Question -
Answer -
In the froth floatation process,the role of the depressants is to separate two sulphide ores by selectivelypreventing one ore from forming froth. For example, to separate two sulphideores (ZnS and Pbs), NaCN is used as a depressant which selectively allows PbSto come with froth, but prevents ZnS from coming to froth. This happens becauseNaCN reacts with ZnS to form Na2[Zn(CN)4].
