Potassium cyanide is a compound with the chemical formula KCN. This colorless, highly toxic crystalline salt, similar in appearance to sugar, is very soluble in water. Most KCN is used in gold mining, organic synthesis and electroplating. Smaller applications include jewelry for electroless gold plating and polishing. [4]

As a result of hydrolysis, the wet solid releases small amounts of hydrogen cyanide and smells like bitter almonds. [5] However, not everyone can smell cyanide. The ability to do so is a genetic trait. [6]

The taste of potassium cyanide formula  has been described as pungent and bitter, with a burning sensation similar to that of lye [7].
KCN is produced by treating hydrogen cyanide with aqueous potassium hydroxide and then evaporating the solution in vacuo:[9]

HCN + KOH → KCN + H2O
The annual output of potassium cyanide is about 50,000 tons. [4]

historical production
Potassium cyanide was the most important source of alkali metal cyanide until 1900 and the invention of the Castner process. [4] During this historical course, potassium cyanide was produced by the decomposition of potassium ferrocyanide