provements relating to the Separation of Arsenic, Antimony, Bismuth, and other Metals from Spirit of Salt (Hydrochloric Aoid), Oil of Vitriol or Sulphuric Acid, and other Acid Solutions, and to Apparatus therefor.
Year: 1894

page_text: Date of Application, 5th Oct.,
1894
Complete Specification Left, 5th July, 1895-Accepted, 10th Aug, 1895
PROVISIONAL SPECIFICATION
Improvements relating to the Separation of Arsenic, Antimony,
Bismuth, and other Metals from Spirit of Salt (Hydrochloric
Aoid), Oil of Vitriol or Sulphuric Acid, and other Acid Solutions,
and to Apparatus therefor.
We, WALTER WHITEHEAD, Surgeon, of 17 Market Street, Manchester, and
CHARLES GELSTHARP, Chemist, of 211 Jubilee Terrace, Clayton, near Manchester,
both in the County of Lancaster, do hereby declare the nature of this invention 'to
be as follows.-
The object of our invention is to provide in a more simple, efficient and
economical mauner than heretofore for the separation of arsenic, antimony, bismuth,
or any other metals precipitable by sulphunetted hydrogen from spirit of salt
(hydrochloric acid), oil of vitriol or sulphuric acid, and other acid solutions.
In carrying om said invention into practice, we provide two or more vats or tanks
made of suntable materials adapted to withstand the action of acids, or one large
vat or tank divided by one o more partitions into any desired number of
compartments These ats o tanks, we connect together by menus of pipes or
tubes provided with controlling valves or cocks so that the acids may
be caused or
may
allowed to circulate from one tank to another as may be required. We also arrange
an, oi at either side of the vats or tanks, another set of pipes or tubes, also inade of
suitable material. These tubes extend downward into the spuit of salt, or
sulphuric acid, in the several vuts or tanks, and the ends of such tubes within the
acid are widened out in the shape of a bell or funnel mouth. The said tubes are so
arranged that, when sulphuretted hydrogen gas, or a mixture of sulphuretted
hydrogen, sulphurous acid gas, and atmospheric air, is forced into oi under the bell
or funuel mouth of the tube in the spirit of salt or sulphuric acid contained in the
first vat, it passes up through the spirit of salt or sulphuric acid in small bubbles
and carries on forces some of the spirit of salt or sulphuric acid up the tube into
the spirit of salt or sulphuric acid in the second vat and under the bell or funnel
mouth of the tube there, and up the said tube and into the spirit of salt or
sulphuric acid in the third vat, and so on, into the fourth, fifth, and sixth vate, or a
larger number of vats when necessary, so that all the sulphuretted hydrogen may
be absorbed. Each of the sand vats or compartments may be provided with either
one or more of the said 'bell-mouthed tubes.
We also provide on the top of or near to the vats one or more small towers or
hollow shafts, the hollow part whereof we pack loosely with bricks or other suitable
materials, leaving spaces between the bricks, or the like After the sulphurettod
hydrogen, or the mixture of sulphuretted hydrogen, sulphurous acid and an, has
been forced through the spirit of salt on sulphuric acid contained in one or more of
the vate, the remaining gases or an, may be passed up through the small tower,
while a small quantity of the spirit of salt or sulphuric acid is caused to percolate
down through it, so that any sulphuretted hydrogen not retained in the spirit of salt
o sulphuric acid in the vat or vats, or any of the spirit of salt or sulphuric acid
mechanically carried away by the gases, will be caught by the acids percolating
down the tower, and will run together therewith into one or other of the vats.
The sulphurotted hydrogen we preferably obtain by decomposing, with weak

page_text: hydrochloric acid, the yellow liquor obtained by lixiviating oxidized tank or vat
waste, or the yellow liquor diaming from the old vat-waste heaps. The sulphuretted
hydrogen may, however, be obtained by other methods if desired.
The vats or tanks are fist filled to the proper level, with the spirit of salt
or sulphuric acid or other acid solution, the sulphuretted hydrogen, or the mixture
of sulphuretted hydrogen, sulphurous acid and an, is then forced through the tubes
into the spirit of salt or sulphinic acid or other acid solution, contained in the first
tank or vat, then up through the Lubes into the spirit of salt, or sulphuric acid
contained in the second vat, then through the tubes into the acids contained in the
third vat, and so on to and through additional vats as may be necessary, and then
up through the small tower ou towers; or the gas, after passing through the acid
contained in the first or the second vat, may be passed up through the small tower,
as may be desired. When all the arsenic and other metals are precipitated in the
fst vat, the sulphuretted bydrogen is shut off from the first vat, and turned into
the acid in the second vat, and so on, to as many other vats as may be deemed
necessary.
The precipitated sulphides of arsenic and other metals in the first vat are then
allowed to settle, and the clean spint of salt or sulphuric acid decanted or run off,
or filtered and run off into another vat, and a cunient of air forced through it until
all the sulphuretted hydrogen is expelled from it, It is then free from arsenic, or
only contains a mere trace thereof, and is ready for use. Or when the sulphuretted
hydrogen is shut off from the fist vat, without waiting for the precipitated arsenic
to settle, a current of air is forced through the spirit of salt or sulphuric acid until
all the sulphuretted hydrogen is expelled therefrom, the precipitated sulphide of
arsenic is then allowed to settle, and the clear spil of salt of sulphuric acid is
decanted or run off through a filter, it is then fiee liom arsenic, or only contams a
mere trace thereof, and is ready for use. The precipitated sulphide of arseme,
which was allowed to settle down, is then run off onto a filter, and washed with
water, and then dried and made ready for use.
Dated the 5th day of October 1894
D. YOUNG & Co.,
11 & 12 Southampton Buildings, London, W.C.,
Agents for the Applicants.
COMPLETE SPECIFICATION.
Improvements relating to the Separation of Arsenic, Antimony,
Bismuth, and other Metals from Spirit of Salt (Hydrochloric
Aold), Oil of Vitriol or Sulphurio Acid, and other Acid Solutions,
and to Apparatus therefor.
We, WALTER Whitehlad, Singeon, of 17 Market Street, Manchester, and
CHARLES GELSTHARP, Chemist. of 211 Jubilee Terrace, Clayton, near Manchester,
both in the County of Lancaster, do hereby declare the nature of this invention
and in what manner the same is to be peiformed, to be particularly described
and ascertained in and by the following statement:―
The object of our invention is to provide in a more simple, efficient and
economical manner than heretofore for the separation of arsenic, antimony, bisinuth,
or any other metals precipitable by sulphuretted hydrogen fiom spirit of salt
(hydrochloric acid). oil of sitol (sulphuric acid), and other acid solutions.
One feature of our said invention consists in precipitating the metals by means of a
mixture of sulphuretted hydrogen, sulphurous acid gas and atmospheric air, such, for
example, as is produced the treatment of the yellow liquor obtained from
oxidized or partly oxidized vat or tank waste, as hereinafter described, for the

page_text: ecovery of the sniphur therefrom We have found that better results are
obtained by the use of this mixture than are usually obtained by the use of pure
sulphurotted hydrogen.
Our said invention, moreover, compuses an improved methol or process of
separating the aforesaid metals from spit of salt and other acul solutions by means
of sulphuretted hydiogen or a mixture of sulphuretted hydrogen, sulphurous
acid and atmospheric air, in which method of process the metals are precipitated
under pressure.
Oui said invention further comprises improved apparatus for the treatment of
the spirit of salt and other acid solutions
In carrying our said invention into practice, we provide two or more closed vats
o tanks made of suitable materials adapted to withstand the action of acids, oi ono
lange vat o tank divided by one or more partitions into any desited number of
compartments. These vats or tanks, we connect together by means of pipes or
tubes provided with controlling valves or cocks so that the acid may be caused ou
allowed to cuculate from one tank to another as may be requied
We also nirange
in, or at either side of the vats on tanks, another set of pipes or tubes, also made of
suntable material. These tubes extand downward into the spit of salt, or
sulphuric acid, in the several vats or tinks, and one end of each of such tubes
within the acid is widened out in the shape of a bell or funnel mouth, on an
injector may be used, made of earthenware or other suitable material that will
withstand the action of the acids The said tubes are so aanged that, when
sulphuretted hydrogen gas, or a mixture of sulphnetted hydrogen, sulphurous acid
gas, and atmospheric air, is forced, under a suitable pressure, into or under the bell
o funnel mouth of the tube in the spirit of salt or sulphuric acid contained in the
first vat, it passes up through the spit of salt on sulph acid in small bubbles
and carries or forces some of the spuit of salt or sulphuric acid up the tube into the
spuit of salt o sulphuric acid in the second vat and under the bell or funnel mouth
of the tube there, and then up the said tube and into the spirit of salt on sulphuric
acid in the third vat, and so on, into the fourth, fifth, and sixth vats, or a larger
number of vats when necessary, so that all the sulphuretted hydrogen may be
absorbed. Each of the said vats o compartments may be provided with either one
or more of the said bell-mouthed tubes.
We also provide on the top of or near to the vats one or more small towers on
llow shafts, packed loosely with bucks or other suitable materials, so as to leave
suitable spaces between the bricks on the like. After the sulphunetted hydiogen,
or the mixture of sulphuretted hydrogen, sulphous acid and an, has been forced
through the spirit of salt on sulphuric acid contained in one or more of the vats, the
remaining gases or air, may be passed up through the small tower, while a small
quantity of the spirit of salt on sulphuric acid is caused to percolate down through
it, so that any sulphuretted hydrogen not retained m the spuit of salt on sulphuric
acid in the vat or vats, or any of the spint of salt or sulphuric acid mechanically
carried away by the gases, will be caught by the acids pei colating down the tower,
and will un together therewith into one on other of the vats
The sulphuretted hydrogen we preferably obtain by decomposing, with weak
bydrochloic acid, and with the application of beat, the yellow liquor obtained by
lixiviating oxidized tank or vat waste, or the yellow liquor draining from the old
vat-waste heaps In this manner we obtain the sulphui etted hydrogen mixed with
sulphurous acid and atmospheric an, and at the same time recover the sulphur.
We can, however, use for the purpose of our invention sulphuretted hydiogen
obtamed by other methods or processes.
The aforesaid vats or tanks are fist filled to the proper level, with the spirit of
salt or sulphuric acid or other acid solution, the sulphuretted hydrogen, or the
mixture of sulphuretted hydrogen, sulphurous acid and an, is then forced under a
suitable pressure through the tubes into the spirit of salt or sulphuric acid or other
acid solution, contained in the first tank or vat, and passes thence through the
tubes into the spirit of salt, on sulphuric acid contained in the second vat, then

page_text: through the tubes into the acids contained in the thud vat, and so on to aud
through as many additional vats as may be necessary, and then up through the
small tower or towers, or the gas, alter passing through the acid contained in the
first on the Eccondivat, may be passed up through the small towor, as may be
desired When all the arsenic and other metals are precipitated in the first vat,
the sulphunetted hydrogen is shut off from the first vat, and tuned into the
acul in the second vat, and so on, to as many other vats as may be deemed
necessary
The precipitated sulphides of arsenic and other metals in the first vat are then
allowed to settle, and the clear spitit of salt or sulphuric acid is decanted o
run off, or filtered and run off into another vat, and a curent of an forced through
it until all the sulphuretted hydrogen is expelled from it. It is then free from
Or when the
arsenic, or only contains a mere trace thereof, and is ready for use.
sulphuretted hydrogen is shut off from the first at, without waiting for the
precipitated sulphides to settle, a current of air is forced through the spirit of salt
or sulphuric acid until all the sulphuretted hydrogen is expelled therefrom, the
precipitated sulphides are then allowed to settle, and the cluar spirit of salt on
Sulphuc acid is decanted or run off through a filter; it is then free from arsenic,
or only contains a mere trace thereof, and is ready for use. The precipitated
sulphide of arsenic or other sulphides which were allowed to settle down, are then
run off into a filter, and washed with wator, and then dried and made ready for
The vat may then be re-filled with unpunified aoul to be treated as above
lise
described.
In the accompanying drawing we have shown how our said invention may be
conveniently and advantageously carried into practice:
Figue is a vertical longitudinal section showing one arrangement of our
improved' apparatus, and
Figure 218 a vertical longitudinal section illustrating another airangement or
modification of our sail' apparatus.
Lake letters indicate corresponding paits throughout the drawing.
A is a closed tank in which the sulplinretted hydrogen on the mixture of
sulphuretted hydrogen, sulphurous acid and air is generated, this tank is provided
with a manhole a closed by a cover a', whereby the matorials from which the
sulphuretted hydrogen, or othor gaseous precipitating agent is to be generated, are
introduced. is a cock or valve whereby the spent or waste liquors and other
products may be removed from the tank A.
Bindicates a force-pump on pressure-blower for drawing the gases from the
generator A through the pipe c and forcing them into the precipitating vat or
vats C, C, through the pipe d. The vats are also provided with manholes e
closed by covers c, whereby the acid solution to be purified may be introduced.
The pipe or gas-main d is provuled with branches d' extending down into the vats C
and having their open ends d' directed upward into the boll-mouthed apertures ot
pipes g leading up to the gas-main d Cocks or valves d', g', are provided on the
pipes
d' and 9 respectively, and a cock or valve is provided on the gas-main d
between the pipes d' and 9, so that, by closing either of the valves and opening
the corresponding valves d³, g', the gas may be caused to pass through the corre-
sponding tank C, whilst, by opening the valve and closing the valves d', g',
commumention between the gas-main and the said tank C may be cut off to. peunit
the removal of the purified acid and of the precipitate therefrom, without interfering
with the supply of gas to the other tanks. The tanks C are also provided, with
cocks or valves for the removal of the precipitated sulphides, and with communi-
cating pipes & provided with oooks or valves foi controlling the circulation of
the acid from one vat to another 1, are.oocks or valves for decanting on drawing
off-the clear acid hquor after the precipitates have settled down. The last tank of
the series 18 in communication, through the pipe m, with a tower E filled with
bricks, coke or the like us at a, over which acid is caused to trickle from, a pipe p,
an outlet 3, in communication with a chimney or with the atmosphere, being, al30
h

page_text: provided for the escape of an or of any unabsorbed gas.
We also find it advan-
tageous to employ a vessel F provided with a stramer F¹ for receiving the
precipitated sulpludes, etc from the cocks on valve- ).
When the sulphunetted hydrogen or mixture of sulphuretted hydrogen,
sulphous acid and air is produced nude nstable pressure, the pump or
blower may be dispensed with, and the gas-mam d connected directly with the
tank or at A
In the anangement shown in Figure 2, the gas from the main d passes through a
cock to an injector G, to which the acid to be purified is supplied from the tank
ovat C through a piper controlled by a cock or valver. The gas under pressure
is forced through the pipes provided with the cock s¹ and carries some of the acid
with it into the next tank or vat, the liquid in the vats remaining at the same level
by reason of the communication through the pipe .
It is obvious that ou apparatus may be somewhat further modified without
departing from the nature of our said invention
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we wish it to be understood
that we do not claim generally or inespectively of our improvements herein set
forth the use of sulphuretted hydrogen for the precipitation of arsenic and other
metals from spirit of salt, oil of vitriol or other acid solutions, as we are aware that
it has already been used for such purposes, but what we claim is .—
First The herein described improved method or process of treating spirit of
salt (hydrochloric acid). oil of vitriol or other acid solutions with sulphuretted
hydrogen or with a mixture of sulphuretted hydrogen sulphons acid and air,
so as to precipitate or separate therefrom arsenic, antimony, bismuth, lead or other
metals.
Second In the treatment of spirit of salt (hydrochloric acid), oil of vitriol o
other acid solutions, the employment of a mixture of sulphuretted hydroger,
sulphurous acid and an for effecting the precipitation or separation therefion of
arsenic, antimony, bismuth, lead or other metals.
Thnd. Au apparatus for the purpose above specified, comprising a series of
tanks, vats or compartments suitably connected so as to cause or permit the circu-
lation of the acid solution from one vat or compartment to anothei as required, and
provided with means for causing the sulphuretted hydrogen or mixture of
sulphunetted hydrogen, sulphurous acid and an, to intunately mix with some of
the acid in one of the said vats or compartments and carry the same into another
vat or compartment, substantially as berembefore described.
Fourth. The combination, with the vat or vais, of one or more hollow towers
filled with bricke, coke or the like, down which acid is caused to percolate and
through which the gases will ascend after passing through the acid in the vat or
vats, so that any sulphuretted hydrogen escaping from or any acid vapours
mechanically carried out of the vats will be absorbed in the said tower or towers
and returned to the vat or vats, substantially as described.
Fifth. The improved apparatus constructed substantially as described with
reference to Figure 1 or to Figure 2 of the accompanying diawing and operating
ne aud for the purpose above specified.
Dated the 5th day of Tul., 1905
D YOUNG & Co.,
11 & 12 Southampton Buildings, London, W.C.,
Agents for the Applicants