Process for production of sodium cyanide

A process for producing anhydrous sodium cyanide crystals by absorbing hydrogen cyanide synthesis gas that contains oxides of carbon and water in aqueous sodium hydroxide in an absorber (1) and feeding the sodium cyanide solution that results from the absorption in a evaporative crystallizer (2) to produce a slurry of NaCN crystals. HCN in the vapor from the evaporative crystallizer is absorbed in absorber (4) and recycled to absorber (1). The sodium carbonate that forms in the absorber (1) is not removed prior to crystallization. The NaCN crystals and mother liquor are separated in separator (3). The mother liquor is recycled to absorber (1). Carbon dioxide is largely lost in the exit gases line (11) of absorber (1).