Explain the role of the following :
(a) NaCN in the separation of ZnS and PbS.
(b) in the metallurgy of Cu containing Fe as impurity.
(c) Iodine in the refining of Ti.
(a) NaCN act as a depressant the separation of ZnS and PbS
(b) SiO2 act as a flux in the metallurgy of Cu containing Fe as impurity.
(c) Iodine is used to convert Ti into volatile compound (TiI4) in the refining of Ti