IMPROVEMENTS IN OBTAINING SULPHUR FROM CERTAIN METALLIC SULPHURETS.
Year: 1852

page_text: LETTERS PATENT to William Gossage, of Widnes, in the County
of Lancaster, Manufacturing Chemist, for the Invention of
"IMPROVEMENTS IN OBTAINING SULPHUR FROM CERTAIN METALLIC
SULPHURETS.
"
Sealed the 26th January 1853, and dated the 9th November 1852
PROVISIONAL SPECIFICATION left by the said William Gossage
at the Office of the Commissioners of Patents, with his Petition,
on the 9th November 1852.
I, WILLIAM GOSSAGE, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN OBTAINING SULPHUR PROM CERTAIN
METALLIC SULPHURETS" to be as follows:-
My Invention applies to the extraction of sulphur, and obtaining this
in a solid form from the sulphuret of calcium contained in the well-
known compound called "alkali waste; " also to the extraction of
sulphur, and obtaining this in a solid form from sulphuret of sodium
produced by the decomposition of sulphate of soda; also from sulphuret
of potassium produced by the decomposition of sulphate of potash.

page_text: I will firstly describe the means by which I effect the object of my
Invention so as to obtain sulphur from "alkali waste." In the Speci-
fication of an Invention for which I obtained Letters Patent on the
Seventeenth day of August, One thousand eight hundred and thirty-
seven, under the title of "Certain Improvements in the Processes or
Operations connected with the Manufacture of Alkali from Common
Salt, and with the Use of the Products obtained therefrom," I have
therein described my discovery that pure carbonic acid gas can be
employed to effect the decomposition of sulphuret of calcium contained
in "alkali waste," thereby causing the production of pure sulphuretted
hydrogen gas, which gas, under certain circumstances, could be used
for the manufacture of sulphuric acid in place of solid sulphur. Not-
withstanding this discovery, "alkali waste" has continued to be (as its
name implies) a valueless product, and large expenses are annually
incurred by the manufacturers of alkali in getting rid of this worthless
and most offensive waste material. In effecting my improvements as
applied to this material I cause the decomposition of sulphuret of
calcium contained therein to be accomplished by means of impure
carbonic acid gas, thereby producing sulphuretted hydrogen gas in
mixture with other gases. I obtain carbonic acid gas (which I use to
effect the said decomposition) by the combustion of coke or coal with
atmospherical air, using a deep furnace for effecting such combustion, so
as to provide for the whole or nearly the whole of the oxygen contained
in such atmospherical air being combined with carbon or hydrogen of
the coke or coal. I conduct the gaseous products of such combustion
(containing carbonic acid gas and nitrogen gas) through the flue of a
boiler or evaporating pan, so as to utilize a portion of the heat generated
by such combustion, and subsequently through pipes so arranged as to
effect a further cooling of the gases, and I then cause these gases to
filter through "alkali waste" (maintained in a state of dampness by
occasional affusion of water) contained in suitable vessels, and using
such a number of these vessels consecutively as I find to be sufficient
to effect the absorption of the greater part of the carbonic acid so
introduced therein. I prefer to use for this purpose the same vessels
which are now employed to effect the lixiviation of rough soda (by

page_text: which lixiviation "alkali waste" remains in the vessels as an undissolved
residuum), and in this case I adapt moveable covers and suitable pipes
to these vessels, for the purpose of confining therein and conveying
therefrom the gases resulting from such operation.
These gases contain sulphuretted hydrogen, some carbonic acid, and
carbonic oxide, and the nitrogen previously existing in the atmospherical
air employed. In consequence of this admixture of other gases with
sulphuretted hydrogen, this last-named gas is rendered unsuitable to be
applied directly to the manufacture of sulphuric acid (as described in
the Specification of my former Patent), and I therefore cause these
mixed gases to be subjected to the following actions so as to obtain free
sulphur therefrom:-I conduct these gases into an apparatus in which
I cause them to become mixed with a sufficient additional quantity of
carbonic acid gas, and occasionally some atmospherical air to effect the
oxidation of the hydrogen of the sulphuretted hydrogen, and thus to
liberate free sulphur in the state of vapour mixed with the other gases,
and these mixed gases being conducted into a suitable condensing
apparatus, the sulphur vapour by cooling becomes liquefied in the first
instance, and is subsequently by further cooling obtained in a solid
state. I have stated that this decomposition of sulphuretted hydrogen
gas can be effected by means of carbonic acid gas or atmospherical air,
but in order to accomplish this it is needful that the mixed gases should
be subjected to a red heat, and I effect this object by causing the mixed
gases containing sulphuretted hydrogen gas (as these are evolved by
decomposing "alkali waste" by means of carbonic acid) to be con-
ducted into an apparatus (constructed of brickwork or other suitable
material) so arranged as to cause an intimate mixture to be made of
all gases passing through such apparatus, and I connect a furnace there-
with in which I burn coke or coal, and I conduct the gaseous products
of the combustion of such coke or coal containing carbonic acid into
such apparatus, and I thereby cause the temperature of the mixed
gases to be raised to that degree of heat which is requisite to effect the
said decomposition at the same time that I supply the required carbonic
acid by the combustion of the coke or coal. I prefer to effect this
decomposition of sulphuretted hydrogen gas entirely by means of

page_text: carbonic acid gas, but when I find (by using a salt of lead applied as a
test to the gases finally escaping from the apparatus) that some sul-
phuretted hydrogen gas is passing through the mixing apparatus without
having undergone decomposition, I avail myself of an aperture con-
nected with such mixing apparatus by which I can admit atmospherical
air, and I so admit such a quantity of atmospherical air as I find
to be sufficient to complete the decomposition of the sulphurretted
hydrogen gas which is being caused to pass into such apparatus.
I can effect the decomposition of impure sulphuretted hydrogen gas
by means of atmospherical air alone, or by means of sulphurous acid
gas (however procured), but to accomplish this it is needful to have
such an arrangement of apparatus as provides for the mixed gases
being subjected to the requisite temperature by means of transmitted
heat, whereas, when I use carbonic acid gas obtained by the combustion
of coke or coal for effecting such decomposition, such combustion
generates sufficient heat to yield the required temperature to the
mixed gases.
When I apply my improvements to the extraction of sulphur from
sulphuret of sodium or sulphuret of potassium (obtained by the decom-
position of sulphate of soda or sulphate of potash by means of carbon
at a high temperature), I place the sulphuret I am using (in the state
of small lumps or coarse powder) in such vessels as I have referred to
in describing my improvements as applied to the sulphuret of calcium
of "alkali waste," and I cause impure carbonic acid gas to filter through
such sulphuret (maintained in a state of dampness by occasional
affusion of water), and I thereby obtain mixed gases containing sul-
phuretted hydrogen, which I subject to the same operations for obtaining
sulphur therefrom as I have herein described for obtaining sulphur
from the mixed gases containing sulphuretted hydrogen procured by the
action of impure carbonic acid gas on "alkali waste."
I have herein-before mentioned that I procure carbonic acid gas
in mixture with other gases, for the purposes of my Invention,
by the combustion of coke or coal by means of atmospherical air.
I can also procure carbonic acid gas in mixture with other gases by
the action of water or steam (with or without atmospherical air) on a

page_text: carbon maintained at a red heat, and such gas is also suitable for the
purposes of my Invention. Carbonic acid gas mixed with other gases
may also be procured by the combustion of carburetted hydrogen gas
or carbonic oxide gas with atmospherical air, and by other processes,
and the gas so procured is also suitable for the purposes of my
Invention.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said William Gossage in the Great Seal Patent Office
on the 9th May 1853.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I,
WILLIAM GOSSAGE, of Widnes, in the County of Lancaster, Manu-
facturing Chemist, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Ninth day of November, in the
year of our Lord One thousand eight hundred and fifty-two, in the
sixteenth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said William Gossage, Her special licence
that I, the said William Gossage, my executors, administrators, and
assigns, or such others as I, the said William Gossage, my executors,
administrators, and assigns, should at any time agree with, and no
others, from time to time and at all times thereafter during the term
therein expressed, should and lawfully might make, use, exercise, and
vend, within the United Kingdom of Great Britain and Ireland, the
Channel Islands, and Isle of Man, an Invention of "IMPROVEMENTS
IN OBTAINING SULPHUR FROM CERTAIN METALLIC SULPHURETS," upon
the condition (amongst others) that I, the said William Gossage, by
an instrument in writing under my hand and seal, should particularly
describe and ascertain the nature of the said Invention, and in what
manner the same was to be performed, and cause the same to be filed
in the Great Seal Patent Office within six calendar months next and
immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said William Gossage, do hereby
declare the nature of my said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in and

page_text: by the following statement, reference being had to the Drawings here-
unto annexed, and to the letters and figures marked thereon (that is
to say):
My Invention of "Improvements in Obtaining Sulphur from certain
Metallic Sulphurets" applies to the extraction of sulphur, and obtaining
this in a solid form from sulphuret of calcium contained in the well-
known compound called "alkali waste; also to the extraction of
sulphur, and obtaining this in a solid form from sulphuret of sodium
produced by decomposing sulphate of soda by means of carbon; also
from sulphuret of potassium produced by decomposing sulphate of potash
by means of carbon.
I will firstly describe the means by which I effect the object of my
Invention, so as to obtain sulphur from sulphuret of calcium contained
in "alkali waste."
In the Specification of an Invention for which I obtained Her present
Majesty's Royal Letters Patent, bearing date the 17th day of August,
1837, under the title of "Certain Improvements in the Processes or
Operations connected with the Manufacture of Alkali from Common
Salt, and with the Use of the Products obtained therefrom," I have
described my discovery that carbonic acid gas can be employed to
effect the decomposition of sulphuret of calcium contained in "alkali
waste," thereby causing the production of pure (or nearly pure)
sulphuretted hydrogen gas, which gas under certain circumstances can
be used for the manufacture of sulphuric acid in place of solid sulphur.
Notwithstanding the said discovery, "alkali waste" has continued to
be a valueless product (as its name implies), and large expenses are
annually incurred by the manufacturers of alkali in getting rid of this
hitherto worthless and most offensive waste material. In effecting my
improvements (as applied to "alkali waste") I cause the decomposition
of sulphuret of calcium contained therein, and the liberation of sulphur
in the state of sulphuretted hydrogen therefrom, to be accomplished by
means of impure carbonic acid gas; and the sulphuretted hydrogen so
produced is consequently obtained in mixture with other gases; or I
effect the decomposition of "alkali waste" by means of liquid muriatic
acid, thereby obtaining sulphuretted hydrogen gas in mixture with
carbonic acid gas. The mixed gases so obtained by either of the said

page_text: decompositions of alkali waste are not suitable to be used for the
manufacture of sulphuric acid by the combustion of sulphuretted
hydrogen contained therein (as described in the Specification of my
former Patent herein-before referred to); therefore I cause such mixed
gases to be subjected to certain processes or operations herein-after
described in order to obtain solid sulphur therefrom. I obtain carbonic
acid I gas (which I use to effect the said decomposition of sulphuret of
calcium) by the combustion of coke or coal with atmospherical air,
using a furnace with a deep bed of fuel for effecting such combustion,
so as to provide for the whole or nearly the whole of the oxygen con-
tained in such atmospherical air becoming combined with carbon or
hydrogen of the coke or coal; or I obtain carbonic acid gas for such
purpose by the calcination of carbonate of lime with coke or coal in a
lime kiln. I conduct the gaseous products of such combustion or
calcination (these products containing carbonic acid, carbonic oxide,
and nitrogen gases) through an apparatus suitably arranged for cooling
gases, and I then cause these gaseous products to filter through alkali
waste (maintained in a state of dampness by affusion of water and
injection of steam) contained in suitable vessels; and I use such a
number of these vessels (containing "alkali waste") consecutively as I
find to be sufficient to effect the absorption of the greater part of the
carbonic acid so introduced therein. I prefer to use for this purpose
the same vessels which are employed to effect the lixiviation of the
compound called "black ash" or "rough soda" (by which lixiviation
"alkali waste" remains in the vessels as an undissolved residuum); and
I adapt moveable covers and suitable pipes to these vessels for the pur-
pose of confining therein and conveying therefrom the gases resulting from
the action of carbonic acid on the "alkali waste." These gases contain
sulphuretted hydrogen, also some carbonic acid, and carbonic oxide and
the nitrogen previously existing in the atmospherical air employed.
When I effect the decomposition of "alkali waste" by means of
muriatic acid, I prefer to employ for this purpose a vessel made of wood,
and lined with lead or other suitable material, and having a pipe for
conducting away the gases generated by such decomposition; also a
pipe with a funnel head for introducing the liquid acid, and an aper-
ture (fitted with a tight cover for introducing "alkali waste" into the

page_text: "
vessel, and taking out undissolved residuum, an arrangement being also
made for running off the liquid products of the decomposition. I also
prefer to adapt a pipe to the vessel, by which steam may be injected into
the fluid contents thereof, so as to drive off the last portions of gas
therefrom. I introduce a suitable quantity of "alkali waste" into such
vessel, and having closed the aperture with its cover I run therein liquid
muriatic acid, which cause" the extrication of gas from the alkali waste,"
and I continue the addition of liquid acid until a sufficient quantity has
been introduced, and I cause the last portions of gas to be driven off by
injection of steam; the gases evolved (contained sulphuretted hydrogen
gas and carbonic acid gas) are conducted from the vessel by a pipe
provided for such purpose. The means by which sulphuretted hydrogen
gus may be conveniently obtained by the action of muriatic acid on
"alkali waste" are described in the Specification of my former Patent
herein-before referred to.
Having herein-before described the means by which I obtain sul-
phuretted hydrogen gas (in mixture with other gas or gases) by
decomposing sulphuret of calcium contained in "alkali waste," I will,
secondly, describe the means by which I obtain solid sulphur by
decomposing such sulphuretted hydrogen gas. I cause such mixed
gases (containing sulphuretted hydrogen) to become mixed with an
additional quantity of carbonic acid gas, and some atmospherical air
or sulphurous acid gas, and I cause the mixture of gases so obtained to
become heated to redness when the hydrogen of the sulphuretted hydrogen
combines with oxygen (forming water), and the sulphur is liberated from
combination, and exists in the state of uncombined sulphur vapour,
which by cooling becomes condensed into liquid sulphur, and by further
cooling, the liquid sulphur becomes solidified.
I effect the required heating of the mixed gases (obtained by decom-
posing sulphuret of calcium, as herein-before described), and at the same
time I add carbonic acid gas thereto by causing the said mixed gases
to become mingled with the highly heated gaseous products obtained by
burning coke or coal with atmospherical air in a suitable furnace. I
accomplish this either by causing the said mixed gases to filter through
the burning coke or coal, together with a suitable quantity of atmo-
spherical air, or to become introduced into a flue conducting from the

page_text: said furnace, in which flue the said mixed gases become mingled with
the highly heated gases produced by the combustion of coke or coal, and
with some atmospherical air. When I use sulphurous acid gas to assist
in decomposing the sulphuretted hydrogen gas of the said mixed gases
I prefer to introduce such sulphurous acid gas into the furnace which
I use for burning coke or coal, or into the flue of such furnace, together
with the said united guses.
In order to effect a perfect decomposition of sulphuretted hydrogen
gas contained in the said mixed gases (obtained from "alkali waste"),
it is essential that such sulphuretted hydrogen gas be intimately mixed
at a red heat with the gas or gases which I have herein-before stated
I use for its decomposition. I accomplish this object by means of an
arrangement of apparatus herein-after described, and I effect the con-
densation of sulphur vapour by means of certain apparatus herein-after
described. I have herein stated that I cause the sulphuretted hydrogen
of the said mixed gases to become mixed with carbonic acid gas and
some atmospherical air or sulphurous acid gas; and I would observe that
no excess of carbonic acid gas will cause oxydation of sulphur, which
oxydation would be occasioned by excess of atmospherical air. I judge
of the suitable quantity of atmospherical air or sulphurous acid gas being
employed by testing the residual gases which pass off from the apparatus
used for condensing the sulphur vapour; and if I find these gases contain
sulphurous acid, I decrease the proportionate quantity of atmospherical
air or sulphurous acid gas employed; or if I find these residual gases
contain sulphuretted hydrogen gas I increase the proportionate quantity
of atmospherical air or sulphurous acid gns employed. I use moistened
litmus paper for the detection of sulphurous acid, and paper impregnated
with salt of lead for the detection of sulphuretted hydrogen.
-
I will now describe the arrangement of apparatus which I prefer to
employ for effecting the objects of my Invention as applied to obtaining
sulphur from sulphuret of calcium contained in "alkali waste." Sheet 1,
of the Drawings hereunto annexed contains a plain view in section of
such apparatus; and Sheet 2, contains a vertical view in section of the
same. In these Drawings the same letters of reference are used to
indicate similar parts.
A, A, are vats used for lixiviating the compound called "black ash"

page_text: or "rough soda," of the same construction as the vats which are used
for what is called "continuous lixiviation," and having a perforated
false bottom. These vats are provided with hydraulic lutes B, B, into
which covers C, C, can be introduced, so as to convert the open topped
vats into air-tight vessels. These perforations are left near the outsides
of one set of such arches H 2, and in the middle of the other side
of such arches H 1, as shewn in the Drawings hereunto annexed. I,
is a pipe of cast iron, connecting the tower G, with another tower Q.
This pipe is partly surrounded with a tank containing water for the
purpose of cooling the gases passing through such pipe. The tower
Q, is constructed of double walls of brickwork, between which walls
I introduce finely slaked lime for the purpose of rendering this
apparatus impervious to air. The tower Q, is nearly filled with
broken bricks, clinkers, or other suitable materials marked W, W,
capable of presenting extensive surfaces to gases passing through the
tower, and thereby facilitating the condensation of sulphur vapour.
The condensing materials W, W, are supported upon iron bars, as
shewn in the Drawing. X, is an iron pan for receiving liquid
sulphur, as this flows from the condensing tower Q. a, is a flue con-
veying the non-condensed gases from the tower Q, to a chimney, or
some other exit channel. r, is a branch pipe connected with the pipe R,
through which atmospherical air is introduced to mix with the gases
passing from the vats A, A, or from the apparatus in which alkali waste
is decomposed by muriatic acid. This branch pipe is furnished with a
regulator to controul the quantity of air admitted into the pipe R. The
mixed gases proceeding from the vats A, A, or the mixed gases obtained
by decomposing alkali waste with muriatic acid together with atmo-
spheric air admitted through the pipe branch r, are conducted from the
fan F, into the ash pit of the furnace D, and percolate through the
burning fuel contained therein, becoming thereby heated to redness,
and passing from thence through the flue E, the resulting gases are
conducted into tower G, wherein the requisite mixing of the gases is
completed. This mixing is effected by causing the gases to pass
alternately through the perforations left at the middle of the arches
marked H', H', and through the perforations left in the outsides of
the arches marked H', H', in the Drawings. The course of the gases

page_text: through the tower G, is delineated in the Drawings by bent arrowA.
I have herein-before stated that when sulphuretted hydrogen is mixed
with carbonic acid gas, and a suitable proportion of atmospherical air
or of sulphurous acid at a red heat, the hydrogen of such sulphuretted
hydrogen becomes oxydized, forming water, and the sulphur is liberated
from its combination with hydrogen, and at such temperature the
liberated sulphur exists in the state of vapour. In order to condense
such sulphur vapour, and to separate sulphur from the gases with
which such sulphur vapour is mixed, I conduct the mixed gåses
proceeding from the tower G, through the iron pipe I, and I cause
such a supply of water to be introduced into the tank d; through
which this pipe passes, as I find to be sufficient to effect the requisite
cooling of the gases.
I place a thermometer in the exit flue a, proceeding from the con-
densing tower Q, and I so regulate the supply of cold water to the
tank d, that the temperature of the gases passing from the tower Q,
shall not be less than 230 degrees of Fahrenheit's thermometer. The
gases passing from the tower G, through the pipe I, become cooled
below the temperature requisite for the existence of sulphur as a per-
manent vapour; and as these gases percolate through the materials
contained in the tower Q, liquid sulphur becomes deposited on such
materials, and flowing down the tower Q, becomes collected in the iron
pan X, from whence it can be removed and allowed to solidify by cooling.
In place of using an apparatus for condensing sulphur vapour constructed
as I have herein-before described, I can use such an apparatus as is
employed by manufacturers of lamp-black for effecting the deposition
of the finely divided carbon which is the product of their operations.
When using such an apparatus, I cause the gases passing from the
tower G, to be cooled, during their transit through the pipe I, to the
temperature of about 300 degrees of Fahrenheit's thermometer, and I
introduce the cooled gases into collecting chambers (constructed similarly
to the chambers used for collecting lamp-black wherein sulphur becomes
deposited in fine powder. I can also use this last-described apparatus
in conjunction with the condensing tower Q, in which case I connect
the exit passage a, leading from such tower with the collecting chambers
herein-before referred to.

page_text: When I apply my Invention to the extraction of sulphur from
sulphuret of sodium, or sulphuret of potassium, I place the sulphuret
(on which I am operating) in vats constructed similarly to the vats
which I have herein described as suitable for obtaining sulphur from
sulphuret of calcium, and having inlet and outlet pipes and mains
constructed and adapted to such vats in the same manner as I have
herein-before described in reference to such other vats; and I cause
carbonic acid gns obtained by the combustion of coke, or by the cal-
cination of carbonate of lime, to be introduced into such vats, and to
percolate through the mass of sulphuret contained therein, the sulphuret
being kept in a suitable state of moistness by affusion of water and
injection of steam, and I thereby obtain sulphuretted hydrogen mixed
with other gases, which I subject to the same operations for obtaining
sulphur therefrom as I have herein described as suitable for obtain-
ing sulphur from impure sulphuretted hydrogen produced by the de-
composition of sulphuret of calcium. The residual product of the
decomposition of sulphuret of sodium or sulphuret of potassium is
carbonate of soda or carbonate of potash (as the case may be), which
products are applicable to well-known useful purposes.
I', I', and I, I', are main pipes connected with the vats A, A,
by means of branch pipes P1, P', and P³, P, for the purpose of intro-
ducing gas into such vats. O', O', and 0, 0, are main pipes con-
nected with the vats A, A, by means of branch pipes 0, 0, for the
purpose of conducting gas away from such vats.
The main pipes
The main pipes
O', O', are connected with the main pipes I', I'
I', I', are also connected with each other, and the main pipes I', I', are
also connected with each other. V, V₁, and V, V, are a series of
hydraulic valves, by means of which the communication between the
main pipes I, I', or I, I, and the vats A, A, may be opened and
closed, as may be required. V, V, and V, V, are a similar series of
hydraulic valves to be used for opening and closing the communication
between the main pipes O', O', and (2, 0, and the vats A, A. K, is a
lime kiln, in which carbonate of lime is calcined in mixture with coke
or coal. L, is a pipe conducting gases from such lime kiln into a
cooling vessel M, into which streams of water are introduced by means
of the pipes N, N. The cooled gases pass from this vessel into the

page_text: main pipes I, I, and from thence into such of the vats A, A, as are in
a suitable condition to receive the same. After passing through these
vats the gases traverse the pipes 0, 0, into the main pipes Iº, I, and
from thence into such of the vats A, A, as are in a suitable condition
for receiving the same. After passing through these vats the gases
traverse the pipes 0, 0, and through the pipe R, into a fan F, by
means of which the requisite current is obtained to draw gases through
the vats, and transfer the gases proceeding from the vats through the
pipe S, into the decomposing apparatus. T. T, are pipes for supplying
steam to the mixed gases passing into the vats; and U, U, are pipes
through which water can be dispersed over the surface of the "alkali
waste" contained in the vats. By these means the waste can be kept
suitably moistened.
By reference to the Drawings, and the foregoing description of the
vats with their main pipes and connections, it will be observed that
each of the vats can be connected with one of the main pipes I, I,
from which gas proceeding from the lime kiln is introduced under the
false bottom of the vat, and after percolating through the mass of
moistened alkali waste the gas is conducted through one of the pipes
O', into the main pipes O', and from thence into the main pipes I, I,
and from thence under the false bottom of a second vat, and are caused
to percolate through the moistened "alkali waste" contained therein,
and after such second percolation the gases produced are conducted
through the pipe 0', into the main pipes O', and from thence into the
pipe R, to be transferred to the decomposing apparatus. I prefer to
have a series of eight vats in use for the two purposes of lixiviating
"rough soda" and decomposing the "alkali waste" produced by such
lixiviation, and to use four of these vats for the lixiviating process, and
the other four vats for the gusing process, and to conduct the two
operations as part of one cycle, so that each of the vats is consecutively
used for the gasing operation, which continually follows the lixiviating
operation; and the "alkali waste," after complete lixiviation with water,
is immediately and without any transference, subjected to the gasing
operation, the vat containing the freshly lixiviated "alkali waste
being immediately closed by its cover c. By these means I prevent the
"alkali waste" from being exposed to the injurious action of atmosphe-
"

page_text: rical air. When working with such an arrangement of vats as I have
herein described, I prefer to connect two of the four vats which may
then be in use for the gasing operation with the main pipes I', I', so
that these two vats receive gus from the lime kiln, and to connect the
other two vats (in use for the gasing operation) with the main pipe
I, I, so that these two vats (which should be those of which the con-
tents have been the most recently lixiviated with water) may receive
gas which has previously percolated through "alcali waste" contained in
the other two vats. I find that the sulphuret of calcium contained in
"alkali waste" which has been thus exposed to a current of mixed
gases
proceeding from another vat during twenty-four hours, and subse-
quently exposed to a current of gas proceeding from a lime kiln during
a similar period, is converted almost entirely into carbonate of lime,
and deprived of nearly all the sulphur it previously contained; but the
period required is influenced by the quantity of gas supplied for decom-
posing the sulphuret of calcium. The solid residuum being removed,
from each vat after the completion of the gasing operation, can be used
for some of the purposes for which carbonate of lime is suitable, and
the vat be then employed for another lixiviating operation, and subse-
quently for another gasing operation.
I will now describe such apparatus as I prefer to use for decom-
posing sulphuretted hydrogen contained in the mixed gases obtained by
the decomposition of "alkali waste," and for condensing sulphur
vapour produced by such decomposition of sulphuretted hydrogen. D,
is a furnace for the combustion of coke or coal. The ash pit of this
furnace is closed by an iron door Y, and the feeding hole is closed by
a door of fire brick Z; these closings are made perfect by means of
luting with fire clay. The pipe S, which conveys gas from the fan F,
is connected with the closed ash pit of the furnace D. E, is a flue
connecting the furnace D, with an apparatus of brickwork G. This is
a square tower, constructed of double walls of brickwork, between
which walls I introduce finely slaked lime for the purpose of rendering
this apparatus impervious to air. I construct a number of brick
arches H, H', extending across the tower G, and closing the same
except where perforations are left in such arches.
I have herein-before described certain arrangements of apparatus

page_text: which I prefer to use for effecting the objects of my Invention, but I
do not confine myself to these precise arrangements, as the same
may be varied to a considerable extent. I have also described cer-
tain methods by which I cause impure carbonic acid gas or liquid
muriatic acid to effect the liberation of sulphuretted hydrogen from
sulphuret of calcium, and by which I cause carbonic acid to effect the
liberation of sulphuretted hydrogen from sulphuret of sodium or
sulphuret of potassium, and by which I cause impure sulphuretted
hydrogen to become decomposed at a red heat by carbonic acid and
atmospherical air or sulphurous acid; but I do not confine myself to
these precise methods, as the same may be varied, to some extent,
without deviating from the nature of my Invention, which Invention
consists in obtaining sulphur from the sulphuret of calcium contained
in "alkali waste," or from sulphuret of sodium or sulphuret of potassium,
such sulphur being firstly obtained from the said sulphurets in the state
of sulphuretted hydrogen gas mixed with other 'gases by the action of
one of the acids herein mentioned for such purpose, and such impure
sulphureted hydrogen gas as so obtained being decomposed by the
oxydation of its hydrogen by means of carbonic acid gas and atmo-
spherical air, or sulphurous acid gas mixed therewith at a red heat, so
as to produce free sulphur vapour, which by cooling is converted into
solid sulphur.
In witness whereof, I, the said William Gossage, have hereunto
set my hand and seal, this Seventh day of May, in the year of
WILLIAM (L.B.) GOSSAGE.
Witness,
A. HOWARD Gossage.
of Widnes, in the County of Lancaster.