Natriumcyanide

Natriumcyanide, also called sodium cyanide, is the chemical compound NaCN. It is a white, odorless crystalline solid that is highly soluble in water and hygroscopic. It functions as a source of cyanide in many industrial processes and is regarded as a highly toxic substance.

Production and chemistry: Sodium cyanide is typically produced by absorbing hydrogen cyanide into a sodium hydroxide solution, forming NaCN and water. Hydrogen cyanide itself is produced industrially by methods such as the Andrussow process, which converts methane and ammonia in the presence of oxygen over a catalyst. In water, NaCN dissociates to CN- and Na+. In acidic conditions, CN- is protonated to form hydrocyanic acid (HCN), a volatile and highly toxic gas.

Applications: The largest single use is cyanide leaching in gold mining and precious metal extraction, where cyanide complexes dissolve gold. It is also used in electroplating and electroforming, organic synthesis for the introduction of the cyanide group, and as a precursor to other nitriles and cyanohydrin derivatives.

Safety, regulation, and environment: Sodium cyanide is extremely toxic; exposure can cause rapid onset of cyanide poisoning by inhibition of cytochrome c oxidase, leading to cellular hypoxia. Handling requires appropriate engineering controls, containment, and personal protective equipment. It reacts with acids to release hydrogen cyanide gas; spills or improper disposal can pose serious environmental hazards to aquatic life. Its use is subject to strict regulatory controls in many countries.