Patent ID: 11905179
Assignee: CYPLUS GMBH
Field: Materials, metallurgy (Chemistry)
Classification: CPC C  F | IPC C  F

Claim 0:
1. A method for producing alkali metal cyanides as solids, comprising at least the following steps:
i) an absorption step, in which hydrogen cyanide from a synthesis gas containing hydrogen cyanide is absorbed in an aqueous alkali metal hydroxide solution to produce an aqueous alkali metal cyanide solution;
iii) a crystallization step, in which the alkali metal cyanide solution is introduced into an evaporative crystallizer, which is heated by heating and in which a pressure below 1013 mbar is provided;
iv) a step of condensation of cyanide-containing vapors arising in step iii) to form a cyanide-containing vapor condensate; wherein the step of the condensation iv) is performed using a multistage steam jet compressor, which suctions the exhaust vapors out of the crystallizer;
characterized in that the steam jet compressor is used so that the compression ratio over all stages is approximately 1:33 to 1:10.