IMPROVEMENTS IN THE REGENERATION FROM CHLORINE RESIDUES OF OXIDES OF MANGANESE SUITABLE FOR USE AGAIN IN THE MANUFACTURE OF CHLORINE, AND CAPABLE OF BEING APPLIED ALSO TO OTHER PURPOSES.
Year: 1868

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 REGENERATION FROM CHLORINE RESIDUES OF OXIDES
OF MANGANESE SUITABLE FOR USE AGAIN IN THE MANUFACTURE OF
CHLORINE, AND CAPABLE OF BEING APPLIED ALSO TO OTHER PURPOSES.
Sealed the 14th August 1868, and dated the 27th February 1868.
PROVISIONAL SPECIFICATION left by the said Walter Weldon at
-the Office of the Commissioners of Patents, with his Petition, on
the 27th February 1868.
I, WALTER WELDON, of Park Villa, West Hill, Highgate, in the
County of Middlesex, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN THE REGENERATION FROM CHLORINE
RESIDUES OF OXIDES OF MANGANESE SUITABLE FOR USE AGAIN IN THE
MANUFACTURE OF CHLORINE, AND CAPABLE OF BEING APPLIED ALSO TO OTHER
PURPOSES," to be as follows:-
This Invention consists, firstly, in peroxidizing in the dry way,
either by furnace operations or otherwise, any low oxide of manganese
recovered from chlorine, manufacturer's residual "still liquor" by
>

page_text: decomposing the chloride of manganese contained therein by means
of magnesia; this decomposition of the chloride of manganese by
means of magnesia being effected either by one or other of the
methods set forth in the Provisional Specification of an Invention
relating to the regeneration of oxides of manganese from chlorine
residues in the wet way and to the manufacture of chlorine by means
of oxides so regenerated, which Provisional Specification is numbered
505, and was deposited at the Patent Office on the Twentieth day of
this present February, in this present year of our Lord One thousand
eight hundred and sixty-eight, or in any other manner whatsoever.
The peroxidation of oxides of manganese so recovered from chlorine
residues may be effected under the present Invention either by simply
exposing them at ordinary temperatures to the action of atmospheric
or other oxygen, or by heating them in contact with either atmospheric
air or other convenient and suitable oxidizing gas or compound or
mixture of gases, or by heating them either with or without contact
of air, and with or without presence of steam in admixture with any
suitable solid oxidizing agent, such for example as nitrate of sodium,
which compound when heated with a low oxide of manganese,
especially in presence of steam, yields a rich oxide of manganese
mixed with caustic soda (which can be dissolved out from the mixture),
while valuable compounds of nitrogen, which can be readily turned
to useful account are given off. The hydrated chloride of magnesium
which is obtained simultaneously with the oxides to be treated under
the first part of the present Invention should be decomposed by heat,
SO as to yield magnesia for use over again, and a specially pure
hydrochloric acid applicable to any purpose for which that compound
is available.
This Invention consists, secondly, in effecting the decomposition of
chloride of manganese by means of magnesia and the peroxidation of
the resulting oxide of manganese by furnacing a mixture of chloride
of manganese with either chloride of magnesium or magnesia. If a
mixed solution of chloride. of manganese and chloride of magnesium
be evaporated to dryness and the residue be then sufficiently heated
in contact with air, with more or less constant stirring or "working,"
the chlorine of both compounds will fly off chiefly as hydrochloric
acid, and there will remain behind a mixture of magnesia with an
oxide of manganese considerably rich in oxygen, which mixture on

page_text: treatment with hydrochloric acid will liberate chlorine, with repro-
duction of the same quantity of mixed solution of chlorido of
manganese and chloride of magnesium as was cominenced with. Or
instead of the mixture of magnesia and oxide of manganese being
treated with acid only the oxide of manganese may be so treated,
the magnesia being first separated from the oxide of manganese by
taking advantage of the difference in density between the two
substances, owing to which they may be readily separated by various
simple methods of washing. When proceeding in this way the
subsequent treatment with acid will yield besides free chlorine only
chloride of manganese, to which the magnesia must be added either
in the furnace or at any stage of its treatment before reaching the
furnace.
Another plan is to heat together chloride of manganese and
magnesia until the chloride of manganese has been converted into a
more or less rich oxide; to then add to the resulting mixture of
oxide of manganese and magnesia a. further portion of chloride of
manganese, and heat again until the chlorine of this second portion
of chloride of manganese shall have been driven off and replaced by
oxygen as before; to then add more chloride of manganese and to
proceed as described again and again until by means of a single
equivalent of magnesia a number of equivalents of chloride of
manganese have been decomposed and the resulting pistoxide
peroxidized by atmospheric oxygen.
This Invention consists, thirdly, in first partially peroxidizing
artificial oxides of manganese in the wet way, and then completing
their peroxidation in the dry way by heating them in contact with
air or other suitable oxidizing agent. This part of the present
Invention is applicable not only to artificial oxides of manganese
recovered by means of magnesia, but also to oxides of manganese
recovered by means of lime, soda, ammonia, or any other agent
whatever.
This Invention consists, fourthly, in systematically purifying the
still liquor, the oxide of manganese to be recovered from which is
to be peroxidized in the dry way in the same manner as I have
described in the previous Specification abovo alluded to for the
purification of still liquor, the oxide of manganese to be recovered
from which is to be peroxidized in the wet way.

page_text: This Invention consists, fifthly, in washing oxides of manganese to
be peroxidized in the dry way, in the same manner as is described
in the former Specification aforesaid for oxides which have been
recovered and peroxidized in the wet way.
This Invention consists, sixthly, in submitting protoxide or other
low oxide of manganese, whether recovered by means of magnesia,
lime, or whatever other agent, to more or less prolonged boiling
before washing it, whereby its subsequent washing is very materially
facilitated.
This Invention consists, seventhly, in separating adherent liquor
from protoxide or other low oxide of manganese which is to be
peroxidized in the dry way by means of centrifugal hydro-extractors.
This Invention consists, lastly, in the use of oxides of manganese
recovered and peroxidized as above described for the liberation of
chlorine from hydrochloric acid, for the production of manganetes
and permanganates in the manufacture of glass as a source of free
oxygen, and for whatever other purposes native oxides of manganese
are available.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Walter Weldon in the Great Seal Patent Office 20
on the 25th August 1868.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WALTER
WELDON, of Park Villa, West Hill, Highgate, in the County of
Middlesex, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her 2
Letters Patent, bearing date the Twenty-seventh day of February, in
the year of our Lord One thousand eight hundred and sixty-eight, in
the thirty-first 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, 3
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

page_text: 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 THE REGENERATION FROM CHLORINE
RESIDUES OF OXIDES OF MANGANESE SUITABLE FOR USE AGAIN IN THE
MANUFACTURE OF CHLORINE, AND CAPABLE OF BEING APPLIED ALSO то OTHER
PURPOSES," 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 (that is to say) :-
-
I. This Invention consists, firstly, in obtaining artificial peroxides of
manganese suitable for use in manufacturing operations for the liberation
of chlorine from hydrochloric acid by peroxidizing in the dry way,
either by furnace operations or otherwise, protoxide or other low oxide
of manganese recovered by means of magnesia from the chloride of
manganese which is a residual product of the manufacture of chlorine,
as that manufacture is at present ordinarily conducted, and in combining
this method of obtaining such artificial peroxides with the decomposition
into magnesia and hydrochloric acid of the hydrated chloride of
magnesium which results, in addition to protoxide of manganese from
the decomposition of chloride of manganese by magnesia, and with the
use over again for the decomposition of more chloride of mangancse of the
magnesia so obtained. It has long been known that protoxide of
manganese can be converted into a rich peroxide by being heated in
contact with air, and into a less rich but still very valuable peroxide by
being simply exposed to air at ordinary temperatures; but all previous
attempts to turn these facts to practical account for the regeneration
of the oxides of manganese used in the manufacture of chlorine have
completely failed, and their failure has arisen from lime having been the
agent employed to effect the transformation of the manganese in the
residual product of the manufacture of chlorine from the state of

page_text: i
-chloride to that of protoxide. Lime precipitates protoxide of manganese
from solution of chloride of manganese as a very bulky hydrate, forming
with a portion of the solution of chloride of calcium produced at the
same time as itself, a semi-gelatinous mass, which never dries unless
heated, and which then formes hard cakes, to the interior of which air
can gain access only very slowly, and which therefore peroxidize only
on the surface, unless their exposure to air be exceedingly prolonged.
.In order, therefore, to render it possible to effect within a reasonable
time the complete peroxidation in the dry way, either under the
influence of heat or otherwise of protoxide of manganese obtained
by decomposing chloride of manganese by means of limc, it is essential
that such protoxide of manganese 'should first be washed free (or
nearly so) from chloride of calcium, and this washing of such
protoxide is exceedingly difficult even in the laboratory, and has hitherto
proved wholly impracticable on the large scale. I have found, however,
firstly, that magnesia, and especially magnesia which has been obtained
by decomposing hydrated chloride of magnesium by heat, precipitates
protoxide of manganese from solution of chloride of manganese in a
'much less bulky and much more granular condition than that in which it
is precipitated by lime, and in a condition in which it can readily be
washed on any scale whatever; secondly, that in the case of protoxide of
manganese which has been precipitated from chloride of manganese by
means of magnesia and is to be peroxidized in the dry way under the
influence of heat washing is not so essential as in the corresponding case
of protoxide of manganese which has been precipitated from chloride of
manganese by means of lime, the readiness with which hydrated chloride
of magnesium is decomposed by heat preventing it from cementing
the particles of oxide of manganese into hard impervious masses, as
chloride of calcium does under the like circumstances; and, thirdly,
that protoxide of manganese obtained by decomposing chloride of
manganese by means of magnesia which has been obtained by de-
composing chloride of magnesium by heat is in a specially favourable
condition for peroxidation in the dry way at ordinary temperatures.
Upon these discoveries I have based a process for the perpetual
regeneration of the oxides of manganese used in the manufacture of
chlorine, whereby not only is the susceptibility of protoxide of
manganese to peroxidation in the dry way turned to practical account,
which it cannot be when obtaining the protoxide by means of lime, but
both the elements of the chloride of manganese (instead of only one of
.

page_text: them, which is all that it has been attempted to obtain by means of lime)
are recovered in a practically useful form. This process consists essentially
in first boiling with magnesia the solution of chloride of manganese which
is a residual product of the manufacture of chlorine, using by preference
magnesia which has been obtained by the decomposition by heat of
the hydrated chloride of magnesium produced by so treating with
magnesia a previous charge of chloride of manganese; in then separating
the resulting oxide of manganese and solution of chloride of magnesium
as completely as possible from each other, either by filtration, or by
subsidence and decantation, or by the use of centrifugal hydro-extractors,
or by a combination of any two of these methods, or of all three of
them, and in then peroxidizing the separated oxide in the dry way,
either by simply exposing it at ordinary temperatures to the action of
atmospheric or other oxygen, or by heating it in contact with either
atmospheric air or other convenient and suitable oxidizing gas or
compound or mixture of gases, or by heating it with or without contact
of air, and with or without presence of steam in admixture with any
suitable solid oxidizing agent, such for example as nitrate of sodium,
which compound, when heated with a low oxide of manganese, especially
in presence of steam, yields a rich oxide of manganese mixed with
caustic soda (which can be dissolved out from the mixture), while
valuable compounds of nitrogen which can readily be utilized are
given off. To these operations I prefer to add that of the decomposition
by heat of the hydrated chloride of magnesium produced by the reaction
of the magnesia on the chloride of manganese.
Instead of the solution of chloride of manganese being boiled with
the magnesia which is to decompose it, the two bodies may be treated
together in any other way which will enable them to react upon each
other, but for the purposes of this first part of the present Invention
I believe that the method of boiling them together is the best. The
magnesia will not completely decompose the chloride of manganese by
being simply boiled therewith, but by being vigourously boiled therewith
for from two to five hours it will decompose more than ninety per
cent. of it, and the remainder may be allowed to pass round with the
chloride of magnesium, during the decomposition of which by heat it
also will be decomposed, the chlorine of both compounds flying off,
either wholly as hydrochloric acid, or principally as hydrochloric acid
and partially as free chlorine, and a residue of magnesia mixed with

page_text: a more or less rich peroxide of manganese remaining behind. The
peroxide of manganese in this mixture will be finally obtained admixed
with the peroxide resulting from the reaction of the magnesia in the
mixture upon the chloride of manganese which it is employed to de-
compose. Before undergoing the peroxidizing operation the protoxide
or mixture of protoxide and peroxide may be either washed or not, as
may be preferred. If washed the washing may be performed either
by any ordinary and well-known method, or by either of the new
methods which will be more particularly mentioned below. The method
which I prefer for the decomposition of the hydrated chloride of
magnesium produced in this process is that which is described in the
Specification of my Patent numbered 505, and dated the Twentieth day
of February in the year now current.
II. This Invention consists, secondly, in effecting the decomposition
of chloride of manganese by means of magnesia and the peroxidation
of the resulting oxide of manganese by furnacing a mixture of chloride
of manganese with either chloride of magnesium or magnesia. If a
mixed solution of chloride of magnesium and chloride of manganese
be evaporated to dryness and the residue be then heated in contact
with air with more or less constant stirring or "working" the chlorine
of both compounds will fly off chiefly as hydrochloric acid, and there
will remain behind a mixture of magnesia with an oxide of manganese
considerably rich in oxygen, which mixture on treatment with hydro-
chloric acid will liberate chlorine with reproduction of the same quantity
of mixed solution of chloride of manganese and chloride of magnesium
as was commenced with; or instead of the mixture of magnesia and
oxide of manganese being treated with acid only the oxide of manganese
may be so treated, the magnesia being first separated from the oxide
of manganese by taking advantage of the difference in density between
the two substances, owing to which they may be separated by various
simple methods of washing. I do not consider this to be so good a
plan as that first mentioned, but when it is followed the still liquor
will consist only of chloride of manganese, to which the magnesia
must be added either in the decomposing furnace or at any stage of
its treatment before reaching the decomposing furnace. Another plan
is to heat together chloride of manganese and magnesia until the
chloride of manganese has been transformed, at least for the most part,
into a more or less rich peroxide; to then add to the mixture of

page_text: magnesia and peroxide of manganese so obtained a further portion of
chloride of manganese, and heat again until the chlorine of this second
portion of chloride of manganese shall have been driven off and replaced
by oxygen, as before; to then add more chloride of manganese, and
to proceed as described again and again until by means of a single
equivalent of magnesia a number of equivalents of chloride of manganese
have been decomposed, their chlorine becoming replaced by atmospheric
oxygen.
III. This Invention consists, thirdly, in first partially peroxidizing
artificial oxides of manganese in the wet way and then completing
their peroxidation in the dry way by any of the methods of peroxidation
which are described above in paragraph I. This part of the present
Invention is applicable not only to artificial oxides of manganese
recovered by means of magnesia, but also to oxides of manganese
recovered by means of lime, soda, ammonia, or any other agent
whatever.
IV. This Invention consists, fourthly, in systematically purifying
still liquor, the oxide of manganese to be recovered from which is to
be peroxidized in the dry way in the same manner as I have described
in the Specification of my Patent numbered 565 and dated the Twentieth
day of February in the year now current for the purification of still
liquor, the oxide of manganese. to be recovered from which is to be
peroxidized in the wet way.
V. This Invention consists, fifthly, in washing oxides of manganese
to be peroxidized in the dry way in the same manner as described in
the Specification the number and date of which are above given for
oxides which have been recovered and peroxidized in the wet way.
VI. This Invention consists, sixthly, in submitting protoxide or other
low oxide of manganese, whether recovered by means of magnesia,
lime, or whatever other agent, to more or less prolonged boiling
before washing it, whereby its subsequent washing is very materially
facilitated.
VII. This Invention consists, seventhly, in separating adherent
liquor from protoxide or other low oxide of manganese which is
to be peroxidized in the dry way by means of centrifugal hydro-
extractors.

page_text: VIII. This Invention consists, lastly, in the use of oxides of
manganese recovered and peroxidized or otherwise treated wholly or
partially as above described for the liberation of chlorine from hydro-
chloric acid for the production of manganates and permanganates in
the manufacture of glass as a source of free oxygen, and for whatever
other purposes native oxides of manganese are available.
IX. Having thus particularly described and ascertained the nature
of my Invention, and in what manner the same is to be performed,
I wish it to be understood that what I claim as my Invention and
desire to be secured to me by the herein in part recited Letters Patent
is, the above-described processes and methods of treatment and pro-
ceedure having for object or being intimately connected with the perpetual
regeneration of the oxides of manganese employed in the manufacture
of chlorine.
In witness whereof, I, the said Walter Weldon, have hereunto
set, my hand and seal, this Twenty-fourth day of August, in
the year of our Lord One thousand eight hundred and sixty-
eight.