Improvements in and relating to the Production of Chlorine and to the Manufacture of Sulphate of Soda.
Year: 1889

page_text: Date of Application, 9th Feb., 1859
Complete Specification Left, 9th Nov., 1889-Accepted, 14th Dec., 1889
PROVISIONAL SPECIFICATION.
Improvements in and relating to the Production of Chlorine and to
the Manufacture of Sulphate of Soda.
We, THOMAS PARKER of the firm of Elwell-Parker Limited, Electrical Engineer,
and ALFRED EDWARD ROBINSON, Technical Chemist, both of Commercial Road
Wolverhampton in the County of Stafford, do hereby declare the nature of this
invention to be as follows:-
According to our present Invention, Chlorine and sulphate of soda aro produced by
the simultaneous electrolysis of two solutions.
In carrying out our Invention, we employ an electrolysing vessel divided into two
parts by a porous diaphragm or equivalent device. Tuo one of the compartments
we introduce a solution of sodic chloride, and into the other a sulphate solution. For
the sulphate solution we prefer to uso sulphate of iron. (this being the cheapest,) but
other sulphates such as the sulphates of zinc and of copper may he employed. Carbon
electrodes may be used in each solution, or a platinum electrode may be used in the
chloride solution and an iron electrode in the iron solution.
Upon the passage of a current of electricity through the solutions, chlorine will be
evolved from the solic solution, while the sulphuric acid will leave the sulphite
solution and combine with the sodium to form sodic sulphate or "salt cake." The
metallic base will therefore be thrown down in the compartment containing the
sulphate solution.
The chlorine may be passed through lime to form bleaching powder or it may be
otherwise uti.ized in any known or suitable manner.
The sulphate of sola may be evaporated, dried, and be mixed with chalk and coal
dust and loated in a known manner for the manufacture of sodic carbonate, or it may
be otherwise dealt with.
Dated this 6th day of February AD 198a
WILLIAM E. HEYS,
Agent for the Applicants.
COMPLETE SPECIFICATION.
Improvements in and relating to the Production of Chlorine and to
the Manufacture of Sulphate of Soda.
We. THOMAS PARKER of the Electric Construction Corporation Limited, Electrical
Engineer, and ALFRED EDWARD ROBINSON Technical Chemist, both of Commercial
Road Wolverhampton in the County of Stifford, 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:-
According to our present Invention, Chlorine and Sulphate of Soda are produced by
the simultaneous electrolysis of two solutions.
In carrying out our Invention we employ an electrolysing vessel divided into two
parts by a septum or porous diaphragm or equivalent device. Into one of the com-
partments of the electrolysing vessel we introduce a solution of sodic chloride and
into the other compartment a suitable sulphate solution. For the sulphate solution
we prefer to use sulphate of iron because of its comparative cheapness but in some
cases where the economical reason does not apply, other metallic sulphates or
sulphates having an insoluble base such as the sulphate of copper or of zine may
be employed.
It is not necessary to use any precise strength of either of the solutions as the
process may be carried out with any strengths varying from about five per cent. of

page_text: the respective salts up to saturated solutions but it may be taken that as a rule
solution having a little more than a hill saturated strength may be alvantageously
employed.
Carbon electrodes may be employed in each of the compartments, or a plationm
electrode may be used in the chloride solution and an iron electrode in the iron
solution, or platinum electrodes may be used in each solution.
The pressure of the current will vary with the thickness of the diaphragmn
separating the solutions and with the resistance of the solutions but such a current
as would pass under a pressure of seven or eight volts when using diaphragms of con-
siderable thickness may be used for solutions of ordinary strength. With a thinner
diaphragm a lower pressure may be employed.
Upon the passage of a current of electricity through the solutions, chlorine will be
evolved from the sodic solution, while the sulphuric acid will simultaneously leave
the sulphate solution and combine with the liberated sodium of the soda solution to
form sulphate of soda or "salt cake." The iron or other metallic base will therefore
be thrown down in the compartiment of the electrolysing vessel containing the
sulphate solution.
The liberated chlorine will be collected from the electrolysing vessel under a hood
or cover and be led away in the gaseous form and be utilisel by passing it through
lime to form bleaching powder, or it may be otherwise utilised as is well understood
by chemists.
The resulting sulphate of soda solution may be evaporated, dried, mixed with chalk
and coal dust and heated in a well known manner for the formation of solic carbonate,
or it may be otherwise dealt with by means and for purposes also well known and
understood by chemists.
Having now particularly described and ascertained the nature of my suid Inven-
tion and in what manner the same is to be performed, we declare that what we
claim is ;-
(1) The manufacture or production of chlorine by the simultaneous electrolysis of
a solution of sodic chloride und of a solution of a suitable sulphate the two solutions
being separated by a septum or porous diaphragm during electrolysis; sub-tantially ns
hereinbetore described."
(2) The manufacture or production of sulphate of soda and of a metallic base by
the simultaneous electrolysis of a solution of sodic chloride and of a solution of a
suitable sulphate, the two solutions being suparated by a septum or porous diaphragm
during electrolysis; substantially as hereinbefore described.
Dated this 8th day of November A.D. 1889.
WILLIAM E. HEYS,
Agont for the Applicants.