Extraction of metal from the ore cassiterite involves

The important ore of tin is cassiterite (tinstone, SnO2). Tin is extracted from cassiterite ore by carbon reduction method in a blast furnace.SnO2+2C⟶Sn+2COThe product often contains traces of iron as an impurity which is removed by blowing air through the melted tin which oxidises Fe to FeO. This iron oxide, FeO floats on the surface of melted metal tin.2Fe+O2⟶2FeO