IMPROVEMENTS IN THE TREATMENT OF LIQUORS PRODUCED IN THE AMMONIA-SODA PROCESS AND IN OBTAINING HYDROCHLORIC ACID THEREFROM
Year: 1883

page_text: LETTERS PATENT to Ludwig Mond of Winnington Hall, Northwich, in the
County of Chester for an Invention of IMPROVEMENTS IN THE TREATMENT
OF LIQUORS PRODUCED IN THE AMMONIA-SODA PROCESS AND IN OBTAINING
HYDROCHLORIC ACID THEREFROM
PROVISIONAL SPECIFICATION left by the said Ludwig Mond at the Office
of the Commissioners of Patents on the 4th August 1883.
LUDWIG MOND, of Winnington Hall Northwich, in the county of Chester,
"IMPROVEMENTS IN THE TREATMENT OF LIQUORS PRODUCED IN THE AMMONIA-
SODA PROCESS, AND IN OBTAINING HYDROCHLORIC-ACID THEREFROM."
"J
"
Hydrochloric acid is at present obtained by treating common salt with sulphuric
acid. By this means sulphate of soda is obtained as a secondary product, which
(in order to utilize it) has to be converted into carbonate of soda by the well
known Leblanc process. This carbonate of soda can now be obtained more
profitably by the ammonia process, but it was hitherto a drawback to this latter
process, that it did not utilize the chlorine of the chloride of sodium. Now my
invention is designed to remedy this drawback, and is carried out in the following
manner.
I treat the chloride of sodium preferably in the form of natural brine, by the
well-known ammonia process, but in place of continually recovering the ammonia.
by acting with lime upon the solutions of the chloride of ammonium obtained, I
concentrate the said solutions, and after separating the chloride of sodium which
they invariably contain. I treat with sulphuric acid the concentrated solution or
the solid chloride of ammonium obtained therefrom by crystallization or complete
evaporation. I thus obtain a pure hydrochloric acid gas which can be condensed
or utilized in any known way, and obtain as a secondary product sulphate of
ammonia, a valuable article of commerce.
By these operations 1 also save the lime now employed in the treatment of
liquors produced in the ammonia-soda process.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Ludwig Mond in the Patent Office on the 30th January 1884.
LUDWIG MOND of Winnington Hall Northwich, in the county of Chester
"IMPROVEMENTS IN THE TREATMENT OF LIQUORS PRODUCED IN THE AMMONIA-
SODA PROCESS, AND IN OBTAINING HYDROCHLORIC ACID THEREFROM
"
Hitherto hydrochloric acid has only been obtained as a bye-product in the
manufacture of soda by the process of Leblanc. The main product of this process,
namely the soda, has however for a number of years been made at a considerably
lower cost by means of the so-called ammonia process. In consequence hereof the
manufacture of soda after Leblanc's method and the production of hydrochloric
acid as a bye-product thereof has of late decreased, and the price of the latter has
risen by so much that various branches of industry dependent upon a cheap supply
of hydrochloric acid are seriously menaced in their existence. Numerous attempts
to obtain hydrochloric acid as a bye-product in the manufacture of soda by the
ammonia process have hitherto been unsuccessful. According to my invention I
treat chloride of sodium preferably in the form of natural brine by the well known
-ammonia-soda-process, but in place of continually recovering the ammonia by-
acting with lime upon the solutions of the chloride of ammonium obtained, I
evaporate the said solutions, and after separating the chloride of sodium which
they invariably contain, and which salts out during the evaporation, I treat with
sulphuric acid the concentrated solution or the solid chloride of ammonium obtained
therefrom by crystallization or complete evaporation, preferably in. the manner
which will be set forth in the specification of my patent No 3922 of 1883 and
which consists in adding the sulphuric acid in sufficient quantity to form acid
sulphate of ammonia with all the ammona presont, and then heating to about two
hundred and fifty degrees Fahrenheit to expel the H Cl, and neutralizing the acid
sulphato by ammonia or carbonate of ammonia passed through the liquid, or
among the dried and broken-up solid salt. I thus obtain a pure hydrochloric acid
gas which can be condensed or utilized in any known way and obtain as a socondary
product sulphate of ammonia a valuable article of commerce.
By these operations I also save the lime now employed in the treatment of the
liquors produced in the ammonia-soda process.
At present large quantities of sulphuric acid are used in manufacturing sulphate
of aminonia from the ammoniacal liquors of gas works and of other origin. My
invention makes available these large quantitics of sulphuric acid for producing
hydrochloric acid as a secondary product. The ammonia obtained by distillation
from the ammoniacal liquors above named is converted by the ammonia-soda
process into chloride of ammonium and by subsequently treating this chloride of
ammonium by sulphuric acid both sulphate of ammonia, and hydrochloric acid
are produced.
Having now described my invention and the best mode known to me of carrying
it into effect, I claim as my invention under the letters patent:-
1st. The improvements in treating tho liquor which remains after fully car-
bonating the soda in the ammonia-soda process, which consist in concentrating the
same by evaporation, separating the crystals of sodium chloride which form, and
treating the residue with sulphuric acid in place of liberating the ammonia with
lime, whereby sulphate of ammonia and bydrochloric acid are formed in place of
ammonia and calcium chloride as heretofore.
2nd. The improvement in obtaining hydrochloric acid from the aforesaid liquor,
which consists in evaporating the surplus water in the liquor, separating the sodium

page_text: chloride as it salts out, and adding sulphuric acid to the concentrated liquor or to
the ammonium chloride obtained therefrom by crystallization or by complete
evaporation, substantially as described.
In witness whereof I the said Ludwig Mond have hereunto set my hand and
seal this 26th day of January in the year of our Lord one thousand eight hundred
and eighty four.
Witness
WP. THOMPSON
Patent Agent
6 Lord Street
Liverpool
LUDWIG MOND (L.S.)