Improvements connected with the Manufacture of Soda by the Ammonia Process.
Year: 1890

page_text: Date of Application, 20th Mar., 1890
Complete Specification Left, 5th ec.. 1810-Accepted, 7th Mar., 1891
PROVISIONAL SPECIFICATION.
Improvements connected with the Manufacture of Soda by the
Ammonia Process.
I, FERDINAND RICARD, of 23, Boulevard de Strasbourg, Paris, France,
Chemical Engineer, do hereby declare the nature of this invention to be as
follows:-
My invention relates to improvements in the manufacture of soda by the
ammonia process, these improvements constituting a process of extraction of chlorine
or of hydrochloric acid from the chloride of ammonium or of any other chloride
resulting from its decomposition by a carbonate by means of the salts of magnesia
(such as oxide or sulphate) and of carbonic acid gas.
It is well known that bicarbonate of soda is obtained in the ammonia process by
causing to react simultaneously ammonia and carbonic acid on chloride of sodium
in solution, or the bicarbonate of ammonia upon the same chloride, and that the
bicarbonate of soda is transformed into neutral carbonate by calcination.
It is also well known that this manufacture gives as mother liquor chloride of
ammonium, and as residues, divers chlorides according to whether the mother
liquor has been distilled with lime, with magnesia etc., with the view of regenerating
therefrom the caustic ammonia.
Instead of effecting the decomposition of the chloride of ammonium by distil-
lation as is usually done, my improved process will allow of its being decomposed
by the dry way, and consequently of substituting carbonates for oxides. In this
case at a comparatively low temperature there will be disengaged carbonate of
ammonia, and there will be formed anhydrous chloride or oxychloride from which
the hydrochloric acid can be readily extracted and the base be regenerated in
the condition of carbonate which will serve for a new decomposition of the primitive
mother liquor.
In order to simplify the description of my process, I will only describe as
example in the chemical formule the use of the salts of manganese, of magnesia and
of anumonia. The operation is as follows:
1. After having obtained the bicarbonate of soda and formed the mother liquor
as above stated, I evaporate this mother liquor to dryness or to the point of
crystallisation of the salts, chloride of sodium and of ammonium, which are contained
therein.
2. The collected salts are heated in contact with pulverised sea salt which may
or may not be maintained in a state of continual agitation and at a temperature
capable of producing the volatilisation of the chloride of ammonium. The sea salt,
which constitutes the sole impurity of this chloride, not being volatile, is added
to that which was already in the apparatus and is thus regenerated. As to the
volatilised chloride of ammonium, it will be deposited in a cooling cylinder connected
to the apparatus.
The salts are introduced into and withdrawn automatically from the apparatus.
3. The hot treatment of the chloride of ammonium or of the dry residues of the
primitive mother liquor by means of an oxide and more particularly by a dry
carbonate of manganese of baryta, of lead and of lime results in the regeneration
of the ammonia in the carbonated condition and the formation of a new anhydrous
chloride or oxychloride.

page_text: 4. The chloride obtained is treated by the methods hereinafter described for
extracting therefrom the hydrochloric acid and for bringing back the base to the
condition of carbonate which may serve either in that form or after calcination for
a new decomposition of chloride of ammonium as above stated.
1st method The chloride in solution treated with magnesia and carbonic acid 5
simultaneously will be regenerated into carbonate, which will be precipitated, and
into chloride of magnesium, which will remain in solution.
The precipitate is separated from the mother liquor and the solution, after
evaporation, will give hydrated chloride of magnesium. This treated by heat and 10
steam will regenerate the magnesia and the hydrochloric acid. The magnesia will
serve for a new operation.
c/Mg Cl 6 HO + HO= Mg 0 + 6 HO + H Cl.
The chloride of magnesium might be previously dried or mixed with the
magnesia derived from a preceding operation and thus be transformed into 1
oxychloride.
2nd method-The dry chloride treated at a more or less elevated temperature
with sulphate of magnesia previously dried will be transformed into sulphate and
the sulphate of magnesia into anhydrous chloride of magnesium.
The precipitate is separated from the mother liquor and the latter by evaporation
or by lowering its temperature will allow the sulphate of magnesia to be deposited,
which will serve for a new operation.
Thus, the two methods above described permit, by means of magnesia and
carbonic acid, of the separation from the same chloride of chlorine in the condition
of hydrochloric acid and the base in the condition of carbonate.
The hydrochloric acid obtained will be condensed by ordinary methods and
delivered afterwards for consumption or transformed into chlorine as will be described
later on.
As to the carbonate, it will be utilised either in that condition or after
calcination for the regeneration of the ammonia, consequently it will reconstitute
the metallic chloride which has served as base of the operations.
The said process with magnesia and carbonic acid can be applied to all the
chlorides in solution, in particular to the residues of manufacture of soda by the
ammonia process, that is to say to the chlorides of calcium and of magnesium.
Production of chlorine. It is known that hydrochloric acid mixed or not with
sulphuric acid or nitric acid in the presence of a superoxide of manganese will give
a development of chlorine with a fixed residue of chloride, of sulphate or of nitrate
of manganese, and consequently that the chloride of manganese or any other metallic
chloride in the presence of a superoxide and of sulphuric or nitric acid disengages

page_text: 1. g/Mn 0 + 2 H Cl= Mn Cl + 2 HO + Cl.
2.
3.
(h/2 Mn 0² + 2 SO³ HO + 2 H Cl=Mn Cl + Mn O² + 2 SO³ HO +
2 HO + Cl.
h/whence Mn Cl + Mn O + 2 SO³ HO
= 2 MnO SO³ + 2 HO + Cl.
Si/2 Mn 2+2 Cl + 2 NO³ HO= Mn Cl + Mn O³ + 2 NO* HO +
2 HO Cl.
whence Mn Cl + Mn 03 + 2 NO' HO + 2 HO= 2 Mn O NO* +
4 HO + Cl.
If the residue of these reactions is treated separately by carbonate of ammonia,
solid or in solution, or by the mother liquor of the manufacture of soda with or
without the addition of ammonia and carbonic acid, the base of the chloride, the
sulphate or the nitrate of manganese will be brought back to the condition of
carbonate suitable for decomposing the chloride of ammonium (reaction a) and for
regenerating the primitive superoxide by its simple calcination in the presence
of air.
I will treat by way of example with the residue of the reaction (9) that is to say
chloride of manganese, by means of the mother liquor of the manufacture of soda by
the ammonia process. This, owing to the bicarbonates of soda and ammonia which
it contains, will precipitate the base of the chloride in the condition of carbonate
with formation of chlorides of ammonium and of sodium which will be added to
those that were already in the solution.
j/4 Mn Cl + Na O HO 2 CO² + NHO HO 2 CO² + 2 NH'O=
4 Mn O CO2 + Na Cl + 3 NH Cl + 2 HO + Cl.
/4 MnO CO +20= 2 *n* Q* +
As to the primitive mother liquor thus transformed it will suffice to treat it by
distillation in the usual manner, or as I have described for regenerating therefrom
the sea salt, the aminonia and the metallic chloride which has served as the basis of
the operation when it was required to extract the hydrochloric acid.
The use of the mother liquor of the manufacture of soda will have the advantage
of not introducing fresh liquid into the manufacture.
It will be evident that an analogous result will be obtained if the chloride of
by
manganese were treated with carbonate of ammonia; in this case by heating or
lowering the temperature of the solution, very pure chloride of ammonium will be
obtained which could be utilised in that condition or which could be decomposed as
above described. Lastly, there will be obtained sulphate or nitrate of ammonia
according as one operates under the same conditions upon the residue of the
reactions (') (i) that is to say upon the sulphate or nitrate of manganese.
As result of the decomposition of the chloride of ammonium by means of a
carbonate (reaction a) or of the simultaneous treatment of the chlorides by magnesia
and carbonic acid (reaction b), or of the transformation of the carbonate of
manganese into superoxide (reaction) and of the production of chlorine by
means of the known reactions (i) (i) I am enabled to treat the nitrates as the
chlorides and to extract directly the chlorine from the chloride of ammonium without
necessarily passing through the hydrochloric acid stage.
In effect, if after having treated the mother liquor of the manufacture of soda
with a view of regenerating therefrom the sea salt by volatilisation as above.
described and the ammonia by means of a carbonate (reaction a), the chloride

page_text: obtained is mixed with a superoxide and is then attacked with nitric acid, there will
be formed a fixed nitrate and chlorine gas will be disengaged in conformity with the
reaction (¹).
It will be sufficient to treat the residue of this reaction by means of magnesia and
carbonic acid simultaneously for transforming the base of the nitrate into carbonate
which will be precipitated and the magnesia into nitrate which will remain in
solution.
1/2 Mn O NO' + 2 Mg O*+ (CO²)" = 2 Mg O*NO' + 2 Mn O‡CO².
It will be possible by means of heat and in utilising the solubility of the salts to
collect first the precipitate, then the nitrate of magnesium which decomposed by
heat and by steam will regenerate nitric acid and magnesia which will be again
utilised, the one for the decomposition of the chloride the other for that of the
nitrate which have served as basis of the operations.
The acid will be condensed by the usual means; as to the carbonate part will
serve as it is for the regeneration of the ammonia, the other calcined in contact with
air will reconstitute the superoxide necessary for the production of the chlorine.
The treatment by means of magnesia and carbonic acid above described can be
equally well applied to residues of the reactions (g) (h) (h¹) (7) above set forth.
employ by preference a chloride and a superoxide of the same base in the above
mentioned reactions, and salts capable of forming at the same time a chloride, a
carbonate, and a superoxide, in particular those of barium and of lead may be
substituted without inconvenience for the salts of manganese in the same reactions.
I do not describe anything in connection with the apparatus employed in the
manufacture as those ordinarily used in the chemical industry, such as the apparatus
for burning pyrites for calcining soda or bicarbonate of soda, as also those employed
for the condensation of acids or for the manufacture of chlorine, are sufficient for the
realisation of the reactions of my process.
Dated the 20th day of March 1890.
COMPLETE SPECIFICATION.
Improvements connected with the Manufacture of Soda by the
Ammonia Process.
I, FERDINAND RICARD, of 23, Boulevard de Strasbourg, Paris, France,
Chemical Engineer, 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 :-
My invention relates to improvements in the manufacture of soda by the ammonia
process, these improvements constituting a process of extraction of chlorine or of
hydrochloric acid from the chloride of ammonium or of any other chloride resulting
from its decomposition by a carbonate by means of salts of magnesia (such as
oxide or sulphate) and of carbonic acid gas.
It is well known that bicarbonate of soda is obtained in the ammonia process by
causing to react simultaneously ammonia and carbonic acid on chloride of sodium in
solution, or the bicarbonate of ammonia upon the same chloride, and that the
bicarbonate of soda is transformed into neutral carbonate by calcination.
It is also well known that this manufacture gives as mother liquor chloride of
ammonium, and as residues, divers chlorides according to whether the mother liquor
has been distilled with lime, with magnesia etc., with the view of regenerating
therefrom the caustic ammonia.
Instead of effecting the decomposition of the chloride of ammonium by dis-
tillation as is usually done, my improved process will allow of its being decomposed
in the dry way, and consequently by substituting carbonates for oxides. In this
case at a comparatively low temperature there will be disengaged carbonate of

page_text: The ammonia will be returned in the process of manufacture.
4. The chloride obtained is treated by the methods hereinafter described for
extracting therefrom the hydrochloric acid and for bringing back the base to the
condition of carbonate which may serve either in that form or after calcination for
a new decomposition of chloride of ammonium as above stated.
1st method. The chloride in solution treated with magnesia and carbonic acid
simultaneously will be converted into carbonate, which will be precipitated, and
into chloride of magnesium, which will remain in solution.
The chloride of magnesium might be previously dried or mixed with magnesia
derived from a preceding operation and thus be transformed into oxychloride.
2nd method. The dry chloride treated at a more or less elevated temperature
with sulphate of magnesia previously dried is transformed into sulphate and the
sulphate of magnesia into anhydrous chloride of magnesium.

page_text: Of carbonate.
Mn O SO + MgO + (CO²)":
1
Mn O CO2 + MgO SO
The precipitate is separated from the mother liquor and the latter by evaporation
or by lowering its temperature allows the sulphate of magnesia to be deposited
which will serve for a new operation.
Thus the two methods above described permit, by means of magnesia and
carbonic acid, of the separation from the same chloride of chlorine in the condition
of hydrochloric acid and the base in the condition of carbonate.
The hydrochloric acid obtained may be condensed by ordinary methods and
delivered afterwards for consumption or transformed into chlorine as will be
described later on. As to the carbonate it may be utilised either in that condition
or after calcination for the regeneration of the ammonia, consequently it will
reconstitute the metallic chloride which has served as base of the operations.
The process described under 4 can be applied to the residues of manufacture of
soda by the ammonia process, that is to say to liquid chloride of calcium.
Production of chlorine. It is known that hydrochloric acid mixed or not with
sulphuric acid or nitric acid in the presence of a peroxide of manganese evolves
chlorine with a residue of chloride, sulphate or nitrate of manganese and conse-
quently that the chloride of manganese or any other metallic chloride in the
presence of a peroxide and of sulphuric or nitric acid evolves the same gas and
gives the same residues in accordance with the known fundamental reactions
as below:
1. g/Mn O2 + 2 H Cl = = Mn Cl + 2 HO + Cl.
fh/2 Mn O2+2 SO HO + 2 H CI: Mn Cl + MnO2 + 2 SO HO + 2 HO+CI.
whence Mn Cl + Mn Q² + 2 SO³ HO =2 Mn O SO³ + 2 HO + Cl.
2.
3.
fi/2 Mn O2 + 2HCl + 2 NO HO= Mn Cl + Mn O² + 2 NO HO+2 HO+Cl.
whence Mn Cl + Mn O2 + 2 NO³ HO + 2 HO2 MnO NO' +4 HO + Cl.
If the residue of these reactions is treated separately by carbonate of ammonia, solid
or in solution, or by the mother liquor of the manufacture of soda with or without the
addition of ammonia and carbonic acid, the base of the chloride, the sulphate or the
nitrate of manganese will be brought back to the condition of carbonate suitable
for decomposing chloride of ammonium (reaction a) and for regenerating the
primitive peroxide by its simple calcination in the presence of air.
I will treat by way of example the residue of the reaction (g) that is to say chloride
of manganese, by means of the mother liquor of the manufacture of soda by the
ammonia process. This, owing to the bicarbonates of soda and ammonia which it
contains, will precipitate the base of the chloride in the condition of carbonate with
formation of chlorides of ammonium and of sodium which will be added to those
that were already in the solution. .
j|4 Mn C1 + Na Ở HỌ 2CO2 + NH* 0 HỘ 2CO3 + 2NH*0=
4 Mn O CO2 + Na Cl + 3 NH Cl + 2 HO + Cl.
The precipitate collected and calcined in contact with the oxygen of air wi
egenerate the peroxide necessary for the production of chlorine in accordance wit
he known reactions.
k/4 Mn O CO² + 40 = 4 Mn O² + 4 CO² or
4 MnO CO2 + 20 = 2 Mn² 0³ + 4 CO²
As to the primitive mother liquor thus transformed it will suffice to treat it by
distillation in the usual manner, or as I have described for regenerating its sea salt,
the ammonia and the metallic chloride which has served as the basis of the operation 5
for extracting the hydrochloric acid.
The use of the mother liquor of the manufacture of soda has the advantage of not
introducing fresh liquid into the manufacture.

page_text: Evidently an analogous result might be obtained if the chloride of manganese
were treated with carbonate of ammonia in this case by heating or by lowering
the temperature of the solution, very pure chloride of ammonium might be obtained
which could be utilised in that condition or could be decomposed as above described.
Lastly there would be obtained sulphate or nitrate of ammonia according as one
operates under the same conditions upon the residue of the reactions (¹) (¹) that is
to say upon the sulphate or nitrate of manganese.
As result of the decomposition of the chloride of ammonium by means of a
carbonate (reaction a) or of the simultaneous treatment of chlorides by magnesia
and carbonic acid (reaction 6) or of the transformation of the carbonate of manganese
into peroxide (reaction k k¹) and of the production of chlorine by means of the
known reactions () () I am led to treat the nitrates as the chlorides and to extract
directly the chlorine from the chloride of ammonium without necessarily passing
through the hydrochloric acid stage.
Indeed, if after having treated the mother liquor of the manufacture of soda with
a view of regenerating therefrom the sea salt by volatilisation as above described
and the ammonia by means of a carbonate (reaction a) the chloride obtained is
mixed with a peroxide and is then attacked with nitric acid, there is formed a fixed
nitrate and chlorine gas is evolved in conformity with the reaction (').
It will be sufficient to treat the residue of this reaction by means of magnesia and
carbonic acid simultaneously for transforming the base of the nitrate into carbonate
which will be precipitated, and the magnesia into nitrate which will remain in
solution.
1/2 Mn O NO³ + 2 MgO + (CO2) = 2 Mg O NO³ + 2 Mn O CO²
It will be possible by means of heat and by acting according to the solubility of
the salts, to collect first the precipitate, then the nitrate of magnesium which
decomposed by heat and steam will regenerate nitric acid and magnesia which will
be again utilised, the one for the decomposition of the chloride the other for that of
the nitrate which have served as basis of the operations.
The acid will be condensed by the usual means, as to the carbonate part will
serve as it is for the regeneration of the ammonia, the other calcined in contact
with air will reconstitute the peroxide necessary for the production of the
chlorine.
The treatment by means of magnesia and carbonic acid above described can be
equally well applied to residues of the reactions (g) (h) (h) (i) above set forth.
I employ by preference a chloride and a peroxide of the same base in the above
mentioned reactions, and salts capable of forming at the same time a chloride, a
carbonate and a peroxide in particular those of barium and of lead may be
substituted without inconvenience for the salts of manganese in the same
reactions.
I do not describe the apparatus employed in the manufacture as those
ordinarily used in chemical industry, such as the apparatus for burning pyrites
for calcining soda or bicarbonate of soda as also those employed for the con-
densation of acids or for the manufacture of chlorine, are sufficient for practically
conducting the reactions of my process.
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 hereinbefore described treatment of the salts resulting from evaporation
of the mother liquor produced in the ammonia soda process by sodium chloride in
constant agitation at a temperature effecting volatilisation of ammonium chloride.
2. The treatment of ammonium chloride by a carbonate for regeneration of the
ammonia and production of an anhydrous metallic chloride or oxychloride as above
described.
3. The treatment of the metallic chlorides resulting from the manufacture of

page_text: soda by oxide, sulphate or other salts of magnesia and carbonic acid, so as to form
a carbonate that can be utilised for regenerating the ammonia of this manufacture
and thus producing magnesium chloride to be decomposed in the known manner into
hydrochloric acid or into chlorine and magnesia.
4. The treatment of the residues of the manufacture of chlorine by oxide sulphate
or other salts of magnesia and carbonic acid, carbonate of ammonia or the mother
liquor of the soda manufacture, for the purpose of first regenerating the manganese
in the state of carbonate, and then converting this into peroxide by calcination
with exposure to air, as above described.
5. The combination of operations constituting the processes herein set forth
whereby the reactions (a) (b) (c) (d) (c) (ƒ) (j) (4) (¹) (1) are applied to the
production of hydrochloric acid or chlorine.
· Dated this 5th day of December 1890.
ABEL & IMKAI,
Agents for the Applicant.