Calcination of ores involves heating the ore below its fusion temperature in

Options

A. presence of superheated steam
B. absence of air or limited supply of air
C. an atmosphare of nirogen
D. presence of air

Answer

b

Explanation

Because metals in their combined forms always have positive oxidation number, the production of a free metal is always a reduction process, Preliminary operation may be necessery to convert the ore to a chemical state more suitable for reduction , for example ,an ore may be calcined (i.e. strongly heated in absences of air or luimited apply of air)to drive off volatile impurities and or the sametime to convert the carbonates to the corresponding oxide, which can be reduced more conveminaly to yied the pure metals
`CaCO_(2) (s) overset (Delta) To CaO(s) + CO_(2)(g)`