Which of the following processes causes are pollution ?

Options

A. Roasting
B. Calctration
C. Froth floatation
D. Both (1) and (2)

Answer

a

Explanation

Some sulphides ores are are convented to oxides by roatsting. That is, heating below their melting point in the presence of oxygen from air, for example
`2ZnS (s) + 3O_(2)(g) rarr 2ZnO(S) + 2SO_(2) + 2SO_(2) (g)`
Reasting sulphide ores causes air pollation large quentities of `SO_(2)` escape into the atmosphere, where it cause great enviromental damage .Regulation now required limiting the amount of `SO_(2)` Now most of `SO_(2)` is trapped and used in the marufacture of sulphuric acid