Improvements in the Manufacture of Cyanides or Ferro-cyanides from their Corresponding Sulpho-cyanides.
Year: 1894

page_text: Date of Application, 20th Dec., 1894
Complete Specification Left, 7th Sept., 1895-Accepted, 26th Oct., 1895....
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PROVISIONAL SPECIFICATION.
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Improvements in the Manufacture of Cyanides or Ferro-cyanides
from their Corresponding Sulpho-cyanides.
We JULIUS RASCHEN Ph.D. Chemist RICHARD HOLDEN DAVIDSON Alkali
Manufacturer and JOHN BROCK Director of the United Alkali Company Limited
all of G 11 Exchange Buildings Liverpool in the County of Lancaster do hereby
declare the nature of this invention to be as follows:-
This invention has for its principal object the economical conversion of sulpho-
cyanides especially of the alkali metals (for instance of potassium) into the corre-
sponding cyanides or ferrocyanides.
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The sulphocyanide may be obtained from any source but we prefer to prepare it
by heating in a closed vessel a mixture of carbon bisulphide, ammonia, calcium
hydrate, and water. The solution of calcium sulpho cyanide so obtained we
decompose after passing carbonic acid through it, with the carbonate or sulphate
(or both) of the base of which we desire to obtain the cyanide, carbonate of potash
for instance. The solution of sulpho cyanide so prepared we filter and evaporate
tó dryness.
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We mix the dry sulphocyanide however obtained with quick-lime (CaO) and
carbonaceous matter, such as pitch, or coal, as free from ash as possible, and heat
the mixture to dull redness. It is important that all the materials. should be dry.
By this operation the sulphocyanide is converted into the corresponding cyanide,
the sulphur combines with the calcium, forming calcium sulphide, carbon oxides
being evolved at the same time.
When the reaction is complete, we withdraw the mass protecting it as much as
possible from oxidation, and allow it to cool. It is then lixiviated with water,
whereby a solution of cyanide is obtained, which may contain a small amount of
calcium sulphide in solution. If necessary we remove the lime by the addition of
a corresponding amount of potassium carbonate, filter the solution and evaporate to
dryness, in order to obtain the solid cyanide..
If ferrocyanide be desired we boil the solution of crude cyanide with a suitable
oxide of iron or a salt of iron filter the solution, concentrate it if necessary and
allow the ferrocyanide to crystallise.
Datel this 20th day of December 1894.
JOHNSONS & WILLCOX,
47 Lincoln's Inn Fields, London, W.C., Agents.
COMPLETE SPECIFICATION.
Improvements in the Manufacture of Cyanides or Ferro-cyanides
from their Corresponding Sulpho-cyanides.
We, JULIUS RASCHEN Ph.D. Chemist RICHARD HOLDEN DAVIDSON, Alkali
Manufacturer and JOHN BROCK Director of the United Alkali Company Limited
all of G 11 Exchange Buildings Liverpool in the County of Lancaster, do hereby
declare the nature of this invention and in what manner the same is to be
FD71

page_text: performed to be particularly described and ascertained in and by the following
statement :-
with
This invention has for its principal object the economical conversion of sulpho-
cyanides especially of the alkali metals (for instance of potassium) into their
corresponding cyanides or ferrocyanides.
"
The sulphocyanide may be obtained from any source, but we prefer to prepare it
by heating in a closed. Wessel, a mixture of carbon bisulphide, ammonia, calcium
hydrate, and water. The solution of calcium sulphocyanide so obtained we
decompose after passing carbonic acid through it, with the carbonate, or sulphate,
(or both) of the base of which we desire to obtain the cyanide, carbonate of
potash, for instance. The solution of sulphocyanide so prepared we filter and
evaporate to dryness.
We mix the dry sulphocyanide however obtained with quick lime (CaO) and
carbonaceous matter, such for example as pitch or coal as free from ash as possible.
We use these materials in about equal proportions and heat the mixture to redness
which may be done in any suitable furnace. We find it best to apply a good red
heat rapidly, and to continually agitate the mass. It is important that all the
materials should be dry. By this operation the sulphocyanide is converted into
the corresponding cyanide, the sulphur combines with the calcium, forming calcium
sulphide, carbon oxides being evolved at the same time.
When the reaction is complete we withdraw, the mass immediately, protecting
as much as possible from axidation, and allow it to cool. It is then lixiviated with
water, whereby a solution of cyanide is obtained, which may contain a small
amount of calcium sulphide in solution. If necessary we remove the lime by the
addition of a corresponding amount of potassium carbonate, filter the solution and
evaporate to dryness, in order to obtain the solid cyanide.
If ferrocyanide be desired we boil the solution of crude cyanide with a suitable
oxide of iron or a salt of iron, filter the solution, concentrate it if necessary, and
allow the ferrocyanide to crystallize..
"
Having now particularly described and ascertained the nature of this inven-
tion, and in what manner the same is to be performed, we declare that what we
claim is
In the manufacture of cyanides or ferro-cyanides from sulpho-cyanides, heating
dry sulphocyanide with lime (CaO) and carbonaceous matter substantially as
herein before described
Dated this 7th day of September Lo
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JOHNSONS & WILLCOX,
47 Lincoln's Inn Fields, London, W.C., Agents for the Applicants.