Improvements in the Treatment of Black Ash and Alkali Waste to Obtain, Sulphuretted Hydrogen, Sulphur, and Cement, and in Apparatus Employed therein.
Year: 1889

page_text: Date of Application, 26th Apr., 1889
Complete Specification Left, 27th Jan., 1890-Accepted, 22nd Mar., 1890
PROVISIONAL SPECIFICATION.
Improvements in the Treatment of Black Ash and Alkali Waste
to Obtain, Sulphuretted Hydrogen, Sulphur, and Cement, and in
Apparatus Employed therein.
We JAMES HARGREAVES Chemist, THOMAS ROBINSON Ironfounder, and JOHN
HARGREAVES Chemist all of Widnes in the County of Lancaster do hereby declare
the nature of this invention to be as follows:-
Under the first part of our invention we pass black ash from the revolvers or the
like into specially constructed lixiviating vessels. These vessels are in series, by
preference double series, and are connected together by pipes or ways and provided
with means whereby any one can be shut off from the others. Said vessels are
constructed in novel manner having each two or more grids placed one above
another formed of bars. Such bars are hooked to one side of its vessel; they
can be lifted one ог more at a time and they serve to prevent the black ash
during lixiviation from becoming too much compressed whilst they also keep the
alkali waste in a somewhat open condition suitable for carbonating as hereinafter
described.
Under the second part we pass amongst the moist alkali waste carbonic acid under
pressure above that of the atmosphere, such gas may be pure, diluted with inert gases,
or mixed with aqueous vapour and
hereinafter referred to as carbonic acid. The
alkali waste is kept moist during treatment by the admission of water vapour or water.
The decomposition of sulphide of calcium into sulphuretted bydrogen and carbonate
of lime is hastened by pressure and the presence of moisture in the waste is necessary
during the entire period of treatment.
We should explain that in lixiviating black ash we allow sufficient soda to remain
in the waste so as to dissolve residual sulphur as hereinafter described.
When strong sulphuretted hydrogen is desired from moist alkali waste under
pressure in a series of vessels the inert gases may be allowed to pass into the
atmosphere but when dilute sulphuretted hydrogen is to be utilized to yield
sulphur or sulphurous acid we proceed as hereafter described under the third
part.
Third. We separately heat the dilute sulphuretted hydrogen and air and admit them
to the combustion chamber when by reason of such heating the necessary temperature,
to effect the reaction, is obtained. Heat from the combustion chamber may be
utilized to beat the dilute sulphuretted hydrogen and air by the use of pipes.
Under the fourth part we pass through the impure carbonate of lime from which
the sulphuretted hydrogen has been driven off, after a vessel has been disconnected and
isolated, air preferably heated to oxidize any unoxidized sulphur compounds. After
oxidation water is added, steam injected, and the mass heated. The carbonate of soda
present renders soluble the insoluble oxy sulphur lime salts. Subsequently caustic
lime or lime sludge from caustic soda manufacture and which usually contains soda,
is added. The lime causticises the carbonate of soda present, by which free
sulphur is dissolved. Any insoluble sulphur remaining in the carbonate of lime is
equally distributed therethrough, thus minimising injurious effects of such sulphur in
cement manufacture from the said carbonate of lime.
The carbonated and subsequently treated waste, is run upon a suitable screen to
separate imperfectly carbonated pieces. The screened magma is filtered washed and
soluble sulphur and alkali eliminated. The filtrate containing alkali and sulphur may
be utilised in any manner convenient. The resulting carbonate of lime is mixed
with clay in suitable proportions and roasted to form cement. The vessels serving
for lixiviating and carbonating are made of iron capable of resisting considerable
internal pressure.

page_text: Openings are made in upper portions and sides of vessel for charging black ash, and
at lower part for discharging treated carbonated waste.
We should state that considerable heat is generated in the carbonating vessels
during decomposition of moist waste, thus evaporating the moisture, the presence
of which is necessary for elimination of sulphuretted hydrogen. We diminish such
heating and supply necessary moisture to the waste by cooling the gases in
passage from one vessel to another, or in the carbonating vessel, by means of
suitable cooling pipes, or by injecting water into the gases or upon the waste
during treatment.
COMPLETE SPECIFICATION.
Improvements in the Treatment of Black Ash and Alkali Waste
to Obtain Sulphuretted Hydrogen, Sulphur, and Cement, and in
Apparatus Employed therein.
We JAMES HARGREAVES, Chemist, THOMAS ROBINSON, Iron founder, and JOHN
HARGREAVES chemist all of Widnes in the county of Lancaster do hereby declare
the nature of this invention and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement:—
Under the first part of our invention we pass black ash from the revolvers or
furnaces into specially constructed lixiviating vessels. These vessels are in series by
preference double series, and are connected together by pipes or ways and provided
with means whereby any one can be shut off from the others. The said vessels are
internally constructed in novel manner by supplying each vessel with two or more
grids placed one above another formed of bars, perforated plates or the like supported
from the side of its vessel. The bars or grids can be lifted or allowed to swing one
or more at a time and they serve to prevent the black ash during lixiviation from
becoming too much compressed whilst they also keep the alkali waste remaining
after lixiviation in a somewhat open condition suitable for carbonating as hereinafter
described.
Pipes, connections and cocks for circulation of black ash liquors and also as
hereinafter described for gases, are such as are ordinarily employed for such
purposes.
After lixiviation of black ash, the vessel containing alkali waste is disconnected
from the series of lixiviating vessels and is connected and becomes the exit vessel
of the series through which carbonic acid is passed as described under the following
head.
Under the second part we pass amongst the alkali waste kept moist and in an open
porous condition carbonic acid gas under pressure above that of the atmosphere.
Considerable margin of pressure may be used, but preferably about 10 lbs. per square
inch so as to inore thoroughly carbonate the alkali waste.
The carbonic acid gas may be pure, diluted with inert gases or mixed with aqueous
vapour, and is hereinafter referred to as carbonic acid.
The alkali waste is kept moist during treatment by the admission of water vapour
or water spray in quantity insufficient to form a paste or magma.
The decomposition of sulphide of calcium into sulphuretted hydrogen and carbonate
of lime is hastened by pressure and the presence of moisture in the waste is
necessary during the entire period of treatment. The necessary pressure may be
limited or regulated by any well known means such as valves placed in the gas
conduits.
We should explain that in lixiviating black ash we allow sufficient excess of
soluble soda say 14 to 21 % Na. O to remain in the alkali waste to readily dissolve
sulphur remaining in carbonated alkali waste for the purpose hereinafter described
under the fourth head.

page_text: When strong sulphuretted hydrogen is desired from moist alkali waste carbonated
under pressure in a series of vessels as hereinbefore described the inert gases may be
allowed to pass into the atmosphere. When dilute sulphuretted hydrogen is to be
utilized to yield sulphur or sulphurous acid we proceed as hereinafter described under
the third part.
Third. We separately heat dilute sulphuretted hydrogen and air and admit them to
a suitable combustion chamber when by reason of such heating the necessary
temperature to effect the reaction is obtained to give free sulphur or sulphurous acid.
Heat from the combustion chamber may be utilised to heat the sulphuretted hydrogen
and air by the use of pipes heated on the exterior and through which the gases pass,
or other heating apparatus may be employed.
To obtain sulphur from a mixture of dilute sulphuretted hydrogen and sulphurous
acid remaining after condensation of free sulphur from partially burned sulphuretted
hydrogen we cool and scrub the gases, separate water and afterwards beat the gases
to about 400° Fab. To give sulphurous acid the necessary air is separately heated
before admixture therewith.
Under the fourth part we pass through the impure carbonate of lime from which
the sulphur has been driven off as sulphuretted hydrogen, after a vessel has been
disconnected and isolated, air preferably heated to oxidize any unoxidized sulphur
compounds. After oxidation, water is added, the grids supporting the carbonated
alkali waste allowed to fall or swing, and steam injected to beat the magna thus
formed. The carbonate of soda present or it may be caustic soda which acts more
slowly, renders soluble the sulphur combined as insoluble oxy sulphur line salts,
caustic lime is added the carbonate of soda present causticised and by the caustic
soda thus formed free sulphur is dissolved. Any undissolved sulphur remaining in
the carbonate of line is equally distributed therethrough thus minimising injurious
effects of such sulphur in cement manufactured from the said carbonate of line.
The carbonated and subsequently treated waste is run upon a suitable screen to
seperate imperfectly carbonated pieces. The screened magma is filtered, washed and
soluble sulphur and alkali thereby eliminated. The filtrate containing alkali and
sulphur is utilized in any suitable manner.
The resulting carbonate of lime is mixed with clay in suitable proportions which we
find to be about three parts of carbonate of lime to one of clay and roasted to form
cement clinker and treated in the ordinary way to yield cement.
The vessels serving for lixiviating and carbonating having series of grids
supporting material under treatment are made of iron and capable of resisting
considerable internal pressure. Openings provided with doors are made in upper
portion for charging black ash and at lower part for discharging the treated
waste.
On the accompanying sheet of drawings. Fig. 1 is a vertical section, and Fig. 2 a
plan of a lixiviating vessel under our invention, a is the vessel, b charging door,
c discharging door for treated material, dinlet for gas, e exit for gas, f, grids
supported at the centre on bars g. The bars g are supported in grooves h at the sides
of the vessel. The grids f' are supported at the side of the vessel on projections 2,
jare chains for raising or lowering the grids f, f into the position shown by the dotted
lines so that material can be charged on to all the grids.
Fig. 3 is a sectional view and Fig. 4 a plan of a modification of vessel having
perforated plates k instead of grids. bars for carrying the perforated plates k at the
centre, set screws for supporting the plates k at the sides of the vessel. To allow of
the plates being lowered the set screws can be withdrawn. jchains for raising and
lowering the plates k.
We should state that considerable heat is generated in the carbonating vessels
during decomposition of moist waste thereby evaporating moisture the presence of
which is necessary for elimination of sulphuretted hydrogen. We diminish such
heating and supply recessary moisture to the waste by cooling the gases in passage
froin one vessel to another in any convenient manner or by injecting water into the
gases or upon the waste during treatment.

page_text: Having now particularly described and ascertained the nature of the said Inven-
tion and in what manner the same is to be performed, we declare that what we
claim is:-
-
First. Lixiviating black ash supported on movable grids placed one above another
in vessels connected in series carbonating in the same vessels without removal by
means of carbonic acid gas under pressure the resulting alkali waste being kept moist
during carbonation by injection of water substantially in the manner and for the
purposes set forth.
Second. During lixiviation of black ash leaving excess of soluble soda in alkali
waste, carbonating, heating, causticising and subsequently using such soda when
causticised to dissolve sulphur remaining in carbonated alkali waste and render it
suitable for the manufacture of cement.
Third. Keeping alkali waste moist during carbonation by injected water for the
purpose set forth under the second head.
Fourth. Heating gases containing small quantities of sulphuretted bydrogen
resulting from the treatment of alkali waste with carbonic acid in manuer and for
purpose described under the third head.
Fifth. Treating carbonated alkali waste substantially as described under the fourth
head to eliminate sulphur and alkali and mixing such purified carbonated waste with
clay roasting and forming cement.
Sixth. The several apparatus and appliances constructed and employed substantially
as and for purposes herein set forth.