IMPROVEMENTS IN AND RELATING TO THE MANUFACTURE OF CHLORINE
Year: 1883

page_text: LETTERS PATENT to Walter Weldon, of Rede Hall, Burstow, in the County of
Surrey Fellow of the Royal Society, and President of the Society of Chemical
Industry. for an Invention of IMPROVEMENTS IN AND RELATING TO THE
MANUFACTURE OF CHLORINE
PROVISIONAL SPECIFICATION left by the said Walter Weldon at the Office
of the Commissioners of Patents on the 27th December 1883.
WALTER WELDON, of Rede Hall, Burstow, in the County of Surrey, Fellow
of the Royal Society, and President of the Society of Chemical Industry,
"IMPROVEMENTS IN AND RELATING TO THE MANUFACTURE OF CHLORINE"
This invention relates to the manufacture of chlorine by the process which is the
subject of an invention for which I applied for Letters Patent on the 23rd. of
August last. In that process, strong chlorine gas and a residual solution of chloride
of manganese are obtained by treating together aqueous hydrochloric acid and an
artificial oxide or mixture of artificial oxides of manganese produced by heating in
a current of air solid chloride of manganese obtained from the residual solution
aforesaid. The present invention relates to a method of obtaining solid manganese
chloride from the said residual solution, in a state in which it can be conveniently
used in the manufacture of chlorine by the process to which I have referred, and
in obtaining dilute chlorine and a residual oxide or mixture of oxides of manganese,
again to be employed for the liberation of strong chlorine from aqueous hydrochloric
acid, with reproduction of the aforesaid residual solution, by heating in a current
of air the solid manganese chloride so obtained.
To obtain solid chloride of manganese from the said residual solution, after that
residual solution has been neutralized, or deprived in any other way of the free acid
which will usually be at first associated with it, I subject it to evaporation, and
after it has reached a certain degree of concentration I agitate it by mechanical
means during the remainder of the evaporation, continuing such evaporation until
no liquid remains in the evaporating vessel. I thus obtain the chloride of
manganese in crystals or small masses, containing a little but not very much water
of crystallization. I then subject the crystals or small masses so obtained to a
ГР

page_text: higher temperature, perferably though not necessarily in another vessel, and so
drive off all or nearly all their water of crystallization. If the crystals or small
masses are not obtained in the first instance sufficiently small, I powder them by
mechanical means either before or after subjecting them to the said further heating.
I perform the said operation of evaporation preferably by means of steam heat,
applied externally to the evaporating vessel; but products of combustion can also
be used to heat the evaporating vessels instead of steam, and may be applied either
externally to the evaporating vessel, in "jackets" or otherwise, or be caused to
pass over the surface of the contents of the evaporating vessel.
The method of evaporation above described may be modified as follows. Instead
of performing the operation of evaporation intermittently, in such wise that each
operation is continued until no liquid remains in the evaporating vessel, it may be
performed continuously in a vessel into which solution of chloride of manganese is
continually fed, the crystals of solid chloride of manganese being continually
""fished" out of such vessel as they form and fall, the said fishing being performed
either by hand or by mechanical means.
The earlier part of the evaporation of the residual solution of chloride of
manganese may conveniently be performed in other vessels than those in which
solid manganese chloride is to be obtained, partially concentrated solution being
supplied to these latter.
Having obtained as thus described more or less finely divided solid manganese
chloride, I heat it in a current of air, and so drive off its chlorine, mixed with other
gases, and obtain its manganese as an oxide or mixture of oxides capable of
liberating strong chlorine from hydrochloric acid, at the same time reproducing
solution of manganese chloride, with which to recommence the series of operations.
To prevent the powder of manganese chloride fusing into large agglomerated masses
in this operation, I adopt one or other of the following methods. Either I mix the
said powder of manganese chloride with powder of oxide or oxides of manganese
obtained by a previous operation before charging the manganese chloride into the
apparatus in which it is to be hented in contact with air, or I charge the chloride of
manganese alone, into such apparatus already containing such oxide or oxides and
mix it therewith in that apparatus itself, or I charge the chloride of manganese
alone into apparatus not containing such oxide or oxides, and regulate the heat
applied to such apparatus in such wise that it shall not reach the fusing-point of
manganese chloride until after the said chloride has been partially decomposed,
and so has become partially mixed with an oxide or mixture of oxides of
manganese.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Walter Weldon in the Patent Office on the 23rd June 1884.
WALTER WELDON, of Rede Hall, Burstow, in the County of Surrey,
"IMPROVEMENTS IN AND RELATING TO THE MANUFACTURE OF CHLORINE,"
This invention relates to the manufacture of chlorine by the process which is
the subject of an invention for which I applied for Letters Patent on the
23rd. August last. In that process, strong chlorine gas and a residual solution
of chloride of manganese are obtained by treating together aqueous hydrochloric
acid and an artificial oxide or mixture of artificial oxides of manganese produced
by heating in a current of air solid chloride of manganese obtained from the
residual solution aforesaid. The present invention relates to a method of obtaining
solid manganese chloride from the said residual solution, in a state in which it can
be conveniently used in the manufacture of chlorine by the process to which I have
referred, and in obtaining dilute chlorine and a residual oxide or mixture of oxides
of manganese, again to be employed for the liberation of strong chlorine from
aqueous hydrochloric acid, with reproduction of the aforesaid residual solution, by
heating in a current of air the solid manganese chloride so obtained.
To obtain solid chloride of manganese from the said residual solution, after that
residual solution has been neutralized, or deprived in any other way of the free
acid which will usually be at first associated with it, I subject it to evaporation,
and after it has reached a certain degree of concentration I agitate it by mechanical
means during the remainder of the evaporation, continuing such evaporation until
no liquid remains in the evaporating vessel. I thus obtain the chloride of
manganese in crystals or small masses, containing a little but not very much
water of crystallization. I then subject the crystals or small masses so obtained
to a higher temperature, preferably though not necessarily in another vessel, and
so drive off all or nearly all their water of crystallization. If the crystals or small
masses are not obtained in the first instance sufficiently small, I powder them by
mechanical means either before or after subjecting them to the said further
heating. I perform the said operation of evaporation preferably by means of
steam heat, applied externally to the evaporating vessel; but products of
combustion can also be used to heat the evaporating vessels instead of steam,
and may be applied either externally to the evaporating vessel, in "jackets,"
or otherwise, or be caused to pass over the surface of the contents of the
evaporating vessel.
The method of evaporation above described may be modified as follows. Instead
of performing the operation of evaporation intermittently, in such wise that each
operation is continued until no liquid remains in the evaporating vessel, it may
be performed continuously, in a vessel into which solution of chloride of manganese
is continually fed, the crystals of solid chloride of manganese being continually
fished" out of such vessel as they form and fall, the said fishing being performed
either by hand or by mechanical means.
The earlier part of the evaporation of the residual solution of chloride of
manganese may conveniently be performed in other vessels than those in which
solid manganese chloride is to be obtained, partially concentrated solution being
supplied to these latter.
Having obtained as thus described more or less finely divided solid manganese
chloride, I heat it in a current of air, and so drive off its chlorine, mixed with
other gases, and obtain its manganese as an oxide or mixture of oxides capable of
liberating strong chlorine from hydrochloric acid, at the same time reproducing

page_text: solution of manganese chloride, with which to recommence the series of operations.
To prevent the powder of manganese chloride fusing into large agglomerated
masses in this operation, I adopt one or other of the following methods. Either
I mix the said powder of manganese chloride with powder of oxide or oxides of
manganese obtained by a previous operation before charging the manganese
chloride into the apparatus in which it is to be heated in contact with air, or I
charge the chloride of manganese alone into such apparatus already containing
such oxide or oxides and mix it therewith in that apparatus itself, or I charge
the chloride of manganese alone into apparatus not containing such oxide or oxides,
and regulate the heat applied to such apparatus in such wise that it shall not
reach the fusing-point of manganese chloride until after the said chloride bas
been partially decomposed, and so has become partially mixed with an oxide or
mixture of oxides of manganese.
What I claim as being novel in the invention to be secured to me by the
herein before in part recited Letters Patent consists:
Firstly, in obtaining solid manganese chloride in small crystals or masses by
subjecting to evaporation solution of manganese chloride and agitating the solution
mechanically during the latter part of the operation of evaporating it, substantially
as is above described.
Secondly, heating in contact with air solid manganese chloride obtained in small
masses as aforesaid, in order so to obtain free chlorine and an oxide of manganese
or mixture of oxides of manganese capable of liberating more chlorine from
aqueous hydrochloric acid.
Thirdly, conducting the operation of so heating the said solid manganese chloride
in contact with air substantially as is above described.
In witness whereof I, the said Walter Weldon, have hereunto set my hand and
seal this twenty first day of June in the year of Our Lord One thousand eight
hundred and eighty four.
WALTER WELDUN
WELDON (L.S.)