New Process for the Production of the Cyanides of the Alkalies and Alkaline-earth by the Simultaneous Employment of a Hydro- carbon and Ammonia Gases, with the Addition, if desired, of Free Nitrogen.
Year: 1892

page_text: Date of Application, 29th Aug., 1892-Accepted, 1st Oct., 1892
COMPLETE SPECIFICATION.
New Process for the Production of the Cyanides of the Alkalies and
Alkaline-earth by the Simultaneous Employment of a Hydro-
carbon and Ammonia Gases, with the Addition, if desired, of
Free Nitrogen.
1, HERBERT JOHN HADDAN, of the firm of Herbert & Co., Patent Agents, of
18 Buckingham Street, Strand, W.C. London, Civil Engineer, do hereby declare
the nature of this invention, a communication to me from abroad by Pierre Rogatien,
Viscount of Lambilly, of Paris, in the Republic of France, and in what manner
the same is to be performed to be particularly described and ascertained in and
by the following statement :-
There is a method for the manufacture of cyanides by means of atmospheric
nitrogen and illuminating gas.
Also another method for the same manufacture by means of ammonia gas. The
first of these methods is based on the decomposition of the hydrocarbon gas in the
presence of free nitrogen to produce carbon in the nascent state, a state most
suitable for combination. The second method however is based on the decom-
position of ammonia gas in the presence of carbon to produce on the contrary
nitrogen in the nascent state, the better to combine with the carbon.
Each of these processes allows of the production of cyanides with ease and
economy, but it may easily be conceived that a third process, a combination of the
two others and designed to produce both carbon and nitrogen in the nascent state
should produce better results than any other system for the manufacture of
cyanides.
It is such a system that I am about to describe.
My new process consists essentially in the simultaneous decomposition by heat
of the mixture of hydrocarbon gas with ammonia gas, to which it is of advantage
to add also free nitrogen, in the presence of an easily cyanisable alkali or alkaline-
earth such as the carbonates or oxides of potassium, sodium, or of barium.
The practical operations under this process are, save for some improvements, the
same as those I have previously described and which I shall here reproduce with
the novelties introduced.
2. PREPARATION OF THE HYDROCARBON TAS.
A hydrocarburetted gas may be obtained by distilling any hydrocarbonated
matter solid or liquid, such as pit-coal, lignite, fatty matters, tar, vegetable or
animal oils.
Whatever the material employed, the distillation should proceed at the lowest
possible temperature in order to produce a gas rich in hydrocarbons.
I have elsewhere indicated a means for carburetting the gas, which is to pass it
at the temperature of red heat over the oxide of copper resulting from the
preparation of the nitrogen. This removes any free hydrogen there may be in the
gas and a part of the combined hydrogen, thus increasing the relative proportion
of carbon.
:
This method not only allows of the improvement of the gas resulting from a
defective distillation but also allows of the renovation of the gas which having

page_text: been used in the process has lost carbon and taken up hydrogen, so that the same
gas may be used again.
It is true that this method of passing the gas over oxide of copper results in a
diminution of the quantity of gas; to prevent this loss I have devised another
very efficient and simple method of carburating. I pass the gas through a scries
of cylinders charged with broken carbon impregnated with a liquid carburet, by
preference heavy, such as coal-tar or heavy oils, or even a mixture of carbon and
dry powdered rosin.
The cylinders should be heated, but slightly, and to a temperature below that
at which the carburet commences to evolve gas; the temperature may vary
between 40 to 50° for petroleums up to 300 to 350° for the rosin.
Gas already used may be recarbonated hy this process and without any special
attention, so that work may be carried on for a long time with a very small
quantity of gas.
3. PRODUCTION OF AMMONIA GAS.
The production of ammonia gas may take place by the known methods;
distillation of sluice waters, distillation of the ammoniacal liquor of gas works,
distillation of an ammonia salt in the presence of lime, etc. The gas thus obtained.
is collected in a gasometer to be mixed either with the hydrocarbon gas alone or
with the latter mingled with free nitrogen.
4. CYANURATION.
1. Preparation of the materials for cyanurising. To a concentrated solution of
carbonate or oxide of potassium or of sodium is added at least 100 parts of
powdered carbon for every 100 parts of the alkali. This solution is evaporated to
dryness and 20 to 30 parts of powdered chalk and 50 parts of iron filings added.
It is useful to agglomerate this mixture by adding pitch or tar or other analogous
materials and making up the mixture into briquettes.
2. Reduction of the alkali. The alkalies and alkaline earths only combine with
cyanogen in the state of pure metal or of anhydrous oxide, it is therefore important
to reduce the alkali to the latter state at least.
This mixture prepared as before described is placed in retorts or cylinders of
iron and heated to bright red heat. The alkaline carbonate or oxide commences
to give off either its carbonic acid or its water of combination in form of oxide of
carbon or oxide of carbon and hydrogen and is reduced as well as the tension of
dissociation is greater than the atmospheric pressure.
At the moment this tension becomes too weak to exert its effect it is of advantage
and very important to employ the means I have shown elsewhere, namely to submit
the mass to the action of a vacuum by means of a pump and to remove the gas
which this proceeding will cause to be evolved. A more complete dissociation and
consequently a greater reduction is thus obtainable.
3. Passage of the gas. When, even with the vacuum, the evolution of gas has
ceased the gaseous mixture intended to produce cyanogen is passed through. As
before mentioned this gaseous mixture may consist of the three gases, ammonia,
hydrocarbon, and free nitrogen, or of the first two of these only; but the free
nitrogen produces a proportion of cyanogen and its employment permits of economy-
in the amount of ammonia.
The gas should be passed at a low pressure so as to assure contact with every
particle of the mass to be cyanurated.
On issuing from the cylinder or retort the gas is collected and submitted to
either of the two carburetting processes described; it may then be employed again..
after addition, if necessary, of more ammonia gas or free nitrogen.
It is almost unnecessary to add that when the cyanuration is complete the mass
is drawn from the cylinder and lixiviated as in ordinary processes to obtain the

page_text: ferro-cyanide of the alkali cyanurated. The solid residue is used again in the
process serving as an absorbent for a fresh solution of alkali.
The principal advantages of this new process are:-
1st. It is very rapid.
2nd. From any given quantity of alkali it permits of larger quantity of the
cyanide being had than by any other process.
3rd. It requires only easy manipulations.
4th. It is very economical.
In conclusion I claim and desire to reserve to myself for application in the
manufacture of cyanides, the principle above explained which consists in decom-
posing by heat in the presence of an easily cyanurisable alkali or alkaline earth, a
mixture of gaseous ammonia with gaseous hydrocarbon to which may be added free
nitrogen.
I reserve also the application in gas works or wherever the gas made contains
naturally a certain proportion of ammonia gas..
'
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. The two methods of carburation that I have described, one consisting in
passing the gaseous hydrocarbon over copper oxide heated to redness, the other
consisting in passing the same through a mixture of broken carbon soaked in a
liquid carbon or a semi solid one heated to a very low temperature.
2. The method of reduction of the alkaline mixture by means of a vacuum.
3. The method of passing the gas by pressure.
·וויז
2011 1
1000
HERBERT & Co.,
Agents to Applicant.