Question

An ore gave so2 on heating with oxygen. How will you concentrate this ore

Answer 1

This ore can  be concentrated by roasting method.

Answer 2

Explanation:

Roasting is the process of heating of an ore in the presence of an excessive air. This process is generally used in heating of sulfide ores to convert them into oxides of metal and sulfur dioxide gas.

$2ZnS(s)+3O_2\rightarrow 2ZnO(s)+2SO_2$

An ore which gives sulfur dioxide gas on heating can be concentrated by heating further in the presence of an excess air that is by the process termed as Roasting.