Problem context A concentrate of zinc sulfide contains 50%Zn,13%Fe,32%S, and 5%SiO2. When 100kg of the concentrate is roasted in air, 85kg of calcine with 54.4%Zn,14.1%Fe, 2.7%S and 5.4%SiO2 is obtained. The remaining portion (percentage) is assumed to be oxygen. The flue dust is assumed to have the same composition as the calcine. The roast gas contains 8 vol. %SO2. Calculate- 1. The mass of flue dust and its content of the various components 2. The volume of flue gas (in Nm3 ) 3. The composition of the roast gas 4. The volume of air used (21%O2,79%N2)