IMPROVEMENTS IN THE MANUFACTURE OF SODA ART AND SHIRDIA or PROVISIONAL SPECIFICATION
Year: 1854

page_text: LETTERS PATENT to William Blythe, of Oswaldtwistle, in the County of
Lancaster, Manufacturing Chymist, and Emile Kopp, of Accrington, in
the County of Lancaster, Chymist, for the Invention of "IMPROVEMENTS
IN THE MANUFACTURE OF SODA ART AND SHIRDIA or
PROVISIONAL SPECIFICATION left by the said William Blythe and Emile
Kopp at the Office of the Commissioners of Patents, with their Peti-
tion, on the 3rd October 1854.
We, WILLIAM BLYTHE, of Oswaldtwistle, in the County of Lancaster,
Manufacturing Chymist and EMILE KOPP, of Accrington, in the County of
Lancaster, Chymist, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN THE MANUFACTURE OF SODA ASH AND SULPHURIC ACID " to be as
follows:-
Our Invention consists in the substitution of the different oxides of iron or
carbonate or iron instead of lime of carbonate of lime in the manufacture of
"black ash," or crude soda. In the ordinary process, sulphate of soda, lime,
or carbonate of lime, and coal slack (in certain proportions) are fluxed together
in a furnace, producing "black ash," or "crude soda." This black ash, when
lixiviated in water, yields a solution of carbonate of soda. This solution is
evaporated to dryness, and the product is soda ash, or carbonate of soda.
Our Invention consists in fluxing sulphate of soda, peroxide of iron, and

page_text: coal slack together in certain proportions, by which we obtain a peculiar kind
of crude soda. This crude soda, when treated in a certain manner, yields a
solution of carbonate of soda and a residue of sulphuret of iron. The solution
we convert into dry carbonate of soda in the usual way.
The residual sulphuret of iron we use instead of iron pyrites in the manufac-
ture of sulphuric acid. By this process it is reconverted into peroxide of iron,
and may be again fluxed with another proportion of sulphate of soda and coal
slack to form crude soda. The peroxide of iron may in this manner be used
in continual rotation in the two processes of making soda ash and sulphuric
acid.
SPECIFICATION in pursuance of the conditions.of. the Letters Patent, filed
by the said William Blythe and Emile Kopp in the Great Seal Patent
Office on the 2nd April 1855.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, WILLIAM
BLYTHE, of Oswaldtwistle, in the County of Lancaster, Manufacturing Chymist,
and EMILE KOPP, of Accrington, in the County of Lancaster, Chymist, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Third day of October, in the year of our Lord
One thousand eight hundred and fifty-four, in the eighteenth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto us,
the said William Blythe and Emile Kopp, Her special license that we, the
said William Blythe and Emile Kopp, our executors, administrators, and
assigns, or such others as we, the said William Blythe and Emile Kopp, 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 MANUFAC-
TURE OF SODA ASH AND SULPHURIC ACID," upon the condition (amongst others)
that we, the said William Blythe and Emile Kopp, by an instrument in writing
under our hands and seals, or under the hand and seal of either of us,
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.

page_text: NOW KNOW YE, that we; the said William Blythe and Emile Kopp,
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 this Specification thereof, and the following statement herein contained
(that is to say):-
Our said Invention of Improvements in the Manufacture of Soda Ash and
Sulphuric Acid consists in the substitution of any. oxide or carbonate of iron
instead of lime or carbonate of lime in the manufacture of "black ash," or
"crude soda," from which soda ash is obtained in manner herein-after described,
and the sulphuret of iron produced by the process we use for the purpose of
forming or reproducing sulphuric acid, as herein-after mentioned.
In the ordinary process of making soda ash, sulphate of soda, lime, or car-
bonate of lime, and coal slack, in well-known proportions, are fluxed together
in a furnace, producing black ash or crude soda. This black ash, when lixiviated
in water, yields a solution of carbonate of soda, and when that solution is
evaporated to dryness, the product is soda ash, or carbonate of soda.
:
In performing our Invention, we flux sulphate of soda and oxide or carbonate-
of iron, and coal slack together, by which we obtain what may be called a
ferruginous barilla, or crude soda. We prefer to use the peroxide of iron for
this purpose, because we believe it can be obtained in this country more cheaply.
than any other oxide or carbonate of iron.
We charge a furnace with these materials when of the ordinary quality in.
about the following proportions, namely, two and a half hundredweight of
sulphate of soda, from one and a half hundredweight to one and three quarters
hundredweight of peroxide of iron, and from one hundred and fourteen pounds
to one hundred and twenty pounds of coal slack, varying these proportions,
however, when rendered necessary, by a different strength or purity of any of
the materials used. And for producing a good result, we deem it expedient to
use the materials in such proportions that there shall not be less than five parts
of pure anhydrous peroxide of iron for every nine parts of pure anhydrous
sulphate of soda in the mixture; and we may also observe that we deem
it better to use the peroxide of iron a little in excess, in order to prevent
as much as possible the presence of sulphuret of sodium in the carbonate of.
soda obtained by the process. The coal slack being used as a deoxidizing
agent, any other carbonaceous fuel may be used, the proportion or quantity
depending upon the quantity of carbonaceous matter which the fuel may
contain; but we avoid as much as possible any excess of the carbonaceous
matter used, because we deem it injurious in the subsequent parts of the
process. We reduce the materials into a state of powder and mix them, after

page_text: which they are fluxed and worked together in a furnace in the same way as in
producing ordinary barilla; but we find that the materials which we use
generally flux somewhat more readily, and become somewhat more liquid in
the furnace, than the materials now generally used. When the materials have
been sufficiently fluxed (which will require about the same time for that
purpose as the ordinary materials), they are to be drawn from the furnace into
a. waggon, or other convenient receptacle, in the usual manner, and set aside to
cool. A lump of ferruginous barilla thus obtained is next made to undergo
what we call a crumbling process before lixiviation, for the purpose of facili-
tating the separation of the soda from the iron. When exposed to the action of
the atmosphere, the exterior of the lump rapidly absorbs carbonic acid, oxygen,
and moisture, and falls to a blackish powder. This powder should not be
allowed to lie. long in a heap near the lump, because it has a tendency to
become hot, by absorbing too much oxygen from the air, by which the quality
of the product becomes deteriorated. To prevent this heating, we cause the
powder to be removed from the lump' as it falls by any convenient means. For
this purpose we find it advantageous to place a floor or shelf of iron grating in
a horizontal position, about five feet or some other convenient distance from
the ground, the bars of the floor or grating being about a quarter of an inch
apart. We place the lump of ferruginous barilla upon this floor or shelf, and
as it crumbles into powder, the powder falls through the grating upon the floor
below, from whence it may be removed from time to time, as required. When
it shall happen to be advantageous to hasten the crumbling process, the
building or apartment in which lumps of ferruginous barilla are placed may be
enclosed, and carbonic acid gas and moisture introduced by artificial means.
The moisture may be supplied by means of jets of steam, and the carbonic acid
gas may be produced by any of the well-known methods in use for that
purpose, care being taken to introduce it in as cool a state as practicable. We
prefer, however, to produce the carbonic acid gas by blowing air first through
a çoke fire, and afterwards through iron tubing immersed in cold water, so as
to cool it before it is introduced into the building or chamber. The powdered
barilla thus obtained is then to be lixiviated, for the purpose of obtaining
the soda in a state of solution, for which purpose we put the powder into a
suitable iron cistern with water, and cause it to be well stirred in the usual
manner. As much of the powdered barilla is put into the water in the cistern
as will produce a clear solution of a specific gravity of from twenty degrees
to thirty degrees of Twaddle's hydrometer..
The black residuum of the, barilla being allowed to settle. to the bottom of
the cistern, the clear solution is then. to be drawn off into a separate vessel.

page_text: The residuum is then to be lixiviated two or three times with fresh water, the
weak solutions thus obtained being used for the purpose of lixiviating fresh
portions of the ferruginous barilla, until it forms a solution sufficiently strong,
or of the specific gravity herein-before mentioned.
A concentrated solution of carbonate of soda obtained in this way, after
standing sufficiently long to allow the undissolved impurities to subside, may
be further concentrated, so as to produce crystallized carbonate of soda, or dried
into soda ash, in the same way as usually adopted in treating the liquor
obtained from ordinary barilla.
When the powdered ferruginous barilla above mentioned has been lixiviated
in water, so as to dissolve the soda or carbonate of soda it contains, a black or
dark coloured residuum will remain, consisting principally of sulphuret of iron.
This residuum, after being well washed; we place in a pit (similar to a plas-
terer's lime-pit), or in any convenient vessel, for the purpose of the water being
drained from it. After being thus drained until it is sufficiently firm or stiff,
we cause the residuum or residual sulphuret of iron to be dried in the air or in
a stove, or by any other convenient means, until (when handled) it crumbles
into a damp powder between the fingers. In this condition the residual
sulphuret of iron, is ready to be applied in the making of sulphuric acid by
burning it, in a similar manner as iron pyrites are usually burnt in the process
of manufacturing sulphuric acid.
This object inay be effected by conducting the sulphurous acid gas evolved
from the burning of this sulphuret of iron into a chamber, where it is con-
verted into sulphuric acid in the ordinary manner. But in doing this, instead
of employing a kiln, such as used for burning ordinary pyrites, we prefer to
employ an oven, constructed in a similar manner to those now in use for
drying and finishing salt cake, or sulphate of soda, in order that we may be
enabled the better to insure the perfect burning of the sulphuret of iron.
We also prefer to divide the oven into two compartments by a brick par-
tition, each compartment being furnished with a door and connected (by a
common flue) with the leaden chambers into which the sulphurous acid gas is
to be conducted for the purpose of being converted into sulphuric acid, as in
the ordinary process of manufacturing sulphuric acid.
The oven being heated to a dull red heat, one of the compartments is
charged with about four hundredweight, or any other convenient quantity, of
residual sulphuret of iron in powder, and by the action of the heat and air
the sulphur contained in the sulphuret of iron is burnt and converted, into
sulphurous acid
gas, which
passes through the chimney into the leaden
chambers of the apparatus in the ordinary manner. When the process of

page_text: burning is complete, a peroxide of iron remains in the oven, which may be
again employed in the production of black ash, or crude soda, in like manner
as herein-before described.
The working of the chambers and the use of nitre, for the purpose of con-
verting the sulphurous acid gas into sulphuric acid, is the same as when
ordinary iron pyrites is used in the manufacture of sulphuric acid. We prefer,
however, after the first commencement of the process, to charge each compart-
ment of the oven with the sulphuret of iron, when the burning operation in
the other compartment is drawing to a close, each operation requiring from.
about two to three hours in the performance of it.
The peroxide of iron from time to time reproduced by the repetition of the
process above described may be repeatedly employed in manner herein-before.
described, until earthy impurities shall accumulate in it, so as to interfere with
its action, or the quality of the products obtained by the process above described,
when it must either be purified, by washing it, in weak muriatic acid, or by
other adequate means, or it must be thrown away and a fresh quantity of oxide
or carbonate of iron used.
The sulphuric acid from time to time produced in manner above mentioned
may also be used in the ordinary manner for decomposing chloride of sodium,
and obtain sulphate of soda, to be treated in manner above described, for the
purpose of manufacturing soda ash and reproducing sulphuric acid.
In witness whereof, we, the said William Blythe and Emile Kopp, have
hereunto set our hands and seals, this Twenty-ninth day of March, in
the year of our Lord One thousand eight hundred and fifty-five.
Witness,
H. B. BARLOW,
Manchester.
WILLIAM BLYTHE. (L.S.)
EMILE KOPP.
(L.S.)