Abstract:For traditional wet limestone wet flue gas desulfurization process, excepting for high cost, a large amount of gypsum byproduct was formed, which was difficult to be reused, and resulted in many new environmental problems. However, flue gas desulfurization with oxide manganese slurry could remove SO₂ and produce MnSO₄ simultaneously. Based on the characteristics of electrolytic manganese industry, a new technology for sulfur dioxide recycling and removal from flue gas of electrolytic manganese residue calcination process was presented using the manganese oxide ore (raw material from electrolytic manganese industry) with anode solution of electrolytic manganese slurry, and the influences of processing parameters were investigated in the present work. The process experimental investigations on flue gas desulfurization and manganese leaching with electrolysis anode solution and manganese dioxide ore slurry indicated that as desulphurizing time increased, the higher SO₂ concentration of flue gas, the lower the desulfurization efficiency was obtained, and the manganese leaching rate increased, thus multistage countercurrent mode should be adopted to realize efficient desulphurization and manganese leaching. The desulfurization rate increased with the decrease of the granule size of manganese oxide and the size of the manganese ore used for desulphurization should be less than 120 mesh. The operating temperature of flue gas desulfurization should be controlled in the range of 50～80 ℃, while the liquid-solid ratio should be in the range of 9∶1～6∶1. For different processing installations, the relative optimum inlet flow was different and for the applied experimental installation, i. e. 2.0 m³/ min. The simulation of anode solution was used to conduct 5 grade manganese oxide slurry desulfurization of the simulated 7% flue gas calcination, and the results showed that with the liquid-solid ratio at 9∶1, ore particle size at 200 mesh, the temperature at 50 ℃, the time of 4 grade desulfurization at 20 min, the outlet SO₂ concentration was 111.4 mg/m³, leaching rate was 93.12%, concentration of Mn²⁺ was 46.26 mg/L in slurry, and concentration of MnS₂O₆ was 4 g/L (for fifth grade (100 min). The present work provided a new technology for sulfur dioxide recycling and removal from flue gas using the manganese oxide ore with anode solution of electrolytic manganese slurry. Compared with the traditional method of sulfur resources utilization, the cost of the present method was significantly reduced.