1.

In roasting :A. Moisture is removedB. non-metals as their volatile oxide are removedC. Ore becomes porousD. All the above

Answer» Correct Answer - D
Roasting removes easily oxidisable volatile impurities like arsenic (as `As_2O_3`) sulphur (as `SO_2`), phosphorus (as`P_4O_10`) and antimony (as `Sb_2O_3`)
`4M(M=As, Sb)+3O_2to2M_2O_3uarr`
`S+O_2toSO_2uarr,P_4+4O_2toP_4O_10uarr`
Organic matter, moisture if present in the ore, also get expelled and the ore becomes porous .


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