IMPROVE- MENTS IN THE MANUFACTURE OF SODA ASH
Year: 1860

page_text: LETTERS PATENT to William Henry Ralston, Analytical Chymist, of
Keele, in the County of Staffordshire, for the Invention of "IMPROVE-
MENTS IN THE MANUFACTURE OF SODA ASH."
PROVISIONAL SPECIFICATION left by the said William Henry Ralston-
at the Office of the Commissioners of Patents, with his Petition, on the
15th November 1860.
I, WILLIAM HENRY RALSTON, Analytical Chymist, of Keele, in the County
of Staffordshire, do hereby declare the nature of the Invention for "IMPROVE-
MENTS IN THE MANUFACTURE OF SODA ASH," to be as follows:-
This Invention has for its object improvements in the manufacture of soda
ash. The soda ash of commerce generally contains a considerable per-
centage of chloride of sodium and sulphate of soda; now these impurities
considerably reduce the market value of the article. According to this
Invention I separate these impurities either in great part, or if desired, till only
traces of them remain, and this I do by washing the soda ash for a sufficient
time by preference with a concentrated or saturated solution of carbonate of soda
or concentrated vat liquor. When the washing process commences, caustic soda.
and ferrocyanide of sodium are first removed, only very minute quantities of
chloride of sodium and sulphate of soda being washed out; but afterwards,
when the caustic soda and ferrocyanide are almost entirely separated as the
washing is continued, the chloride of sodium will be dissolved out, and
similarly when but a small quantity of this salt remains, the sulphate of soda
will, as the washing is still continued, be also separated. Now soda asb, or

page_text: the salt obtained by evaporating black ash liquor, has before in some cases
been washed, but with the object only of removing the caustic soda and the
ferrocyanide of sodium; consequently the washing process has always heretofore
been stopped when this object has been attained sufficiently nearly, and conse-
quently when but very small quantities of chloride of sodium and sulphate of
soda have been removed; certainly in no case has soda ash been washed.
' sufficiently to raise the quantity of alkali (soda) in the ash so high as fifty-
six per cent. of the whole. The present Invention, therefore, does not consist
generally in washing soda ash, but in continuing such washing after the
caustic soda and the ferrocyanide of sodium have been removed (with
sufficient completeness), and until the ash contains fifty-six per cent. of alkali
(soda) at the least.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Henry Ralston in the Great Seal Patent Office on
the 15th May 1861.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
HENRY RALSTON, Analytical Chemist, of Keele, in the County of Stafford-
shire, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fifteenth day of November, in the year of our Lord
One thousand eight hundred and sixty, in the twenty-fourth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
William Henry Ralston, Her special licence that I, the said William Henry
Ralston, my executors, administrators, and assigns, or such others as I, the:
said William Henry Ralston, 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, exercise, and vend, within the United Kingdom of Great Britain and
Ireland, the Channel Islands, and Isle of Man, an Invention for "IMPROVE-
MENTS IN THE MANUFACTURE OF SODA ASH," upon the condition (amongst others)
that I, the said William Henry Ralston, my executors or administrators, by an
instrument in writing under my, 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 imme-
diately after the date of the said Letters Patent.

page_text: NOW KNOW YE, that I, the said William Henry Ralston, 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 thereof, that is to say :-
per-
This Invention has for its object improvements in the manufacture of
soda ash. The soda ash of commerce generally contains a considerable
centage of chloride of sodium and sulphate of soda; now these impurities
considerably reduce the market value of the article. According to this
Invention, I separate these impurities either in great part, or if desired till
only traces of them remain, and this I do by washing the soda ash for a suffi-
cient time, by preference with a concentrated or saturated solution of carbonate
of soda or concentrated vat liquor. When the washing process commences,
caustic soda and ferrocyanide of sodium are first removed, only very minute
quantities of chloride of sodium and sulphate of soda being washed out, but
afterwards, when the caustic soda and ferrocyanide are almost entirely sepa-
rated as the washing is continued, the chloride of sodium will be dissolved out,
and similarly when but a small quantity of this salt remains, the sulphate of
soda will, as the washing is still continued, be also separated. Now soda ash,
or the salt obtained by evaporating black ash liquor, has before in some cases
been washed, but with the object only of removing the caustic soda and the
ferrocyanide of sodium; consequently the washing process has always here-
tofore been stopped when this object has been attained sufficiently nearly, and
consequently when but very small quantities of chloride of sodium and sulphate
of soda have been removed, certainly in no case has soda ash been washed
sufficiently to raise the quantity of alkali (soda) in the ash so high as fifty-six
per cent. of the whole. The present Invention, therefore, does not consist
generally in washing soda ash, but in continuing such washing after the
caustic soda and the ferrocyanide of sodium have been removed (with
sufficient completeness), and until the ash contains fifty-six per cent. of alkali
(soda) at the least,
And in order that my said Invention may be most fully understood and
readily carried into effect, I will proceed to describe the manner in which I
prefer to conduct the process.
I employ wrought-iron vessels with drainers, into which the salts are
delivered from the concentrating pans, and through them I cause to flow either
a solution of carbonate of soda or other liquor, as before mentioned; this
liquor circulates through the series,. as in the lixiviation of the black ash, when
the same is conducted in vats through which the liquor circulates, an
arrangement which is now generally employed in that stage of alkali manu-

page_text: facture. I prefer to use a solution of carbonate of soda for separating and
removing by displacement the chloride and sulphate of soda from the alkaline
'salts; in place thereof there may, however, be employed either the liquor
obtained from the lixiviation of the black ash or other available liquor at the
convenience of the manufacturer.
- To facilitate the operation, I prefer to employ such liquors heated, although
this is not absolutely necessary for the removal of the foreign salts. The
process can also be conducted by commencing the operation with water, but
when practicable, I prefer to employ hot concentrated vat liquors, as before
described, for ordinary operations and for obtaining the most complete results;
when soda ash of very high strength is required, I employ a concentrated
solution of purer carbonate of soda.
Another method of conducting the operation is to subject the salts to the
action of steam in a closed vessel, applying steam of a sufficient pressure to
permeate through the alkaline salts; this process is continued until the
solution resulting from the condensation of the steam, and which is drawn off
as it is formed, ceases to contain any appreciable quantity of chloride or
sulphate of soda..
Having thus described the nature of my Invention, and the manner of
performing the same, I would have it understood that I do not confine myself
to any particular form of vessel or arrangement of apparatus, nor do I confine
myself to the precise details herein-before described in the application of such
liquor or steam to the removal of the foreign salts from the alkali, as the same
object may be obtained by other simple mechanical arrangements without
departing from my Invention, which consists in the separation and displace-
ment from the alkaline salts obtained by the concentration of black ash
liquor of the undecomposed chloride of sodium and the unconverted sulphate,
of soda, producing thereby alkali or soda ash for market containing fifty-six
per cent. of alkali. (soda) at the least when drained and finished.
In witness whereof, I, the said William Henry Ralston, have hereunto
set my hand and seal, this Eleventh day of May, in the year of our
Lord One thousand eight hundred and sixty-one.
WILLIAM HENRY RALSTON. (LS.)