IMPROVEMENTS IN THE MANUFACTURE OF SULPHURIC ACID AND SULPHATES, AND IN APPARATUS EMPLOYED THEREIN
Year: 1871

page_text: LETTERS PATENT to James Hargreaves, of Appleton-within-Widnes,
in the County of Lancaster, Chemist, and Thomas Robinson, of
Widnes, in the same County, Ironfounder, for the Invention of
"IMPROVEMENTS IN THE MANUFACTURE OF SULPHURIC ACID AND SULPHATES,
AND IN APPARATUS EMPLOYED THEREIN."
"
Sealed the 17th November 1871, and dated the 21st July 1871.
PROVISIONAL SPECIFICATION left by the said James Hargreaves and
Thomas Robinson at the Office of the Commissioners of Patents,
with their Petition, on the 21st July 1871.
We, JAMES HARGREAVES, of Appleton-within-Widnes, in the County
of Lancaster, Chemist, and THOMAS ROBINSON, of Widnes, in the same
County, Ironfounder, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN THE MANUFACTURE OF SULPHURIC ACID AND SULPHATES,
AND IN APPARATUS EMPLOYED THEREIN," to be as follows:-
First. We procure sulphide of hydrogen to be used as a source of
sulphuric acid by decomposing alkali waste with hydrochloric acid in a
decomposing apparatus which does not admit of the escape into the
atmosphere of sulphide of hydrogen. We prepare the alkali waste by

page_text: agitating or mixing it with some liquid, preferably a solution of chloride
of calcium, and getting the sulphide of calcium of which the said waste
principally consists into suspension in the said solution of chloride of
calcium. We then separate the fine suspended particle from the cinder
and other coarse particles, and pass the said solution of chloride of
calcium containing sulphide of calcium in suspension through a tube
into the decomposing apparatus. By means of another tube we pass
hydrochloric acid into the said decomposing apparatus. Sulphide of
hydrogen is thereby liberated. We prefer to use the sulphide of calcium
in slight excess of what is required to neutralize the hydrochloric acid
used. To ensure that the proportion of sulphide of calcium shall be as
evenly proportioned as possible we keep the said solution of chloride of
calcium containing sulphide of calcium in suspension agitated by
any suitable means while it is being run into the said decomposing
apparatus. The solution of chloride of calcium which is produced from
the decomposition of the said sulphide of calcium is then allowed to
flow from the said decomposing apparatus by means of a pipe opening
at or near the bottom of the said decomposing apparatus. A portion of
the said chloride of calcium is again used to hold sulphide of calcium in
suspension by being agitated with more alkali waste, and the process of
decomposition by means of hydrochloric acid is repeated as herein-
before described. The excess of sulphide of calcium after being allowed
to settle from the solution of chloride of calcium which flows from the
decomposing apparatus may be again put into the said decomposing
apparatus so as to keep the sulphide of calcium in excess as aforesaid
without using any more alkali waste than is absolutely necessary. If
desirable we heat the chloride of calcium previous to its flowing from
the decomposing apparatus, so as to expel the last traces of sulphide of
hydrogen, which if allowed to escape not only causes a loss of sulphide
of hydrogen, but gives rise to a serious nuisance. The said sulphide of
hydrogen is afterwards burnt to produce sulphurous acid, and the said
sulphurous acid is converted into sulphuric acid by any suitable means,
or we pass the said sulphurous acid through a series of vessels con-
taining chlorides of sodium and potassium, or either of them, and form
sulphates of soda and potassa, or either of them, direct.
To prevent
the extinction of the flame of sulphide of hydrogen while being burnt
and also to increase the temperature of the sulphurous acid produced
we previously heat the said sulphide of hydrogen by passing it through
a heated pipe or pipes, or by any other suitable means.
In some

page_text: instances we also heat the air used to effect the combustion of the said
sulphide of hydrogen.
Second. To moderate the temperature of combustion and also to
produce an increased proportion of sulphuric acid at the instant of
› combustion when burning sulphur, or pyrites, or any other suitable
compound of sulphur, we moisten the air used for the combustion of the
said sulphur. We do this either by putting steam amongst the air used
for combustion, or we pass the air over water heated to a sufficiently
high temperature to cause the air to absorb the desired quantity of
moisture. We maintain the temperature of the aforesaid water
contained in a suitable vessel by means of the waste heat from
the sulphate apparatus where the sulphates of soda or potassa are
produced by the direct action of sulphurous acid, or of sulphuric acid
vapour.
Third. We produce sulphates of soda and potassa or cither of
them by the use of sulphuric acid vapour, which we pass through,
amongst, or over chloride of sodium or chloride of potassium, or either
of them.
Fourth. When preparing chloride of sodium or chloride of potassium
for use in the manufacture of sulphates of soda and potassa, or either
of them, we use hollow plates heated by steam preferably under high
pressure. The said hollow plates are made with a series of tubes
running through them and with flanges on two of the sides. The end
plates are provided with flanges on three of the sides, including that
side which forms the end of the series of plates when bolted together.
The said hollow plates are provided with lugs at the corners, so as
to allow the whole to be bolted together. The said series of plates is
then placed in a horizontal or nearly horizontal position, and steam
admitted at the higher end. The condensed water is allowed to flow
back into the steam boiler.
Fifth. When making sulphate of soda by the direct action of sul-
phurous acid or of sulphuric acid vapour upon chloride of sodium we
use the "pan scale" which is produced in the manufacture of salt.
We break the said pan scale into rather smaller pieces than are usual
when using salt, which has been formed into lumps by moistening and
drying ordinary salt in consequence of its being less porous.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said James Hargreaves and Thomas Robinson in the
Great Seal Patent Office on the 20th January 1872.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, JAMES
HARGREAVES, of Appleton-within-Widnes, in the County of Lancaster,
Chemist, and THOMAS ROBINSON, of Widnes, in the same County, Iron-
founder, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-first day of July, in the year of
our Lord One thousand eight hundred and seventy-one, in the thirty-
fifth year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto us, the said James Hargreaves and Thomas Robinson,
Her special licence, that we, the said James Hargreaves and Thomas
Robinson, our executors, administrators, and assigns, or such others as
we, the said James Hargreaves and Thomas Robinson, our 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 for "IMPROVEMENTS IN
THE MANUFACTURE OF SULPHURIC ACID AND SULPHATES, AND IN APPARATUS
EMPLOYED THEREIN," upon the condition (amongst others) that we, the
said James Hargreaves and Thomas Robinson, our executors or ad-
ministrators, by an instrument in writing under our, or their, or one
of their hands and seals, 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 we, the said James Hargreaves and Thomas
Robinson, do hereby declare the nature of our said Invention, and in
what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement, reference being had
to the accompanying Sheet of illustrative Drawings, and to the figures
and letters marked thereon, that is to say:—
First. We procure sulphide of hydrogen to be used as a source of
sulphuric acid by decomposing alkali waste with hydrochloric acid in a

page_text: decomposing apparatus which does not admit of the escape into the
atmosphere of sulphide of hydrogen. We prepare the alkali waste by
agitating and mixing it with some liquid, preferably a solution of
chloride of calcium, and getting the sulphide of calcium of which the
said waste principally consists into suspension in the said solution of
chloride of calcium. We then separate the fine suspended particles
from the cinder and other coarse particles, and pass the said solution
of chloride of calcium containing sulphide of calcium in suspension
through a tube into the decomposing apparatus; by means of another
tube we pass hydrochloric acid into the said decomposing apparatus ;
sulphide of hydrogen is thereby liberated. We prefer to use the sulphide
of calcium in slight excess of what is required to neutralize the hydro-
chloric used. To ensure that the proportion of sulphide of calcium shall
be as evenly proportioned as possible we keep the said solution of
chloride of calcium containing sulphide of calcium in suspension
agitated by any suitable means while it is being run into the said
decomposing apparatus. The solution of chloride of calcium which is
produced from the decomposition of the said sulphide of calcium is then
allowed to flow from the said decomposing apparatus by means of a pipe
opening at or near the bottom of the said decomposing apparatus. A
portion of the said chloride of calcium is again used to hold sulphide
of calcium in suspension by being agitated with more alkali waste,
and the process of decomposition by means of hydrochloric acid is
repcated, as herein-before described. The excess of sulphide of calcium
after being allowed to settle from the solution of chloride of calcium
which flows from the decomposing apparatus may be again put into the
said decomposing apparatus so as to keep the sulphide of calcium in
excess as aforesaid without using any more alkali waste than is absolutely
necessary. If desirable we heat the chloride of calcium previous to its
flowing from the decomposing apparatus so as to expel the last traces
of sulphide of hydrogen, which, if allowed to escape into the atmosphere,
not only causes a loss of sulphide of hydrogen but gives rise to a serious
nuisance. The said sulphide of hydrogen is afterwards burnt to produce
sulphurous acid, and the said sulphurous acid is converted into sul-
phuric acid by any suitable means; or we pass the said sulphurous acid
through a series of vessels containing chloride of sodium and potassium,
or either of them, and form sulphates of soda and potassa or either of
them direct. To prevent the extinction of the flame of sulphide of
hydrogen while being burnt, and also to increase the temperature of the

page_text: sulphurous acid produced we previously heat the said sulphide of
hydrogen by passing it through a heated pipe or pipes, or by any other
In some instances we also heat the air used to effect
the combustion of the said sulphide of hydrogen.
suitable means.
Second. We produce sulphates of soda and potassa, or either of them,
by the use of sulphuric acid vapour, which we pass through, amongst, or
over chloride of sodium, chloride of potassium, or either of them. In
practice we prefer to use the apparatus previously patented by us for the
conversion of chlorides into sulphates by the use of sulphurous acid, air,
and water vapour. Ordinary sulphuric acid may be vapourized in any
convenient manner by the application of heat, or sulphuric acid in the
state of vapour may be used immediately after its formation from
sulphurous acid, whether such sulphuric acid is produced in the ordinary
vitriol chambers or by passing sulphurous acid and atmospheric air over
oxidizing or catalytic substances, or again, from the distillation of
metallic sulphates.
Third. When preparing chloride of sodium or chloride of potassium
for use in the manufacture of sulphates of soda and potassa or either of
them, by the direct action of sulphurous acid, air, and water vapour
or sulphuric acid vapour upon the said chlorides, we use hollow plates
heated by steam, preferably under high pressure. The said hollow
plates, shewn in Figs. 3 and 4, are made with a series of tubes running
through them, and with flanges on two of the sides. The end plates
are provided with flanges on three of the sides, including that side which
forms the end of the series of plates when bolted together. The said
hollow plates are provided with lugs at the corners so as to allow the
whole to be bolted together. The said series of plates is then placed
in a horizontal or nearly horizontal position and steam admitted at the
higher end.
The condensed water is allowed to flow back into the
steam boiler when placed above the boiler. The moist chloride of
sodium or potassium is laid on the plates and beaten down, and when
dry is removed and broken into pieces of suitable size.
Fourth. When making sulphate of soda by the direct action of
sulphurous acid or of sulphuric acid vapour upon chloride of sodium
we use the pan scale which is produced in the manufacture of common
salt. We break the said pan scale into rather smaller pieces than are
usual when using salt which has been formed into lumps by moistening
and drying ordinary salt in consequence of its being less porous.

page_text: Apparatus constructed in accordance with the first part of our Inven-
tion are delineated by Figs. 1 and 2 of the accompanying Drawings.
Fig. 1 being a longitudinal vertical section, and Fig. 2 a plan view.
a denotes an open vessel to contain a solution of chloride of calcium;
b, cock to regulate the flow of the said solution into the open vessel c;
d, spindle fitted with agitating arms e; f, overflow from c. The solution
of chloride of calcium with the finer particles of sulphide of calcium
flows through the inclined grating 9, whilst the coarser particles remain
on the grating whence they are removed from time to time. The bars
of the grating may be half an inch wide and half an inch apart, or the
grating may be variously formed with about half inch openings, wrought
iron being preferred; h is an inclined way for conducting the solution
into the funnel pipe i terminating in the closed vessel k, said closed
vessel is provided with a partition plate k', and the whole is by preference
made of wood; j is a funnel pipe curved at the bottom for conducting
hydrochloric acid into the said closed vessel ; l is a spindle fitted with
agitating arms m and cup n so that these parts, namely l, m, and n, shall
be rotated together. The object in curving the bottom of j and of the
cup n is to prevent the evolved sulphide of hydrogen from rising through
i and j into the atmosphere. The chloride of calcium flows over the
partition plate k¹, and finally escapes through the bent pipe o; p is a
passage leading the gas into a separating vessel q. Any liquid carried
over flows down the piper into the closed vessel k; & is an outflow pipe
conducting the sulphide of hydrogen to the burners to produce sulphurous
acid, which said sulphurous acid may be converted into sulphuric acid,
or it may be passed through or amongst chlorides so as to form sulphates,
as herein-before mentioned.
Fig. 3 is a view in plan and horizontal section, and Fig. 4 a transverse
section of our steam heated plates to be employed in the preparation
by drying of chloride of sodium or chloride of potassium as herein-before
mentioned; t are plates bolted together by lugs A, said plates having
steam passages u and raised sides and ends v.
น
Steam is supplied through
thre pipe w from any convenient generator.
steam passages u may be variously formed.
It will be obvious that the

page_text: Having now described the nature and particulars of our said Invention
we would have it understood that what we claim under this our final
Specification is,
-
First. The production of sulphide of hydrogen as a source of sul-
phurous acid (to be employed in the manufacture of sulphuric acid and
sulphates by the means and apparatus substantially as herein described.
Second. The manufacture of sulphates of soda and potassa by reacting
upon chlorides of sodium and potassium with sulphuric acid vapour,
substantially as herein described.
Third. The steam heated hollow plates with lugs and raised sides and
ends to be employed in the preparation by drying of chlorides to be
converted into sulphates, substantially as described.
Fourth. Producing sulphates of soda and potassa from broken pan
scale by reacting upon it with sulphurous acid, gas, air, and water vapour
or sulphuric acid vapour, substantially as described.
In witness whereof, I, the said James Hargreaves, have hereunto
set my hand and scal, the Eighteenth day of January, in the
year of our Lord One thousand eight hundred and seventy-
two.
In the presence of
J. T. KING,
Patent Agent,
Liverpool.
JAMES HARGREAVES. (L.S.)