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Sintering flue gas SO 2 emissions account for the steel industry emissions of 50% to 70% of the total direct emissions will cause serious environmental pollution and waste of resources. The circulating fluidized bed flue gas desulfurization technology because of its small footprint, simple operation, no wastewater is produced, in particular, has a strong adaptability characteristics of existing enterprises, has been applied in the sintering flue gas desulfurization. Desulfurization by-products - but the desulfurization process in desulfurization ash the CaSO 3 higher levels, restricting its effective comprehensive utilization. This paper analyzes the circulating fluidized bed sintering flue gas desulfurization ash physical and chemical properties, phase structure, established on the basis of thermal stability, temperature, time, and gas-solid ash conversion rate between the mathematical model, and draw The optimal conditions of the modification process, ash oxidation kinetics equation, the desulfurization ash can be used in the production of modified cementitious materials, retarder, pioneering a new way of desulfurization ash resource utilization. Using the GB chemical analysis method, iodometric method and SEM, BET, XRD, and other means of modern analytical analysis of the results of the physical and chemical characteristics of desulfurization ash: circulating fluidized bed sintering flue gas desulfurization ash in dry environment at room temperature more stable, no significant chemical composition change; particles of irregular shape, is porous, smooth the surface of the particles, loose structure; mineral phase mainly composed the CaSO 3 the CaSO 4 , CaCO , corundum and mullite also contains the the amorphous substances vitreous and unburned carbon copies. With SEM and XRD ash thermal stability studies show that the calcium sulfite is either in the air or nitrogen, before the decomposition has been oxidized to generate a stable calcium sulfate, and is relatively stable when the temperature is below 450 ° C, only loss of water of crystallization occurs change; wet desulfurization ash than dry state easily oxidized: under high temperature conditions, the oxygen in the atmosphere in the higher the concentration, the more easily oxidized to CaSO 3 desulfurization CaSO the 4 , alkaline oxides CaO ash stability inhibition and the Fe 2 O 3 oxidation of ash to promote role. The single factor experiment of circulating fluidized bed sintering flue gas desulfurization gray middle CaSO 3 converted to CaSO 4 modification process research results show that: in the 45 ~ 90 ℃ manganese dioxide, ferric oxide, vanadium pentoxide as the catalyst, ash conversion rate does not exceed 3%, the catalytic effect is followed by manganese dioxide> the iron sesquioxide> ash> vanadium pentoxide; at 100 ~ 400 ℃ ash between the conversion rate increased slowly with increasing temperature, increase sharply with increasing temperature between 400 to 550 ° C; when t <30 min reaction time, the ash conversion rate increased with the increase of time 81.3% conversion rate in the 30 min, when t> 30 min, the conversion rate of change over time is not obvious; gas-solid ratio of 0.01 to 0.06 m 3 · h -1 · g -1 , the conversion rate with the gas-solid than a positive correlation between growth, while the gas-solid ratio continues to increase, the conversion rate would decrease. Combined with BOX-Behnken central composite experimental design and response surface analysis, temperature, time, and gas-solid ash conversion rate between the mathematical model by model analysis of the influence of temperature on the conversion rate of ash, while interaction of temperature and gas-solid ratio, temperature and time interaction effects of ash conversion rate improved prediction model is Y = 0.841 0.195X 1 0.0748X 3 -0.113X 1 2 , where X 1 and X , 3 represent the temperature and gas-solid ratio encoding level, and desulfurization ash the best modification process conditions for the temperature of 453 ° C, time 30 min, the gas-solid than 0.04 m 3 · h -1 · g < sup> -1 . Desulfurization ash oxidation kinetics of the non-homogeneous reaction system, and the establishment of the relationship between the function of the time - conversion rate results showed that: when t <30 min, the diffusion process at this stage for the control process, when t> 30 min relations function of time - the conversion rate remains showed oxygen diffusion and mass transfer rate, and the chemical reaction rate decreased. Therefore, the chemical reaction process in the later reaction to become a control step of the conversion reaction. Conversion reaction is not elementary reactions of CaSO 3 · 1/2H 2 O 0.7 reaction of O 2 2.0 reactions.
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