Review of Emission and Simultaneous Control of Multiple Pollutants from Iron-steel Sintering Flue Gas

According to the statistics and analysis of the emission characteristics of the multiple pollutants in the flue gas from the scores of iron-steel sinters, the proportion of outlet dust concentration from electrostatic precipitators below 50 mg/m³ occupied 63%, and that from bag dust collectors was 100%. The proportion of the SO₂ concentration below 4000 mg/m³ occupied 92%, and over 4000 mg/m³ occupied 8%; therefore, the desulfurization efficiency should be higher than 95% and 97% respectively. The proportion of the NO_x concentration over 300 mg/m³ was 16%, and the denitration efficiency should be higher than 50% to meet the emission standard. The dioxins concentration was between 1.0 and 5.0 ng-TEQ/m³ should be treated by special removal device with the efficiency of over 80% or by simultaneous control technologies with over 50%. Four simultaneous control technologies for multiple pollutants from iron-steel sintering flue gas were outlined, and their technical and economic characteristics were discussed. In Technology Routes 1 and 2, the dust, SO₂ and dioxins were removed by wet and semi-dry desulfurization devices combined with dust collector and injection activated carbon, while in Technology 3 and 4, the dust, SO₂, nitrogen oxide and dioxins were removed by active carbon method or SCR combined with dust collector and desulfurization devices.