Process and Apparatus for Obtaining Magnesium Manganite and Hydrochloric Acid from the Double Chloride of Manganese and Magnesium, or for Utilizing Certain Residual Liquors Produced in the Manufacture of Chlorine.
Year: 1894

page_text: Date of Application, 27th Aug., 1894
Complete Specification Left, 27th May, 1895-Accepted, 6th July, 1895
PROVISIONAL SPECIFICATION.
Process and Apparatus for Obtaining Magnesium Manganite and
Hydrochloric Acid from the Double Chloride of Manganese
and Magnesium, or for Utilizing Certain Residual Liquors
Produced in the Manufacture of Chlorine.
I, ERNEST BÜCKSE, Manufacturing Chemist, of Wadens Kaia 18, Qu. 9,
St. Petersburg, Russia, do hereby declare the nature of this invention to be as
follows:-
When Deacon had succeeded to utilize with his process up to 70 per cent. of the
available hydrochloric acid, in the shape of chlorine for the manufacture of chloride
of lime or of chlorate, Weldon (as is well known) tried to modify his own process
in such a manner as to obtain a more complete utilization of the hydrochloric acid.
Weldon therefore proposed to precipitate the manganese by means of magnesia,
instead of lime. However, by carrying out this proposal, an important advantage
of the old process is lost.
The MnO of the compound MnO MgO (for the sake of simplicity equal
equivalents are here assumed, although the precipitation is complete already
with 08 equivalents, and for the same reason, the oxide is assumed instead of the
hydrate) cannot be converted into MnO, by an air blast in aqueous mixture, but
the oxidation must be effected dry, by roasting in the open air, which necessitates
the separation of the manganese-imagnesia-mud from the magnesium-chloride
solution. The magnesium chloride is decomposed into MgO and hydrochloric acid
in the known manner. According to my experience made on a large scale, the
oxidation is by no means a smooth and simple process. This process is altogether
complicated and presents considerable technical difficulties.
Weldon's later magnesia process, which he carried out on a large scale and
which promised to become a dangerous competitor of Deacon's process, was based
on the fact, that anhydrous MnCl2MgCl, gives off its chlorine, when roasted in the
open air, and is thereby converted into MuO,MgO. The MnO,MgO thus obtained
is decomposed with hydrochloric acid, thereby liberating chlorine and again
producing MuCl,MgC₁₁.
The chlorine obtained by the decomposition of MnCl, MgCl, is of course, strongly
diluted with air or nitrogen, which circumstance weighs heavily, when it is desired
to produce strong chloride of lime. This evil, Weldon has tried to meet in various
ways, but other difficulties have probably contributed to the result, that the process,
where it had already been adopted, was finally discarded in favour of the old lime
process.
The following description relates to a process which not only serves to recover
from 60 to 70 per cent. of the hydrochloric acid as chlorine, but which has the
advantage of obtaining the latter in a concentrated condition. The starting point
form the acid manganese liquors as obtained in the manufacture of chlorine from
peroxide of manganese and hydrochloric acid. These liquors are neutralized with
magnesia, and it may be easily arranged, that for 1 equivalent of MnCl, there are
about 0.8 equivalents of MgCl,.
The neutralized liquors are boiled down in pans of lead, wrought iron or cast iron,
until vapours of hydrochloric acid commence to appear (the temperature being
from 150 to 160° C.). The further dehydration may be effected in a reverberatory

page_text: furnace or in muffles, and if these give off considerable quantities of waste gases, it
is advantageous to utilize them for the abovementioned purpose. The dried mass
forms porous lumps and retains from 25 to 30 per cent. of water, which does not,
however, injure the subsequent process. The decomposition of the MnCl2MgCl,
according to the equation
MnCl,MgCl2 + 2 H₂O + O
==
MnO,MgO + 4 HCl
takes place in vertical shafts built of fireproof bricks, said shafts being heated from
the outside and kept at a red heat.
The air and steam necessary for the reaction enter at the top. The resulting
hydrochloric acid leaves the shafts by being drawn off at the bottom and is
condensed by ordinary condensing plant. The average strength of the hydro-
chloric acid was 18° Be. It can be easily obtained quite colourless and free from
impurities. The MnO2MgO produced is discharged at the base of the shafts and
forms lumps, which easily crumble to powder and have a black colour.
The MnO,MgO dissolves easily in hydrochloric acid without leaving any
residue.
For producing chlorine, it is either introduced into the generators in a dry state
and hydrochloric acid is added, the rise of temperature caused by the reaction
being sufficient, to dispense with the heating by steam, or it is mixed with
generator liquor to form a mud, and (as in the case of the Weldon process) filled into
the generators which have been previously charged with acid.
In this manner, besides chlorine, liquors of MnCl2 MgCl, are obtained. The
process therefore provides a means for utilizing the hydrochloric acid, except the
unavoidable waste for the production of chlorine.
The quantity of oxide of manganese and of magnesia need only be sufficient to
replace the mechanical losses of manganese and magnesium.
Dated this 27th day of August 1894.
FAIRFAX & WETTER,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Process and Apparatus for Obtaining Magnesium Manganite and
Hydrochloric Acid from the Double Chloride of Manganese
and Magnesium, or for Utilizing Certain Residual Liquors
Produced in the Manufacture of Chlorine.
I, ERNEST BÜCKSE, Manufacturing Chemist, of Wadens Kaia 18, Qu. 9,
St. Petersburg, Russia, 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 :-
When Deacon had shown, that it was possible to utilize with his process up to
70 per cent. of the available hydrochloric acid, in the shape of chlorine, for the
manufacture of chloride of lime or of chlorate, Weldon (as is well known) tried to
modify his own process in such a manner, as to obtain a more complete utilization
of the hydrochloric acid. Weldon therefore proposed to precipitate the manganese
by means of magnesia, instead of lime. However, by carrying out this proposal, an
important advantage of the old process is lost.
The MnO of the compound MOMgO (for the sake of simplicity equal
equivalents are here assumed, although the precipitation is complete already with
0-8 equivalents, and for the same reason, the oxide is assumed instead of the
hydrate) cannot be converted into MnO, by an air blast in aqueous mixture, but
the oxidatiou must be effected dry, by roasting in the open air, which necessitates

page_text: the separation of the manganese-magnesia-mud from the magnesium-chloride
solution. The magnesium chloride is decomposed into MgO and hydrochloric acid
in the known manner. According to my experience made on a large scale, the
oxidation is by no means a smooth and simple process. Altogether this process is
complicated and presents considerable technical difficulties.
Weldon's later magnesia process, which he carried out on a large scale and which
promised to become a dangerous competitor of Deacon's process, was based on the
fact, that anhydrous MnCl,MgCl, when roasted in the open air, gives off its
chlorine, and is thereby converted into MnO,MgO. The MnO2MgO thus
obtained is decomposed with hydrochloric acid, thereby liberating chlorine and
again producing MnCl,MgCl.
The chlorine obtained by the decomposition of MnCl,MgCl, is, of course, strongly
diluted with air or nitrogen, which circumstance weighs heavily, when it is
desired to produce strong chloride of lime. This evil, Weldon tried to meet in
various ways, but other difficulties have probably contributed to the result, that
the process, where it had already been adopted, was finally discarded in favour of
the old lime process.
The following description relates to a process which not only serves to recover
from 60 to 70 per cent. of the hydrochloric acid as chlorine, but which has the
advantage of obtaining the latter in a concentrated condition. The starting point
form the acid manganese liquors as obtained in the manufacture of chlorine from
peroxide of manganese and hydrochloric acid. These liquors are neutralized with
magnesia, and it may be easily arranged, that for 1 equivalent of MuCl, there are
about 0.8 equivalents of MgCl2.
The neutralized liquors are boiled down in pans of lead, wrought iron or cast
iron, until vapours of hydrochloric acid commence to appear (the temperature
heing from 150 to 160° C.). The further dehydration may be effected in a
reverberatory furnace or in muffles, and if these give off considerable quantities
of waste gases, it is advantageous to utilize them for the above mentioned purpose.
The dry mass forms porous lumps and retains from 25 to 30 per cent. of water,
which does not, however, injure the subsequent process. The decomposition of
the MuCl,MgCl, according to the equation:
MnCl2MgCl, + 2 H₂O + O
====
MnO2MgO +4 HC1
takes place in vertical shafts built of fireproof bricks, said shafts being heated
from the outside and kept at a red heat.
The air and beat necessary for the reaction enter at the top. The resulting
hydrochloric acid leaves the shafts by being drawn off at the bottom and is
condensed by ordinary condensing plant. The average strength of the hydro-
chloric acid was 18° Bé. It can be easily obtained quite colourless and free
from impurities. The MnO2MgO produced is discharged at the base of the shafts
and forms lumps, which easily crumble to powder and have a black colour.
The MnO,MgO dissolves easily in hydrochloric acid, without leaving any
residue.
For producing chlorine, it is either introduced into the generators in a dry
state, and hydrochloric acid is added, the rise of temperature caused by the
reaction being sufficient to dispense with the heating by steam, or it is mixed
with generator liquor to form a mud, and (as in the case of the Weldon process)
filled into the generators which have been previously charged with acid.
In this manner, besides chlorine, liquors of MnCl,MgCl, are obtained. The
process therefore provides a means for utilizing the hydrochloric acid, except the
unavoidable waste for the production of chlorine.
The quantity of oxide of manganese and of magnesia need only be sufficient to
replace the mechanical losses of manganese and magnesium.
The loss of hydrochloric acid depends wholly or chiefly on the nature of the
condensing appliances. As the chlorine recovered is in a concentrated condition,
it will be easily absorbed by the lime in the chambers, and chloride of lime of

page_text: a high grade is obtained without difficulty. Altogether the process is simple,
and the plant required is comparatively inexpensive, the consumption of fuel,
however, is greater, and the price of the latter must therefore be considered, in
estimating the utility of the process for any particular case.
A decomposing kiln or furnace suitable for use in conjunction with the new
process is illustrated by the accompanying drawings,
Fig. 1 being a perspective view,"
Fig. 2 a vertical section, and
Fig. 3 a horizontal section along line A-B of Fig. 2.
The said kiln chiefly comprises a group of vertical shafts S₁ to S₁ adapted
for external heating by means of flues F. The admission of air and of superheated
steam takes place at the top, while the MnO,Mg is discharged and the hydrochloric
acid drawn off at the bottom.
In the drawings:
a are fire doors,
T discharge doors for the MnO, Mg,
E auxiliary doors for drawing off any powder, that may have passed through,
Fare flues for the flames and gases of combustion,
D is a steam superheater,
C are lids or covers for the shafts S₁-S.,
Rare the grates, each of which consists of earthenware plates placed upright and
cut off obliquely,
Jare outlets for hydrochloric acid vapours,
K, upright tubes for discharging the hydrochloric acid vapours.
Each outlet canal J is placed between two shafts and so connected as to
receive the acid vapours from both and to deliver them into the corresponding tube
or uptake K.
The fuel is burnt on grates G, each of which in the example shown may have an
area of about 40 × 80 centimeters.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is ;-
1. The herein described process for the recovery of magnesium manganite and
hydrochloric acid from the double chloride of manganese and magnesium (1 equi-
valent of MnCl, to about 0-8 equivalents of MgCl,) obtained in the manufacture
of chlorine from MnO,Mg and hydrochloric acid.
2. A decomposing kiln or oven comprising in its construction externally heated
shafts adapted to be supplied with air and superheated steam at the top, and
to discharge the MnO,Mg and the hydrochloric acid at the bottom, substantially
as described and for the purpose specified.
Dated this 14th day of May 1895.