JEE Main · 2022 · 29 Jun 2022 · Shift 1 · General Principles and Processes of Isolation of Metals

In isolation of which one of the following metals from their ores, the use of cyanide salt is not commonly involved?

Answer: (D)

Solution

Cyanide salts are used in metallurgy for:

Zinc: KCN is used as a depressant in the froth flotation process for ZnS ore.
Gold and Silver: The cyanide process (leaching) is used to extract these metals from their ores, forming soluble complexes like $[Au (CN)_{2}]^{-}$ and $[Ag (CN)_{2}]^{-}$ .
Copper: Copper extraction typically does not involve cyanide salts. It is extracted by processes like roasting, smelting, and electrolytic refining.

Therefore, copper isolation does not commonly involve cyanide salts.

Answer: (D)

JEE Main · 2022 · 29 Jun 2022 · Shift 1 · Single correct option