Year: 1886

page_text: We NEIL MATHIESON of Widnes in the County of Lancaster Chemical
Manufacturer and JOSEF HAWLICZEK of the same place Chemist do hereby declare
the nature of this Invention to be as follows:-
This Invention is for the purpose of manufacturing either pure bicarbonate or
high degree Soda Ash from the bicarbonate of the Ammonia Soda process or from
the Carbonate liquor commonly called vat liquor of the Le Blanc process.
I have discovered that if to a solution of Chlorides or Sulphates of Alkali there
is added a solution of Carbonate of Soda or Potash and the mixture submitted to
a current of Carbonic Acid pure Bicarbonate is obtained of a Crystalline form
which may easily be separated from the above mentioned Chloride or Sulphate
liquor by Hydro-extractor or other well known means.
The Chloride or sulphate left in contact with the bicarbonate may be got rid of
by washing the same.
In carrying out this Invention I prefer to mix the Carbonate solution with a
saturated solution of Sodium Chloride.
This mixture is placed in an absorber and Carbonic Acid is forced through with*
the resulting precipitation of the pure Bicarbonate.
If vat liquor from the Le Blanc process is thus treated all the impurities are got
rid of; the Cyanides which are displaced by the Carbonic Acid and pass over in a
gaseous form may be recovered.
The precipitated Bicarbonate is now brought on to a suitable filter and the
filtrate consisting mostly of Chlorides may be used over again for mixing with a
fresh solution of Carbonate. The Bicarbonate which remains. in contact with a
certain amount of Brine must necessarily be washed with water.
The Bicarbonate which is now in a pure state may either by drying be converted
into marketable Bicarbonate or by calcining into a high degree Soda Ash of a high
strength and purity.
J. HENRY JOHNSON,
47, Lincoln's Inn Fields, London,
Agent for the said Niel Mathieson and
Josef Hawliczek.

page_text: Improvements in the Manufacture of Bicarbonate of Soda and
Soda Ash.
We NEIL MATHIESON of Widnes in the County of Lancaster Chemical
Manufacturer and JOSEF HAWLICZEK of the same place Chemist do hereby declare
the nature of this invention and in what manner the same is to be performed,
to be particularly described and ascertained in and by the following statement:
This Invention has for its object the manufacture of either pure bicarbonate of
Soda or of pure mono carbonate of Soda (Soda Ash) direct from the crude
carbonate of Sodium liquors commonly called vat liquor" or (after the deposition
of the Soda Salts by boiling) "red liquor" or from crude carbonate of Sodium
commonly called "black ash" all of the Le Blanc process or from a solution of
crude sulphide of sodium or for obtaining pure sodium bicarbonate from the crude
bicarbonate of the ammonia soda process.
We find that if to a solution of chlorides or sulphates of. an Alkali such as sodium
potassium or ammonium there be added a solution of crude carbonate of Soda
commonly called vat liquor and the mixture be submitted to the action of Carbonic
acid Gas as hereinafter described pure bicarbonate of Soda is precipitated in a
crystalline form which may be easily separated from the above mentioned Chloride
or Sulphate liquor by filtration or by the use of a hydro-extractor or other well
known means of separating liquids from solids.
The chloride or sulphate liquor left in contact with the Bicarbonate may be got
rid of by washing the latter with water.
"
One method of carrying out this invention is to mix a solution of Sodium
Carbonate called Vat liquor with a strong solution of Sodium Chloride.
A second mode is to use a solution of Sodium Chloride or Brine direct for
lixiviating the crude Sodium Carbonate usually termed "Black Ash."
When we
lixiviate direct with brine, we use the Brine of such a strength that the resulting
solution of Carbonate and Chloride is most suitable for precipitating the Bicarbonate
therefrom by Carbonic acid gas so that the brine can be used over and over again.
The mixture of Brine and crude Carbonate of Sodium is now ready for the first
treatment with Carbonic acid gas and we call this first treatment the "Purifying
process."
By this treatment we get rid of certain impurities in the Black Ash liquor such
as Alumina, Silica and Iron.
This purification of the liquor is one of the main points of our invention as by
this treatment impurities are got rid of which if allowed to remain would render it
impossible to manufacture pure soda products of good colour.
The said purifying process may be performed in any suitable vessel but we
prefer to use a cylindrical iron vessel which is provided with shelves for the
distribution of the Carbonic acid gas. We preferably use the Carbonic acid gas

page_text: which is passing over from the "absorption column" being the excess of the
carbonic acid gas used for the precipitation of the pure Bicarbonate as hereinafter
described. By this purifying treatment the Alumina, Silica and Iron are precipi-
tated and after the solution is filtered, we obtain a clear liquor free from these
impurities and ready for the precipitation of the pure Bicarbonate of Soda.
To effect this precipitation we subject the purified liquor to the further action of
a current of Carbonic acid.gas; this operation is preferably performed in a high
cylindrical tower provided with compartments and gas distributors for the purpose
of ensuring the mixing of the liquor with the Carbonic acid gas. In this apparatus
which we call the "Absorbing Column" the precipitation of the pure Bicarbonate
takes place.
We have found that during the precipitation of the pure Bicarbonate the
Carbonic acid gas has a very marked action on the Sulphides and Cyanides
remaining in the liquor. These compounds are by the second treatment with the
Carbonic acid gas decomposed, precipitating the equivalent quantity of Sodium
Bicarbonate with the evolution of Sulphuretted hydrogen and cyanogen.
After the precipitation of Bicarbonate has taken place we allow the liquor with
the Bicarbonate to run on to an ordinary vacuum filter or we use a hydro-extractor
in order to separate the Bicarbonate from the Chloride liquor: The Bicarbonate is
then washed with a quantity of water sufficient to remove any Chloride liquor
which may be left in contact there with.
The Bicarbonate is now in chemically pure state or nearly so and is either by
drying converted into pure marketable Bicarbonate of Soda or by calcining into
pure monocarbonate (Soda Ash).
The liquor remaining consists mostly of Sodium chloride and can be used over
again for lixiviating fresh Black ash.
To make pure Bicarbonate from crude Bicarbonate of Soda produced by the
Ammonia Soda process we preferably dissolve the cru le Bicarbonate direct in a
solution of Sodium Chloride or Sulphate or a mixture of both of a suitable strength
and subject this liquor to a similar treatment with Carbonic acid gas by which
means we precipitate Bicarbonate of Soda in a purified condition.
If a solution of crude Sulphide of Sodium be treated in the way above described
and the mixture subjected to the action of Carbonic acid gas, the Sulphide of
Sodium is decomposed Sodium Bicarbonate is precipitated and sulphuretted
hydrogen is evolved.
The sodium Bicarbonate thus obtained when further treated as hereinbefore.
described can be either converted into pure marketable Bicarbonate of Soda or by
calcination into pure Sola Ash.
The sulphuretted hydrogen resulting from the decomposition of the aforesaid
Sodium sulphide can either be burnt for manufacturing Sulphuric acid or be
utilised by any known means.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed we declare that what
we claim is: -
First The processes substantially as herein described for the manufacture of
either pure Sodium bicarbonate or pure Soda Ash direct from the crude Carbonate
of Sodium liquor termed "Vat liquor" or from that termed "Red liquor" (both
from the Le Blanc process) mixed with a Sodium chloride or Sodium sulphate
solution (or other solution of a chloride or sulphate of 'an alkali) or from crude
Carbonate of Sodium termed "Black_ash" (also from the Le Blanc process).
lixiviated with a Sodium chloride solution or a solution of Sodium Sulphate (or
other solution of a chloride or sulphate of an Alkali) or direct from a crude sulphide
of Sodium solution mixed with a solution of Sodium Chloride or sodium sulphate
(or other solution of a chloride or sulphate of an alkali) the mixtures aforesaid
being treated with carbonic acid gas as herein before described or for obtaining

page_text: pure Sodium bicarbonate direct from the crude bicarbonate of the Ammonia Soda
process by treatment with carbonic acid gas as herein before described.
Second-The purification of crude Carbonate of Sodium or crude sulphide of
Scium when in admixture with chloride or Sulphate of sodium liquor (or liquor of
other chloride or sulphate of an alkali) by means of carbonic acid gas applied
beore the precipitation of the bicarbonate substantially as herein before described.
Dated this 5th day of October 1986
NEIL MATHIESON.
JOSEF HAWLICZEK.