Engineering Operation Analysis Of Red Mud And Limestone Wet Flue Gas Desulfurization

Alumina red mud has not been utilized effectively due to its strong alkaline. High emission and Long-term stockpiling occupied cultivated land, caused soil alkalization and groundwater pollution. Industrial flue gas which has high SO2should be desulfurized to manage up to the standards. This study stands on the composition and phase characteristics of red mud, using red mud to disposal flue gas is make two kinds of harmful substances to the environment interaction, realize "using waste treat waste" and the comprehensive utilization of resources.First, the chemical composition, mineral composition and granularity of red mud were analyzed by XRD and particle size analysis. Results show that red mud contains abundant solid sulfur components, and has small particle size, large specific surface area, which is a kind of useful desulfurization agent. On the basis, designed and installed1700x60mm absorption tower, and the experimental research of red mud wet desulphurization has been carried at the scene of Zhengzhou Xinli electric power co.. Single factor investigation got the better process conditions of red mud circulation desulfurization were:liquid-solid ratio was7:1(kg/kg), flue gas flow rate was3.6m3/h, the liquid-gas ratio was15:1(L/m3), then the red mud desulfurization rate could reach more than95%. In the continuous operation of desulphurization, when the pH value got down to5.9to add10%of the fresh slurry, the desulfurization rate remained above95%.Second, on the basis of pilot study, referencing of "GB13223-2011Emission Standards of Air Pollutants for Thermal Power Plant" and considering of the engineering operation characteristics and amplification effect, the control indicators of red mud desulfurization mainly include:red mud slurry pH value, the slurry level in absorber, the slurry density, the pressure of blower fan inlet, etc. The desulfurization parameters have been theory analysis and calculation, the suitable liquid-gas ratio is (11.86～21.54)(L/m3), the liquid-solid ratio is7:1(kg/kg), flue gas flow rate is (1.78～2.97)×106m3/h. Finally, system operation of limestone wet desulfurization process has been analyzed. The main operating parameters are:liquid-gas ratio is10-15(L/m3), liquid-solid ratio is6-9(kg/kg), the flue gas flow rate is3-5m/s. The reliability of limestone-gypsum wet flue gas desulfurization is high, the security and stability are respectively affected by the scale and control systems. At present the main problem of the desulfurization technology is the cost is higher, and it emits the same amount of CO2when absorption of SO2. Comparative analysis of engineering operation between red mud and limestone wet flue gas desulfurization showed that red mud wet flue gas desulfurization had advantages of desulfurization costs less, emit less CO2, by-products used wider, etc.Red mud wet desulfurization is a new type of desulfurization technology, Desulfurization by-products can be used as construction materials, Silicon-calcium fertilizer in other industries, really solve waste stockpiling problem of aluminum industrial, realize the comprehensive utilization of red mud.