Improvements in the Production of Hydrochloric Acid from Certain Industrial Residues together with the Recovery of Sulphur and Oxide of Magnesium.
Year: 1889

page_text: Date of Application, 30th Oct., 1889
Complete Specification Left, 22nd Aug., 1890-Accepted, 27th Sept., 1890
PROVISIONAL SPECIFICATION.
Improvements in the Production of Hydrochloric Acid from Certain
Industrial Residues together with the Recovery of Sulphur and
Oxide of Magnesium.
We FARNHAM MAXWELL LYTE, of 60, Finboro Road, in the County of Middlesex,
Chemist, and JAMES GRAHAM TATTERS, of The Manse, Runcorn, in the County of
Chester, Chemist, do hereby declare the nature of this invention to be as follows
:-
This invention relates to the production of hydrochloric acid from certain industrial
residues together with the recovery of sulphur and oxide of magnesium.
In another application of even date herewith, we have described a method for the
recovery of the chlorine from ammonia-soda waste, etc., by the formation of either of
the anhydrous magnesic oxychlorides, but it may in some cases be desirable to recover the
chlorine as strong hydrochloric acid, using such condensed acid for the manufacture
of chlorine in the usual way, that is by means of binoxide of manganese.
To effect this, we pass over the heated magnesium chloride or oxychloride,
atmospheric air (or oxygen gas) mixed with sulphuretted hydrogen gas in proportion
just sufficient to effect, the decomposition without having any sulphurous acid formed
or any sulphuretted hydrogen left undecomposed.
We get by this means, 1st oxide of magnesium, which remains in the cylinder
2nd sulphur Brd hydrochloric acid. The two latter are volatilized and on passing away
from the oxide of magnesium to the condensers the sulphur condensers and falls out
in brick chambers (which are placed between the condensers and the kiln, furnace,
pot, or pan, in which the decomposition is effected) whilst the hydrochloric acid passes
on and into the condenser where it is condensed as in the usual way, or it may be
employed in any of those cases where the use of strong hydrochloric acid is desirable.
The decomposition thus effected may be thus expressed.
By this means, we obtain from the chlorine present in ammonia-soda waste liquors,
hydrochloric acid free from arsenic and other impurities, suitable for many purposes
besides the manufacture of chlorine.
At the same time we are enabled by the same decomposition to recover the sulphur
from Leblanc soda waste after such sulphur has been converted into gaseous sulphuretted
hydrogen.
"Dated this 20th love of Ustaba 1980

page_text: COMPLETE SPECIFICATION.
Improvements in the Production of Hydrochloric Acid from Certain
Industrial Residues together with the Recovery of Sulphur and
Oxide of Magnesium.
We, FARNHAM MAXWELL LYTE of 60, Finboro' Road in the County of Middlesex,
Chemist, and JAMES GRAHAM TATTERS of The Manse, Runcorn, in the County of
Chester, 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 the production of hydrochloric acid and of sulphur from
certain industrial residues and to the recovery of oxide of magnesium.
The residues in question are the waste chloride liquors of the ammonia-soda process
and soda waste from the Leblanc process, and the present invention has for its object
to produce hydrochloric acid (free from arsenic and other impurities) from the chlorine
present in the ammonia-soda waste liquors and from the hydrogen present in sulphuretted
hydrogen obtained from the treatment of the Leblanc soda waste and at the same time
and by the same decomposition to recover the sulphur from the Leblanc soda waste
and likewise magnesium oxide from magnesium chloride or oxychloride produced in
the course of the treatment of ammonia-soda waste liquors for the production of
hydrochloric acid as above mentioned.
The process (so far as it relates to the conjoint treatment of both kinds of residue)
therefore divides itself into two preliminary operations, viz.
(A) the treatment of the ammonia-soda waste liquors for the production in the first
instance of magnesium chloride or of either of the anhydrous magnesie oxychlorides,
and
(B) the treatment of the Leblanc soda waste for the conversion of the sulphur
contained into gaseous sulphuretted hydrogen.
The treatment of the waste chloride liquors of the ammonia soda process to produce
anhydrous magnesic chloride, forms the subject of another application for Letters
Patent of even date herewith No. 17217 and is as follows;-The liquor which has been
distilled with lime and consists chiefly of calcic and sodic chloride is to be concentrated
by evaporation until on cooling to the ordinary temperature the calcic chloride it
contains would form a saturated solution. Most of the sodic chloride will deposit
during evaporation and the rest deposits on allowing the liquor to cool and repose.
Sufficient soft burnt magnesia is now to be added to the purified solution of calcic
chloride which is at same time to be diluted until its specific gravity is 1.2445 at 15° (
whereupon it is to be converted in the known way by carbon dioxide into a solution
of pure magnesic chloride, calcic carbonate being precipitated. The pure solution
having been decanted there is to be added to it ammonic chloride (obtained by
sublimation from a previous batch of anhydrous ammonic-magnesic double chloride)
whereupon there is obtained a pure solution of ammonic-magnesic double chloride
which only requires to be evaporated to dryness and desiccated. This new batch of
anhydrous double chloride is equal in amount to the previous one and from it, and
from every subsequent batch, we obtain. by sublimation the anhydrous magnesic
chloride required, and ammonic chloride for use as above described in producing the
next succeeding batch of anhydrous double chloride. The anhydrous magnesic
chloride may then be treated as hereafter described or may first be converted into
anhydrous magnesic oxychloride by being fused or ground with say half its weight
of dry magnesia and the whole agglomerated by heating in a closed vessel.
The treatment of the Leblanc soda waste to obtain sulphuretted hydrogen is as
follows The Leblanc soda waste is to be mixed with water until it marks about
50° Twaddell and then run into closed iron cylindrical vessels. Carbonic acid gas is
then to be pumped through it as in Chance's process (Patent No. 8666 dated
June 16th 1887) whereby carbonate of lime and sulphuretted hydrogen gas are
obtained.

page_text: The final operation consists in passing over heated magnesium chloride or
oxychloride atmospheric air (or oxygen gas) nixed with sulphuretted hydrogen gas in
proportion just sufficient to effect the decomposition of the chloride or oxychloride withou
forming sulphurous acid or leaving any sulphuretted hydrogen undecomposed. This
operation is performed in cylinders or retorts, made of iron and lined with brick the
cylinders being either vertical or horizontal and placed in a kiln or furnace wherein
the magnesium chloride or oxychloride is heated to about 600° to 800° Fahrenheit,
and by this means oxide of magnesium is obtained in the cylinder whilst vapors of
sulphur and hydrochloric acid pass off to brick chambers. wherein the sulphur
condenses and falls down whilst the hydrochloric acid passes on and may either he
employed in the ga cous state or be conveyed to condensers where it is condensed
in the usual way.
The haun duzanikal daarmensition may be thus acnonsend •
It should, however, be understood that the process so far as it relates to the
treatment of the waste chloride liquors of the ammonia-soda process may be conducted
independently of the treatment of the soda waste from the Leblanc process by using
in the manner above described sulphuretted hydrogen obtained from any other source.
Similarly, sulphuretted hydrogen obtained from Leblanc soda waste as above mentioned
may be mixed with air or oxygen and used for treating magnesium chloride or
oxychloride other than that obtained from ammonia-soda waste.
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;
F
1. The herein described process of producing hydrochloric acid from the wasi
chloride Liquors of the ammonia-soda process and of recovering magnesium oxide and
obtaining sulphur, which process consists in first producing magnesium chloride or
oxychloride by treating the said liquors in the manner described and then exposing
the heated chloride or oxychloride to sulphuretted hydrogen in the presence of oxygen
as described and separating the sulphur from the hydrochloric acid gas by condensation,
as specified.
2. The herein described process of obtaining sulphur from Leblanc soda waste and
of producing hydrochloric acid and magnesium oxide, which process consists in firsi
converting the sulphur in the soda waste into gaseous sulphuretted hydrogen as
described and bringing it, in the presence of oxygen, into contact with magnesium
chloride or oxychloride in a heated state and finally condensing the sulphur vapors, as
specified.
3. The herein described process of conjointly obtaining hydrochloric acid from the
waste chloride Liquors of the ammonia-soda process and sulphur from the soda waste
of the Leblanc process, which consists in obtaining magnesium chloride or oxychloride
from the ammonia-soda waste in the manner described and sulphuretted hydrogen
from the Leblanc soda waste and exposing the chloride or oxychloride in a heated state
to the action of sulphuretted hydrogen in the presence of oxygen, as specified.
Dated this 22nd day of August 1890.