A NEW OR IMPROVED PROCESS FOR EXTRACTING SULPHUR FROM SULPHIDE OF HYDROGEN
Year: 1884

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I, GEORGE FREDERICK REDFERN, of the General Patent Office N° 4 South Street,
Finsbury, in the County of Middlesex, Patent Agent do hereby declare the nature
of the said Invention for A NEW OR IMPROVED PROCESS FOR EXTRACTING
SULPHUR FROM SULPHIDE OF HYDROGEN 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 a new or improved process for extracting sulphur
froin sulphide of hydrogen.
Until now, no process has been known by which the sulphur contained in
sulphuretted hydrogen-gas could be extracted in an economical manner on a large
scule.
According to this Invention the said object is effected by conducting the sulphide
of hydrogen through a heated sulphate of an alkali or an alkaline earth, when the
oxygen of the sulphate combines with the hydrogen of the sulphuretted hydrogen-
gas and the sulphide corresponding with the sulphate employed remains in the
apparatus, while sulphur flows out or is sublimated. Atinospheric air is then
blown into the heated sulphide thus obtained and this sulphide is thereby oxidized
again, that is to say converted into the corresponding sulphate which may be
employed afresh for the said purpose of extraction.
This process will more especially give very satisfactory results, when employed
for the utilization of soda waste or the residuum from soda works, where the
Leblanc process is carried on. To carry the Invention into practice, the sulphide
of hydrogen to be decomposed is led through a retort or a series of tubes, filled by
preference with small pieces of gypsum and heated to red heat, the outlet of the
said retort or series of tubes communicating with a suitable condenser for the liquid
sulphur. The following equation represents the reaction which takes place.
Ca SO, +4 H, S = Ca S + 4 H₂ O + 4 S.
In order to effectually prevent the freed oxygen from combining with sulphur,
care must be taken to lead in, continuously, a surplus of sulphide of hydrogen

page_text: sufficient quantity of atoms of hydrogen for which it possesses a closer affinity.
The sulphide of hydrogen which in this way is introduced into the condenser is
thence led back into the lye from which this gas is developed, and so it is
subsequently worked into sulphur.
When the whole of the gypsum is reduced to sulphide of calcium, the sulphuretted
hydrogen-gas to be decomposed is led into another apparatus similarly arranged to
that herein before described and in which the process goes on in a similar manner
while atmospheric air is blown into the first apparatus for the purpose of oxidizing
the sulphide of calcium again into sulphate of lime (gypsum).
In order that the considerable quantity of caloric which is freed by this oxidation
may be utilized, the two retorts or scries of tubes above mentioned are so combined
with each other, that the heat escaping from one retort or series of tubes serves for
heating the alkaline or alkaline-earthy sulphate in the other.
Having now particularly described and ascertained the nature of my said
Invention, and in what manner the same is to be performed, I declare that what
I claim is
(1.) The described process for extracting the sulphur contained in sulphide of
hydrogen the said process consisting in conducting the sulphide of hydrogen
through a heated mass consisting of small pieces of an alkaline or alkaline-carthy
sulphate which is thereby reduced to its relative sulphide while water and sulphur
escape, substantially as herein before described.
(2.) In the process above claimed, regenerating the sulphate by blowing atmo-
spheric air into the sulphide obtained substantially as described.
(3.) In the combined process above claimed, utilizing the caloric, which is freed
by the oxidation of the sulphide into sulphate, for heating the sulphate used to
decompose the sulphuretted hydrogen, in such a manner that the two retorts or
two series of tubes, in which the processes of reducing the sulphate and oxidizing
the sulphide are being carried on alternately heat each other, substantially as
described.