IMPROVEMENTS IN THE PRODUCTION OF SODIUM AND POTASSIUM
Year: 1869

page_text: PROVISIONAL SPECIFICATION left by Henry Larkin and William White
at the Office of the Commissioners of Patents, with their Petition,
on the 1st July 1869.
We, HENRY LARKIN, of No. 6, Torriano Cottages, Leighton Road,
and WILLIAM WHITE, of No. 30, Thurlow Road, Hampstead, both
in the County of Middlesex, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN THE PRODUCTION OF SODIUM AND POTASSIUM,"
to be as follows:-
Sodium and potassium are usually obtained by the reaction of
carbon on their several carbonates at a high temperature. The carbonate,
or in some cases the hydrate of the required metal, is intimately mixed in
proper proportions with powdered coke or coal, sometimes with the
addition of chalk, and placed in an iron retort. It is then exposed to a
bright red heat, approaching to whiteness, in a suitable furnace, when the
metal distils off and is collected by a condenser. We greatly facilitate
the bringing of the entire mass to the requisite high heat, by previously
adding to the materials employed a proportion of nitrate of the metal to
be obtained. By this addition as soon as any portion of the contents of
the retort becomes heated to redness, the nitrate by freely parting with
two-thirds of its oxygen to the heated carbon carries a vivid com-

page_text: bustion into the very centre of the retort, and its entire contents
become rapidly and spontaneously heated almost to the points of
reduction; at the same time the oxide which remains from the nitrate
becomes material for a further quantity of metal in addition to that
contained in the carbonate. We thoroughly mix the ingredients in the
form of fine powder, and work them into a stiff paste with water;
this paste is then dried in cakes in a hot oven, and broken into
small lumps ready for the retort; this not only ensures an intimate
mingling of the nitrate with every part of the material, but also prevents
waste of material which would otherwise arise from its being blown
out of the retort as dust by the rapidity of the combustion. We use a
cylindrical retort somewhat similar to that generally employed but with
a wide neck, or preferably we keep the exit end of the retort the full
diameter of the retort itself; to this open end of the retort we attach a
tranverse condenser so constructed as to oppose an extended surface to
the issuing metallic vapours; against this surface they condense and
are then conducted into a receiver below while the carbonic oxide
simultaneously generated is allowed to escape through apertures
arranged above. We also construct a vessel upon the outer surface of
the condensing plate to contain water or any suitable cooling mixture, and
through which the tubes for the escape of the carbonic oxide are made to
pass. We place the retort in the furnace vertically, or at an angle with
the mouth above the level of the closed end, instead of horizontally as is
the usual practice. We construct the furnace so that the side or upper
portion through which the mouth of the retort passes shall be inclined
from the perpendicular with the flue or chimney of the furnace directly
above it; this side or upper portion may consist of an iron plate. By
this arrangement nearly the entire length of the retort may easily be
kept at an uniform heat, and the condensation of the metallic vapours be
very suddenly effected, a point of the greatest importance for preventing
waste of metal. The same arrangement of apparatus may also be
employed for redistilling potassium for the purpose of purifying it.
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