Improvements in the Manufacture of Cyanides.
Year: 1895

page_text: Date of Application, 1st May, 1895
Complete Specification Left, 31st Jan., 1896-Accepted, 7th Mar., 1896
PROVISIONAL SPECIFICATION.
Improvements in the Manufacture of Cyanides.
We, HORACE WOODWARD CROWTHER, of The Beeches, West Bromwich,
EDMUND CHARLES ROSSITER, of Smethwick, near Birmingham, both Chemists,
and GEORGE STACEY ALBRIGHT, of The Elms, Edgbaston, Birmingham,
Gentleman, do hereby declare the nature of this invention to be as follows:-
On the 26th day of April 1894 we applied for a Patent for "Improvements in
the manufacture of ferrocyanides of potassium and sodium from their sulphocyanides
and apparatus relating thereto."
On the 21st day of February 1895 we left at the Patent Office a Complete
Specification of the said improvements.
Our Complete Specification has not yet been accepted nor has a Patent been
granted.
Now we find the means of freeing the sulphocyanide of potassium and sodium
from water, and the apparatus described therein, are very suitable means and
apparatus for preparing cyanides from sulphocyanides by the known method of
heating such sulphocyanides with metallic zinc or lead or other metals that
combine with the sulphur of the sulphocyanide to form a sulphide, which does not
when dissolved in water form a double or compound cyanide and sulphide of the
alkali or only to a small extent.
The apparatus we employ is shown by the drawings annexed.
Figure 1 is a plan partly in section.
Figure 2 is a vertical section through line E F.
Figure 3 is a front elevation.
Figure 1 shows a convenient arrangement of four furnaces, riz. two furnaces with
no mechanical apparatus overhead for stirring which may be used for drying the
potassium sulphocyanide and two furnaces with the overhead mechanical apparatus
for agitation required for the fusion of the dried sulphocyanide with a metal such
as zinc or lead. The drying and decomposing furnaces are alike. The furnaces
are cylindrical lined with fire-brick and built in the manner shown in the drawings
the top of each is covered with an iron plate having a hole in the centre somewhat
larger than the outside diameter of the pot, near the top are a number of lateral
openings which connect to the flue e and thence to the chimney. The heated
gases from the fire underneath the pot pass up all round the pot, whereby it is
heated uniformly. Dampers are provided to regulate the draught.
The mechanical arrangements for agitating the mixture of sulphocyanide and
zine or lead or other suitable metal are a main shaft driven by an engine which by
means of the pulleys and belts as shewn communicates its motion to bevelled
wheels el and and thence to the vertical shaft I, which is so arranged as to be
exactly over the centre of the pot when the pot is in position in the furnace. The
shaft is so arranged at its lower end that it may be coupled with the removeable
piece g and then to the stirrer or agitator in the pot beneath. The removal of this
piece
allows of the introduction or withdrawal of the pot from the furnace.
The stirrer h consists of an axis, square at its lower part and having strong iron
arms or paddles bolted on as shown. The stirrer is supported in the pot by the
collar on the agitator axis resting upon the cross bar which is supporte 1 -ome
little distance above the top of the pot by the pillars pp fastened on the top flange
of the put the top cross bar serving to keep the shaft vertical and to add rigidity
to the stirring apparatus. The cross bars are so fixed on the pillars that they are
removeable with the nvitator.

page_text: The pot we prefer to use is cylindrical; the top flange besides serving for
supporting the pillars for carrying the cross bars mentioned above, also serves for
fastening the cover on to the pot, it has also a lower flange x to support the pot in
the furnace at a proper height above the fire, this flange is of sufficient width so
that it rests firmly on the iron plate covering the top of the furnace as mentioned
above. The pot is also furnished with lugs k k to receive hooks attached to crane
chains to enable the pot either to be removed from the drying furnace to the
decomposing furnace, or from this to a place to cool. An overhead travelling
crane not shown in the drawings is convenient for the purpose. The pot is also
furnished with a moveable cover j made in two halves and nearly air tight, it is
fastened on to the pot by means of bolts, with a joint of asbestos packing between
it and the pot. A small sight hole is provided in the lid and also a hole through
which molten zinc or lead can be poured when necessary which are closed by plugs
when not in use.
The drying of the sulphocyanide and the fusion of the sulphocyanide with zinc
or lead or other suitable metal is done in the same pot, but in the case of sulpho-
cyanide of potassium, the first operation of drying takes place in the drying
furnace and the decomposition in the decomposing furnace.
We procced to perform the operations as follows; in the case of sulphocyanide
of potassium, a known quantity of the sulphocyanide is put into the pot, which
when melted will occupy about one third the capacity of the pot. The pot is then
put into the drying furnace and the sulphocyanide is just melted by the fire
underneath. The heating is continued whilst inert gases (lime kiln gases) are
passed through by means of a pipe having a ring at the bottom perforated with
a number of small holes. This pipe is connected by means of a stout india
rubber tube or pipe to a main supplying the inert gas (lime kiln gases) under
pressure and free from water. When the temperature reaches 450° to 500° F.,
and the fused sulphocyanide is free from water, the gas pipe is removed and the
pot transferred to the decomposing furnace, the agitator is introduced and connected
Ly means of the piece g to the vertical shaft f. The necessary amount of zinc
or lead or other metal in a suitable state of division or in the molten state is
then added, or preferably a portion is added and the remainder at a later period.
The lids having been fastened on, the pot is fired, the materials being continually
stirred. As the reaction takes place the mass inside becomes red hot and samples
are from time to time withdrawn to find when the decomposition of the sphy
cyanide plently complete. When this is found the connecting piece is
disconnected from the agitator and shaft, the agitator is removed and the put is
taken from the furnace to cool.
The
In the case of sulphuryanide of sodium the pot with the agitator fittel and
containing a charge of sulpheryanide of solium is at once put into the decomposing
furnace, and the sulphocyanile melted in its water of crystallisation.
charge is dried by heat and continuous stirring until a greater part of the water
has been removed, then a stream of inert gas (lime kiln gases) is passed into the
pot to prevent oxidation of the sulphocyanide. The heat is then raised with
continual stirring and passage of lime kiln gases over the surface until the mass
is fused, the lid is then fastened on and the necessary quantity of zinc, lead or other
suitable metal is added. The subsequent procedure is then exactly the same as
described in the case of the potash salt.
The mixture of cyanide of the alkali and sulphide of zinc, lead or other metal
that is not decomposed by a solution of alkaline cyanide, is then lixiviated with
water, the insolubile sulphide separatel by filtration, the solution evaporated in
cuento and the resulting solid alkaline eyenile driel if necessary in
fusid.
7:

page_text: Improvements in the Manufacture of Cyanides.
We, HORACE WOODWARD CROWTHER, of The Beeches, West Bromwich,
EDMUND CHARLES ROSSITER, of Smethwick, near Birmingham, both Chemists,
and GEORGE STACEY ALBRIGHT, of The Elms, Edgbaston, Birmingham,
Gentleman, 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 :-
66
A Patent has been granted to us dated the 26th day of April 1894 for
Improvements in the manufacture of ferrocyanides of potassium and sodium
from their sulphocyanides and apparatus relating thereto."
Now we find the means of freeing the sulphocyanide of potassium and sodium
from water, and the apparatus described in the Specification of the said Patent,
are very suitable means and apparatus for preparing cyanides from sulphocyanides
by the known method of heating such sulphocyanides with metallic zinc or lead or
other metals that combine with the sulphur of the sulphocyanide to form a sulphide,
which does not when the melt is dissolved in water form a double or compound
cyanide and sulphide of the alkali or only to a small extent.
The apparatus we employ is shown by the drawings annexed to our Provisional
Specification.
Figure 1 is a plan partly in section.
Figure 2 is a vertical section through line E F.
Figure 3 is a front elevation.
Figure 1 shows a convenient arrangement of four furnaces, viz. two furnaces
with no mechanical apparatus overhead for stirring which may be used for drying
the potassium sulphocyanide and two furnaces with the overhead mechanical
apparatus for agitation required for the fusion of the dried sulphocyanide with a
metal such as zinc or lead. The drying and decomposing furnaces are alike. The
furnaces are cylindrical lined with fire-brick and built in the manner shown in the
drawings the top of each is covered with an iron plate having a hole in the centre
somewhat larger than the outside diameter of the pot, near the top are a number
of lateral openings b which connect to the flue c and thence to the chimney. The
heated gases from the fire underneath the pot pass up all round the pot, whereby
it is heated uniformly. Dampers are provided to regulate the draught.
The mechanical arrangements for agitatiug the mixture of sulphocyanide and
zinc or lead or other suitable metal are a main shaft driven by an engine which by
means of the pullies and belts as shewn communicates its motion to bevelled
wheels e and f and thence to the vertical shaft I, which is so arranged as to be
exactly over the centre of the pot when the pot is in position in the furnace. The
shaft is so arranged at its lower end that it may be coupled with the removeable
piece y and then to the stirrer or agitator in the pot beneath. The removal of
this piece g allows of the introduction or withdrawal of the pot from the furnace.
The stirrer consists of an axis, square at its lower part and having strong iron
arms or paddles bolted on as shewn. The stirrer is supported in the pot by the
collar on the agitator axis resting upon the cross bar which is supported some
little distance above the top of the pot by the pillars pp fastened on the top
flange of the pot the top cross bar i serving to keep the shait vertical and to add
rigidity to the stirring apparatus. The cross bars are so fixed on the pillars that
they are removeable with the agitator.
The pot we prefer to use is cylindrical, the top flange besides serving for
supporting the pillars for carrying the cross bars mentioned above, also serves for
fastening the cover on to the pot, it has also a lower flange to support the pot

page_text: in the furnace at a proper height above the fire, this flange is of sufficient width so
that it rests firmly on the iron plate covering the top of the furnace as mentioned
above. The pot is also furnished with lugs to receive hooks attached to crane
chains to enable the pot either to be removed from the drying furnace to the
decomposing furnace, or from this to a place to cool. An overhead travelling
crane not shewn in the drawings is convenient for the purpose. The pot is also
furnished with a moveable coverj made in two halves and nearly air tight, it is
fastened on to the pot by means of bolts, with a joint of asbestos packing between
it and the pot.
A small sight hole is provided in the lid and also a hole through
which molten zine or lead can be poured when necessary which are closed by plugs
when not in use.
The drying of the sulph cyanide and the fusion of the sulphocyanide with zinc
or lead or other suitable metal is done in the same pot, but in the case of sulpho-
cyanide of potassium, the first operation of drying takes place in the drying
furnace and the decomposition in the decomposing furnace.
We proceed to perform the operations as follows; in the case of sulphocyanide
of potassium, a known quantity of the sulphocyanide is put into the pot, which
when melted will occupy about one third the capacity of the pot. The pot is then
put into the drying furnace and the sulphocyanide is just melted by the fire
underneath. The heating is continued whilst inert gases (lime kiln gases) are
passed through by means of a pipe having a ring at the bottom perforated with a
number of small holes. This pipe is connected by means of a stout india-rubber
tube or pipe to a main supplying the inert gas (lime kiln gases) under pressure and
free from water. When the temperature reaches 450° to 500° F., and the fused
sulphocyanide is free from water, the gas pipe is removed and the pot transferred
to the decomposing furnace, the agitator is introduced and connected by means of
the piece g to the vertical shaft. The necessary amount of zinc or lead or other
metal in a suitable state of division or in the molten state is then added, or
preferably a portion is added and the remainder at a later period. The lids having
been fastened on, the pot is heated to the desired temperature, the materials being
continually stirred. As the reaction takes place the mass inside becomes red hot
and samples are from time to time withdrawn to find when the decomposition of
the eulphocyanide is sufficiently complete. When this is found the connect.ng
piece is disconnected from the agitator and shaft, and the pot together with
agitator is taken from the furnace to cool.
In the case of sulphocyanide of sodium the pot with the agitator fittel and
containing a charge of sulphuryanide of s lium is at once not into the dicasing
furmare and the culpey all arited in it water of cytation.
The cage is dried by heat and continuous stirring until a grunt part of the
water has been removel, the decam of inert gas (lime kiln gases) i passed into
the pot to prevent oxidation of the sulphory mulle. The heat in then raised with
continual tirring and passage of lime kiin
ver the surface until the mis
ful, the lid is then fasteurd on and the necessary quantity of zine, lead or other
suitable metal is added. The subsequent procedure is then exactly the same as
de-cribed in the case of the potash salt.
The mixture of cyanide of the alkali and sulphide of zinc, lead or other
metal that is not decomposed by a solution of alkaline cynide, is then lixiviated
with water, the insoluble sulphide separated by filtration, the solution evaporated
in vacuo and the resulting solid alkaline cyanide dried if necessary in vacuo and
fused.
Having now particularly described and ascertained the nature of our said invez-
tion and in what manner the name is to be performed, we declare that what we
claim in :-
1
3
ying a
T
'

page_text: 2. The manufacture of cyanides by the aid of zinc or other metal as herein-
before described from sulphocyanides of potassium and of sodium by causing the
reaction to take place in apparatus substantially as described in an air tight or
nearly air tight pot with mechanical agitation; the arrangement being such that
the pot can be removed from the furnace and the agitator withdrawn from the pot.
Dated this 23rd day of January 1896.
HORACE WOODWARD CROWTHER.
EDMUND CHARLES ROSSITER.
GEORGE STACEY ALBRIGHT.