Improvements in Means to be Employed in the Manufacture or Production of Cyanides.
Year: 1895

page_text: Date of Application, 18th Feb., 1895
Complete Specification Left, 18th Nov., 1895-Accepted, 15th Feb., 1896
PROVISIONAL SPECIFICATION.
Improvements in Means to be Employed in the Manufacture or
Production of Cyanides.
We JOSEPH WILSON SWAN of Lauriston Bromley in the County of Kent
Chemist and JAMES ALFRED KENDALL of 3 Ashlake Road Streatham in the
County of Surrey Manufacturing Chemist do hereby declare the nature of this
invention to be as follows:-
It is well known that when nitrogen gas such as that of the atmosphere is passed
over a mixture of an alkali and carbon heated to a high temperature cyanide of the
alkali metal is produced but hitherto no practical application of the process on a
manufacturing scale has been possible on account of the small yield of cyanide and
of the rapid destruction of the apparatus. It is the object of the present invention
to overcome these objections.
According to this invention we provide an inner vessel and an outer vessel with a
space between and means for passing gas into this space means being also provided
for heating the vessels to a high temperature. The inner vessel is made of nickel
or of fine sheet cobalt and has a continuation of platinum.
The outer vessel (or jacket) surrounds the inner vessel or so much of it as is
exposed to a high temperature and it extends for some length beyond that part of
the inner vessel where the "continuation" joins the main inner vessel. The outer
vessel may be made of refractory earthenware or of nickel cobalt or fine iron (of
difficult fusibility) which may be enclosed in or covered by refractory earthenware
especially when using iron or cobalt.
Hydrogen gas is passed into the jacket and the said gas permeates the nickel or
cobalt of which the inner vessel is made and by this physical or physico-chemical
action protects the metal from the corrosion which it would otherwise undergo from
the heated mixture which it is intended to hold.
The mixtures by which under the influence of heat the nitrogen is absorbed, are
put into the inner vessel but not in the platinum part thereof which latter is
intended for the vapour of the metallic cyanide to condense in, or to escape from
the apparatus by.
When cyanide of potassium, which we will take for an example, is to be made we
prepare a mixture of charcoal in the form of granules or powder and finely divided
tungsten in the proportions of one hundred parts charcoal and fifteen parts of
tungsten. Or the charcoal may be soaked in a solution containing a corresponding
amount of tungstate of potash and then dried. We do not confine ourselves to the
exact proportions stated as they may be largely varied without detriment to the
process. The mixture is put into the inner vessel and hydrogen gas is passed
continuously into and through the space between the two vessels while the apparatus
is heated to the proper temperature. The heat should be applied so that the main
inner vessel attains a yellow heat and so that the part where the "continuation"
joins the main vessel is heated to at least a bright red heat. Then a regulated flow
of nitrogen gas is passed through the inner vessel and carbonate of potash in a
molten state is continuously run into the inner vessel by means for instance of a
funnel and small tube which may conveniently be made of platinum. The rate at
which the carbonate of potash is added should be carefully regulated so that
nitrogen is in excess and so that potassium is not carried out of the main vessel in
the free or metallic state.

page_text: When the operation is conducted as above described, cyanide of potassium more
or less pure distils from the mixture and condenses in the platinum * continuation."
If the latter be an inclined tube the cyanide may be allowed to flow out as a liquid
into a suitable vessel placed to receive it. The operation may be continued so as
to get the greater part or all of the cyanide in the form of a distillate. From time
to time when through the removal of the carbon by the chemical reaction, a
considerable amount of residuum has accumulated it may be removed and fresh
charcoal mixture be introduced when necessary. Any alkali and cyanide which is
contained in the residues from the retort may be saved by allowing the residues to
cool in a vessel closed from access of air and then percolating them with water by
which a solution of crude cyanide or alkali is obtained.
To make cyanide of sodium the process may be conducted in the same way using
carbonate of soda instead of carbonate of potash.
In making cyanide of lithium the same method may be followed as in the case of
the cyanides of potassium and sodium or we find that good results can be got by
making an intimate mixture of carbonate of lithium, charcoal and tungsten and
placing the mixture in the inner vessel instead of adding the lithia afterwards.
The following proportions give good results :-
"
When the operation is conducted as above described, cyanide of potassium more
or less pure distils from the mixture and condenses in the platinum continuation."
If the latter be an inclined tube the cyanide may be allowed to flow out as a liquid
into a suitable vessel placed to receive it. The operation may be continued so as
to get the greater part or all of the cyanide in the form of a distillate. From time
to time when through the removal of the carbon by the chemical reaction, a
considerable amount of residuum has accumulated it may be removed and fresh
charcoal mixture be introduced when necessary. Any alkali and cyanide which is
contained in the residues from the retort may be saved by allowing the residues to
cool in a vessel closed from access of air and then percolating them with water by
which a solution of crude cyanide or alkali is obtained.
To make cyanide of sodium the process may be conducted in the same way using
carbonate of soda instead of carbonate of potash.
In making cyanide of lithium the same method may be followed as in the case of
the cyanides of potassium and sodium or we find that good results can be got by
making an intimate mixture of carbonate of lithium, charcoal and tungsten and
placing the mixture in the inner vessel instead of adding the lithia afterwards.
The following proportions give good results :—
100 parts carbonate lithia.
100 to 150 parts charcoal.
15 parts tungsten.
Cyanide of barium may also be made in the apparatus but the cyanide of barium
does not distil like the cyanides of the above mentioned metals and although it can
be dissolved out by water the yield is not so good.
Air may be used instead of nitrogen provided that sufficient carbon is used in the
mixture in the retort.
The nitrogen may contain an admixture of hydrogen without detriment to the
process. Also a small or moderate proportion of carbon oxide does not prevent
good results being obtained. Instead of nitrogen ammoniacal gas may be used.
Instead of the carbonates of the metals being used for making the cyanides the
oxides or bydrates may be used.
Instead of tungsten any of the following metals or their reducible compounds
for instance may be used-titanium, molybdenum, chromium manganese and
uranium.
Instead of using hydrogen gas as such it may be employed in admixture with
other gases for example water gas may be used.
Dated this 18th day of February 1895.
JOHNSONS & WILLCOX,
47 Lincoln's Inn Fields, London, W.C., Agents.
COMPLETE SPECIFICATION.
Improvements in Means to be Employed in the Manufacture or
Production of Cyanides.
We, JOSEPH WILSON SWAN late of Lauriston, Bromley, in the County of
Kent now of 58 Holland Park in the County of London Chemist, and JAMES
ALFRED KENDALL of 3 Ashlake Road, Streatham, in the County of Surrey,
Manufacturing 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 :—
It is well known that when nitrogen gas, such as that of the atmosphere, is
passed over a mixture of an alkali and carbon, heated to a high temperature,
cyanide of the alkali metal is produced, but hitherto no practical application of

page_text: the process, on a manufacturing scale, has been possible on account of the small
yield of cyanide and of the rapid destruction of the apparatus. It is the object of
the present invention to overcome these objections.
According to this invention we provide an inner vessel and an outer' vessel with
a space between and means for passing gas into this space, means being also
provided for heating the vessels to a high temperature. The inner vessel is made
of nickel, or of fine sheet cobalt, and has a continuation of platinum, or equivalent
metal, which is not attacked, or only slightly attacked, by alkaline cyanide at high
temperatures.
The outer vessel (or jacket) surrounds the inner vessel, or so much of it as is
exposed to a high temperature, and it extends for some length beyond that part of
the inner vessel where the "continuation" joins the main inner vessel. The outer
vessel may be made of refractory earthenware, or of nickel, cobalt, or fine iron,
(of difficult fusibility), which may be enclosed in, or covered by, refractory
earthenware, especially when using iron, or cobalt.
Hydrogen gas is passed into the space enclosed between the inner and outer
vessels, and the said gas permeates the nickel, or cobalt, of which the inner vessel
is made, and by this physical, or physico-chemical action protects the metal from
the corrosion which it would otherwise undergo from the heated mixture which it
is intended to hold.
The mixtures by which, under the influence of heat, the nitrogen is absorbed,
is intended for the
are put into the inner vessel. The aforesaid "continuation"
vapour of the metallic cyanide to condense in, or for the escape or removal thereof
from the apparatus.
When cyanide of potassium (which we will take for an example) is to be made
we prepare a mixture of charcoal in the form of granules, or powder, and finely
divided tungsten, in the proportions by weight of one hundred parts of charcoal
and fifteen parts of tungsten. Or the charcoal may be soaked in a solution con-
We do
taining a corresponding amount of tungstate of potash, and then dried.
not confine ourselves to the exact proportions stated as they may be largely varied
without detriment to the process. The mixture is put into the inner vessel and
hydrogen gas is passed into or continuously through, the space between the two
vessels while the apparatus is heated to the proper temperature. The heat should
be applied so that the inner vessel attains a yellow heat and so that the part
where the "continuation" joins the main vessel is heated to at least a bright red
heat. Then a regulated flow of nitrogen gas is passed through the inner vessel
and carbonate of potash in a molten state is continuously run into the inner vessel
by means, for instance, of a funnel and small tube which may conveniently be
niade of platinum. The rate at which the carbonate of potash is added should be
carefully regulated so that nitrogen is in excess and so that potassium is not carried
out of the main vessel in the free, or metallic, state.
When the operation is conducted as above described cyanide of potassium, more
or less pure, distils from the mixture and condenses in the "continuation." If the
latter he an inclined tube the cyanide may be allowed to flow out as a liquid into
a suitable vessel placed to receive it. The operation may be continued so as to get
the greater part, or all, of the cyanide, in the form of a distillate. From time to
time, when through the removal of the carbon by the chemical reaction, a con-
siderable amount of residuum has accumulated, it may be removed and fresh
charcoal mixture be introduced when necessary. The cyanide produced may be
fused in an iron vessel in order to remove any metallic impurity which may
have been taken up in passing through the "continuation." Any alkali and
cyanide which is contained in the residues from the retort may be saved by
allowing the residues to cool in a vessel closed from access of air and sub-
sequently percolating them with water by which a solution of crude cyanide, or
alkali is obtained.
To make cyanide of sodium the process may be conducted in the same way,
using carbonate of soda instead of carbonate of potash.

page_text: In making cyanide of lithium the same method may be followed as in the
case of the cyanides of potassium and sodium, we find that good results can be
got by making an intimate mixture of carbonate of lithium, charcoal, and
tungsten, and placing this mixture in the inner vessel instead of adding the lithia
afterwards.
m
11
100 to 150 parts of wood charcoal.
15 parts tungsten.
Cyanide of barium may also be made in the apparatus, but the cyanide of
barium does not distil like the cyanides of the above mentioned metals, and,
although it can be dissolved out by water, the yield is not so good.
Air may be used instead of nitrogen provided that sufficient carbon is used in
the mixture in the retort.
The nitrogen may contain an admixture of hydrogen without detriment to
the process.
Also a small or moderate proportion of carbon oxide does not
prevent good results being obtained. Instead of nitrogen ammoniacal gas may
be used.
Instead of the carbonates of the metals being used for making the cyanides, the
oxides, or hydrates, may be used.
Instead of tungsten any of the following metals, or their reducible compounds,
for instance, may be used-titanium, molybdenum, chromium, manganese, and
uranium.
Instead of using hydrogen gas as such, for passing through the space between
the two vessels, it may be employed in admixture with other gases for example
"water gas" may be used.
The accompanying drawing illustrates an apparatus suited for the purposes of this
invention, but we wish it to be understood that we do not limit ourselves to the
precise details shewn in this drawing.
A is the inner vessel, in which the mixture of materials is placed and B is
the outer metallic vessel or jacket enclosing a space B³, between itself and
the inner vessel A. C is a tube by which the hydrogen, or equivalent gas, is
supplied to the space B2 and D is an outlet for the escape of the surplus of
such gas.
E is a tube, or cylinder, of refractory earthenware surrounding the vessel B and
set in a furnace the upper part of the interior, or flue, of which is indicated at F,
and the walls and top of which are indicated at G. H is a casing which forms a
heating chamber which may be made of fire resisting earthenware, preferably in
sections. This chamber can be heated to the required temperature by gas burners
applied at the holes I.
J is a platinum funnel tube by which the fused alkali is admitted to the inner
vessel A.
K is a platinum vessel for holding a supply of fused alkali and it is provided
with a tap at L which is opened or closed by means of a lever handle as at M.
The said vessel K is held by platinum arms N let into holes in a cylinder of fire-
brick o held in position by means of any suitable clamps and supports which are
not shown in the drawing. This cylinder is kept heated, which may be done by
means of gas burners, (not shewn in the drawing) to a full red heat in order to keep
the alkali in the liquid state.
P is the "continuation" leading to the receiver for the cyanide it being inclined
for facilitating the flow of the cyanide and surrounded by a continuation B³ from
the chamber B.
Q is the pipe by which the nitrogen, or equivalent gas is supplied to the inner
vessel A.
R is an orifice and shaft by which residues may be passed into the vessel S by
means of a rake T.

page_text: The communication between the shaft R and vessel S may be closed when
shews a door or
required by means of a disc, or blank flanges, put in at U.
plate which can be removed when it is required to introduce material to the
vessel A. The door or plate V is provided with a tube W through which the
rake can be worked.
X is a tube closed by a cap which tube can be used to view the interior of the
apparatus while it is at work.
Y are supports which can be made of magnesia for supporting the inner
vessel A and maintaining the space between it and the outer vessel B.
Z is a collar made say of earthenware or metal which closes the upper end of
the space between the inner vessel A. and outer vessel B the tube c passing through
a hole in the said collar.
1 is the receiving vessel (which can be made of iron) provided with an opening
at 2 for the insertion of the end of the "continuation " P and with an outlet at 3
for the waste gases. 4 is an opening which is covered by a moveable plate, or cap,
and which may be provided with a glass plate to constitute a sight hole for
observing the flow from the "continuation."
The various joints in the above apparatus can be made tight when necessary by
suitable luting. Such metallic parts of the apparatus as are exposed to much heat
with access of air such as those in the chaniber H may with advantage be covered
over with thin sheet platinum to protect them.
In making cyanide of lithium a platinum "continuation " P is suitable, but when
making cyanide of potassium, or of sodium, the continuation may be of nickel
in-tead of platinum, if desired. The heating chamber H and burners are provided
to maintain a high temperature at the "continuation" to prevent the cyanide
solidifying in it.
The furnace should be arranged to give a very uniform temperature throughout
the length, or nearly all the length, of the inner vessel A, and we prefer to use
liquid, or gaseous, fuel. We find that the production of cyanide takes place with
facility at a temperature a little below the melting point of nickel, and that the
cyanide distils off at such a temperature. The heat should be regulated so that
there is at least a bright red heat at the place where the "continuation" begins,
as it is desirable to prevent the cyanide vapour from condensing to the liquid form
before it passes from the vessel A.
Having now particularly described and ascertained the nature of our said inven-
tion, and in what manner the same is to be performed, we declare that what we
claim is :-
1. In the manufacture, or production of cyanides, the treatment of the cyanide
making materials in an inner vessel of the nature specified, and surrounded by
a vessel, casing, or jacket, into which hydrogen gas, or its equivalent, is passed
during the operation, substantially as and for the purpose herein before described.
"
2. In apparatus for use in the manufacture, or production, of cyanides, a
vessel of the nature specified and provided with a " continuation as described,
and surrounded by a vessel, casing, or jacket, provided with means for passing
hereinbefore
hydrogen gas, or its equivalent, therethrough, substantially as
described.
3. Apparatus for use in the manufucture or production of cyanides, the said
apparatus consisting of an arrangement, or combination, of parts, substantially as
herein before described, and illustrated in the accompanying drawings.
Dated thin 19th done of No-1805
JOHNSONS & WILLCOX,
47 Lincoln's Inn Fields, London, W.C., Agents.