Year: 1894

page_text: Date of Application, 21st Aug., 1894
Complete Specification Left, 20th June, 1835-Accepted, 21st Sept., 1895
I. JOHN EDLINGTON CHASTER, of 30, Epple Road, Fulham, in the County of
Middlesex, Chemist, do hereby declare the nature of this invention to be as
follows:-
This invention relates to an improved method of manufacturing cyanides on a
commercial scale.
1
In carrying out my invention, I cause dry ammoniacal gas to pass over a suitable
mixture of carbon or charcoal and a carbonate of an alkali or alkaline earth contained
in a retort or retorts or other vessel or vessels and heated to a temperature
sufficiently high to effect dissociation, the result being the formation of cyanogen
compounds.
The ammoniacal gas need not be pure and can therefore be prepared from the
ammoniacal liquor incidentally obtained in the manufacture of illuminating gas or
from crude ammonium sulphate.
The process described above is specially adapted for enabling the nitrogen given
off from coal in the manufacture of illuminating gas to be employed in the
production of cyanide of potassium or other metallic cyanide instead of being
utilized in forming the comparatively valueless ammonium sulphate of commerce.
The ammoniacal gas is made perfectly anhydrous by passing it through a cylinder
or cylinders filled with quick-lime. The quick-lime becomes converted into slacked
slime, which can under certain conditions be utilized in making a fresh quantity of
ammoniacal gas or may be otherwise used. The retorts or vessels containing the
mixture through which the anhydrous ammoniacal gas is drawn may be fitted with
pipes or cocks so that one or more of the retorts or vessels may be thrown out of
action if required. The aminoniacal gas may be acted upon by an exhaust pump
prior to its entering the retort or other vessel or subsequent to its leaving the
condenser or cooler to which it is conducted on leaving the retort or other vessel.
In order to avoid leakage, the pressure within the retort or other vessel should be
equal to the pressure outside it.
The unabsorbed ammoniacal gas and the other gaseous or volatile products
arising from the chemical change which occurs in the heated retorts or other vessels
are conveyed to a series of condensers or coolers; and, when sufficiently cool, ȧre
led to an absorber, in which the soluble ammoniacal gas is taken up by water or
other suitable agent, whilst the insoluble gases are allowed to escape or are
otherwise dealt with. The water or other agent which has been employed to absorb
the ammoniacal gas may be returned to the apparatus whence the ammoniacal gas
used in the process is obtained.
The carbonate employed in the mixture contained in the heated retort or other
vessel is the carbonate of the alkali or alkaline earth of the metallic cyanide I wish
to produce. If, for instance, I desire to form barium cyanide, I use a mixture of
carbon or charcoal and carbonate of barium. If potassium cyanide is to be produced,
I employ a mixture of carbon or charcoal and carbonate of potassium. In the latter
case, I treat the carbon or charcoal with a concentrated solution of carbonate of
potassium so that the mass of the carbon or charcoal may be thoroughly permeated
with carbonate of potassium. It is preferable, when the carbonate is soluble, to

page_text: treat the carbon or charcoal with a concentrated solution of the carbonate (carbonate
of potassium, sodium, &c., as the case may be). If necessary, more of the carbonate
of potassium (or other carbonate, according to the particular description of product
required) may be added to the carbon or charcoal after treatment with the
solution.
When the action has proceeded far enough in the heated retort or other vessel,
the door is opened or removed, and the heated mass raked out into a suitable
distillation retort, having a large removable condenser-head. The latter is luted
or screwed up joint-tight with the lower part of the retort and is also connected to
a suitable coudensing worm; alcohol or water or alcohol and water being added to
dissolve the soluble matter. If alcohol be used, the condenser serves to prevent
waste of the alcohol when poured on the heated mass. The liquid passes through
a syphon to a tank with a removable top. This tank is provided with a false
bottom on which rests a filtering medium. After the solution has passed through
une filtering medium, it is conveyed by a syphon into a second retort, where
distillation is carried on until nothing but a solid residuum remains, such residuum
containing the cyanide. This residuum can be sold in the form in which it is
produced, or can be fused and cast into bricks.
The distillation retorts and the filtering tank may be heated by separate furnaces,
but I prefer to heat them by means of the products of combustion escaping from
the furnace which heats the cyanide-producing retort or vessel.
I, JOHN EDLINGTON CHASTER, of 30, Epple Road, Fulham, in the County
of Middlesex, Chemist, 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 :-
This invention relates to an economical method of manufacturing cyanides on a
commercial scale.
In carrying out my invention, I cause dry ammoniacal gas to pass over a
suitable mixture of carbon or charcoal and a carbonate of an alkali or alkaline
earth contained in a retort or retorts or other vessel or vessels and heated to a
temperature sufficiently high to effect dissociation; the result being the formation
of cyanogen compounds.
The ammoniacal gas need not be pure, and can therefore be prepared from the
ammoniacal liquor incidentally obtained in the manufacture of illuminating gas or
from crude ammonium sulphate or chloride.
The process described above is specially adapted for enabling the nitrogen given
off from coal in the manufacture of illuminating gas to be employed in the pro-
duction of cyanide of potassium or other metallic cyanide instead of being utilized
in forming the comparatively valueless ammonium sulphate of commerce.
The ammoniacal gas is made perfectly anhydrous by passing it through a
cylinder or cylinders filled with quick-lime. The quick-lime becomes converted
into slacked lime, which can under certain conditions be used in making a fresh
quantity of ammoniacal gas or may be otherwise utilized. The retorts or vessels
containing the mixture through which the anhydrous ammoniacal gas is drawn or

page_text: forced may be fitted with pipes and cocks so that one or more of the retorts or
vessels may be thrown out of action if required. The ammoniacal gas may be
acted upon by an exhaust pump prior to its entering the retort or other vessel or
subsequent to its leaving the condenser or cooler to which it is conducted on leaving.
the retort or other vessel. In order to avoid leakage, the pressure within the
retort or other vessel should be equal to the pressure outside it.
The unabsorbed ammoniacal gas and the other gaseous or volatile products
arising from the chemical change which occurs in the heated retorts or other
vessels are conveyed to a series of condensers or coolers; and, when sufficiently
cool, are led to an absorber; in which the soluble ammoniacal gas is taken up by
water or other suitable agent, whilst the insoluble gases are allowed to escape or
are otherwise dealt with. The water or other agent which has been employed to
absorb the ammoniacal gas may be returned to the apparatus whence the
ammoniacal gas used in the process is obtained.
The carbonate employed in the mixture contained in the heated retort or other
vessel is the carbonate of the alkali or alkaline earth of the metallic cyanide I
wish to produce. If, for instance, I desire to form barium cyanide, I use a
mixture of carbon or charcoal and carbonate of barium. If potassium cyanide is
to be produced, I employ a mixture of carbon or charcoal and carbonate of
potassium. These materials may be in the proportion of 20 per cent. of carbon
to 80 per cent. of carbonate; but in practice, I prefer to employ a considerably
larger proportion of carbon. In the latter case, I treat the carbon or charcoal
with a concentrated solution of carbonate of potassium, so that the mass of the
carbon or charcoal may be thoroughly permeated with carbonate of potassium.
It is preferable, when the carbonate is soluble, to treat the carbon or charcoal with
a concentrated solution of the carbonate (carbonate of potassium, sodium, &c., as.
the case may be). If necessary, more of the carbonate of potassium (or other
carbonate, according to the particular description of product required) may be
added to the carbon or charcoal after treatment with the solution.
When the action has proceeded far enough in the heated retort or other vessel,
the door is opened or removed, and the heated mass raked out into a suitable
distillation retort, having a large removable condenser-head. The latter is luted
or screwed up joint-tight with the lower part of the retort and is also connected
to a suitable condensing worm; alcohol or water or alcohol and water being added
to dissolve the soluble matter. If alcohol be used, the condenser serves to prevent
waste of the alcohol when poured on the heated mass. The liquid passes through
a syphon to a tank with a removable top. This tank is provided with a false
bottom on which rests a filtering medium. After the solution has passed through
the filtering medium it is conveyed by a syphon into a second retort, where dis-
tillation is carried on until nothing but a solid residuum remains, such residuum
containing the cyanide. This residuum can be sold in the form in which it is
produced, or can be fused and cast into blocks.
The distillation retorts and the filtering tank may be heated by separate
furnaces, but I prefer to heat them by means of the products of combustion
escaping from the furnace which heats the cyanide-producing retort or vessel.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I claim :-
1. The herein described process for the manufacture of cyanides, consisting in
passing anhydrated ammonia through an incandescent mass of carbon previously
permeated with a carbonate of the metal forming the metallic base of the cyanide
to be produced, leaching out, the cyanide by means of alcohol or water, and
ultimately distilling off the solvent for the recovery of the cyanide.
2. In the manufacture of cyanides in the manner referred to in the preceding
claiming clause, the employment of a mass of carbon permeated with a metallic
carbonate, substantially as and for the purpose set forth.

page_text: 3. In the separation of cyanides from metallic carbonates, the employment of
alcohol as a sofvent of the cyanides, substantially as herein described.
Dated this 17th day of June 1895.
G. G. M. HARDINGHAM,
191, Fleet Street, London, E.C., Chartered Patent Agent.