Question

Extraction of gold and silver involves leaching the metal with $C{N}^{-}$ ion. The metal is recovered by:

• A. displacement of metal by some other metal from the complex ion
• B. roasting of metal complex
• C. calcination followed by roasting
• D. thermal decomposition of metal complex

Answer 1

Answer: (A)

displacement of metal by some other metal from the complex ion

$Ag$ and $Au$ are extracted by Mac-Arthur process. In which the ore is converted to complex ion and then $Ag$ or $Au$ in the complex is replaced by other metal (Mainly Zinc)