Improvements in the Treatment of Bicarbonate or soda for Obtaining Useful Products therefrom.
Year: 1885

page_text: Improvements in the Treatment of Bicarbonate or soda for
Obtaining Useful Products therefrom.
I HOLBROOK GASKELL the younger of Widnes in the County of Lancaster
Chemical Manufacturer do hereby declare the nature of my said Invention for
IMPROVEMENTS IN THE TREATMENT OF BICARBONATE OF SODA FOR OBTAINING
USEFUL PRODUCTS THEREFROM to be as follows:-
"
"
My Invention relates to the treatment of Bicarbonate of Soda made by what is
known as the "Ammonia Soda Process" in which process Ammonia and Carbonic
Acid are caused to react upon Sodium Salts in solution in such a way as to
precipitate Bicarbonate of Soda more or less impregnated with Ammonia.
According to my Invention I dissolve this precipitated Bicarbonate of Soda in
water at or near a boiling temperature so that steam Ammonia and Carbonic Acid
are evolved.
This steain and ammonia are condensed and the liquid of condensation may be
used for the solution of more Bicarbonate of Soda or may be treated for the
recovery of the Ammonia or may be used for other purpose. The Carbonic Acid
may be used in the manufacture of Soda by the Ammonia process or in the
manufacture of Bicarbonate of Soda or for other purpose.
The solution obtained by dissolving the precipitated Bicarbonate of Soda in
water as hereinbefore described may be used for the direct production of Soda
Crystals or may be evaporated by heat. During the evaporation crystals of
Monohydrated Carbonate of Soda are deposited and are removed by "fishing" or
otherwise and may be prepared for sale as Monohydrated Carbonate of Soda,
or may be exposed to the action of Carbonic Acid and so be converted into
Bicarbonate of Soda or may by exposure to sufficient heat be converted into
Anhydrous Carbonate of Soda as is well understood.

page_text: UI DIcarbonate Of Soda for
Obtaining Useful Products therefrom.
I HOLBROOK GASKELL the younger of Widnes in the County of Lancaster
Chemical Manufacturer 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 :-
My Invention relates to the treatment of Bicarbonate of Soda made by what are
known as Ammonia Soda processes in which processes Ammonia and Carbonic
Acid are caused to react upon Sodium Salts in solution in such a way as to
precipitate Bicarbonate of Soda more or less impure and impregnated with
Ammonia.
According to my Invention I dissolve this precipitated Bicarbonate of Soda in
water at or near a boiling temperature and I boil the solution until it is free from
Ammonia.
During this operation the Bicarbonate of Soda is decomposed a solution of
mono-carbonate of Soda is produced and Steam, ammonia and Carbonic Acid Gas
are evolved. These gases are conveyed together to a condenser, in which the
steam and the Ammonia condense and flow off as a solution of Ammonia or
carbonate of Ammonia in water, from which solution the Ammonia may be
recovered by distillation as is well understood. The carbonic acid gas thus freed
froin the Ammonia and steam, is passed on and may be utilised in the manufacture
of soda by the ammonia process, or in the manufacture of bicarbonate of soda or
for other purposes.
The solution of mono-carbonate of soda which may not be perfectly clear and
must then be settled or filtered so as to remove any lime magnesia and iron, is
then ready for further treatment and may be allowed to crystallise, thus producing
ordinary soda crystals, or the clarified solution may be evaporated. During the
evaporation crystals of mono-hydrated Carbonate of soda are deposited and are
removed by fishing or otherwise, which crystals may be sold or be exposed to the
action of Carbonic acid and so converted into Bicarbonate of soda, as is well
understood, or the crystals may be heated and converted into anhydrous carbonate
of soda. Or the solution of mono-carbonate of soda may be causticised and further
treated as is well known for obtaining caustic soda.
Many kinds of apparatus may be used for the purpose of obtaining a solution of
carbonate of soda from the ammoniacal bicarbonate of soda, and I do not confine
myself to any particular apparatus, but in order to more clearly indicate how the
Invention is to be carried out I give a description and drawings of the apparatus
which I prefer.
The illustration represents an apparatus which works intermittently. A is a
cylindrical vessel provided with an agitator B driven by suitable gearing C This
vessel is partially filled with cold water through the pipe D and then while the
agitator is constantly working the finely divided damp bicarbonate of soda as it is
obtained directly from the ammonia soda process, is charged into this vessel in
such proportion that the solution may afterwards become a saturated or nearly

page_text: saturated solution of carbonate of soda. The bicarbonate of soda does not dissolve
in the cold water but forms an emulsion. The liquid constantly agitated is then
allowed to flow through valve and pipe E into the dissolver or still F, a cylindrical
vessel of iron or other suitable material. This vessel F is closed at the top and if
desired may be provided with an agitator, but the contents are usually sufficiently
agitated by means of open steam introduced through the pipe & for the purpose of
heating and boiling. the solution. The gases, carbonic acid, ammonia, and steam
evolved during boiling, pass off through the pipe H and are conveyed to a tubular
or any other suitable condenser, the incondensible carbonic acid passing on to be
used again for other purposes. When all ammonia has been driven off (which may
be ascertained by testing a sample from time to time drawn through sampling
tap K) the solution containing monocarbonate of soda is run off through the valve I
to any other apparatus in which it may be required.
The process may be worked continuously if an ordinary continuous ammonia
still with the usual dephlegmating arrangements is substituted for the still F shewn
in the drawing. In this case the bicarbonate is mixed in the agitator with water
so as to form an emulsion which is then introduced into the ordinary continuous
ammonia still.
Having now particularly described and ascertained the nature of my said
Invention and in what manner the same is to be performed I declare that what
I claim is
The herein before described treatment of Bicarbonate of Soda impregnated with
ammonia, by submitting it to a boiling temperature and obtaining useful products
therefrom, substantially as herein before described.
Dated this 4th dow of Tam