Improvements in Extracting Sulphur from Materials Employed in the Purification of Gas or from other Materials Containing Sulphur.
Year: 1885

page_text: Improvements in Extracting Sulphur from Materials Employed
in the Purification of Gas or from other Materials Containing
Sulphur.
I JAMES YATE JOHNSON of 47 Lincoln's Inn Fields in the County of Middlesex
Gentleman.do hereby declare the nature of this Invention which has been com-
municated to me from abroad by Charles Dubois of Paris in the Republic of France,
to be as follows
This Invention relates to an improved process for extracting sulphur from
various materials containing sulphur and especially from the mixtures used in the
purification of lighting gas.
By means of my Invention I am enabled to extract the sulphur from these
mixtures or materials by heating them to a temperature of say about 400 degrees
Centigrade (a lower temperature than that required for the volatilisation of
sulphur) in a closed chamber or vessel provided with an outlet orifice and at the
same time causing a current of steam (or of steam and an inert gas) likewise
superheated to about 400 degrees to pass through the materials thus distilling and
carrying off the tarry matter and the volatile products of the wood or sawdust that
is present in certain mixtures used in the purification of gas. Laming's mixture
for example. When these tarry and pyrogenous products and the like resulting
from the aforesaid distillation cease to be given off the sulphur may be separated
from the magma by fusion or by any other suitable means but it is preferred to
sublime it by raising the temperature to say about 500 degrees at the same time
keeping up the current of superheated steam also at a temperature of about
500 degrees, the sulphur is then sublimated and carried off and is deposited and
collected in a cold chamber or receptacle wherein it may be afterwards melted into
cakes if desired.

page_text: L
Improvements in Extracting Sulphur from Materials Employed
in the Purification of Gas or from other Materials Containing
NATO PI
Sulphur.
T-
Í JAMES YATE JOHNSON of 47 Lincoln's Inn Fields in the County of Middlesex
Gentleman do hereby declare the nature of this Invention which has been com-
municated to me from abroad by Charles Dubois of Marseilles in the Republic of
France Manufacturer of chemical products 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 an improved process for extracting sulphur from
various materials containing this substance especially from the mixtures used in
the purification of lighting gas (such as Lamings mixture for example). Various
means have been tried with a view to accomplishing this object but 'have heretofore
failed to lead to practical results. The mixtures have been placed in boilers
containing water and heated under pressure to a temperature above that of melting
sulphur the materials being stirred and the liquid sulphur drawn off. Attempts
have also been made to the advantage of the solubility of sulphur in coal oils and
sulphuret of carbon but none of these processes have been worked commercially;
the sulphur so obtained is unfit for the market being contaminated with tarry
matter and other impurities. The aforesaid mixtures have also 'heen employed in
making sulphuric acid for the manufacture of artificial manure and as a protection
against diseases incidental to vines and patents have been obtained for several of
these applications.
-
By means of this invention sulphur is .enabled to be extracted from these
mixtures or materials by heating them to a temperature of say about 400 degrees
Centigrade (a lower temperature than that required for the volatilisation of sulphur)
in a closed chamber or vessel provided, with an outlet orifice and at the same time
causing a current of steam (or of steam.and an inert gas) likewise superbeated to
about 400 degrees to pass through.the materials thus distilling and carrying off the
tarry matter and the volatile products of wood chips or sawdust that is present in
the mixture (when treating Lamings mixtures for example) the sulphur being left
in the vessel. When these tarry and pyroligneous products and the like cease to
be given off the sulphur may be separated. I raise the temperature from the
magma by fusion or by any other suitable means 'but it is preferred 'to sublime it
by raising the temperature to say about 500 degrees at the same time keeping up
the current of superheated steam also at a temperature of about 500 degrees, the
sulphur is then sublimated and carried off and is deposited and collected in a cold
chamber or receptacle wherein it may be afterwards melted and formed into cakes
if required.
If it be desired to obtain the sulphur in cakes it is simply necessary to heat this.
receptacle to from 120 to 130 degrees that is to say to the melting point for
sulphur.
In order to extract the sulphur containing in exhausted Laming's mixture for
example the process may be conducted as next hereinafter described.
The materials from which the sulphur is to be extracted are placed in a vessel
such as a cast iron cylinder or retort arranged over a furnace. This retort is

page_text: connected with the steam space of a boiler means being provided for superheating
the steam on its passage from the said boiler to the retort. This retort as well as
the coil or other apparatus for superheating the steam are gradually heated to
about 400 degrees Centigrade.
Vapours produced by the distillation of the tar and of the wood chips or shavings
contained in the Laming mixture then escape at the open end of the cast iron tube
and may be recognised by their odour. They may be allowed to escape into the
atmosphere or they may be collected in a suitable receiver. The outlet from the
tube is preferably covered with wire gauze in order to keep back dust or other
impurities. The temperature is maintained until the said vapours have completely
disappeared; the temperature of the steam superheater and of the retort or vessel
containing the materials is then raised to about 500 degrees without interrupting
the supply of steam.
The sulphur vapours now make their appearance and may be recognised by their
yellow colour and by the deposit which they form upon a cold glass when it is
brought in contact with them. The retort is then to be connected with a cooling
chamber which may consist of a cylindrical vessel made of galvanised sheet iron
the axis of this vessel being in a line with the axis of the retort and containing
the mixture. This vessel is closed on the other or opposite side by a cover
provided with a hole at the lower edge and is cooled by a stream of water for
example in order to maintain the temperature of the vessel below 100 degrees.
When it has been ascertained by looking through a glazed hole or by means of a
valve or cock for example that all the sulphur has been distilled the cooling vessel
may be removed in order to collect the sublimed sulphur deposited on its sides the
water of condensation having escaped through the hole in the cover.
The sulphur thus obtained is moist but simply requires drying in the air or
otherwise before storing it. The residue remaining in the retort being composed
chiefly of lime, iron and carbon may be pulverised and used as artificial manure.
Any suitable apparatus may be employed in carrying out this invention the
essential point being the employment of the distillation process performed with the
aid of superheated steam as herein before described.
The current of steam in place of being continuous may be intermittent or only
intervene at a certain stage or stages of the operation and a mixture of steam and
some more or less inert gas may be employed if preferred in place of steam alone.
The operation may be arrested after the pyroligneous and tarry or other matters
have gone over or been removed the sulphur remaining in the magma in the retort
being collected by a direct separation process such as fusion under water for
example or by any other known means.
Having now particularly described and ascertained the nature of this Inven-
tion and in what manner the same is to be performed I declare that what
I claim is
First In extracting sulphur from materials used in the purification of gas or
from other like sulphurous materials distilling or driving off the volatile impurities
liable to contaminate the sulphur by the application of heat and superheated steam
or vapour substantially as hereinbefore described.
Second-The improved process for extracting sulphur from materials used in
the purification of gas or from other like materials the said process consisting in
distilling or driving off the volatile impurities and subliming the sulphur in the
presence of superheated steam or vapour substantially as hereinbefore described.
Dated this 30th day of July 1886.