Name:

(a) the processes involved in (i) dressing of the ores (ii) refining of the ores.

(b) two metallic oxides which cannot be reduced by carbon, carbon monoxide or hydrogen.

Why does iron or zinc not occur free in nature?

Compare roasting and calcination.

(a) Name an ore of zinc

(b) Which process is applied to concentrate it?

(c) How is concentrated ore changed to oxide?