IMPROVEMENTS IN THE MANUFACTURE OF CAR- BONATE OF SODA
Year: 1841

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
SHANKS, of Saint Helens, Lancashire, Chemist, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria by Her
Letters Patent under the Great Seal of Great Britain, bearing date at West-
minster, the Twenty-seventh day of May, in the fourth year of Her reign,
did for Herself, Her heirs and successors, give and grant unto me, the said
James Shanks, Her especial licence, full power, sole privilege and authority,
that I, the said James Shanks, my exors, adiiors, and assigns, or such
others as I, the said James Shanks, my exors, adiriors, or assigns, should
at any time agree with, and no others, from time to time and at all times
during the term of years therein expressed, should and lawfully might make,
use, exercise, and vend, within England, Wales, and the Town of Berwick-
upon-Tweed, my Invention of "IMPROVEMENTS IN THE MANUFACTURE OF CAR-
BONATE OF SODA;" in which said Letters Patent is contained a proviso, that
I, the said James Shanks, shall cause a particular description of the nature
of my said Invention, and in what manner the same is to be performed,
to be enrolled in Her said Majesty's High Court of Chancery within six
calendar months next and immediately after the date of the said in part
recited Letters Patent, as in and by the same, reference being thereunto had,
will more fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
James Shanks, do hereby declare that the nature of my Invention, and the
manner in which the same may be performed, is fully made known in the
description hereunto annexed.

page_text: It is well known that the carbonate of soda of commerce, or white ash, as it
commonly called, as usually prepared by manufacturers, is not a pure car-
bonate, but contains more or less of caustic soda and silicate of soda, in
proportions liable to much variation; my object is to convert these substances
into carbonate of soda, and in the case of the manufacture of, crystals to
increase the quantity of these to be obtained from the soda liquors. This I
do in either of the two following methods :-
First, I take the masses of black ash, or impure carbonate, of soda as
prepared by manufacturers, and break them into fragments about the size of
a cubic inch; I then place them into a stone or iron close vessel or chamber,
in layers of three or four inches in thickness, which layers are then moistened
with water. Into this chamber, which I call a carbonator, there are fitted
at opposite ends, an entrance and an exit pipe for the gases; I introduce a
stream of carbonic acid gas, which is kept up till the whole of the soda and
lime are carbonated. This point may be easily ascertained by the escape of
sulphuretted hydrogen, which is well known by its peculiar smell. The black
ash thus prepared is then removed to the vats and treated in the ordinary way;
I prefer to stop the carbonating process at this point, but it may be carried on
till all the suphuretted hydrogen is expelled. A pipe of one inch in diameter,
with a pressure equal to one quarter of an inch of a column of water, will
admit a sufficient quantity of gas to carbonate one ton of ash at a time..
In my second method for obtaining similar results, which is the plan I
prefer, I treat the black ash in the manner usually adopted by manufacturers,
that is to say, I make a lye from the black ash, and then operate on the
solution in the following manner I construct a vessel or chamber which I call
a carbonator, made of any suitable material, such as iron or stone; the form
I prefer to be square, and not less than ten feet high, and providing sixteen cubic
fect of space for every ton of soda ash; and six cubic feet of space for every ton
of crystals to be made per diem. Into this apparatus I throw an arch of open
brickwork across the bottom, and fill the remaining space with pebbles, about
a cubic inch in size, and introduce a stream of carbonic acid gas by a pipe
under the arch, which immediately diffuses itself among the pebbles. The
soda lipuor from the vats is then conveyed to the top of the carbonator, either
by means of a pump or by spouts, as the relative levels of the carbonator and
vats may suit, and the impure lye falling in numberless rills through the
interstices of the pebbles; meets the carbonic acid in its ascent and becomes
perfectly carbonated. This point is ascertained by the liquor - having lost.its
greenish yellow color, and having assumed a transparent or whitish appearance,
which is readily seen on its leaving the bottom of the carbonator by a water

page_text: trap provided for this purpose. The quantity of carbonic acid to be applied in
this case is not material provided it is in excess, which is indicated as already
described. I vary this process by taking the last or weakest liquors from the
vats and passing them through the carbonator, thereby surcharging them
with carbonic acid gas, and then using these liquors for lixiviating the fresh
charges of black ash in the vats.
The carbonic acid may be obtained by any of the known means, but I
prefer (because most suitable under the general circumstances of soda or
alkali making) to produce it by the action of muriatic acid on limestone.
I
find that a cubic generator of six feet in the side, and a cubic carbonator of
ten feet in the side, are sufficient to carbonate sixty tons of soda ash per
week.
Having thus described the nature of my Invention, I would have it under-
stood that I do not confine myself to the precise details, provided the peculiar
character of my Invention be retained. And I claim as my Invention the
taking of black ash, as commonly made by manufacturers, or the solutions
made therefrom, and the converting the caustic soda and silicate of soda
therein contained into carbonate of soda by the means herein-described.
In witness whereof, I, the said James Shanks, have hereunto set my
hand and seal, this Twenty-fourth day of November in the year of our
Lord One thousand eight hundred and forty-one