Improvements in the Preparation of Alkaline Cyanides and in Apparatus therefor.
Year: 1889

page_text: Date of Application, 30th Aug., 1889
Complete Specification Left, 30th May, 1890-Accepted, 26th July, 1890
PROVISIONAL SPECIFICATION.
Improvements in the Preparation of Alkaline Cyanides and in
Apparatus therefor.
We, HERMANN GRÜNEBERG Dr. Phil., Holzmarkt 25, Cöln, HUGO FLEMMING
Dr. Phil., 165 Hauptstr., Kalk, and WILHELM SIEPERMANN Dr. in Elberfeld, do
hereby declare the nature of this invention to be as follows:-
If a quantity of coal and alkaline carbonate are heated together to a dark red heat
and ammoniacal gas be added to the same, then a quantity of alkaline cyanate is formed
together with a little alkaline cyanate; if the same experiment be made at a light
red-heat, then alkaline cyanate alone will be formed but with less profit.
If however ammoniacal gas be first introduced at a dark red heat and be after-
wards heated to a light red-heat then the alkaline cyanate which is formed at first
is reduced to alkaline cyanide and the gain of alkaline cyanide will be considerably
more.
For a continual performance of these reactions of the preparation of the alkaline
cyanates in two phases the apparatus hereinafter described is specially designed.
The two reactions are effected in different parts of one and the same retort of which
a certain number are put in an oven at the same time, whilst a part of each of the
retorts is heated to dark red another part is heated to light red. For this purpose
vertical retorts are used so that the substance submitted to the test sinks down by its
own weight from the more heated to the less heated part.
The vertical retorts A are built in an oven whose flues as the drawing shows
are arranged in such a way that the lower part of the said retorts can be heated to
light-red and the upper part to dark-red.
The retorts have each a short additional pipe C, on its lower part which projects
into the oven, in which the product of the reaction cools, and is continually or
intermittently allowed to escape by flowing through a suitable coil D, or in a different
manner into a suitable receiver E.
A cooling pipe, an arrangement for drawing off liquid, and receiver are so
arranged that an outward escape of gases cannot take place, and therefore the gases
evolved in the retort are compelled to take their upward course.
Close shutting funnels or hoppers F are placed on the retorts through which pass
sufficiently large pipes H for letting out the evolved gases.
Through each of these pipes H a longitudinally adjustable pipe G of smaller
diameter passes which pipe serves to introduce the ammonia.
The work proceeds by opening the funnels or hoppers F and charging the retorts
with coarse charcoal, and carbonic-acid alkali. The funnels are then closed again.
When the retort has attained the desired temperature the before mentioned
smaller pipe G is moved so that its lower end approaches the place where the
light-red heat of the retorts is superseded by a dark-red heat.
Thereupon a steady stream of ammoniacal gas is introduced and the reacting
substance is let off into the receiver E. The funnels or hoppers F are re-filled
at suitable intervals.
A revolving drum J in the side flues of the oven serves for drying the substance
to be treated which substance ought not to be put in the funnel or hopper wet.
The molten mass which is formed in the above described apparatus is washed in lye
and the alkaline cyanide may then be separated from the lye in the known manner.
For the restoration of the potassic salts a new method is employed.
The molten mass is submitted when warm to a systematic washing in lye till the
Iva is about 402 Beame

page_text: This lye is charged when either at an ordinary or higher temperature with alkaline
carbonate.
The greater part of the cyanide of potassium then separates at once at the ordinary
temperature; or if a higher temperature has been used, after cooling.
Dated this 30th day of August 1889.
W. P. THOMPSON & BOULT,
Agents for the Applicants.
COMPLETE SPECIFICATION.
Improvements in the Preparation of Alkaline Cyanides and in
Apparatus therefor.
We, HERMANN GRÜNEBERG Dr. Phil., Holzmarkt 25, Coln, HUGO FLEMMING
Dr. Phil., 165 Haüpstr., Kalk, and WILHELM SIEPERMANN Dr. in Elberfeld, 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:-
When gaseous ammonia is passed over a mixture of charcoal and carbonates of the
metals of the alkalis heated to redness, small quantities of cyanides of those metals
are formed together with large quantities of cyanates of the same metals; if the
misture be heated to bright redness when performing the same experiment cyanides
alone are formed but the amount obtained is small.
If however ammonia be passed first over the mixture while it is at a dark red heat,
the supply of ammonia then cut off, and the mixture raised to a bright red heat, the
cyanates of the metals of the alkalis first formed will be reduced to cyanides and the
yield will be much improved.
The apparatus described below serves to enable these reactions to be carried out
continuously and the cyanides of the metals of the alkalis to be produced in two
stages. In the drawing accompanying the Provisional Specification of this
application the apparatus is shown in Figs. 1 and 2 in vertical and horizontal
section.
We conduct both reactions simultaneously in one and the same retort a number of
which are enclosed in one furnace, and this is done by employing upright retorts, and
heating one part of them to dark redness, the other to bright redness, the mass to
be acted upon falling by its own weight from the portions of the retort less highly
heated into that at a higher temperature.
The vertical retorts A are built in an oven whose flues as the drawing shows are
arranged in such a way that the lower part of the said retorts can be heated to light-
red and the upper part to dark-red.
The retorts have each a short additional pipe or length C on its lower part which
projects into the oven, in which the product of the reaction cools and is through the
inotion of an endless band D or in another suitable manner continually or inter-
mittently discharged into a receiver E.
A cooling pipe, an arrangement for drawing off liquid, and receiver are so
arranged that an outward escape of gases cannot take place, and therefore the
gases evolved in the retort are compelled to take their upward course.
Close shutting funnels or hoppers F are placed on the retorts through which pass
sufficiently large pipes H for letting out the evolved gases.
Through each of these pipes H a longitudinally adjustable pipe G of smaller
diameter passes which pipe serves to introduce the ammonia.
The work proceeds by opening the funnels or hoppers F and charging the retorts
with coarse charcoal, and carbonate of alkali. The funnels are then closed again.
When the retort has attained the desired temperature the before mentioned smaller
pipe G is moved so that its lower end approaches the place where the light-red heat of
the retorts is superseded by a dark-red heat.

page_text: Thereupon a steady stream of ammoniacal gas is introduced and the reacting
substance is let off into the receiver E. The funnels or hoppers F are re-filled at
suitable intervals.
A revolving drum J in the side flues of the oven serves for drying the substance to
be treated which substance ought not to be put in the funnel or hopper wet.
The salts formed in the apparatus described above are dissolved out, and the
cyanide in solution can thus be separated out by one of the methods in ordinary
usc.
For the manufacture of cyanide of potassium, we employ a special method viz;
The salt formed, is dissolved out, until the resulting solution shows 40° Beaumé.
This solution is then supersaturated with carbonate of soda at ordinary or at
higher temperature; in the former case the potassium cyanide precipitates at once, in
the latter case it does so as soon as the solution cools.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is
-
1. The employment of upright retorts for the manufacture of the cyanides of the
metals of the alkalis, arranged in a furnace in such a manner that the passage of the
heating gases round them brings the upper portion of the retorts to a dark red heat
while the part below is at a bright red heat, substantially as described.
2. The employment in the retort of a movable tube for the introduction of the
current of ammonia substantially as described.
3. The precipitation of potassium cyanide from its aqueous solution by sodium
carbonate, substantially as described.
Dated this 30th day of May 1890.
W. P. THOMPSON & BOULI,
Agents for the Applicants.