Improvements in Obtaining Cyanides from Residuary Liquors formed in Chemical Processes.
Year: 1889

page_text: Date of Application, 21st Feb., 1889
Complete Specification Left, 20th Nov., 1889-Accepted, 21st Dec., 1889
PROVISIONAL SPECIFICATION.
Improvements in Obtaining Cyanides from Residuary Liquors formed
in Chemical Processes.
:
I, JOHN STEWART MACARTHUR, Analytical and Technical Chemist, of 15 Princes
Street; Pollokshields. in the County of Renfrew, North Britain, do hereby declare the
nature of this invention to be as follows:-
This Invention has for its object the economical treatment of residuary liquors
formed in chemical processes in which cyanides have been used as active agents, in
order to obtain cyanides suitable for being used again.
In carrying out, the Invention the residuary liquor to be treated may be taken in
the alkaline condition in which it usually is or it may be acidified. To the liquor,
there is added either a protosalt of iron, such as the protosulphate, or a mixture of
proto and per salts of iron, which causes the cyanogen to be precipitated as a com-
pound of iron in the state of sludge. The iron salt is added in sufficient quantity to
précipitate all the cyanogen. The sludge is collected and freed from liquor by means
of a filter press-or other suitable apparatus. The sludge may be treated with dilute
acid or with a solution of a per salt of iron; and the liquor separated from the sludge
may be again treated with iron salts, if found desirable or it may be evaporated to
crystallise out salts containing cyanogen.
The sludge is carefully dried, and is next fused with carbonate of soda or of potash,
cyanide of sodium or of potassium being thereby formed. The cyanide is separated
from insoluble matters by lixiviation. Or the sludge may be treated with caustic soda,
potash, lime, baryta, or other alkaline earth, whereby the cyanogen compound will be
converted into a ferro-cyanide of the base added; and such ferro-cyanide may be
converted into a cyanide by known means.
DfW1000
ALLISON BROS.,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Obtaining Cyanides from Residuary Liquors formed
in Chemical Processes.
I, JOHN STEWART MACARTHUR, of 15 Princes Street, Pollokshields, in the County
of Renfrew, North Britain, Analytical and Technical 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 has for its object the economical treatment of residuary liquors
formed in chemical processes in which cyanides have been used as active agents, in
order to obtain cyanides suitable for being used again.
In carrying out the Invention the residuary liquor to be treated may be taken in
the alkaline condition in which it usually is or it may be acidified. To the liquor
there is added either a protosalt of iron, such as the protosulphate, or a mixture of
proto and per salts of iron, which causes the cyanogen to be precipitated as a com-
pound of iron in the state of sludge. The iron salt is added in sufficient quantity to
precipitate all the cyanogen. The sludge is collected and freed from liquor by means
of a filter press or other suitable apparatus. The sludge may be treated with dilute
acid or with a solution of a per salt of iron; and the liquor separated from the sludge
may be again treated with iron salts if found desirable, or it may be evaporated to
crystallize out salts containing cyanogen.

page_text: The sludge is carefully dried, and is next fused with carbonate of soda or of potash,
cyanide of sodium or of potassium being thereby formed. The cyanide is separated
from insoluble matters by lixiviation. Or the sludge may be treated with caustic
soda, potash, lime, baryta, or other alkaline earth, whereby the cyanogen compound
will be converted into a ferro-cyanide of the base added; and such ferro-cyanide may
be converted into a cyanide by known means.
Having now particularly described and ascertained the nature of my said Inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is
1. Obtaining cyanides from residuary liquors by precipitation with a protosalt of
iron or with a mixture of proto and per salts of iron and by fusion of the precipitate
with carbonate of sodium or of potassium, substantially as hereinbefore described.
2. Obtaining cyanides from residuary liquors by precipitation with a protosalt of
iron or with a mixture of proto and per salts of iron, by treatment of the precipitate
with caustic soda, potash, lime, baryta, or other alkaline earth, and by conversion
by known means, of the ferro-cyanide thereby formed, substantially as hereinbefore
described.
Dated this 7th day of November 1889.
ALLISON BROS.,
Agents for the Applicant.