Improvements in the Manufacture of Caustic Alkalies or Carbonated Alkalies.
Year: 1893

page_text: Date of Application, 4th Mar., 1893-Accepted, 8th Apr., 1893
COMPLETE SPECIFICATION.
Improvements in the Manufacture of Caustic Alkalies or Carbonated
Alkalies.
I, IGNAZ LEDERER, of Pflastergasse 6, Prague, in the Empire of Austria,
Chemist 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 invention relates to improvements in manufacturing caustic alkalies or
carbonated alkalies from the sulphates or chlorides of these alkalies, the new
process having in view the regaining of the oxide of strontium used in the process
and which is converted during the process into sulphate of strontium this regaining
being effected by carbonate of sodium or ammonium.
The process is described in the following statement as being carried out with
potassium salts but it will be understood that the process may be carried out with
Bodium salts as well as with the other alkalies, and that I do not limit my process
to the manufacture of caustic or carbonated alkalies out of the sulphates or
chlorides of these alkalies, as they can even be manufactured out of saline deposits
or waste products containing these sulphates or chlorides either alone or in
mixtures.
The new process is carried out as follows:-
(1) Chloride of potassium is changed into chloride of ammonium and sulphate of
potassium by means of sulphate of ammonia according to the following equation :-
(NH),SO, + 2 KCl = K₂SO, + 2 NHCI.
:-
The sulphate of potassium is separated from the chloride of ammonium either by
boiling the solution in or by stirring the chloride of potassium or its mixture with
the sulphate of ammonium to a thick pulp and subsequently subjecting it to
sublimation.
It should be noted that when this takes place the sulphate of ammonium must
not be in excess.
(2) The sulphate of potassium is changed into caustic potassium and sulphate of
strontium by the hydroxyde of strontium, according to the following equation ;-
K,SO + Sr(HO), = 2 KHO + Sr80¸.
(3) The ammonium chloride (sal-ammoniac) obtained by the process characterized
in the paragraph 1, or the sulphate of ammonia, as the case may be, is in the well-
known manner, by means of caustic lime, converted into caustic ammonia, and the
caustic ammonia, by means of carbonic acid is converted into carbonate, while
chloride or sulphate of calcium, as the case may be, is obtained as a residue in
accordance with the following formula ;-
2 NH,Cl + Ca(HO), = 2 NH¸HO + CaCl,
NH 00
0
ANT LA

page_text: formation of sulphate of ammonium and carbonate of strontium according to tho
following equation ;-
SrSO, + (NH₁),CO, = SrCO, + (NH),SO.
The carbonate of strontium obtained in these 2 ways (paragraphs 4a and b) is
converted into oxide of strontium in strontium-furnaces, as in the manufacture of
strontium-sugar.
It is to be understood that the method cited (paragraph 4a) can only be
materially successful with potassium-salts, whereas 46) is only applicable to tho
manufacture of caustic hydrate of soda.
The caustic alkalies obtained in that way can be changed if desired into the
respective carbonates by carbonating.
By these methods it has been made possible to apply the so-called "ammonia-
soda-process" to the manufacture of caustic alkalies especially potassium, which
has never been accomplished hitherto in any other way.
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. A process for manufacturing caustio or carbonated alkalies characterized by
the following processes
a) Decomposing the chlorides or their mixtures by means of sulphate of
ammonium substantially as described.
b) Decomposing the sulphate of alkali by strontium hydroxyde substantially
as described.
c) Regenerating the sulphate of strontium by carbonate of ammonium or
carbonate of sodium substantially as described.
2. The process for manufacturing caustic or carbonated alkalies substantially as
described.
Dated this 4th day of March 1893.
W. P. THOMPSON & BOULT,
Agents for the Applicant.