Question

How can Ag precipitated from a silver-cyanide complex?

Answer 1

Silver is extracted from its Argentite ore i.e. Ag2S. NaCN is used for the extraction of silver. The process is known as cyanide process.
This ore, Ag2O reacts with NaCN to form a complex sodium argento cyanide Na[Ag(CN)​2]. This complex reacts with zinc dust to form the precipiated silver. The precipitated silver is fused with KNO3 to get the pure silver.

Reactionss involved:
Ag2S + 4 NaCN⇌2Na[Ag(CN)4] + Na2S Sodium argento cyanideZn + 2Na[Ag(CN)4]→Na2[Zn(CN)4] + 2 Ag