Process for the Production of Alkali Cyanides.
Year: 1893

page_text: Date of Application, 15th July, 1893-Accepted, 6th Jan., 1894
Process for the Production of Alkali Cyanides.
I, Dr. WILHELM SIEPERMANN of Konigstrasse, Elberfeld, in the German
Empire, 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 :-—
The processes hitherto employed for the production of alkali cyanides have been
faulty in that the apparatus could not withstand the requisite very high
temperature and at a lower temperature the yield is too small for profitable
working.
The apparatus with which the highest temperatures may be used and which is
employed in carrying out the invention is the shaft or blast furnace in which by an
operation similar to smelting I obtain alkali cyanides from alkaline carbonates or
such alkaline compounds as in the process are converted into carbonates, as for
example, caustic alkalies, organic salts or nitrates and nitrites, by means of fuel
preferably aided by a hot blast.
In carrying out the process it is desirable to introduce the air into the furnace,
not as in metal smelting underneath near the hearth to pass out at top, but at the
top to be discharged laterally near the bottom of the furnace, in order that the
formed liquid alkali cyanide may not be oxidised through passing in front of
the blast nozzles.
In the drawing the apparatus is shewn in vertical section. A is the blast furnace
with a floor inclining downwards to the tapping hole and with a hearth extending
in the opposite direction so that the fuel with which the furnace is charged may
not reach pipe B which serves for carrying away the gases. F is the charging box
with double closure and serving for charging furnace A without the operatives
being incommoded by the escape of poisonous gases.
In using carbonates the charge may be prepared by mingling the same, preferably
in pieces, with pieces of wood or coke fuel or by saturating the fuel with a
solution of the alkaline carbonates and then drying it. The proportions are from
2 to 3 parts of fuel and 1 part of the carbonate. The furnace being thus charged
after having been previously heated, heated air is blown through pipe or nozzle D
from the regenerator R. By the heat developed in the blast furnace the alkaline
carbonates are reduced and converted into alkali cyanides which partly collect in a
fluid state upon the hearth and are drawn off through the tapping hole whilst the
larger portion of the same volatilise and pass off with the gases of combustion
through iron pipe B provided internally with a fire proof lining, and serving as a
preliminary cooler in which the gases are so far cooled that the alkali cyanide
separating therefrom remains in the fluid state and flows into the main cooler C,
which by means of spiral wings or plates causes the gases to travel a long distance,
and by reason of the rotary movement thereby called into action facilitates the
settling of the alkali cyanide in the form of powder. The cooler C which is a large
iron vessel is mounted on flange wheels running on rails for the purpose of removing
it and replacing it with another when convenient. It may for better cooling be
played upon or sprinkled over the outside with water. S is a scrubber into which
the gases pass from the cooler C. It is charged with pieces of coke and the gases
freed from the remaining portions of alkali compounds carried along with them by
water flowing in a contrary direction. The gases chiefly composed of carbonic
oxide and nitrogen then pass into one of two regenerators R where they are
burnt.

page_text: In using nitrates and nitrites the furnace is charged only with fuel or fuel with a
small addition of alkaline carbonate and the salts in the melted state supplied
through funnel G, flowing thence in a quantity regulated by a conical plug in the
funnel into pipe or nozzle D where they are formed into spray and blown into the
furnace with the air.
The residual cyano compounds contained in the gases are obtained in the form of
red or yellow prussiate of potash by washing with water to which iron salts have
added.
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. A process for the production of alkali cyanides by treating (smelting) with
fuel in a shaft furnace the alkaline carbonates or such alkaline compounds as in the
process yield alkaline carbonates, substantially as described.
2. In the process referred to when nitrates or nitrites are used the introduction
of the same into the furnace with the air of the blast substantially as described.
Dated this 15th day of July 1893.
CAPITAINE & VON HERTLING,
89, Chancery Lane, London, W.C., Agents for the Applicant.