Improvements in the Manufacture or Production of Alkaline Chlorates.
Year: 1895

page_text: Date of Application, 9th Dec., 1895
Complete Specification Left, 15th Jan., 1896-Accepted, 15th Feb.. 1896
PROVISIONAL SPECIFICATION.
Improvements in the Manufacture or Production of Alkaline
Chlorates.
I, CARL KELLNER, of 29, Wasagasse, Vienna IX, Austria, Doctor of
Philosophy, do hereby declare the nature of this invention to be as follows:
The electrolytical production of alkaline chlorates has hitherto been attended
with various difficulties. For obviating these difficulties several methods have been
proposed but the desired object has only been attained thereto in an imperfect
manner.
One of these proposed methods consists in the addition to the electrolyte of an
alkaline hydrate. According to a second method a carbonate is added to the
electrolyte. The first method has the disadvantage that the alkaline hydrate when
added all at once participates in the work of the current and absorbs a certain part
of the same for the decomposition of water, an operation that is useless for carrying
out the desired process. On the other hand the constant admission of the alkaline
hydrate to the electrolyte, necessitates the arrangement of apparatus too
complicated for carrying out the process on a large industrial scale.
The addition of carbonates, according to the said second method, gives rise to
the formation of free hypochlorous acid, which, although it is immediately
connected to the cathode by the alkaline hydrate, will nevertheless act at the anode
in a disturbing manner.
The present invention has reference to a simple and economical process by means
of which the chlorates of the alkaline metals can be produced by electrolysis on a
large scale, direct from the alkaline chlorides, and without using a diaphragm.
For this purpose during the whole of the electrolytical process an oxide or
bydroxide, which is not easily soluble in water, is maintained in a suspended
condition in the electrolyte whereby the latter is caused to remain constantly
alkaline during the whole of the electrolysis, and the oxide or hydroxide is
prevented from participating in the work of the current.
This process, which, according to a number of experiments that have been made,
yields excellent results, will be explained by the following example in which it
is assumed that chlorate of potassium is to be produced according to the improved
process.
In this case the electrolyte will consist of a cold saturated solution of chloride of
potassium to which about 1 to 3% of hydrate of calcium is added. During the
electrolytical process the hydrate of calcium is kept in motion and thereby
maintained in a suspended condition in the electrolyte. This has for result that
the electrolyte will remain alkaline as long as the current passes through it,
without the hydrate of calcium participating in the least degree in the conduction.
of the current.
During the electrolysis, the hydrate of calcium thus maintained in a suspended
state, combines with the chlorine which escapes at the anode, and forms therewith
chemical compounds the nature of which will be dependent on the respective
process. These compounds when flowing along the cathode are at once converted
by the hydrate of potassium there produced into the corresponding compounds of
chlorate of potassium whilst hydrate of calcium is being simultaneously reformed.
In this manner the bydrate of calcium effects during the process, the transfer of
the chlorine from the anode to the cathode and obviates the loss of electric current,

page_text: which, if an alkali soluble in water were employed, would inevitably arise owin:
to the circumstances that the alkali itself would co-operate as electrolyte.
Instead of hydrate of calcium other oxides or hydrates, as for instance those of
magnesium, may be employed, without departing from the nature of this invention.
The process can also be modified in such a manner that the hydrate is separated
from its chloride by electrolysis, and the metallic chlorate thus formed is converted
into the alkaline chlorate by the addition of the chloride of the alkaline metal. In
this way, the utilization for the production of alkaline chlorates, of the chlorides
of calcium, magnesium etc., which are frequently obtained as waste products in
other processes, is rendered possible.
Dated this 9th day of December 1895.
F. WISE HOWORTH,
46, Lincoln's Inn Fields, London, W.C., Agent for the Applicant.
Improvements in the Manufacture or Production of Alkaline
Chlorates.
I, CARL KELLNER, of 29, Wasagasse, Vienna IX, Austria, Doctor of Philosophy,
do hereby declare the nature of this invention and in what manner the same is to
be performed to be particularly described and ascertained in and by the following
statement:-
The electrolytical production of alkaline chlorates has hitherto been attended
with various difficulties. For obviating these difficulties several methods have
been proposed but the desired object has been attained hitherto only in an
imperfect manner.
One of these proposed methods consists in the addition to the electrolyte of an
alkaline hydrate. According to a second method a carbonate is added to the
electrolyte. The first method has the disadvantage that the alkaline hydrate,
when added all at once, absorbs a certain part of the electrical energy of the
current for the decomposition of water, an operation that is useless for carrying out
the desired process. On the other hand, the continuous admission of the alkaline
hydrate to the electrolyte, necessitates the arrangement of apparatus too compli-
cated for carrying out the process on an industrial scale.
The addition of carbonates, according to the said second method, gives rise to
the formation of free hypochlorous acid, which, although it is immediately connected
to the cathode by the alkaline hydrate formed will, nevertheless, act at the anode
in a disturbing manner.
The present invention has reference to a simple and economical process by
means of which the chlorates of the alkaline metals can be produced by
electrolysis on a large scale, direct from the alkaline chlorides, and without
using a diaphragm.
For this purpose, during the whole of the electrolytical process, an oxide or
hydrate, which is not easily soluble in water, is maintained in a suspended condition
in the electrolyte, so that the latter is caused to remain constantly alkaline during
the whole of the electrolysis, and the oxide or hydrate is prevented from
participating in the work of the currents. This process, which, according to a
number of experiments that have been made, yields excellent results, will be
explained by the following example in which it is assumed that chlorate of
potassium is to be produced according to the improved process.
In this case the electrolyte will consist of a cold-saturated solution of chloride of
potassium to which about 1 to 3% of hydrate of calcium is added. During the
whole of the electrolytical process, the hydrate of calcium is agitated and thereby
maintained in a suspended condition in the electrolyte. This has for result that

page_text: the electrolyte will remain alkaline as long as the current passes through it,
without the hydrate of calcium participating in the least degree in the conduction
of the current.
During the electrolysis, the hydrate of calcium thus maintained in a suspended.
state, combines with the chlorine which escapes at the anode and forms therewith
the intermediate chemical compounds corresponding to the process such as, in the
given instance, chlorate of calcium. These compounds, when flowing over the
cathode, are at once converted by the hydrate of potassium, there produced, into
the corresponding compounds of chlorate of potassium, whilst hydrate of calcium is.
simultaneously re-formed.
In this manner the hydrate of calcium effects during the process, the transference
of the chlorine from the anode to the cathode and obviates the loss of electric
current, which, if an alkali soluble in water were employed, would inevitably
arise owing to the circumstance that the alkali itself would co-operate as
electrolyte.
Instead of hydrate of calcium, other oxides or hydrates, as for instance those
of magnesium, may be employed, without departing from the nature of this
invention.
A modification of this process consists in separating the hydrate as for instance
that of calcium, magnesium or the like-from its chloride by electrolysis, and then
converting the metallic chlorate thus formed, into the required alkaline chlorate by
the addition thereto of a solution of the chloride of the corresponding alkaline
metal. In this way the utilisation for the production of alkaline chlorates, of the
chlorides of calcium, magnesium, etc. and the like which are frequently obtained as
waste products in other processes, is rendered possible.
I am aware that the addition of milk of lime to a solution of an alkaline chloride
has already been proposed, but this proposal has been made for quite other purposes
and in carrying out a process which is absolutely different from that to which the
present invention relates.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. In the manufacture or production of an alkaline chlorate by electrolysis,
mixing the chloride of the alkaline metal of which a chlorate is desired, with an
oxide or hydrate such as hydrate of calcium or magnesium that is not easily
soluble in water and keeping the said oxide or hydrate in suspension in the
electrolyte during the whole of the electrolytical process the said process being
carried out without the employment of a diaphragm, substantially as hereinbefore
described.
2. The manufacture or production of an alkaline chlorate by subjecting a
solution of chloride of calcium or magnesium, or other metal the oxide or hydrate
of which is not easily soluble in water, to electrolysis and converting the chlorate
thus produced into the required alkaline chlorate by the addition thereto of a
solution of a chloride of the corresponding alkaline metal, substantially as herein-
before described.
1000
F. WISE HOWORTH,
46, Lincoln's Inn Fields, London, W.C., Agent for the Applicant.