Efficient method for decontaminating waste gases and waste water containing cyanide in a method for producing alkali metal cyanides

US11905179B2 · kind B2 · utility

Assignee

• Cyplus GmbH · DE

Inventors

• Jens Henkel · Meuselbach-Schwarzmühle, DE
• Jürgen Rassbach · Arnstadt, DE
• Klaus Trenkmann · Rudolstadt, DE
• Markus Jafeld · Frechen, DE
• Bernd Glöckler · Bruchköbel, DE

Key dates

• Filing date: Mar 2, 2020
• Grant date: Feb 20, 2024
• Expiry date: Jun 11, 2041

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F23G2209/14
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

The invention relates to a method for producing alkali metal cyanides as solids, comprising the steps: i) an absorption step in the form of the absorption of hydrogen cyanide from a syngas containing hydrogen cyanide in an aqueous alkali metal hydroxide solution; ii) a preparation step for the waste gases containing cyanide that have accumulated in step i); iii) a crystallization step in the form of the introduction of the alkali metal cyanide solution into an evaporative crystallizer; iv) a condensation step for the vapour containing cyanide that has accumulated in step iii) to obtain a vapour condensate containing cyanide; v) a recirculation step, in which the vapour condensate containing cyanide that has been obtained in step iv) is used as an aqueous liquid in step ii).