CERTAIN IMPROVEMENTS IN THE METHOD OF RECOVERING SULPHUR WHICH HAS BEEN USED IN THE MANUFACTURE OF SODA ASH, AND IN THE APPARATUS CONNECTED THEREWITH
Year: 1858

page_text: LETTERS PATENT to Harrison Blair, of Kearsley, in the County of
Lancaster, Manufacturing Chemist, for the Invention of "CERTAIN
IMPROVEMENTS IN THE METHOD OF RECOVERING SULPHUR WHICH HAS BEEN
USED IN THE MANUFACTURE OF SODA ASH, AND IN THE APPARATUS CONNECTED
THEREWITH."
Sealed the 14th August 1858, and dated the 18th February 1858.
PROVISIONAL SPECIFICATION left by the said Harrison Blair at the
Office of the Commissioners of Patents, with his Petition, on the
18th February 1858.
I, HARRISON BLAIR, of Kearsley, in the County of Lancaster, Manu-
facturing Chemist, do hereby declare the nature of my said Invention
for "CERTAIN IMPROVEMENTS IN THE METHOD OF RECOVERING SULPHUR WHICH
HAS BEEN USED IN THE MANUFACTURE OF SODA ASH, AND IN THE APPARATUS
CONNECTED THEREWITH," to be as follows:-
This Invention consists in procuring a deposition of sulphur from
hydrosulphuric acid (formed by the decomposition of the residuum in
soda ash manufactories, known as "vat waste," by the action of an acid
which has a stronger affinity for the base than sulphur, or by the action
of carbonic acid or sulphuret of sodium,) by furnishing such a quantity
of atmospheric air during the combustion the hydrosulphuric acid so
formed as will be sufficient to provide oxygen equal or nearly equal

page_text: atomically to combine with the hydrogen contained in the hydrosulphuric
acid acted upon; by which means, and the high temperature produced,
the sulphur is left in an uncombined state, and is deposited from the
atmosphere so produced in apparatus provided for the purpose.
In case pure carbonic acid (or with "vat waste" hydrochloric acid) be
used as the agent, the hydrosulphuric acid gas will burn with the proper
supply of atmospheric air, and may be at once taken to the combustion
furnace; but as it is most economical to effect the decomposition both of
vat waste" and sulphuret of sodium by means of carbonic acid formed
by the combustion of coke or charcoal with atmospheric air, the hydro-
sulphuric acid then generated is much diluted with nitrogen and possibly
with carbonic acid. In order to effect its combustion in this state it is
passed through fireclay retorts, similar to those used in many gas works,
kept at a red heat, and the proper quantity of atmospheric air mixed
with it, either before or after having passed through the retort into the
combustion furnace. The mixed gases and vapour pass thence through
a sufficient range of pipes to be cooled down below the subliming point
of sulphur, when they enter a brick chamber filled with reticulated
bricks or large stones in which part of the sulphur is filtered out, and
from time to time may be drawn from the bottom of the chamber, the
deposition being completed by the gases and vapours being then cooled
down in a large chamber formed of lead flags or other cooling medium.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Harrison Blair in the Great Seal Patent Office on the 18th
August 1858.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, HARRISON
BLAIR, of Kearsley, in the County of Lancaster, Manufacturing Chemist,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Eighteenth day of February, in the year of our
Lord One thousand eight hundred and fifty-eight, in the twenty-first
year of Her reign, did, for Herself, Her heirs and successors, give and
grant unto me, the said Harrison Blair, Her especial license that I, the
said Harrison Blair, my executors, administrators, and assigns, or such
others as I, the said Harrison Blair, 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

page_text: 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 "CERTAIN IMPROVEMENTS IN THE METHOD OF RECOVER-
ING SULPHUR WHICH HAS BEEN USED IN THE MANUFACTURE OF SODA ASH, AND
IN THE APPARATUS CONNECTED THEREWITH," upon the condition amongst others,
that I, the said Harrison Blair, 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 Harrison Blair, 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, that is to say:-
My Invention is an improved method of extracting sulphur from a
certain constant residuum in the manufacture of soda ash, known by the
name of "vat waste." This residuum contains a notable quantity of
sulphuret of calcium, and being acted upon by an acid evolves hydro-
sulphuric acid, from which I separate the sulphur, as herein-after
described. When hydrochloric or other strong acid is directly employed
for the decomposition of "vat waste," the hydrosulphuric acid evolved
may be collected in a gas-holder similar to those used in gasworks, and
thence taken in a continuous stream to the combustion furnace; but as
hydrochloric acid is of considerable value, I prefer the use of carbonic
acid for the decomposition of the "vat waste," as being more economical,
and which may be produced by any of the following methods:-
1st. The liquid residuum from chlorine generators is admitted into a
close vessel of a material not acted upon by acids, in which limestone
has been placed, when carbonic acid is evolved, and at the same time the
liquid residuum is rendered neutral and in a fit state to be acted upon
for the recovery of the manganese therein dissolved.!"
2nd. Coke or charcoal is burned in a furnace closed, so that atmo-
spheric air may be excluded except through the grate bars, where it is.
freely admitted, and the gases resulting from the combustion collected.
3rd. The vapour of water is forced through a retort filled with coke
or charcoal kept at a red heat by an external fire.
By both the latter-named methods a considerable quantity of carbonic.

page_text: oxide is produced, which I decompose into carbonic acid by the admis-
sion of a small quantity of water or its vapour to the mixed gases whilst
at a red heat, the water providing the requisite quantity of oxygen for
that purpose, its hydrogen being set free. The apparatus I use in
which to effect the decomposition of the vat waste is built of bricks or
flags, and divided into compartments, each compartment being four feet
six inches wide, five feet long, and eight feet deep, inside measure. Iron
bars, one and a quarter inch square, having two journals resting on
notched bearers two feet from the ground, are placed one inch apart
across its breadth, and in sufficient number to fill up its length. These
bars can be turned on their journals or made to vibrate with a rocking
motion by hand or machinery; one foot above the bars are four strong
square rods of iron parallel with the bars, which pass through the brick-
work of the sides in order that they may be moved when requisite, and
are placed equally distant from the ends and from each other; one foot
above these are three similar rods similarly placed, and again four rods
are placed a foot above these, and six inches above these last-mentioned
rods is a grid of quarter-inch iron bars two inches apart. The grid and
rods are intended to keep the charge of "vat waste" loose and open for
the passage of the gases. There are also six loose bricks in the front
side of the decomposer, which can be removed for the insertion of a
poker to stir the vat waste from time to time, as I have discovered that
a perfect decomposition cannot be effected if it be allowed to remain
continually in a state of rest. It is requisite, however, that all apertures
by which atmospheric air might be admitted, so as to come into contact
with the vat waste during the operation, should be kept carefully closed
and plastered with mortar, except when required to be open for the
purposes of drawing or stirring, as the admission of free oxygen will
cause the formation of hydrosulphite or sulphate of lime and diminish
the production of hydrosulphuric acid. A large flag closes the top of
the decomposer pierced with an aperture four inches diameter, to which
is fitted an iron pipe connected with the mains leading to the exhaust-
ing pumps. There is a charging door in the upper part of the decom-
poser and two drawing doors under the bars. The exhausters I now use
are three vessels similar to gas-holders luted by water, and are so
worked as to cause a continuous flow of gas through the exit pipe; the
inlet and outlet valves are formed of sheets of caoutchouc. From the
exhausters the gases pass through heated iron pipes, in which are
fragments of bricks or pumice-stone, where their temperature is raised, so

page_text: circumstances.
as to cause the inflammable gases contained to burn readily when brought
in contact with atmospheric air. The gases then pass to the combustion
furnace, which is built of bricks, and is three feet wide, six feet long, and
three feet deep, to the crown of the arch, having a false bottom of per-
forated tiles under, and through which atmospheric air is admitted into
the furnace, the quantity being regulated by a valve, so as barely to
support a flame, by which mode of combustion the sulphur is separated
from the hydrosulphuric acid in the same way that carbon is separated
from the hydrocarbons when they undergo combustion under similar
A chimney of bricks, sufficiently high to produce a
draft, is placed at the opposite end of the furnace from that where the
gases are admitted to convey the vapours and gases to an iron vertical
trunk, through which they descend to the condensing chamber. This
chamber is formed of flags of suitable size and dimensions, the roof being
supported by brick pillars and the flags made tight at the joints by caulk-
ing and gas tar. An aperture permits the escape of the residue gases
after they have traversed the whole length of the chamber.
deposited sulphur may be withdrawn from the chamber from time to
time, and in order to prevent the operation being stopped during the
time so occupied a duplicate chamber should be provided.
The
Having described the apparatus, I will now proceed to state the mode
of operating. When carbonic acid is used, as prepared by the first-named
method, it may be taken either directly or through a gas-holder to the
decomposers; but if by the second or third method, the gases will have
to be traversed through such a length of iron pipe as will reduce their
temperature so much below redness as to ensure that the vat waste in
the decomposers shall not be fired, as in that case sulphuret of calcium
is re-formed. The carbonic acid is prepared by any of the before-named
methods, either separately or mixed, is admitted under the bars of the
decomposer by an aperture, about four inches square, and is drawn
through the vat waste therein by means of the exhausters, when by its
action the sulphuret of calcium and the water contained in the vat waste
are decomposed and carbonate of lime and hydrosulphuric acid formed,
the latter of which passes away to the exhauster.
The decomposers at starting are nearly filled with old dry vat waste
to form a bed, and are then topped up with fresh waste, made as dry as
possible by drainage.
The bars are stirred from time to time, or if by machinery by a slow
continuous motion, which causes the lower part of the charge to drop

page_text: through the bars into the ash pit, and the rest of the charge descending
to supply the place of that so removed ensures with the aid of the rods
a constant motion of the vat waste, by which caking is partially avoided,
and an occasional stirring with pokers prevents the mass becoming solid,
the charge being continually renewed by fresh vat waste being added
at the charging doors.
If the gases passing from the decomposers are much mixed with
carbonic acid and nitrogen, they will require to be considerably heated
before being admitted into the combustion furnace; but if hydro-
sulphuric acid, hydrogen, and carbonic oxide be present in considerable
quantities, little or no increased temperature is required.
An iron pipe, about three feet long and three inches diameter is
inserted in the combustion furnace near the level of the false bottom,
with a moveable glass door at the outer end, which serves for the double
purpose of firing the gases at the commencement of the operation and
also for inspection of the flame. Samples of the gases from different
parts of the apparatus may be taken for testing by means of small iron
pipes with taps being placed for that purpose.
Having above particularly described the nature of my said Invention,
and the manner in which the same is to be practically performed, I desire
it to be understood that I claim, first, the separation of sulphur from
its combination with hydrogen by means of combustion with such a
quantity of atmospheric air as will support a flame, but be insufficient
to provide oxygen for the combustion of the sulphur therein contained.
Secondly, the use of such decomposer, as herein-before described, for
the purpose of acting on the vat waste by carbonic acid.
Thirdly, the use of water or its vapour for procuring an increased pro-
duction of carbonic acid to be applied to such decomposition of vat waste.
And fourthly, the use of sulphur, separated and deposited, as above
described, for the manufacture of sulphuric acid,
In witness whereof, I, the said Harrison Blair, have hereunto set
my hand and seal, this Seventeenth day of August, in the year
of our Lord One thousand eight hundred and fifty-eight.