IMPROVEMENTS IN THE PREPARATION OF SODA AND ITS VARIOUS SALTS IN A HIGH DEGREE OF PURITY
Year: 1871

page_text: LETTERS PATENT to William Henry Balmain, of Saint Helens, in
the County of Lancaster, Manufacturing Chemist, for the Invention
of "IMPROVEMENTS IN THE PREPARATION OF SODA AND ITS VARIOUS SALTS IN
A HIGH DEGREE OF PURITY."
Sealed the 7th November 1871, and dated the 13th May 1871.
PROVISIONAL SPECIFICATION left by the said William Henry
Balmain at the Office of the Commissioners of Patents, with his
Petition, on the 13th May 1871.
I, WILLIAM HENRY BALMAIN, of Saint Helens, in the County of
5 Lancaster, Manufacturing Chemist, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN THE PREPARATION OF SODA AND ITS
VARIOUS SALTS IN A HIGH DEGREE OF PURITY," to be as follows :—
I have discovered that bi-carbonate of soda is almost insoluble in a
saturated solution of salt or of sulphate of soda, or in a solution of the

page_text: two together, so that bi-carbonate of soda may be purified with a loss
of only about one per cent. by simple washing by letting water percolate
through it. I have availed myself of this fact as furnishing not only a
ready means of obtaining bi-carbonate of soda free from chloride and
sulphate, but also as an economical and profitable method of obtaining
in a state of great purity the simple carbonate, the caustic alkali,
and other salts of soda produced therefrom where great purity is a
desideratum.
According to my Invention I take ordinary soda ash, or what is called
black ash liquor, or that form of sodium carbonate which is technically
called " 'salts," or any other carbonate of soda, whether native or
artificial, and of any degree of purity; or I take any form of caustic
soda and convert any one of them into bi-carbonate by exposing either a
solution of the same, or the carbonate of soda in a solid form to carbonic
acid. The carbonic acid may be derived from a lime kiln, or the products
of fermentation, or from other sources or processes, or it may be prepared
specially by any of the known processes. The carbonate of soda if in
the solid form may be placed in a chamber with or without shelves to
be exposed to the carbonic acid, or it may be exposed in a revolving
cylinder or in any other convenient manner, but to facilitate the absorp-
tion it should contain at least one half of its own weight of water which
can be added to it if not already present. If the carbonate of soda is
in solution or in a liquid state it should be concentrated to saturation,
and it may be exposed in a revolving cylinder or in an agitator, or in
any other convenient manner to the carbonic acid, or the carbonic acid
may be pumped or drawn or otherwise driven through it.
Having thus obtained a bi-carbonate of soda in an impure state I
place it in an ordinary drainer of any convenient form, and just put so
much water upon it as will cover it, which water is allowed to stand for
about one hour or more as may be required, and is then allowed to drain
off it being followed by a little additional water, which is spread over
the top of the material so as to follow the first in descent. These
drainings are watched and divided at that point at which the proportion
of bi-carbonate contained in solution becomes such as to be considered
worth saving. The first portions may be rejected altogether or may be
used to produce crystals of sulphate of soda and the second portions may
be used instead of water for the next operation: When drained the
purified bi-carbonate may be employed cither as such or be converted

page_text: into a carbonate by furnacing or other convenient means, or it may be
converted into caustic soda or into any other salts of soda that it may
be desired to obtain economically in a high state of purity.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said William Henry Balmain in the Great Seal Patent
Office on the 11th November 1871.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
HENRY BALMAIN, of Saint Helens, in the County of Lancaster, Manu-
facturing Chemist, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Thirteenth day of May, in the year
of our Lord One thousand eight hundred and seventy-one, in the thirty-
fourth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said William Henry Balmain, Her special
license that I, the said William Henry Balmain, my executors, adminis-
trators, and assigns, or such others as I, the said William Henry
Balmain, my executors, administrators, or assigns, should at any time
agree with, and no others, from time to time and at all times there-
after 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 Inven-
tion for "IMPROVEMENTS IN THE PREPARATION OF SODA AND ITS VARIOUS SALTS
IN A HIGH DEGREE OF PURITY," upon the condition (amongst others) that
I, the said William Henry Balmain, my executors or administrators, by
an instrument in writing under my hand and scal, 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 Henry Balmain, do hereby
declare the nature of my 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 :—
My said Invention is based on the discovery that bi-carbonate of soda
is almost insoluble in a saturated solution of salt, or of sulphate of soda,

page_text: or in a solution of the two together, so that bi-carbonate of soda may be
purified with a loss of only about one per cent. by simple washing by
letting water percolate through it. I have availed myself of this fact
as furnishing not only a ready means of obtaining bi-carbonate of soda
free from chloride and sulphate, but also as an economical and profitable
method of obtaining in a state of great purity the simple carbonate, the
caustic alkali, and other salts of soda produced therefrom, where great
purity is a desideratum.
According to my Invention I take ordinary soda ash or that form of
sodium carbonate which is technically called "salts" or any other
carbonate of soda whether native or artificial, and of any degree of
purity, or I take any form of caustic soda and convert any one of them
into bi-carbonate by exposing either a solution of the same or the
carbonate of soda in a solid form to carbonic acid. The carbonic acid
may be derived from a lime kiln or the products of fermentation, or
from other sources or processes, or it may be prepared specially by any
of the known processes. The carbonate of soda if in the solid form may
be placed in a chamber with or without shelves to be exposed to the
carbonic acid or it may be exposed in a revolving cylinder or in any
other convenient manner, but to facilitate the absorption it should con-
tain at least one half of its own weight of water which can be added to
it if not already present. If the carbonate of soda is in solution or in
a liquid state it should be concentrated to saturation, and it may be
exposed in a revolving cylinder or in an agitator, or in any other
convenient manner to the carbonic acid, or the carbonic acid may be
pumped or drawn or otherwise driven through it.
Having thus obtained a bi-carbonate of soda in an impure state, I
place it in an ordinary drainer of any convenient form, and just put
so much water upon it as will cover it, which water is allowed to stand
for about one hour or more, as may be required, and is then allowed to
drain off, it being followed by a little additional water which is spread
over the top of the material so as to follow the first in descent. The
drainings are watched and divided at that point at which the proportion
of bi-carbonate contained in solution becomes such as to be considered
worth saving. The first portions may be rejected altogether or may
be used to produce crystals of sulphate of soda and the second portions
may be used instead of water for the next operation. When drained the
purified bi-carbonate may be employed either as such, or be converted

page_text: into a carbonate by furnacing or other convenient means. Or it may be
converted into caustic soda, or into any other salts of soda that it may
be desired to obtain economically in a high state of purity.
Having now described and particularly ascertained the nature of my
said Invention, and the manner in which the same is or may be
used or carried into effect, I would observe in conclusion that what I
consider to be novel and original, and therefore claim as the Invention
secured to me by the herein-before in part recited Letters Patent is,
the preparation of soda and of its various salts of a high degree of purity
by firstly converting the soda when existing either in the state of caustic
or of carbonate of soda into bi-carbonate of soda which is sparingly
soluble in water and nearly insoluble in a solution containing the
impurities which usually occur in crude soda and separating the soluble
impurities therefrom as herein-before described.
In witness whereof, I, the said William Henry Balmain, have to
this my Specification set my band and seal, the Ninth day of
November One thousand eight hundred and seventy-one.
WILLIAM HENRY BALMAIN. (L.S.)