The metal extracted by leaching with cyanide is

Leaching is often used if the ore is soluble in some suitable solvent. In the metallurgy of silver and that of gold,  the respective metal is leached with a dilute solution of NaCN or KCN in the presence of air (for O2​) from which the metal is obtained later by replacement.4M(s)+8CN−(aq)+2H2​O(aq)+O2​(g)→4[M(CN)2​]−(aq)+4OH−(aq) (M = Ag or Au)2[M(CN)​2]−(aq)+Zn(s)→[Zn(CN)4​]2−(aq)+2M(s)