Improvements in Carbons for Electrodes and other purposes.
Year: 1893

page_text: Date of Application, 20th Oct., 1893
Complete Specification Left, 9th July, 1894-Accepted, 15th Sept., 1894
PROVISIONAL SPECIFICATION.
Improvements in Carbons for Electrodes and other purposes.
I, HAMILTON YOUNG CASTNER of 13 Abchurch Lane, in the City of London,
Managing Director of The Aluminium Company Limited, do hereby declare the
nature of this invention to be as follows:-
Carbon electrodes have long been used in electrolytic processes, in electric
lighting, and in other forms of electrical apparatus. The present invention relates
more particularly to the preparation of electrodes for use in electrolytic processes
(such for example as in that set out in my prior Specification No. 16046 of 1892)
although the carbon prepared according to this invention may be used for other
purposes.
In all electrolytic processes wherein carbon is employed as an electrode and in
which the electrolytic decomposition results in the production of oxygen and
chlorine or a mixture of these gases from solutions, the carbons disintegrate more
or less rapidly and so form a considerable item of expense in carrying on the
process.
I judge from experiments that the disintegration of the electrodes is largely due
to the oxidization and solution of the carbon or hydrocarbons present in the
carbons and which to a considerable extent may act as binding agents by the
combined action of oxygen, chlorine, and water.
To prevent as far as possible this rapid disintegration of the electrodes I propose
to treat the carbon in such a manner as will to a large extent convert the ordinary
gas retort or like carbon and its contained hydrocarbons into the more fixed and
permanent variety of carbon, and this end may be attained by highly heating the
material by special means in an unoxidizing atmosphere or when it is surrounded
by charcoal. The power of an electrode so prepared to resist subsequent dis-
integration will depend to a large extent upon the temperature to which it has
been submitted.
According to my invention I propose to heat the carbon to the required degree
or sufficiently to accomplish the end in view by the passage of an electric current,
while the carbon is surrounded by charcoal powder or otherwise protected from
any oxidizing action. I have found by experiment that a current of 350
to 400 amperes passed through a carbon rod one inch square is sufficient to heat it
to dazzling whiteness in a few minutes. The ordinary gas retort carbon while
being so treated will give off an inflammable gas, decrease in weight from 3 to 7%,
will swell slightly and increase in electrical conductivity.
Not only does this treatment convert any hydrocarbon into a fixed carbon and
so help to bind together the particles of carben by a more permanent material, but
it tends to change the whole mass of carbon into the variety more closely
resembling graphite, and the electrodes so produced will be found of more uniform
character and less susceptible to chemical action than those now usually employed.
Dated this 20th day of October 1893.
PHILIP M. JUSTICE,
55 & 56, Chancery Lane, London, Chartered Patent Agent,
For the Applicant.

page_text: COMPLETE SPECIFICATION.
Improvements in Carbons for Electrodes and other purposes.
I, HAMILTON YOUNG CASTNER of 13 Abchurch Lane, in the City of London,
Managing Director of The Aluminium Company Limited 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:-
Carbon electrodes have long been used in electrolytic processes, in electric
lighting, and in other forms of electrical apparatus. The present invention relates
more particularly to the preparation of electrodes for use in electrolytic processes,
(such for example as in that set out in my prior Specification No. 16046 of 1892)
although the carbon prepared according to this invention may be used for other
purposes.
In all electrolytic processes wherein carbon is employed as an electrode, and in
which the electrolytic decomposition results in the production of oxygen and
chlorine, or a mixture of these gases from solutions, the carbons disintegrate more
or less rapidly, and so form a considerable item of expense in carrying on the
process.
I judge from experiments that the disintegration of the electrodes is largely due
to the oxidization and solution of the carbon or hydrocarbons present in the
carbons, and which to a considerable extent may act as binding agents by the
combined action of oxygen, chlorine and water.
To prevent as far as possible this rapid disintegration of the electrodes I propose
to treat the carbon in such a manner as will to a large extent convert the ordinary
gas retort or like carbon and its contained hydrocarbons into the more fixed and
permanent variety of carbon, and this end may be attained by highly heating the
material by special means in an unoxidizing atmosphere or when it is surrounded
by charcoal. The power of an electrode so prepared to resist subsequent dis-
integration will depend to a large extent upon the temperature to which it has been
submitted.
According to my invention I propose to heat the carbon to the required degree,
or sufficiently to accomplish the end in view by the passage of an electric current,
while the carbon is surrounded by charcoal powder or otherwise protected from any
oxidizing action. I have found by experiment that a current of 350 to 500 amperes
and about 15 volts passed through a carbon rod one inch square is sufficient to
heat it to dazzling whiteness in a few minutes. The ordinary gas retort carbon
while being so treated will give off an inflammable gas, decrease in weight from
3 to 7%, will swell slightly and increase in electrical conductivity.
Not only does this treatment convert any hydrocarbon into a fixed carbon and so
help to bind together the particles of carbon by a more permanent material, but it
tends to change the whole mass of carbon into the variety more closely resembling
graphite, and the electrodes so produced will be found of more uniform character
and less susceptible to chemical action than those now usually employed.
I am aware it has heretofore been proposed to carbonize paper and other
substances and also to heat various materials by the passage of an electric current,
and I do not desire to make any broad claim to such methods of manufacture, but
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 :-
1. The improved process of treating gas retort and like carbon consisting in
submitting it while in an unoxidizing atmosphere to the action of intense heat by
the passage through it of an electric current, substantially as and for the purposes
set forth.

page_text: 2. As an article of manufacture the improved carbon resulting from electrically
treating gas retort or like carbon, substantially as described.
Dated the 9th day of July 1894.
PHILIP M. JUSTICE,
55 & 56, Chancery Lane, London, Chartered Patent Agent,
For the Applicant.