Problem 3: Material and heat balance

In a multiple hearth roaster, copper, concentrate of composition 
 and moisture  is roasted. All iron is oxidized to  oxidizes to  and rest to . The furnace gases analyze and leaving the furnace at 900 K. The roast product is also discharged at 900K. reactants enter at 298 K. No fuel is used. Assume heat loss to be 10% of the heat input. Calculate

• Weight of roasted product per ton of concentrate
• % S in the roast product and express it as % of original S,
• Volume of air and excess air.
• Composition of the gases, and
• Heat balance of the process