JEE Main202226 Jun 2022Evening ShiftChemistryGeneral Principles and Processes of Isolation of MetalsActual
The role of depressants in 'Froth Floation method' is to
Options
- Aselectively prevent one component of the ore from coming to the froth.
- Breduce the consumption of oil for froth formation.
- Cstabilize the froth.
- Denhance non-wettability of the mineral particles.
Correct answer
A. selectively prevent one component of the ore from coming to the froth.
Step-by-step solution
In the froth floatation process, the role of the depressants is to separate two sulphide ores by selectively preventing one ore from forming froth. For example, to separate two sulphide ores, PbS and ZnS , NaCN is utilised. NaCN forms a combination with zinc on the surface of zinc sulphide, Na 2 Zn CN 4 , preventing ZnS from foaming selectively. 4 NaCN   +   ZnS ⇒ Na 2 Zn CN 4 + Na 2 S