EFFICIENT METHOD OF NEUTRALIZING CYANIDE-CONTAINING GASEOUS WASTES AND WASTE WATER IN METHOD OF PRODUCING ALKALI METAL CYANIDES Russian patent published in 2021 - IPC C01C3/10 

FIELD: chemistry.

SUBSTANCE: present invention relates to a method of producing alkali metal cyanides in form of solid substances and to cyanides of alkali metals obtained using said method. Method includes a step of absorbing hydrogen cyanide from a reaction gas containing hydrogen cyanide in an aqueous solution of an alkali metal hydroxide to obtain an aqueous solution of an alkali metal cyanide, a crystallisation step in the form of adding an alkali metal cyanide solution to an evaporative crystalliser which is heated by heating and in which pressure is lower than atmospheric pressure, and a step for condensation of cyanide-containing vapours occurring at the crystallisation step to form a cyanide-containing steam condensate, wherein the condensation step is carried out using a multistage steam jet compressor which takes spent vapours from the crystalliser.

EFFECT: invention provides efficient production of alkali metal cyanides and reduction of gaseous wastes and waste water.

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