Improvements in Materials for Diaphragms for Use in Electrolytic Processes, applicable also for Filtering and other Purposes.
Year: 1893

page_text: Date of Application, 29th Mar., 1893
Complete Specification Left, 30th Nov., 1893-Accepted, 13th Jan., 1894
PROVISIONAL SPECIFICATION.
Improvements in Materials for Diaphragms for Use in Electrolytic
Processes, applicable also for Filtering and other Purposes.
I EDWIN THORLEY PARKER, of Newbridge House Tettenhall Road
Wolverhampton in the County of Staffordshire, Electrical Engineer, do hereby
declare the nature of this invention to be as follows:-
The usual diaphragms are acted upon by the liberated ions, in the electrolysis of
alkalis, and, are subject to great variation of electrical resistance, & rapid
disentegration.
I have discovered that fluoride of calcium made into wool, or, finely divided, is
not so acted upon, and, is practically satisfactory for such employment. It may be
woven and used as cloth between solutions, or, perforated vessels may be lined with
it. It may be used in any suitable mechanical manner. The object, being to
prevent diffusion, of liquids, or, gasses, while allowing electrolysis through itself, at
small, and constant electrical resistance.
I prefer fluoride of calcium on account of its price. Cryolite or other fluorides
may be used.
The "wool" will be found of great use as a means of filtering and other uses in
chemical processes where glass and silicates will be attacked.
Dated this 27th day of March 1893.
EDWIN THORLEY PARKER.
Improvements in Materials for Diaphragms for Use in Electrolytic
Processes, applicable also for Filtering and other Purposes.
I, EDWIN THORLEY PARKER of Newbridge House, Tettenhall Road,
Wolverhampton in the County of Stafford, Electrical Engineer, 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:-
Diaphragms usually hitherto used in electrolytic processes are acted upon by the
liberated ions in the electrolysis of alkalis and are subject to great variation of
electric resistance and to rapid disintegration and it is the object of my invention
to obviate these objections.
I have discovered that fluoride of calcium, made into wool, or finely divided, is
not subject to the said objections and is not so acted upon and that it can be
practically employed in place of ordinary diaphragms with satisfactory results.
The said fluoride may be divided, or made into the form of wool by any suitable
process, such, for instance, as that by which slag wool is made. It may be used in
any suitable manner as a diaphragm; for instance, it may be woven, or otherwise
incorporated, or made into a coherent article, and be used as a cloth between the
solutions in the electrolytic processes, or perforated vessels may be lined with it, so
that the object is attained of preventing diffusion of liquids, or gases, whilst
allowing electrolysis through itself with small, and constant, electrical resistance.
The said "wool," or divided fluoride of calcium, will also be of great use as a
filtering medium and in other operations in chemical processes where glass and the
silicates would be attacked or acted upon.

page_text: I have mentioned fluoride of calcium as I prefer it on account of its cheapness,
but aluminium fluoride (cryolite), may be used in place thereof if desired.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
The use of fluoride of calcium, or fluoride of aluminium in, or as, diaphragms for
use in electrolytic processes, or for filtering, or other purposes in chemical
operations; substantially as hereinbefore explained.
Dated this 30th day of November 1893.
J. H. JOHNSON & Co.,
Agents.