IMPROVEMENTS IN THE MANU- FACTURE OF SODA AND POTASH
Year: 1857

page_text: LETTERS PATENT to William Gossage, of Widnes, in the County of
Lancaster, Chemist, for the Invention of "IMPROVEMENTS IN THE MANU-
FACTURE OF SODA AND POTASH."
Sealed the 12th March 1858, and dated the 12th September 1857.
PROVISIONAL SPECIFICATION left by the said William Gossage at the
Office of the Commissioners of Patents, with his Petition, on the
12th September 1857.
I, WILLIAM GOSSAGE, of Widnes, in the County of Lancaster, Chemist, do.
hereby declare the nature of the said Invention for "IMPROVEMENTS IN THE
MANUFACTURE OF SODA AND POTASH," to be as follows:-
In the Specification of an Invention for improvements in the manufacture of
soda and potash, for which I obtained Letters Patent, bearing date the Twenty-
first day of February in the current year, I have described certain means
by which I obtain sulphur from alkali waste (which is a constant and unavoid-
able product of the ordinary manufacture of soda and potash), using carbonic
acid or muriatic acid as the agent for effecting the liberation of sulphur in the
state of sulphuretted hydrogen gas from such waste. Subsequent to the grant
of the said Letters Patent, I have discovered that I can obtain sulphur in the
state of sulphuretted hydrogen gas from such waste by the action of steam
thereon at a high temperature, at the same time liberating lime therefrom.
The Invention for which I am now applying for Letters Patent comprises
the obtainment of sulphur (in the state of sulphuretted hydrogen) and of lime

page_text: from alkali waste by the action of steam thereon at a high temperature; also
the decomposition of sulphuretted hydrogen so obtained, by the action of
atmospherical air or sulphurous acid thereon or by other means, so as to produce
free sulphur. By the employment of these means I effect an important
economy in the manufacture of soda and potash by obtaining supplies of
sulphur and lime (articles which are essentially requisite in such manufacture)
from a waste material ordinarily produced during the manufacture, in place of
having to purchase such articles at a heavy cost.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Gossage in the Great Seal Patent Office on the
12th March 1858.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
GoSSAGE, of Widnes, in the County of Lancaster, Chemist, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twelfth day of September, in the year of our Lord
One thousand eight hundred and fifty-seven, in the twenty-first year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said William Gossage, Her special license 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 there-
after 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 for "IMPROVE-
MENTS IN THE MANUFACTURE OF SODA AND POTASH," 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 per-
formed, to be particularly described and ascertained in and by the following
statement, reference being had to the Drawings hereunto annexed, and to the
letters and figures marked thereon (that is to say) :-

page_text: In the Specification of an Invention for " Improvements in the Manu-
facture of Soda and Potash," for which I obtained Letters Patent, bearing date
the Twenty-first day of February, 1857, I have described certain means by
which I obtain sulphur from alkali waste (which is a constant and unavoid-
able product of the ordinary manufacture of soda and potash), by using
carbonic acid or muriatic acid as the agent for effecting the liberation of
sulphur, in the state of sulphuretted hydrogen gas, from such waste. Subse-
quently to the grant of the said Letters Patent I have discovered that
I can obtain sulphur, in the state of sulphuretted hydrogen gas, from such
waste, by the action of steam thereon at a high temperature, at the same
time liberating lime therefrom.
My present Invention comprises the obtainment of sulphur (in the state of
sulphuretted hydrogen), and of lime from alkali waste (produced in the
manufacture of soda and potash), by the action of steam thereon at a high
temperature; also the decomposition of sulphuretted hydrogen so obtained by
the action of atmospherical air or sulphurous acid thereon, or by other means,
so as to produce free sulphur; also the conversion of such sulphuretted
hydrogen into sulphurous acid by combustion, and the application of sulphurous
acid so obtained to the manufacture of sulphuric acid. By the employment of
these means I effect an important economy in the manufacture of soda and
potash, by obtaining supplies of sulphur or sulphuric acid and lime (which
articles are essentially requisite in such manufacture,) from a waste material
ordinarily produced during the said manufacture, in place of having to
purchase or manufacture such articles at a heavy cost.
I will now describe the means, by the employment of which I effect the
objects of my present Invention. Alkali waste is a well-known. material
(containing sulphuret of calcium and carbonate of line,) resulting from the
lixiviation of black ash" or "ball alkali" in the manufacture of soda and
potash. It remains as an undissolved residuum in the vats in which such
process of lixiviation has been effected. In the ordinary course of manufacture
this material contains a considerable proportion of coke, which gives it the
quality of being permeable by liquids and gases. I can subject such material
to the decomposing action of steam at a high temperature, either by the use of
retorts made of fire clay, to which heat is applied externally, in a manner
similar to that by which heat is applied to retorts in the manufacture of coal
gas, or by the use of apparatus similar to a lime kiln, in which the requisite
,heat is generated and applied within the apparatus employed.
When I use retorts for such purpose I prefer to have these set vertically in
the heating oven, each retort having a moveable lid or cover at its upper part for

page_text: the introduction of material, and a similar lid or cover at its lower part for
discharging its contents, also having a pipe at the lower part, for the intro-
duction of steam, and a pipe at the upper part for conducting off the gases
produced. I prefer to prepare the alkali waste previously to its introduction
into the retorts in the form of balls or cakes, which is readily effected by
tempering the alkali waste with water to a stiff paste, and either moulding
such paste into balls and drying these, or spreading it on a flat heated surface
to dry in the form of a cake, which should be broken into pieces. I introduce
such balls or cakes into the retorts (previously heated to a full red heat and
the heat kept up by continued firing), and having properly applied the upper
lids or covers to the retorts, I allow the heating to continue about half an
hour, and I then cause a small supply of steam to be introduced at the lower
part of each retort. I increase such supply as I consider the heating of the
material to have advanced, and I continue the introduction of steam untill
the evolution of gas has nearly ceased, I then remove the lower lids or covers
of the retorts, and having discharged their contents I replace the covers and
introduce a fresh charge. By the action of the elements of steam on sulphuret
of calcium contained in the alkali waste, the calcium is converted into lime by
the absorption of oxygen, and sulphur combines with the liberated bydrogen,
forming sulphuretted hydrogen gas, which passes off through the escape pipes
connected with the retorts into an " hydraulic main," from which it may be
conducted into a gas holder or be at once applied to the production of sulphur
or sulphurous acid. When I subject alkali waste to the action of steam in
retorts without previously preparing this in the form of balls or cakes, I prefer
to dry the waste and mix with it an additional proportion of pieces of coke, so
as to give it increased permeability; I then introduce the mixture into the
heated retorts and apply steam in the same manner as I have herein-
before mentioned for decomposing alkali waste in the form of balls or cakes.
The Drawings hereunto annexed represent such an apparatus as I prefer
to employ for subjecting alkali waste to the decomposing action of steam at
a high temperature when the requisite heat is generated and applied within
the apparatus.
Fig. 1 is a vertical section taken through the middle of such apparatus;
and Fig. 2 is also a vertical section taken at right angles to the section Fig. 1.
A is a grating formed of iron bars (similar to an ordinary furnace grate), on
which alkali waste is supported; B is a kiln-shaped chamber containing
heated alkali waste. The lower part of this chamber is expanded at C, as.
shewn in the Drawings, so as to form a channel C, C, surrounding the cone
of alkali waste, which proceeds from the chamber B and rests on the grating

page_text: A; D is a pipe communicating with a steam boiler, through which a regulated
supply of steam can be introduced into the channel C, C, from which it
percolates through the alkali waste contained in the chamber B. E is a pipe
communicating with a blowing machine, through which atmospherical air can
be forced into the ash-pit F of the apparatus, from which it percolates
through the alkali waste resting on the grating A; G, G, are inclined shelves
formed of brickwork, on which alkali waste is supported previously to its
being passed into the chamber B; H, H, are apertures, closed with moveable
doors I, I, for gaining access to move and push down the alkali waste from
the inclined shelves G, G, into the chamber B; K is an aperture closed with
a moveable door k, through which lime, produced by the decomposition of
alkali waste, can be withdrawn from the ash-pit F; L is an aperture (closed
by a moveable door I) through which alkali waste is introduced into the
apparatus; M is a pipe through which gases produced by the decomposition
of alkali waste are conducted to other apparatus. The apparatus (shewn in
the annexed Drawings) is constructed of fire brick's inclosed in an air-tight
iron casing, to which the moveable doors I, I, k, and I are fitted and made
air-tight with luting, being retained in their places by proper screw clamps.
In commencing to work with this apparatus I introduce a quantity of
burning fuel on the grating A, and throw into the chamber B sufficient dry
alkali waste mixed with about one-fourth of its bulk of small pieces of coke,
to nearly fill the chamber, I also introduce on to each of the inclined shelves
G, G, a quantity of alkali waste mixed with small pieces of coke; having
closed the apertures II, II, L, and K, I cause a supply of air to be forced
through the pipe E, which passes through the burning fuel on the grating A
and through the alkali waste contained in the chamber B, and occasions
combustion of coke mixed with such waste, and the contents of chamber B
become red bot, I then open the steam cock d and cause a supply of steam
to pass into the channel C, and from thence to percolate through the red hot
waste in the chamber B. I regulate the supply of air through the pipe E
and of steam through the pipe D so that the contents of the chamber may
be kept at a bright red heat, and I continue the operation until I find that
the decomposition of the alkali waste by steam in the chamber B is nearly
completed. I judge of the progress of such decomposition by taking out
samples from the chamber through the aperture H* and testing such samples
with muriatic acid to evolve sulphuretted hydrogen therefrom. The heated
gases resulting from the decomposition of the alkali waste proceed from the
chamber B in the direction shewn by arrows on the Drawing Fig. 1, com-
municating heat to the alkali waste supported on the shelves G, G, and pass

page_text: off through the pipe M, and are conducted to other apparatus in which the
decomposition of sulphuretted hydrogen is effected, as herein-after mentioned.
When I find that the decomposition of the alkali waste in the chamber B has
become sufficiently completed, I stop off the supplies of air and steam and I
shake the bars of the grating A, so as to let down the greater part of the
contents of the chamber B, and I withdraw the product obtained through
the aperture K; I then cause the alkali waste contained on the inclined
shelves G, G, to be pushed down into the chamber B, and having recharged
the inclined shelves G, G, with a fresh portion of alkali waste mixed with
coke, I close the apertures and introduce a supply of air and of steam through
the pipes D and E, and proceed again as herein-before described.
In place of introducing steam through the channel C, C, I can introduce
this into the ash-pit F, in which case it mingles with the air introduced
through the pipe E, and percolates through the alkali waste supported on the
grating A.
I take care to regulate the admission of steam so that the
quantity introduced shall not be sufficient to prevent combustion of coke
mixed with the alkali waste by the air introduced.
When I obtain sulphuretted hydrogen gas from the decomposition of alkali
waste by means of steam in retorts to which heat is applied externally, the
gas so obtained is sufficiently pure to be subjected to combustion with atmo-
spherical air, so as to produce sulphurous acid gas, which can be applied in
the manufacture of sulphuric acid in the same manner as sulphurous acid gas
obtained by the combustion of sulphur with atmospherical air is ordinarily
applied to such manufacture.
When I effect the decomposition of alkali waste by means of steam in such
an apparatus as I have berein-before described, in which heat is generated
and applied in the interior of the apparatus, the sulphuretted hydrogen gas so
produced is largely mixed with other gases, and is consequently unfit to be
applied directly to the manufacture of sulphuric acid; I therefore decompose
such impure sulphuretted bydrogen gas by the action of sulphurous acid gas
or of atmospherical air in the manner described for effecting the decom-
position of impure sulphuretted bydrogen gas in the Specification of my
Invention for which I received the grant of Letters Patent, bearing date the
Twenty-first day of February, 1857, and I thereby obtain sulphur resulting
from the decomposition of alkali waste in a state suitable to be applied to the
production of sulphuric acil. In place of obtaining sulphur by the decom-
position of sulphuretted bydrogen gas by the action thereon of sulphurous
acid gas or of atmospherical air, as herein-before mentioned, I can convert
all or nearly all the sulphur contained in such sulphuretted hydrogen gas

page_text: into sulphurous acid gas by causing such sulphur to become burned with
atmospherical air, and in such case I prefer to effect the conversion of the
sulphurous acid gas so produced into sulphuric acid by the means for which
I obtained Letters Patent, bearing date on or about the Sixth day of October,
1857, under the title of "Improvements in the Manufacture of Sulphuric
Acid."
I have herein-before particularly described and ascertained the means by
which I perform my Invention, but I do not confine myself in performing the
same to the precise details herein-before described, as these may be modified
to some extent without deviating from the nature of my Invention, nor do
I claim an exclusive right to use such means except so far as such use may
be comprised within the nature of my Invention, as herein-after particularly
defined; I claim as my Invention of improvements in the manufacture of
soda and potash, secured to me by the herein-before in part recited Letters
Patent,-
First, the obtainment of sulphuretted hydrogen gas, also of lime by the
action of steam at a high temperature on alkali waste produced in the
manufacture of soda and potash.
Second, the obtainment of sulphur from sulphuretted hydrogen gas so
produced.
Third, the application of sulphuretted hydrogen so produced and of sulphur
obtained therefrom in the manufacture of sulphurous acid and sulphuric acid.
In witness whereof, I, the said William Gossage, have hereunto set my
hand and seal, this Tenth day of March, in the year of our Lord 1858.
WILL GOSSAGE. (L.S.)
WILL GOSSAGE. (L.S.)