Failed to connect to MySQL: Access denied for user 'examnext_online'@'localhost' (using password: YES) When ZnS and PbS minerals are present together than NaCN is added to separate them in the concentration process becacuse - - Sarthaks eConnect

When ZnS and PbS minerals are present together than NaCN is added to separate them in the concentration process becacuse :-

Pb `(CN)_2` is precipitated while no effect on Zns

PbS forms soluble complex `Na_2[Pb(CN)_4]`

ZnS forms soluble complex `Na_2[Zn(CN)_4]`

They cannot be separated by adding NaCN