IMPROVEMENTS IN THE MANUFACTURE OF CHLORINE
Year: 1877

page_text: LETTERS PATENT to Ernest Solvay, of Brussels, in the Kingdom of Belgium,
Manufacturer, for the Invention of "IMPROVEMENTS IN THE MANUFACTURE OF
CHLORINE."
Sealed the 18th May 1877, and dated the 8th January 1877.
PROVISIONAL SPECIFICATION left by the said Ernest Solvay at the Office of
the Commissioners of Patents on the 8th January 1877..
ERNEST SOLVAY, of Brussels, in the Kingdom of Belgium, Manufacturer.
PROVEMENTS IN THE MANUFACTURE OF CHLORINE."
"
'IM-
My Invention consists in abstracting chlorine directly from chloride of calcium
and chloride of magnesium by means of silica, alumina, or silicate of alumina, as..
herein-after described.
According to my Invention I take chloride of calcium and chloride of magnesium,
either separately or mixed together, in various proportions, and I mix them with
silica, with alumina, or with a suitable and sufficiently soft silicate of alumina,
such, for instance, as clay, either separately or mixed together, in various pro-
portions, and I subject the said substances to the influence of great heat and a blast
or current of air. The silicious or aluminous substances thus treated are to a
great extent converted into silicates or aluminates of lime and of magnesia, and the
chlorine is disengaged, mixed with the nitrogen of the air and any oxygen which..
has not been absorbed in the reaction. If the materials or the air used in the said
process be damp, hydrochloric acid will also be disengaged, but this may bé pre:
vented by drying the said materials, and also drying the air before using them.
The necessity of lixiviating the gas evolved so as to purify the chlorine from hydro-
chloric acid will thus be avoided.
In carrying out practically this Invention I use any of the well-known apparatus
by which a current of gas may be made to act upon a material heated to a red
heat.
I prefer to agglomerate a mixture of the chloride used with clay or sand, or both,
in a damp, pasty condition, and then to dry it, or to agglomerate the said mixture
by inteneration or fusion by the application of heat so as to form balls, cakes, or
bricks, which I charge into towers or columns made of iron or brickwork heated.
externally, and into which a current or blast of ordinary or superheated air is made

page_text: to pass. If the air be sufficiently heated the tower or column need not be heated
more than is required to keep it from cooling.
The operation may be continuous or not, and it may be carried on in a single
vertical chamber, into which the balls, cakes, or bricks are charged at the top, and
from which the residuum is discharged at the bottom; but I prefer to combine
together a certain. number of chambers so as to work methodically or gradually,
the air being caused to pass first through that chamber, the chlorine from which is
nearly entirely abstracted, and after having traversed the intermediate chambers
finally to pass through the chamber which has been most recently charged.
The proportions of the materials to be mixed together vary according to the
nature of the silicious and aluminous substances to be operated on, and more
particularly according to their purity, their tenuity, and their hardness. In general
it will be found that equal parts by weight of the two kinds of substances required
for the reaction give good results, but it is frequently more advantageous to increase
the proportion of the earthy substances.
The chlorine evolved in the process above described is ready for use in any of
the usual processes in which chlorine is used, such as the manufacture of chloride
of lime (bleaching powder). I prefer to draw off the said chlorine by suction so as
to prevent any part of it escaping, and the losses that would be caused thereby.
The facility with which chloride of magnesium may be made to abandon its
chlorine renders the use of silica, alumina, or silicate of alumina with it of much
less importance than when the said substances are used with chloride of calcium."
Moreover the reaction which takes places between the said silica, alumina, or silicate
of alumina and magnesium is never very complete.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Ernest Solvay in the Great Seal Patent Office on the 26th June
1877.
ERNEST SOLVAY, of Brussels, in the Kingdom of Belgium, Manufacturer.
PROVEMENTS IN THE MANUFACTURE OF CHLORINE."
"IM-
My Invention consists in abstracting chlorine directly from chloride of calcium
and chloride of magnesium by means of silica, alumina, or silicate of alumina, as
herein-after described.
· According to my Invention I take chloride of calcium and chloride of magnesium,
either separately or mixed together, in various proportions, and I mix them with
silica, with alumina, or with a suitable and sufficiently soft silicate of alumina,
such, for instance, as clay, either separately or mixed together, in various pro-
portions, and I subject the said substances to the influence of great heat and a blast
or current of air. The silicious or aluminous substances thus treated are to a great
extent converted into silicates or aluminates of lime and of magnesia, and the
chlorine is disengaged, mixed with the nitrogen of the air and any oxygen which
has not been absorbed in the reaction. If the materials or the air used in the said
process be damp, hydrochloric acid will also be disengaged, but this
may be pre-
vented by drying the said materials, and also drying the air before using them.
The necessity for lixiviating the gas evolved so as to purify the chlorine from hydro-
chloric acid will thus be avoided.
In carrying out practically this Invention I use any of the well known
apparatus by which a current of gas may be made to act upon a material heated to
a red heat.
:
I prefer to agglomerate a mixture of the chloride used with clay or sand, or both,
in a damp, pasty condition, and then to dry it or to agglomerate the said mixture
by inteneration or fusion by the application of heat so as to form balls, cakes, or
bricks, which I charge into towers or columns made of iron or brickwork heated

page_text: externally, and into which a current or blast of ordinary or superheated air is made
to pass. If the air be sufficiently heated the tower or column need not be heated
more than is required to keep it from cooling.
The operation may be continuous or not, and it may be carried on in a single
vertical chamber, into which the balls, cakes, or bricks are charged at the top, and
from which the residuum is discharged at the bottom; but I prefer to combine
together a certain number of chambers so as to work methodically or gradually,
the air being caused to pass first through that chamber, the chlorine from which is
nearly entirely abstracted, and after having traversed the intermediate chambers
finally to pass through the chamber which has been most recently charged.
The proportions of the materials to he mixed together vary according to the
nature of the silicious and aluminous substances to be operated on, and more par-
ticularly according to their purity, their tenuity, and their hardness. In general.it
will be found that equal parts by weight of the two kinds of substances required
for the reaction give good results, but it is frequently more advantageous to increase
the proportion of the earthy substances.
The chlorine evolved in the process above described is ready for use in any of
the usual processes in which chlorine is used, such as the manufacture of chloride
of lime (bleaching powder). I prefer to draw off the said chlorine by suction so as
to prevent any part of it escaping, and the losses that would be caused thereby.
The facility with which chloride of magnesium may be made to abandon its
chlorine renders the use of silica, alumina, or silicate of alumina with it of much
less importance than when the said substances are used with chloride of calcium.
Moreover the reaction which takes place between the said silica, alumina, or silicate
of alumina and magnesium is never very complete.
Having now described the nature of my said Invention and the manner of per-
forming the same, I claim as my Invention, the process of extracting chlorine from
chloride of calcium and chloride of magnesium, either separately or mixed together,
in various proportions by means of silica, of alumina, or of silicate of alumina under
the influence of great heat and a blast or current of air, substantially as herein-
before described, the essence of my Invention being to use, in the conditions herein-
before set forth, silica, alumina, or silicate of alumina, for the purpose of extracting
chlorine directly from the said chlorides, and nothing beyond that.
In witness whereof, I, the said Ernest Solvay, have hereunto set my hand
and seal, this Twenty-first day of June, in the year of our Lord One thousand
eight hundred and seventy-seven.