Sulfur dioxide for the production of sulfuric acid is produced from pyrite roasting. The furnace is fed with pyrite (FeS2) that contains moisture and inert slag. The facilities manager believes that the composition in the contract is not correct based on the products obtained. Air is fed at 25C and 700 mmHg with a relative humidity of 40%. The gas product has a dew point of 12.5C and the furnace is operated with twice the stoichiometric oxygen. The slag collected after 10 min contains 0.36 t of FeS, 36 t of Fe2O3, and 6.6 t of inert slag. Determine the composition of the mineral that was sold to the plant and the heat losses, assuming cp,slag50.16 kcal/kg K and the pyrite is fed to the furnace at 25C.