Requirements on coal charging particle size:0 ~ 10 mm d50 = 2 mm, oil for ignition is 0 # light diesel oil (in winter ,  - 10 # diesel oil is used);  low calorific value is 41000 kJ/kg,  S < 0.2%, the  carbon residual is < 0.4% ; the requirement on limestone purity is:CaCO3: ≦ 95%;MgCO3: ≧ 2%; Moisture≧0.12%; inert material: ≧ 0.12%. The requirement on limestone charging size: The particle size range is 0 ~ 2 mm, d50 = 0.3 mm.