IMPROVEMENTS IN THE MANUFACTURE AD SU CARROW OF
Year: 1852

page_text: LETTERS PATENT to William Edward Newton, of the Office for
Patents, 66, Chancery Lane, in the County of Middlesex, Civil
Engineer, for the Invention of "IMPROVEMENTS IN THE MANUFACTURE
AD SU CARROW OF "A communication.
Sealed the 5th March 1853, and dated the 8th November 1852.
PROVISIONAL SPECIFICATION left by the said William Edward
Newton at the Office of the Commissioners of Patents, with his
Petition, on the 8th November 1852.
I, WILLIAM EDWARD NEWTON, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN THE MANUFACTURE OF THE CARBONATES
OP BODA" to be as follows:-
The object of this Invention is, to produce carbonate of soda in a
more economical manner and with greater facility than by the pro-
cesses now in use.
In carrying out the Invention sulphate of soda, as obtained by any
of the known processes, is reduced to a coarse powder, and mixed with
about one half its weight, more or less, of powdered coal, charcoal, saw-
dust, or other combustible matter. This mixture is subjected to a low
red heat in a suitable furnace until the mass is melted and thoroughly
decomposed into sulphuret of sodium. It is then withdrawn from the
furnace, and when cool enough dissolved in water and run into suitable

page_text: air-tight vats, provided with pipes and stop-cocks, and connected with
each other in the manner known among chemists as Woulf's apparatus,
which vats, for greater convenience, are placed one above another;
then, by means of an air-pump or other suitable means, carbonic acid
is made to pass through the liquid in the series of vats, entering the
lower ones first. This carbonic acid is obtained by preference from
the waste gases from chimneys or other parts of furnaces, or by
burning anthracite or other mineral coal, and especially from the
chimneys of steam boilers. The gases are first passed through water
in a suitable vessel so as to remove ashes, smoke, or other dirt; a little
lime, carbonate of lime, or alkaline matter being mixed with the
water in the said vessel to absorb and remove any sulphurous acid,
the presence of which would injure both apparatus and materials. The
carbonic acid is transmitted through the liquid in the vats until the
decomposition of sulphuret of sodium into carbonate of soda is found
in the lower vat to be complete, when it may be drawn off to be
filtered and evaporated in the usual manner. The liquor in the upper
vat is then to be brought into the lower vat, and fresh liquor into the
upper one, and the process repeated as before. I do not confine
myself to this particular arrangement of apparatus, but use any that
will bring carbonic acid into intimate contact with sulphuret of sodium.
During the whole process a constant stream of gases is escaping
from a pipe in the upper vat, consisting of sulphuretted hydrogen,
nitrogen, and other gases. The whole of the sulphur originally in the
sulphate of soda is contained in the sulphuretted hydrogen, which may
be recovered or made into compounds of sulphur by means well known
to chemists.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said William Edward Newton in the Great Seal
Patent Office on the 7th May 1853.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I,
WILLIAM EDWARD NEWTON, of the Office for Patents, 66, Chancery
Lane, in the County of Middlesex, Civil Engineer, send greeting.

page_text: WHEREAS Her most Excellent. Majesty Queen Victoria, by Her
Letters. Patent, bearing date the Eighth day of November, in the
sixteenth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said William Edward Newton, Her
special license that I, the said William Edward Newton; my executors,
administrators, and assigns, or such others as I, the said William
Edward Newton, 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 and lawfully
might make, use, excrcise, 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 THE CARBONATES OF
SODA," being. a communication from a foreigner residing abroad, upon
the condition (amongst others) that I, the said William Edward Newton,
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 William Edward Newton, do
hereby declare the nature of the said Invention, and in what manner the
same is to be performed, to be particularly described and ascertained
in and by the following statement (that is to say):
.
This Invention of "Improvements in the Manufacture of the Car-
bonates of Soda" has been communicated to me from abroad, and the
nature and object of the improvements, and the manner of carrying them
into effect, is described by my foreign correspondent in the following
manner-I take sulphate of soda, as obtained by any of the known
processes, and reduce it to a coarse powder, which I mix with about one
half its weight, more or less, of powdered coal, charcoal, sawdust, or
other combustible matter. This mixture I, subject to a low red heat in.
a suitable furnace until the mass is melted and thoroughly decomposed
into sulphuret of sodium. It is then withdrawn from the furnace, and
when cool enough dissolved in water and run into suitable air-tight
vats provided with pipes and stop-cocks, and connected with each

page_text: other in the manner known among chemists as Woulfe's apparatus,
which vats, for greater convenience, are placed one above another; I
then, by an air-pump or other suitable means, transmit carbonic acid
through the liquid in the series of vats, entering the lower ones first.
This carbonic acid I prefer to obtain from the escape gases from
chimneys or other parts of furnaces burning anthracite or other mineral
coal, and especially from the chimnies of steam boilers. I first pass the
gases through water in a suitable vessel to remove ashes, smoke, or
other dirt; a little lime, carbonate of lime, or alkaline matter being
mixed with the water in the said vessel to absorb and remove any
sulphurous acid, the presence of which would injure both apparatus
and materials. I have found in practice that one pound of lime was
sufficient for ten thousand cubic feet of gas. The carbonic acid is
transmitted through the liquid in the vats until the decomposition of
sulphuret of sodium into carbonate of soda is found in the lower vat to
be complete, which is easily known by suitable chemical tests, when it
may be drawn off to be filtered and evaporated in the usual manner.
The liquor in the upper vat is then to be brought into the lower vat,
and fresh liquor into the upper one, and the process repeated as before.
I do not confine myself to this particular arrangement of apparatus,
but use any that will bring carbonic acid into intimate contact with
sulphuret of sodium. During the whole process a constant stream of
gases is escaping from a pipe in the upper vat, consisting of sulphuretted
hydrogen, nitrogen, and other gases. The whole of the sulphur
originally in the sulphate of soda is contained in the sulphuretted
hydrogen, which may be recovered or made into compounds of sulphur
by means well known to chemists.
The process generally in use for making soda ash consists in mixing
one hundred parts of sulphate of soda with one hundred and twenty
parts of carbonate of lime and fifty parts of coal, all in powder, and
heating the mixture to a white heat in large furnaces; double decom-
position will then take place, forming carbonate of soda and oxy-
sulphuret of calcium. The mass is then raked out of the furnaces and
allowed to cool, then powdered coarsely and dissolved in water. The
water extracts about forty per cent. of the mass; the rest is thrown

page_text: away as useless. The liquors thus obtained are evaporated to dryness,
and if too caustic (which is generally the case) they must be mixed
with coal or sawdust and again heated to redness, by which means the
caustic soda becomes carbonated with carbonic acid forined, from the
combustion of the coal. All the sulphur originally contained in the
sulphate of soda is now in the insoluble mass, but cannot be extracted
so as to pay, and is therefore lost. In practice, from fifty to fifty-five
per cent. of the weight of sulphate of soda used is obtained as carbonate;
it should yield seventy-five per cent., but from the high heat and
incomplete decomposition the rest is unavoidably lost.
The advantages of the improved plan over the common process for
making soda ash, as above mentioned, are :-First, not employing car-
bonate of lime in any form, of which, in the old plan, ten tons at least are
used for every seven tons of soda ash made. The first cost of the said
carbonate of lime is very considerable; it requires to be finely powdered,
and as hard limestone is generally used this process is rendered very
expensive. The carbonate of lime which is added according to the old
plan also doubles the weight of matter to be heated, and therefore
requires twice as much fuel and twice as large furnaces as when the
improved process is employed; it also requires a much higher tempe-
rature to be maintained for a longer period. In consequence of some of
these inconveniences and objections, which are incidental to the old plan,
a saving of about seventy-five per cent. in fuel, in addition to the saving
of the cost of the carbonate of lime, is effected by the improved process.
Second, most, if not all, of the sulphur originally used in making the
sulphuric acid consumed in the manufacture of sulphate of soda can,
in the improved process, be recovered from the sulphuretted hydrogen
by well known means, and at little or no expense; but in the old
process all the sulphur is lost, being united with the lime in the form
of oxysulphuret of calcium, for which no use exists, and from which
the sulphur cannot be separated excepting at a greater cost than it is
worth. The sulphur recovered by the improved process effects a
saving of about twenty per cent. on the cost of the soda ash. Third,
the yield of soda ash is greater, and its quality better, by the improved
process, the great bulk of insoluble matter (occurring when the

page_text: common plan is pursued) rendering it impossible to extract all the
soda from it; but in the improved plan all is soluble except a very
small quantity of coal used in excess, nor is its purity injured by lime
or other foreign matters as it is by the present mode of manufacturing.
If bicarbonate of soda, or soda salaratus as it is called when impure,
is to be made, the solution of carbonate of soda, obtained from the vats
wherein the sulphuret of sodium is converted into carbonate by means
of carbonic acid, as previously described, is filtered and boiled down
until the carbonate of soda separates from the liquor as a crystalline
powder, consisting of one equivalent of real carbonate of soda united
with one equivalent of water, or, if thought desirable, commercial soda
ash or sal soda may be dissolved in water, and substituted for the
solution spoken of above. The powder of carbonate of soda above
mentioned is handled out of the liquor, drained, and allowed to cool.
This is coarsely powdered and spread upon frames, which are piled one
upon another in air-tight chambers. When the chambers are full the
openings are closed, except a vent at the top, and carbonic acid, by pre-
ference, obtained and purified as mentioned in the preparation of soda
ash, is forced into them until the saturation is complete, when the soda
will be found to have absorbed a second equivalent of carbonic acid,
forming bicarbonate of soda, or soda salaratus as it called when not
pure. The bicarbonate of soda is then taken out, dried, and powdered.
In the processes heretofore in use for making bicarbonate of soda
the crystals of sal soda (Na O. CO₂ + 10 aq.) are dissolved in water,
and carbonic acid passed through the solution until the soda is bi-
carbonated; part of the bicarbonate thus formed is deposited from the
solution in a crystalline form, and more may be obtained by evaporating
the mother liquor at a low temperature. Another plan in use for
making bicarbonate of soda is, to put the crystals of sal soda into a
suitable vessel, and then to pass carbonic acid into the vessel until the
bicarbonation is complete. Or, lastly, to take a mixture of effloresced
and crystallized sal soda in the proportion of four of the former to one of
the latter, and subject the mixture to the treatment with carbonic acid as
above. In the above processes the first has been generally abandoned
from the difficulty of effecting a complete bicarbonation, from the small

page_text: product obtained from the great quantities operated upon, and from the
loss of time attending the slow concentration of the mother liquors,
which is unavoidable, as the bicarbonate in solution is decomposed at a
boiling temperature. In the second process, which is the one generally.
in use, the bicarbonation is complete, but as sal soda contains ten equi-
valents of water, of which only one is retained by the bicarbonate, the
remaining nine equivalents of water are set free and drain off from the
crystals, holding so large a quantity of carbonate of soda in solution
that not more than half of the bicarbonate is obtained, the rest remain-
ing in the mother liquors, mostly in the form of sesqui-carbonate, from
which it cannot be obtained without great loss. In the third and last
process the difficulty arising from the presence of water of crystalliza-
tion is removed by exposing the crystals to a dry atmosphere, by which
means all or nearly all of the water is lost by efflorescence. The
peculiar disadvantage of this plan is, the enormous loss of time and
labor attending the efflorescence of the sal soda, which is necessarily a
very tedious operation, since a temperature much over one hundred
degrees Fahrenheit will cause the crystals to melt in their water of
crystallization instead of efflorescing, thus rendering the manufacture
of bicarbonate in large quantities very expensive by this process.
all of the above plans sal soda is used directly or indirectly, the pre-
paration of which is a heavy expense in the manufacture of bicarbonate
of soda.
In
The advantages that I claim for the improved processes over any of
the above are:-First, the saving of time and money attending the
preparation of sal soda, which has always heretofore been used for
preparing bicarbonate of soda. Second, the preparation of the mono-
hydrated carbonate of soda directly from the solutions of crude carbonate
of soda, thereby avoiding even part of the expenses that necessarily
attend the drying down of these solutions into soda ash. Third, the em-
ployment of the mono-hydrated carbonate of soda for the manufacture
of bicarbonate of soda, thereby obtaining bicarbonate of soda better
and cheaper than it can be made from any other known material.
Fourth, the employment and purification (as above mentioned) of car-
bonic acid, obtained from the combustion of anthracite or other mineral

page_text: coal, in combination with the aforesaid processes, thereby avoiding the
expense attending the employment of carbonate of lime and sulphuric
or muriatic acid, which have been generally used for procuring the said
carbonic acid. The effect of the above improvements is, that bicarbo-
nate of soda can be made perfectly pure at very considerably less than
the ordinary price.
What I claim is, First, the decomposition of sulphuret of sodium by
carbonic acid for making soda ash and other preparations of carbonate
of soda. Second, the preparation and use of the mono-hydrated car-
bonate of soda for the manufacture of bicarbonate of soda and soda
salaratus. Third, in combination with each of the above, the employ-
ment and purification of carbonic acid, derived from the combustion of
coke, anthracite or other mineral coal, for the manufacture of the
carbonates of soda, substantially in the manner herein specified.
In witness whereof, I, the said William Edward Newton, have
hereunto set my hand and seal, this Fifth day of May, in the
year of our Lord One thousand eight hundred and fifty-three.
Witness,
J. W. MOFFATT,
66, Chancery Lane.
W. E. NEWTON. (L.B.)