Improvements in the Manufacture of Chlorine.
Year: 1887

page_text: U
مار
Date of Application, 15th Dec., 1887
Complete Specification Left, 28th Aug.,
1888
Complete Specification Accepted, 19th Oct., 1888
Improvements in the Manufacture of Chlorine.
We, LUDWIG MOND of Winnington Hall Northwich, in the County of Chester,
and GEORGE ESCHELLMANN Ph. D. of Winnington Park, Northwich aforesaid,
Manufacturing Chemists, do hereby declare the nature of this invention to be as
follows:-
This improvement relates to the manufacture of chlorine from hydrochloric acid or
ammonium chloride by means of magnesia.
If magnesia is treated with H Cl or Am Cl at a certain temperature, in the first
case magnesium chloride or oxychloride and steam is formed, in the second case
magnesium chloride or oxychloride and steam and ammonia gas.
In order to obtain chlorine, this magnesium chloride or oxychloride is heated to a
higher temperature and oxydised with dried air. By this method all the chlorine
is set free, but not without being mixed with a large amount of hydrochloric
acid gas.
Treating magnesia with hydrochloric acid or ammonium chloride, a considerable
amount of the steam, which is formed by the reactions, is absorbed by the magnesium
chloride or oxychloride formed, and this absorbed quantity of water being evolved in
the treatment at a higher temperature by air, causes the retrograde formation
of H Cl, which quantity varies from 20 to 40 per cent. of the total quantity of
the chlorine.
This invention has for its object the prevention of this hydrochloric acid formation.
For this purpose we mix with the magnesia, before it is treated with hydrochloric
acid or ammonium chloride, a certain amount of a fixed alkali chloride, preferably
chloride of potassium or sodium, or a mixture of the two. The quantity of the alkali
chlorides can be varied considerably, we find that 5 to 10 per cent. of the quantity of
the magnesia is sufficient.
If this magnesia mixed with the alkali chloride is treated in the way above
described, no water or very little of it is absorbed by this magnesia, and during the
oxydation all the chlorine is obtained as such, and free or nearly free from
hydrochloric acid.

page_text: In order to carry out this improvement in a practical way, the magnesia is ground
with a solution of a certain strength of the alkali chlorides, or a mixture of the two,
by which means the magnesia is intimately mixed with the alkali chloride. This mass
is formed in any known way into balls, lumps, blocks etcetera, and dried. We also
find it advantageous to add to the magnesia a certain amount of an agglomerating
substance. Amongst many others we prefer an addition of about 5 to 10 per cent. of
China clay, which is inert to the reactions in our process.
After the finished oxydation, the magnesia is ready for a renewed treatment with
hydrochloric acid or ammonium chloride, as the alkali chloride remains unaltered, and
retains its activity continually.
In order to obtain a continuous manufacture of chlorine from hydrochloric acid gas,
we pass a mixture of hydrochloric acid gas and air at a suitable temperature,
preferably 450 to 550 degrees centigrade, over or through the balls,. blocks, etcetera, of
the magnesia and alkali chloride as described before. The decomposition of the
hydrochloric acid is very much more complete than when using certain copper salts
for the same purpose.
Throughout this specification we have spoken only of alkali chlorides, it is obvious,
however, that if any alkaline salt easily decomposed by hydrochloric acid or ammonium
chloride, so as to form the alkali chloride, such for instance as the hydrate or the
carbonate, were used, they would soon be converted into the chloride, and would then
be as efficacious as if the chloride were used originally. We find too, that alkali
fluorides can be used in whole or in part, instead of the alkali chlorides.
Dated this 14th day of December 1887
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool,
Patent Agents for the Applicants.

page_text: We, LUDWIG MOND of Winnington Hall, Northwich, in the County of Chester,
and GEORGE ESCHELLMANN Ph. D. of Winnington Park, Northwich, aforesaid,
Manufacturing Chemists, 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 :-
This improvement relates to the manufacture of chlorine from hydrochloric acid or
ammonium chloride by means of magnesia.
If magnesia is treated with H Cl or Am Cl at a certain temperature, in the first
case magnesium chloride or oxychloride and steam is formed, in the second case
magnesium chloride or oxychloride and steam and ammonia gas.
In order to obtain chlorine, this magnesium chloride or oxychloride is heated to a
higher temperature and oxidized with dried air. By this method, all the chlorine
is set free, but not without being mixed with a large amount of hydrochloric
acid gas.
Treating magnesia with hydrochloric acid or ammonium chloride, a considerable
amount of the steam, which is formed by the reactions, is absorbed by the magnesium
chloride or oxychloride formed, and this absorbed quantity of water being evolved in
the treatment at a higher temperature by air, causes the retrograde formation
of H Cl, which quantity varies from 20 to 40 per cent, of the total quantity of the
chlorine.
This invention has for its object the prevention of this hydrochloric acid formation.
For this purpose, we mix with the magnesia before it is treated with hydrochloric
acid or ammonium chloride, a certain amount of a fixed alkali chloride, preferably
chloride of potassium or sodium, or a mixture of the two. The quantity of the alkali
chlorides can be varied considerably, we find that 5 to 10 per cent. of the quantity of
the magnesia is sufficient.
If this magnesia mixed with the alkali chloride is treated in the way above
described, no water or very little of it is absorbed by the magnesia, and during
the oxidation all the chlorine is obtained as such, and free or nearly free from
hydrochloric acid.
In order to carry out this improvement in a practical way, the magnesia is ground
with a solution of a certain strength of one of the fixed alkali chlorides, or a mixture
of the two, (that is with a solution of the required amount of fixed alkali chloride in
a sufficient quantity of water to form with the magnesia a plastic mass) by which
means the magnesia is intimately mixed with the alkali chloride. This mass may be
formed in any known
way into balls, lumps, blocks, etcetera, and dried, but we find it
advantageous for this purpose to add to the magnesia a certain amount of an
agglomerating substance. Amongst many others, we prefer an addition of about 5
to 10 per cent. of China clay, which is inert to the reactions in our process.

page_text: After the finished oxidation the magnesia is ready for a renewed treatment with
hydrochloric acid or ammonium chloride, as the fixed alkali chloride remains unaltered,
and retains its activity continually.
In order to obtain a continuous manufacture of chlorine from hydrochloric acid
gas, we pass a mixture of hydrochloric acid gas and air at a suitable temperature,
preferably 450 to 550 degrees centigrade, over or through the balls, blocks, etcetera,
of the magnesia and alkali chloride as described before.
The decomposition of the hydrochloric acid is very much more complete than whon
using certain copper salts for the same purpose.
Almost any plant now used for treating solids with gases at about the temperature
above mentioned will suit this process. We have not designed any special plant
therefor, but would recommend the ordinary Deacon chlorine plant as useful for the
continuous process.
Throughout this specification, we have spoken only of alkali chlorides, it is obvious,
however, that if any alkaline salt easily decomposed by hydrochloric acid or ammonium
chloride so as to form the alkali chloride, such for instance as the hydrate carbonate,
or even fluoride were used, they would soon be converted into the chloride, and would
then be as efficacious as if the chloride were used originally.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed, we declare that what we
claim is
1st. The process of obtaining chlorine from hydrochloric acid or chloride of
ammonium, by the action of such substance, preferably in the form of gas or vapour,
upon a mixture of magnesia and a chloride of a fixed alkali, and subsequently treating
the product, so obtained, with air or oxygen at the requisite temperature, substantially
as described.
2nd. The manufacture of chlorine from hydrochloric acid, by passing a mixture of
this gas and air or oxygen over or through a mixture of magnesia with the chloride
of a fixed alkali (preferably made into lumps or balls) at the requisite temperature.
Dated this 27th day of August 1888
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool,
Patent Agents for the Applicants.