Improvements in Treating Chlorides for the Production of Chlorine and Alkalies or Alkaline Earths, and the Recovery of Bye Products.
Year: 1895

page_text: Date of Application, 30th May, 1895
Complete Specification Left, 8th Feb., 1896-Accepted, 21st Mar., 1896
PROVISIONAL SPECIFICATION.
Improvements in Treating Chlorides for the Production of Chlorine
and Alkalies or Alkaline Earths, and the Recovery of Bye
Products.
We, ROBERT MAIN, of Ardeer Cottage, Stevenston, Ayrshire, Iron Works
Manager, and WILLIAM DONALD, of Canal Street, Saltcoats, Ayrshire,
Analytical and Practical Chemist, do hereby declare the nature of this invention
to be as follows :-
This invention has for its object the production of chlorine and of alkalies such
as soda and potash as hydrate or in other form, from the corresponding alkaline
chlorides, as also of certain bye-products, by a simple and inexpensive process of
treatment.
Under the invention common salt aul manganese dioxide intimately incorporated
are treated with a mixture of nitric acid and water.
On the application of heat decomposition takes place there being evolved chlorine
charged with moisture and a residue consisting of nitrate of manganese, nitrate of
soda, nitric acid and water. This is now submitted to a higher temperature when
further decomposition takes place, there being evolved oxides of nitrogen and
watery vapours which are conveyed into a known oxidising arrangement and by
the addition of air converted into nitric acid and water.
The resulting residue consists of a compound of manganese and soda. This is
dissolved in water and whilst hot, air is blown in, the caustic soda passes into
solution, and the manganese is precipitated. The caustic solution is now treated
for any of the purposes required in the arts and manufactures.
Instead of sodium chloride there may be employed any other analogous chloride
as for example barium chloride, potassium chloride, calcic chloride or other
chloride or mixtures of these in which case the corresponding caustic alkali or
alkaline earth would be produced.
In lieu of binoxide of manganese any other metallic oxide capable of parting
with part of its oxygen and of combining with the alkali may in some cases
be used.
Dated this 29th day of May 1895.
WALLACE FAIRWEATHER,
Chartered Patent Agent,
62 St. Vincent Street, Glasgow, Agent for the Applicants.
Improvements in Treating Chlorides for the Production of Chlorine
and Alkalies or Alkaline Earths, and the Recovery of Bye
Products.
We, ROBERT MAIN, of Ardeer Cottage, Stevenston, Ayrshire, Iron Works
Manager, and WILLIAM DONALD, of Canal Street, Saltcoats, Ayrshire,
Analytical and Practical Chemist, do hereby declare the nature of this invention

page_text: 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 production of chlorine and of alkalies such
as sola and potaslı as hydrate or in other form, from the corresponding alkaline
chlorides, as also of certain bye-products, by a simple and inexpensive process of
treatment.
Under this invention common salt, or rock salt, and the black oxide of
manganese, intimately incorporated, are treated with a mixture of nitric acid and
water.
The relative quantities of the salt, manganic oxide, nitric acid, and water should
be proportioned to the purity of the salt and the required decomposition. For
example equal parts by weight of salt and peroxide of manganese may be incor-
porated, and a sufficiency of nitric acid of 68 degrees Twaddle or 1-34 specific
gravity may be used to decompose the whole or part of the salt.
Heat is applied, and the chemical reactions take place at temperatures between 15°
and 120° Centigrade.
Chlorine, charged with varying small proportions of moisture, is evolved; and
there is left a residual product consisting of nitrate of soda, nitrate of manganese,
water, and free nitric acid.
The residual product is evaporated and roasted. In this operation the nitrates
are decomposed, with formation of watery vapours and oxides of nitrogen. The
removal of the last traces of the nitrates may be assisted by the further addition
of manganic oxide.
The gaseous products of decomposition are conveyed into known oxidising
towers, and by the addition of air by air-blowing converted into nitric acid and
water.
The residue, resulting from the roasting, consists of a compound of soda, and a
compound of manganese. This is dissolved in water whilst hot or treated with
water and steam, and air is blown in, with the object of raising the manganese to a
higher form of oxidation.
The caustic soda, which is in solution, is withdrawn and may be carbonated with
carbonic acid to form sodium carbonate or bicarbonate, or it may be concentrated
or otherwise used for any of the purposes to which caustic soda is applied in the
arts and maunfactures.
The peroxidized manganese is deposited, washed, dried, and again used for a fresh
operation.
Instead of sodium chloride there may be employed any other alkaline chloride,
as for example barium chloride, potassium chloride, calcic chloride, magnesic
chloride, or other chloride, or mixture of these, in which case the corresponding
caustic alkali, or alkaline earth, would be produced.
In cases where the caustic alkali may not be so soluble as that of soda or of
potash, for instance, lime and magnesia, the manganese contained in the roasted
residue may be treated for oxidation by the hot-air method. That is, the substance
is contained in shallow trays and exposed to the action of heated air. This mixture
of caustic lime and peroxidized manganese may now be employed for treating
ammonic chloride. Calcic chloride and manganic oxide is produced and may now
be treated with nitric acid and water for the production of chlorine.
In lieu of black oxide of manganese, cobaltic oxide, nickelic oxide, or other
metallic oxide capable of parting with part of its oxygen to form water, of setting
the chlorine free and of combining with the alkali may in some cases be used.
The chlorine may be generated in an ordinary stoneware still, or other suitable
apparatus, such as a trickling tower, kept at the required temperature by an
external application of heat.
The evaporating and roasting may be conducted in an arrangement of furnace
or furnaces after the manner of a blind-roaster, or muffle-salt-cake furnace;
preferably with a mechanical means for the continuous motion of the charge
throughout the operation.

page_text: 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 :-
1. The herein described process of treating alkaline chlorides for the production
of chlorine and the alkalies contained in such chlorides and the recovery of bye-
products.
2. The production of chlorine from alkaline chlorides by treating a mixture of
the chloride and manganic oxide or analogous metallic oxide with nitric acid and
water substantially as described.
3. In the manufacture of chlorine by treating an alkaline chloride and manganic
oxide or analogous metallic oxide with nitric acid and water, recovering the alkali
corresponding to the chloride employed by roasting the residual product to
decompose the nitrates, dissolving the residue in water and separating the manganese
or other metallic oxide by decomposition from the alkali in solution substantially
as described.
4. In the manufacture of chlorine by treating an alkaline chloride and manganic
oxide with nitric acid and water, peroxidizing and recovering the manganese by
roasting the residual product, dissolving in water, blowing in air and separating
the manganic oxide by deposition substantially as described.
5. In the manufacture of chlorine by treating an alkaline chloride and manganic
oxide or analogous metallic oxide with nitric acid and water, obtaining nitric acid
as a bye-product by roasting the residual nitrates and subjecting the oxides of
nitrogen evolved to oxidation substantially as described.
Dated this 7th day of February 1896.
WALLACE FAIRWEATHER,
Chartered Patent Agent,
62 St. Vincent Street, Glasgow, Agent for the Applicants.