Improvements in the Revivification of Materials employed for the Purification of Coal Gas, and in the Treatment of the Residues.
Year: 1890

page_text: Date of Application, 20th Sept., 1890
Complete Specification Left, 6th July, 1891-Accepted, 5th Sept., 1891
PROVISIONAL SPECIFICATION.
Improvements in the Revivification of Materials employed for the
Purification of Coal Gas, and in the Treatment of the Residues.
I, CHARLES WILLIAM Jones, of the Gas Works, Milan, in the Kingdom of
Italy, Gas Engineer, do hereby declare the nature of this invention to be as
follows:-
My invention chiefly relates to the revivification of oxide of iron and other
materials used for the purification of coal gas.
The method of revivifying the purifying material generally employed for the
manufacture of gas, (for example Lamings' oxide) by simple exposure and turning
over in the open air, is defective in so far that after a time the said material is
exhausted and so rendered unfit for further use as a purifying agent.
The object of my said invention is to render the said material again active and
to obtain at the same time, as a. residue, the composition of ferric-cyanide which
renders the material inert as a purifying agent.
According to my invention the exhausted material is watered and mixed with
quicklime in the proportion of, say, six per cent. It is then placed in a heap and
allowed to remain until the reaction is complete, which is noticeable by its change
of colour, owing principally to the oxidation of the sulphates of iron and the
expulsion of a certain quantity of sulphur.
The lime has now transformed the sulphates and compounds of ferric-cyanide
into the corresponding salts of lime, the oxide is reformed and is ready to be washed
in order to take out the cyanides in combination with the lime.
The washing may be conducted as follows:-
The material is placed into a series of vessels or receptacles connected together
by means of circulating pipes, and clean water (soft water being preferred) is passed
therethrough. The circulation is so arranged that one of the receptacles remains.
full, and after being subjected to the washing is emptied of the material and
recharged and retakes its place in the circuit. The material when washed is ready
to be used in the purifiers.
The whole of the receptacles are in communication with a reservoir which
receive the washings when the necessary strength and richness in cyanides is
attained. The washing liquor is put into a series of boilers, the first boiler of
which is closed by means of a syphon containing sulphuric acid, which collects the
ammonia during evaporation. The succeeding boilers are simple evaporating
pans exposed to the air and from which the cyanides are obtained in the form of
a paste.
בד
L 11
201 1
1000
COMPLETE SPECIFICATION.
Improvements in the Revivification of Materials employed for the
Purification of Coal Gas, and in the Treatment of the Residues.
I, CHARLES WILLIAM JONES, of the Gas Works, Milan, in the Kingdom of
Italy, Gas 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 :-
My invention chiefly relates to the revivification of oxide of iron and other
materials used for the purification of coal gas.

page_text: The method of revivifying the purifying material generally employed for the
manufacture of gas, (for example Lamings' oxide) by simple exposure and turning
over in the open air, is defective in so far that after a time the said material is
exhausted and so rendered unfit for further use as a purifying agent.
The object of my said invention is to render the said material again active and
to obtain at the same time, as a residue, the composition of ferric-cyanide which
renders the material inert as a purifying agent.
According to my invention the exhausted material is watered and is mixed with
say about six per cent. of quicklime. It is then placed in a heap and allowed to
remain until the reaction is complete, which is noticeable by its change of colour,
owing principally to the oxidation of the sulphates of iron and the expulsion of a
certain quantity of sulphur.
The lime has now transformed the sulphates and compounds of ferric-cyanide
into the corresponding salts of lime, the oxide is reformed and is ready to be washed
in order to take out the cyanides in combination with the lime.
The washing and subsequent treatment of the washing liquor may be effected
in the following manner, reference being bad to the accompanying drawing, in
which :-
Figure 1 is an elevation of the washing apparatus:
Figure 2 is an elevation; and,
Figure 3 is a plan of an arrangement of boilers for evaporating the washing
liquor.
d
The material is placed into a series of vessels or receptacles numbered 1, 2, 3,
and 4 in Figure 1, and connected together by means of circulating pipes a, a, and
clean water (soft water being preferred), supplied by an arrangement of pipes b, c,
from a tank e, is passed therethrough, its direction of flow through the vessels and
circulating pipes being indicated by arrows. The circulation is so arranged that
one of the receptacles remains full, and after being subjected to the washing is
emptied of the material and recharged and retakes its place in the circuit. The
material when washed is ready to be used in the purifiers.
The whole of the receptacles are in communication with a reservoir (not shewn
in the drawing) which receives the washings when the necessary strength and rich-
ness in cyanides is attained. The washing liquor is put into a series of boilers
shewn in Figures II and III, the first boiler A of which is closed by means of a
syphon dipping into a vessel B containing sulphuric acid, which collects the
ammonia during evaporation. The succeeding boilers C and D are simple
evaporating pans exposed to the air and from which the cyanides are obtained in
the form of a paste.
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 revivification of materials employed for the purification of coal gas by
mixing the spent or exhausted materials with quicklime in about the proportion
named and afterwards washing them to recover the cyanides, substantially as set
forth.
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.