This specification covers two types of commercial grade sodium cyanide salt corresponding approximately to the formula NaCN. Both Types are for use primarily in plating and heat treating; GM1852M for processes which can tolerate a relatively large sulfur content, and GM1857M for any process including those in which sulfur is a critical factor, such as silver and most bright copper plating.
CAUTION NOTE. Contact of cyanides with nitrates or nitrites will cause a very damaging explosion. These materials should never be stored or used in close proximity to each other. Parts moving from carbonate salts to nitrate salts must be thoroughly washed between operations. Mixtures of nitrates and carbonates create toxic gases. These materials should never be stored or used close together. Materials containing cyanide are extremely toxic and must not be taken into the human body. Contact of moisture with molten cyanide mixtures will cause dangerous eruptions or explosions. Hence every precaution must be taken to avoid introduction of moisture from overhead pipes, leaky roof or other sources.
In heat treating, their principal use is for activating or sweetening baths made up of salts having lower sodium cyanide content. They may be used for small batch case hardening. Due to their high cyanide concentration. These salts will deteriorate to sodium carbonate faster than those containing less sodium cyanide. Potassium cyanide is sometimes substituted for this material, but at considerable increase in operating costs. (See Caution Note.)