Improvements in the Electrolytic Production of Caustic Soda or Caustic Potash.
Year: 1892

page_text: Date of Application, 15th July, 1892
Complete Specification Left, 14th Apr., 1893-Accepted, 20th May, 1893
PROVISIONAL SPECIFICATION.'
Improvements in the Electrolytic Production of Caustic Soda or
Caustic Potash.
I CHARLES ANTHONY BURGHARDT of 35 Fountain Street Manchester in the
County of Lancaster Analytical Chemist do hereby declare the nature of this
invention to be as follows:-
--
My invention relates to the production of caustic soda or caustic potash from
the sodium or potassium produced by means of the process for which Letters Patent
were granted to Ludwig Grabau No. 15792 of 1889 and No. 16060 of 1890. In
order to carry this invention out into practice I cause the metallic sodium or
potassium passing from the apparatus there described to pass through a suitable tube
or pipe which is heated to a heat above the point at which these metals become
vapour. At a point in this heated tube where the metals are entirely in the state
of vapour I introduce a regulated amount of steam by means of a suitable injector
which produces two effects the first being an exhaust which assists the passage of
the melted metals into the vaporising portion of the tube and the second effect is
the combination of the water with the respective metals resulting in the production
of caustic soda or caustic potash. By keeping the tube or pipe heated above the
fusing points of the respective caustic alkalies and bent in such a manner as to
cause the melted material to flow solid melted caustic soda or caustic potash flow
out at the delivery end of the pipe or tube and can at once be collected in suitable
iron drums for transmission. The melted caustic alkali sets hard on cooling. By
this means I obtain solid caustic alkali direct from the metals sodium or potassium
without a tedious and costly evaporation of water from a solution.
Dated this Fourteenth day of July 1892.
CHARLES ANTHONY BURGHARDT.
COMPLETE SPECIFICATION.
Improvements in the Electrolytic Production of Caustic Soda or
Caustic Potash.
I CHARLES ANTHONY BURGHARDT of 35 Fountain Street in the City of
Manchester in the County of Lancaster Analytical 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 :-
My invention relates to the production of caustic soda or caustic potash from
metallic sodium or metallic potassium produced electrolytically from a melt
consisting of sodium chloride principally in the production of metallic sodium
and potassium chloride principally in the production of metallic potassium. In
some cases I take the sodium produced by the process for which Ludwig
Grabau of Hanover Germany has obtained Letters Patent numbered 157928
and 160600 as a basis as it enables one to melt sodium chloride at a convenient
temperature.
The negative pole where the metallic sodium or potassium is produced is
enclosed in a chamber dipping into the melted chloride extending below the
bottom of the negative pole. The enclosing chamber is made of iron or pot
if of iron the surface above the melt and facing the positive pole is coated with
plastic clay baked on or with asbestos paint or some other suitable covering to
protect the iron from the corrosive action of the chlorine gas evolved at the
positive pole. The enclosing chamber is preferably contracted at the upper

page_text: part in order to cause the melted metal to rise more readily & completely
cover the molten chloride below. By thus covering the surface of the melted
chloride of sodium or potassium with a seal of molten sodium or potassium the
volatilization of the said chlorides with the respective metals is prevented thus
enabling the caustic alkali subsequently obtained to be free from contamination
with chlorides of sodium or potassium. To the upper part of the enclosing
chamber I attach a wide tube or pipe of iron properly insulated which is
heated above the volatilizing temperature of metallic sodium or potassium so
that when the melted metal rises into the tube it is at once converted into
vapour. This heated iron tube or pipe is connected with an exhaust or fan
which draws the metallic vapour into a wide pipe or chamber placed at right
angles to it the latter pipe or chamber being in a vertical position. Into this
vertical pipe or chamber a jet of steam is introduced which serves the double
purpose of drawing off the metallic vapour and converting it into caustic alkali.
The lower portion of the vertical pipe or chamber dips into a layer of water
contained in a tank placed underneath it and the caustic liquor collected in
the tank can afterwards be drawn off & concentrated or not as may be required.
By using the steam-jet in the manner described the necessary freedom from
atmospheric air is ensured & the working of the process is rendered safe.
my
Having now particularly described and ascertained the nature of said
invention & in what manner the same is to be performed I declare that what
I claim is
(1.) The process for the preparation of caustic soda or caustic potash by
volatilizing the metallic sodium or metallic potassium & causing steam or water
vapour to act upon the said metallic vapours substantially as set forth.
(2.) The causing the metallic vapours to be drawn into a heated tube or
chamber previously rendered as free from atmospheric air as possible by any
suitable means and combining the metallic vapours with water vapour substantially
as set forth.
Dated this Twelfth day of April 1893.