Extraction of gold and silver involves leaching with ${\text{CN}}^{-}$ ion. Silver is later recovered by:

In the Mac-Arthur Forrest cyanide process:Leaching: $4\text{Ag}+8{\text{CN}}^{-}+2{\text{H}}_2\text{O}+{\text{O}}_2\to 4[\text{Ag}(\text{CN}{)}_2{]}^{-}+4{\text{OH}}^{-}$.Recovery: The complex is treated with a more reactive metal like Zinc, which displaces the silver.$2[\text{Ag}(\text{CN}{)}_2{]}^{-}+\text{Zn}\to [\text{Zn}(\text{CN}{)}_4{]}^{2-}+2\text{Ag}$.