Improvements in the Manufacture of Sulphur from Sulphuretted Hydrogen and Sulphurous Acid, or a Salt thereof.
Year: 1885

page_text: Improvements in the Manufacture of Sulphur from Sulphuretted
Hydrogen and Sulphurous Acid, or a Salt thereof.
"
I, JOSIAH WYCKLIFFE KYNASTON, of Kensington Liverpool in the County
of Lancaster, Manufacturing Chemist, do hereby declare the nature of my
said invention for IMPROVEMENTS IN THE MANUFACTURE OF SULPHUR FROM
SULPHURETTED HYDROGEN AND SULPHUROUS ACID OR A SALT THEREOF to be as
follows:-
-
"
By whatever means sulphuretted hydrogen is caused to react upon sulphurous
acid, so as to obtain therefrom sulphur according to the equation
2 H₂ S + SO₂ 3 S + 2 H₂ O.
there is always simultaneously produced more or less considerable quantities of one
of the thionic acids, and so there is a failure to obtain the quantity of sulphur
which is contained in the materials employed.
By the process I am about to describe this difficulty is overcome, and I obtain in
the free state all the sulphur contained in the sulphuretted hydrogen and in the
sulphite used, and the sulphur is obtained in the pulverulent form.
Into a mixture of calcium sulphite and water maintained in agitation, I pass
a current of sulphuretted bydrogen, and at the same time run in a stream of liquid
hydrochloric acid so regulated that two equivalents of H. Cl shall be added for
every equivalent of sulphuretted hydrogen passed into the mixture in a given time.
The result is that the sulphurous acid being liberated from the sulphite whilst in
contact with sulphuretted hydrogen, there is instantaneous mutual decomposition
of the two sulphur compounds, and the whole of the sulphur is set free. In place
of liquid hydrochloric acid, gaseous H. Cl can be used, and if so it is passed into
the aqueous mixture of sulphite in intimate mixture with the sulphuretted hydrogen
gas in the proportion of two equivalents of H. Cl to one equivalent of H, S when
the reaction ensues as before described.
The sulphur is separated from the chloride of calcium solution by means well
known.

page_text: Improvements in the Manufacture of Sulphur from Sulphuretted
Hydrogen and Sulphurous Acid, or a Salt thereof.
I, JOSIAH WYCKLIFFE KYNASTON, of Kensington, Liverpool, in the County of
Lancaster, Manufacturing 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:—
The processes hitherto employed or suggested for obtaining sulphur from
sulphuretted hydrogen, by the mutual reaction between that gas and sulphurous
acid, have not given the result sought to be attained, namely the liberation of the
whole sulphur contained in both gases, in the free state. The reaction which it has
been sought to establish would be expressed by the following equation:-
2 H₂ S + SO₂ 3 S + 2 H₁ O.
But whilst this equation represents the main reaction, there is always at the same
time a subsidiary action which gives rise to the production of some of the thionic
acids and thus much sulphur passes into solution and is lost.
By my new process this difficulty is overcome, and I obtain in the free state
practically all the sulphur contained in the sulphuretted hydrogen, and in the
sulphite used, and the sulphur is obtained in the pulverulent condition.
The vessel in which the operation is conveniently performed is a flag stone still
similar to those in common use in the chlorine manufacture, but fitted with a
wooden agitator. This is about half filled with water and a quantity of sulphite
of calcium or magnesium is added either in the dry state, or preferably, it is
pumped in after mixing with water to a creamy consistence. The agitator is
caused slowly to revolve and then a current of sulphuretted hydrogen which must
be delivered under sufficient pressure is forced in through a leaden pipe reaching to
the bottom of the vessel and connected with a leaden coil pierced with holes so that
the issuing gas may be distributed evenly. through the mixture of sulphite and
water. After a few minutes, or as soon as the mixture in the still is saturated with
sulphuretted hydrogen, a stream of hydrochloric acid of from 8 to 10 degrees
Twaddell is run in and so regulated that for each two equivalents of sulphuretted
hydrogen passing in, two equivalents of hydrochloric acid are added when decom-
position ensues according to the equation:-
.
Ca SO, +2 HCl + 2 H₂ S = Ca Cl₂ + 3 S + 3 H₂ Q.
The operation is completed when the whole of the sulphite of calcium or magnesium
has been decomposed. The current of sulphuretted hydrogen is then diverted to a
second decomposer and the stream of acid is turned off. The agitator is allowed to
continue at work for a few minutes until the sulphur has agglomerated together
and the batch is run off on to a filter bed where the sulphur is retained, and the
solution of chloride of calcium or magnesium allowed to run away.
It is desirable in order to avoid nuisance or inconvenience to the workmen
engaged in the operation, to examine the batch before running it off, and if it
contains free sulphuretted hydrogen, to add a small quantity of sulphite of calcium

page_text: or magnesium, and hydrochloric acid (if necessary) and to continue the agitation
for a few moments. The batch is then perfectly inodorous.
The hydrochloric acid used in the process should be prepared beforehand by
mixing the ordinary commercial acid with water so as to reduce the strength
to from 8 to 10 degrees Twaddell, and it must be allowed to become perfectly
cold before being used. The success of the operation depends greatly upon the
temperature being kept as low as possible throughout.
The hydrochloric acid is best supplied to the decomposer from a cistern placed at
a sufficient elevation overhead, and the cistern and decomposer are connected by a
substantial ebonite pipe.
If it be desired to have perfect absorption of the sulphuretted hydrogen, this
inay be accomplished by connecting the decomposer with a second one of exactly
the same description, and then using the two decomposers alternately as the first,
and the second one.
The process may be varied by passing into the mixture of sulphite of calcium or
magnesium and water in the decomposer, an intimate mixture of sulphuretted
hydrogen gas, and hydrochloric acid gas in the proportion of two equivalents of the
former to two of the latter, but this is much less convenient than the mode of
working first described.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I wish it to be
understood that. I do not bind myself to the exact details of working as above
described, but what I claim as my invention is
The manufacture of sulphur from sulphuretted hydrogen and sulphite of calcium
or magnesium, by passing H, S along with hydrochloric acid into a mixture of the
sulphite of calcium or magnesium and water in such proportion that the sulphite
shall be decomposed only whilst in contact with H, S.
Dated this 23rd day of November 1885.
WM P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, and
323, High Holborn, London,
Patent Agents for the Applicant.