Process for the Production of Graphite.
Year: 1897

page_text: Date of Application, 18th Oct., 1897-Accepted, 27th Nov., 1897
Process for the Production of Graphite.
I, FRANZ JOSEF BERGMANN, of Neheim on the Ruhr, in the German Empire,
Manufacturer, 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, that is to say :-
This Invention relates to a new process for the commercial production of graphite,
in which acetylene heated under pressure with an oxidising medium causes the
carbon, in the form of graphite, to separate, while the hydrogen becomes oxidised
into water.
The oxidation is advantageously effected by means of commercial hydrogen
peroxide, but other oxidising media, which act in a similar manner on acetylene, may
be employed.
The process is carried out as follows: Acetylene with a suitable quantity of an
aqueous solution of hydrogen peroxide is heated in a closed vessel to about 150° C. and
under a pressure of about 5 atmospheres. On the reaction, graphite and water
are formed, and the former can be collected by filtration. The reaction is represented
by the following acreation
Instead of using acetylene ready prepared, it can be produced from the carbides of
calcium, sodium, or the like.
Although in the above process pure hydrogen peroxide may be employed instead
of the aqueous peroxide of hydrogen, it is different when using carbides, as then the
presence of water is necessary. The process is that by the action of water on the
carbide acetylene is first generated and is then oxidised by hydrogen peroxide, as
hereinbefore described, so setting free the carbon. The reaction is represented by
the following equation:
When using acetylene gas, the graphite is directly obtained in a form suitable for
immediate use, while, where carbides are employed a solid reaction mass is formed
from which the graphite is separated by dissolving in hydrochloric acid, or other
suitable acid, and then filtering.
When producing graphite from carbides, crushed or pulverized carbide is introduced
into the aqueous solution of the hydrogen peroxide, in the autoclave. This apparatus
is then quickly closed and heated to about 1500 C., care being taken to keep up
therein a constant pressure of about 5 atmospheres. The reaction is completed in
from 1 to 2 hours. After the autoclave has cooled down, the gases are allowed to
escape and the mass is then treated with hydrochloric acid: the hydrate of lime (if
calcium carbide is used) is converted into easily soluble chloride of calcium, and by
ГРміла 025

page_text: dissolving out the calcium chloride in water, and then filtering and washing, the
whole of the carbon is obtained in a pure state.
Having now particularly described and ascertained the nature of my said Invention,
and in what manner the same may be performed, I declare that. I claim:
1. The process for producing graphite by heating under pressure acetylene with
hydrogen peroxide, or other suitable oxidising medium.
2. The alternative form of the process above claimed, consisting in using, in place
of acetylene, calcium or other carbide with hydrogen peroxide, or other suitable
oxidising medium, in the presence of water and heat, whereby graphite is obtained
from the reaction mass by dissolving out the metallic oxide and then filtering.
ERNEST DE PASS,
Chartered Patent Agent,
78, Fleet Street, London, & 5 Market Street, Nottingham,
Agent for the Applicant.