Question

After the extraction process of gold, the traces of Cyanide can be removed by

• A. INCO-licensed process
• B. Caro’s acid process
• C. Both a and b
• D. None of these

Answer 1

The correct option is C

Both a and b

Both processes utilize oxidants to oxidize cyanide to cyanate, which is non-toxic and which can react to form carbonates and ammonia. Thus traces of cyanide are removed.

$C{N}^{-}+\left[O\right]$ $\to$ $OC{N}^{-}$

$OC{N}^{-}$ $+2H_{2}O$ $\to$ $(HC{O}_3{)}^{-}+N{H}_3$