Improvements in the Manufacture of Nitrogen Compounds.
Year: 1898

page_text: Date of Application, 2nd Dec., 1898
E
Complete Specification Left, 31st Aug., 1899-Accepted, 4th Nov.,
1899
Improvements in the Manufacture of Nitrogen Compounds.
We, Dr. ADOLPH FRANK, Chemist, of 80, Leibnitzstrasse, Charlottenburg, and
Dr. NIKODEM CARO, Chemist, of 1, Roonstrasse, Berlin, both in the German
Empire, do hereby declare the nature of this invention to be as follows:-
:-
In the action of nitrogen on carbide or carbide-forming mixtures (such for
example, as mixtures of oxides of the alkaline-earth-metals or alkali-metals or
compounds thereof, such as carbonates, with carbon) the corresponding cyanides
are produced.
It has been shown that the formation of these compounds is, however, only
a limited one, since, as established by us, when employing a minimum tempera-
ture approximating a dark red-heat, practically not higher than bright yellow
heat, the greater part of the nitrogen taken up by the carbide is fixed in the
form of other nitrogen compounds, partly by the action of the already formed
cyanide and partly by direct action on the reacting mass, for example, according
to the cauations:
We have discovered that metal salts of cyanamide (also called amidocyanide)
M, NCN, paracyanogen (CN), and other nitrogen compounds are present in
the reacting mass. For the present invention it is immaterial in what form the
carbide is employed, whether as already formed carbide (pure, or contained in
compounds or mixtures) or carbide in process of formation, or in the form of its
reaction components, and consequently, for the purpose of the present invention
and in the following description, the term "carbide" includes all these stated
forms, of the carbide to be employed.
The further preparation of the reacting mass produced, as above mentioned, by
the action of nitrogen (i.e. nitrogen pure or contained in mixtures or in chemical
combinations e.g. ammonia) on carbide," takes place, according to the present
invention, in the following manner:-
66
This mass is worked into cyanides by melting it. This operation can be
effectively carried out by adding a suitable flux (for example, caustic soda, caustic
potash, sodium carbonate, potassium carbonate, or other salts) to the reacting
mass before or during the melting. Should the mass not contain sufficient
carbon set free in the previous reactions, it is advantageous to add a further
quantity of carbon.
When nitrogen-compounds not combined with metal, such for example, as
paracyanogen, are present in the mass to be treated, the said mass must contain
sufficient of the base to bind the cyanogen formed in this process. If this is not
the case, a basic material, for example, oxygenic alkali-compounds or alkaline-
earth compounds, such as caustic soda, caustic potash, sodium carbonate, potas-
sium carbonate, lime, calcium carbonate, etc., must also be added.

page_text: on carbide, there are formed, from the metal compounds of the cyanamide (or
amidocyanide) and of the paracyanogen, the corresponding cyanides according to
the equations:
M, NC NC = 2 M¹, CN, and
+ (No. CO)² + (0)). 9xN ON+3xGO
(CN) (Ne
Cyanides also form from the other nitrogen compounds present, with partial
destruction of the molecule.
Cyanamide (or amidocyanide) is obtained from the above-mentioned product
of the action of the nitrogen preferably by leaching the same with water and
driving out the hydrocyanic acid, for example, by the addition of an acid (such as
carbonic acid). In this the free cyanamide (or amidocyanide) is partly separated.
The cyanamide (or amidocyanide) remaining in solution can then be obtained by
shaking with ether or other suitable solvent, separating and evaporating, or in
any other suitable manner.
Cyanides also form from the other nitrogen compounds present, with partial
destruction of the molecule.
Cyanamide (or amidocyanide) is obtained from the above-mentioned product
of the action of the nitrogen preferably by leaching the same with water and
driving out the hydrocyanic acid, for example, by the addition of an acid (such as
carbonic acid). In this the free cyanamide (or amidocyanide) is partly separated.
The cyanamide (or amidocyanide) remaining in solution can then be obtained by
shaking with ether or other suitable solvent, separating and evaporating, or in
any other suitable manner.
Improvements in the Manufacture of Nitrogen Compounds.
We, Dr. ADOLPH FRANK, Chemist, of 80, Leibnitzstrasse, Charlottenburg, and
Dr. NIKODEM CARO, Chemist, of 1, Roonstrasse, Berlin, both in the German
Empire, 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:-
1
In the action of nitrogen on carbide or carbide-forming mixtures (such for
example, as mixtures of oxides of the alkaline-earth-metals or alkali-metals or
compounds thereof, such as carbonates, with carbon) the corresponding cyanides
are produced.
It has been shown that the formation of these compounds is, however, only
a limited one, since as established by us when employing a minimum tempera-
ture approximating a dark red-heat, practically not higher than bright yellow
heat, the greater part of the nitrogen taken up by the carbide is fixed in the
form of other nitrogen compounds, partly by the action of the already formed
cyanide and partly by direct action on the reacting mass, for example, according
to the equations;

page_text: in process of formation, or in the form of its reaction components, and conse-
quently, for the purpose of the present invention and in the following descrip-
tion, the term carbide includes all these stated forms of the carbide to be
employed.
66
"
The further preparation of the reacting mass produced, as above mentioned, by
the action of nitrogen (i.e. nitrogen pure or contained in mixtures or in chemical
combinations e.g. ammonia) on "carbide,” takes place, according to the present
invention, in the following manner:-
"
This mass is worked into cyanides by melting it. This operation can be
effectively carried out by adding a suitable flux (for example, caustic soda, caustic
potash, sodium carbonate, potassium carbonate, or other salts) to the reacting
mass before or during the melting.
The process of acting by means of nitrogen (free or in its combined state) on
"carbide" is hereinafter explained by describing the same, employing carbide
of barium as an example. In employing, e.g., carbide of barium, the process
may be performed by finely comminuting the carbide material and then spread-
ing it out in a muffle or retort of refractory material; e.g., iron, fire-clay or the
like are, in general, sufficiently refractory for this purpose. The retort or muffle,
having in any known manner an inlet and outlet through which gas can be
introduced and can flow off respectively, is now heated in any suitable
or usual manner, e.g., from outside by means of a suitable furnace (such as a gas
furnace or the like), to the temperature of the reaction, which lies, e.g., when
barium carbide is employed, at a very favourable height, i.e., at about
700 degrees C. Now nitrogen as pure and dry as possible, is led to and over the
said layer of barium-carbide practically by means of a pressure pump. Instead
of gaseous nitrogen also a liquid or solid nitrogeniferous substance can be brought
into contact with the carbide. This may be carried out, by converting such
substances by heating the same into vapours and by leading these vapours to and
ever the layer of carbide as described for the employment of gaseous nitrogen
or the said substances may be mixed with the carbide and the mixture may then
be heated in a muffle or retort. In the latter case it is preferred to throttle the
gas-exit of the retort in order to prevent the vapours or gases developed in the
retort from escaping too rapidly therefrom.
This leading of the nitrogen to and over the carbide is continued until no
nitrogen is taken up by the carbide material, which can be seen from the fact
that the nitrogen escapes almost unabsorbed. For each hundred parts by weight
of barium carbide or for equivalent quantities of other carbides about 25-35 parts
by weight of nitrogen are utilized.
Should the mass not contain sufficient carbon set free in the previous reactions,
it is advantageous to add a further quantity of carbon.
When nitrogen-compounds not combined with metal, such for example, as
paracyanogen, are present in the mass to be treated, the said mass must contain
sufficient of the base to bind the cyanogen formed in this process. If this is not
the case, a basic material, for example, oxygenic alkali-compounds or alkaline-
earth compounds, such as caustic soda, caustic potash, sodium carbonate, potas-
sium carbonate, lime, calcium carbonate, etc., must also be added.
In these meltings of the above mentioned product of the action of the nitrogen
on carbide, there are formed, from the metal compounds of the cyanamide (or
amidocyanide) and of the paracyanogen, the corresponding cyanides according to
the uationa

page_text: driving out the hydrocyanic acid, for example, by the addition of an acid (such as
carbonic acid). In this the free cyanamide (or amidocyanide) is partly separated.
The cyanamide (or amidocyanide) remaining in solution can then be obtained by
shaking with ether or other suitable solvent, separating and evaporating, or in
any other suitable manner.
Having now particularly described and ascertained the nature of our said
invention, and in what manner the same is to be performed, we declare that what
we claim is:-
1. The manufacture of cyanides by a process wherein masses containing amido-
cyanide are melted in the presence of carbon, for the purpose of converting into
cyanides, the nitrogen compounds (mainly amidocyanide and paracyanogen)
contained in the said masses in addition to cyanide, substantially as described.
2. The manufacture of cyanides by a process wherein masses containing amido-
cyanide are melted in the presence of carbon and a flux, for the purpose of convert-
ing into cyanides, the nitrogen compounds (mainly amidocyanide and para-
cyanogen) contained in the said masses in addition to cyanide, substantially as
described.
3. The manufacture of cyanides by a process wherein masses containing amido-
cyanide and paracyanogen are melted in the presence of carbon and basic material,
substantially as described.
4. The manufacture of cyanides by a process wherein masses containing amido-
cyanide and paracyanogen are melted in the presence of carbon and basic material
and a flux, substantially as described.
5. In the manufacture of cyanides, the production of masses containing amido-
cyamide by bringing nitrogen into contact with carbide at a minimum temperature
approximating a dark red heat, substantially as described.
6. The herein described process of obtaining amidocyanide from masses con-
taining the same, produced by the action of nitrogen on carbide at a minimum
temperature approximating a dark red heat, by the addition of an acid, whilst
removing the hydrocyanic acid formed from the cyanides and setting free the
amidocyanide, substantially as described.
Dated this 31st day of August 1899.
D. YOUNG & Co.,
11 and 12, Southampton Buildings, London, W.C.,
Agents for the Applicants.