, an Invention for
* IMPROVEMENTS IN THE MANUFACTURE OF CHLORINE, AND IN THE PRODUCTION OF
ARTIFICIAL OXIDES OF MANGANESE FOR EMPLOYMENT BOTH IN THAT AND IN OTHER
MANUFACTURES," upon the condition (amongst others) that I, the said Walter
Weldon, 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 Walter Weldon, 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:
In the Specification of an Invention for "Improvements in the Manufacture
of Chlorine," for which Letters Patent, numbered 1948, and bearing date the
26th day of July 1866, bave been granted to me, I have described a novel and very
simple method of converting protoxide of manganese, obtained by decomposition
of protochloride of manganese, into sesquioxide available for the manufacture
of chlorine, and a process based on that method of transforming protochloride
of manganese into sesquioxide, whereby chlorine can be manufactured by
means of the same manganese used over and over again perpetually.
The process to which I thus refer effects two very important economies,
inasmuch as it enables a given quantity of hydrochloric acid to yield a very
much larger proportion of free chlorine than is practically obtainable there-
from by any process previously known, and as it moreover dispenses with
very nearly, if not quite, the whole of the exceedingly heavy cost which the
manufacture of chlorine by the old methods entails for native peroxide of
manganese.

page_text: The further improvements which constitute my present Invention have
reference mainly to the process just referred to, but are partly applicable also
to other processes; these further improvements effect additional economies
in the manufacture of chlorine, and are available for the production of a very
pure artificial peroxide of manganese, suitable for use not only in that
manufacture but in other manufactures as well.
The most important of the further improvements comprised in my present
Invention consists in the transformation of protoxide of manganese obtained
by decomposing by means of any suitable oxide of other metal the chloride of
manganese which is one of the results of the reaction between any oxide of
manganese and bydrochloric acid, instead of into sesquioxide merely into a
richer peroxide, and in the use in the manufacture of chlorine, and for other
purposes of the richer artificial peroxide so obtained. I have found that
when protoxide of manganese has been converted by the method described
in the Specification of the Invention, the number and date of the Letters Patent
for which are mentioned above, into hydrated sesquioxide, the sesquioxide so
obtained may be converted into a richer and more valuable peroxide by simply
further continuing the operation by means of which the sesquioxide was itself
produced. Accordingly when practising my present Invention, instead of
stopping, when only sesquioxide has been formed, the injection of air into the
mixture, by injecting air into which I form sesquioxide of manganese under
my former Invention, I continue such injection of air until an oxide richer than
sesquioxide has been formed. Sesquioxide of manganese may be regarded as
a mixture of 55 per cent. of binoxide with 45 per cent. of protoxide; but I
have found it possible by a sufficient continuance of the oxidizing operation
described in my former Specification, already twice above referred to, to obtain
a product consisting almost entirely of binoxide, while a less rich oxide, but
one containing appreciably more than 55 per cent. of binoxide, or the proportion
of binoxide which sesquioxide may be regarded as containing (and the difference
in practical value between a 55 per cent. oxide and a richer oxide is considerably
greater than the difference between the per-centage proportions in which they
respectively contain binoxide), is thus obtainable with the utmost ease.
use the artificial peroxide obtained under my present Invention for the
manufacture of chlorine in precisely the same manuer as is described for
sesquioxide in my former Specification aforesaid, but especially preferring
(though not confining myself thereto) that one of the plans described in that
Specification whereby all the successive operations of the process, including
both the production of the artificial peroxide, and the liberation of chlorine
by means of it, are performed in one vessel, and I also use it in the
I

page_text: manufacture of glass, and likewise for the generation of free oxygen, for the
production of manganates and permanganates, and indeed for every purpose
for which the native peroxide of manganese is available.
Another of the improvements collectively constituting my present Invention
consists in artificially heating the blast of air before injecting it into the
mixture of oxide and water or other neutral liquid, whether with a view to
producing sesquioxide only, or with a view to producing a richer peroxide.
In nearly all states of the atmosphere this preliminary heating of the injected
air, or what comes to much the same thing, the application of heat instead
of to the blast to the mixture into which it is injected, which application may
be effected either by the injection of steam or in any other convenient way,
more or less facilitates the operation of oxidation; but I doubt whether it
does so to an extent worth its cost, except when, as sometimes happens, the
oxygen of the atmosphere possesses much less than its average degree of
chemical activity; under such circumstances, however, it is decidedly
advantageous to heat either the blast or the mixture, I need scarcely add
that it is essential for obvious reasons of a different kind to heat one or the
other when the atmosphere is at such a temperature that the injection of
unheated air into a cold mixture would cause in the latter a large formation
of ice.
By an improvement constituting a third feature of my present Invention I
am enabled to dispense when employing for the liberation of chlorine from
hydrochloric acid either the artificial sesquioxide of manganese obtained as
described in my former Specification above indicated, or the richer artificial
peroxide obtained as described above, with the preliminary condensation of
the hydrochloric acid, I have found that when either the said artificial
sesquioxide or the said artificial peroxide is used in a sufficiently moist state,
the state of not very thick mud is a very suitable one, it will absorb gaseous
hydrochloric acid with extreme avidity; therefore, by using either oxide in
that state I can use the hydrochloric acid with which it is to react in the
condition of hot gas, passing it directly from the ovens, furnaces, or other
vessels in which it is generated into the stills containing the oxide, and can
thus avoid both the whole of the expense of first cooling and condensing the
hydrochloric acid gas as is invariably done at present before employing it in
the manufacture of chlorine, and also the greater part, if not the whole, of
the further expense which is afterwards incurred for heating the cooled and
condensed acid when in the chlorine stills.
Lastly, another of the improvements forming part of my present Invention
consists in a method of recovering the chlorine contained in the chlorido of

page_text: calcium or other metal which is produced when chloride of manganese is
decomposed by means of lime or other oxide. This method consists in first
decomposing the said calcic or other chloride by means of carbonate of
ammonium; in then decomposing the resulting chloride of ammonium by
means of either oxide of zinc, oxide of magnesium, or other suitable metallic
oxide; and, lastly, in then decomposing the resulting chloride of zinc,
magnesium, or other metal by heating it either in a current of air or in a
current of steam. The third of these three operations liberates the chlorine
(either in the free state if the chloride of zinc or other metal be heated in a
current of air, or as hydrochloric acid if the said chloride be heated in a
current of steam), at the same time reproducing in a form in which it is fit
for use over again the oxide of zinc or other metal which had been employed
to decompose the chloride of ammonium; and the second of the three
operations yields free ammonia which only requires to be associated with a
fresh portion of carbonic acid in order to render it capable of decomposing a
fresh charge of chloride of manganese. Both the ammonia and the metallic
oxide employed can thus be used over and over again perpetually. This part
of my Invention is applicable also to the chloride of ammonium formed by
causing carbonate of ammonium to react directly upon chloride of manganese.
Having thus fully and particularly described and ascertained the nature of
my said Invention, and the manner in which the same is to be performed, I
wish it to be understood that what I consider novel therein, and therefore
claim as my Invention and desire to have secured to me by the herein-before
in part recited Letters Patent is as follows:-
Firstly, the production of an artificial peroxide of manganese, meaning
thereby an oxide containing more than 55 per cent. of binoxide, by injecting
atmospheric air into a mixture of an inferior oxide of manganese with water
or other neutral liquid,
Secondly, the use of the artificial peroxide so obtained in the manufacture
of chlorine, as described, and also in the manufacture of glass, manganates,
and permanganates, etc., etc.
Thirdly, the operation of all the successive transformations of the manganese
when my artificial peroxide is employed in the manufacture of chlorine;
namely, the transformations, first of protochloride into protoxide, then of
protoxide into peroxide, then of peroxide back to chloride, then of chloride
into protoxide again, then of protoxide into peroxide again, and so on perpetually
in a single vessel.
Fourthly,
the application of heat to facilitate the oxidation by the injection

page_text: of air into a mixture thereof with water or other neutral liquid of inferior
oxides of manganese, whether into sesquioxide or into peroxide.
Fifthly, the employment of the hydrochloric acid in the state of gas without
preliminary condensation when manufacturing chlorine by means either
of the artificial sesquioxide or of the artificial peroxide produced by my
processes.
And, sixthly, the method above described of recovering the chlorine
contained in the metallic chloride formed by double decomposition between
chloride of manganese and a suitable metallic oxide, and also of recovering
the chlorine contained in the chloride of ammonium formed by double
decomposition between chloride of manganese and carbonate of ammonium.
In witness whereof, I, the said Walter Weldon, have hereunto set my
hand and seal, this Eleventh day of July, in the year of our Lord One
thousand eight hundred and sixty-seven.
WALTER WELDON.
(L.S.)