【作者】 魏仁零；

【导师】 吴晓琴；

【作者基本信息】 武汉科技大学 ， 化学工艺， 2011， 硕士

【摘要】 生石灰干式消化工艺对石灰粉的转化率、固体颗粒大小以及消石灰的比表面积和孔隙率都有很大影响,直接关系到脱硫剂品质的好坏。通过研究消化条件对脱硫剂结构和脱硫性能的影响,寻求最合适的消化条件,有助于提高烟气脱硫率。本文通过正交实验和单因素实验方法,考察了水灰比、消化水初始温度、搅拌速度及消化时间等消化过程参数脱硫剂结构和脱硫性能的影响;通过物料和热量计算,研究生石灰干式消化工艺过程中热力学和动力学特征;通过向生石灰添加SiO₂、Fe₂O₃、Al₂O₃、MgO等物质,研究石灰干式消化过程中杂质种类和数量对石灰消化速度、脱硫剂物理结构特性的影响。实验结果表明,以比表面积（S）和孔隙率（P）为特征参数,本研究体系中消化参数对工艺过程影响程度由大到小的顺序为:消化时间>水灰比>搅拌速度>消化水初始温度。在此基础上,研究得到的本体系优化的消化工艺参数范围为:消化时间5 min¹0 min、水灰比1.3:1¹.6:1、搅拌速度300 r/min⁴00 r/min、消化水初始温度25℃⁴5℃。热力学计算表明,在最佳水灰比范围内,生石灰消化反应平衡常数大,消石灰含水率适中,具有最佳的理化性质,与实验结果一致。动力学计算表明,生石灰干式消化过程属于扩散控制,利用Carter方程基本上能够描述生石灰干式消化反应的机理过程。不同含量的石灰杂质对石灰消化过程的影响不一样,SiO₂组分含量在6.0 %⁸.0 %,MgO的添加量在1.0 %左右,Fe₂O₃为2.0 %³.0 %,Al₂O₃的加入量在1.0 %左右时,所得消化产物的物理结构性能较佳。更多还原

【Abstract】 Dry slaking of quick lime impacts greatly on the conversion rate of lime, solid particle size, specific surface area and porosity, and determines the quality of the prepared desulfurization agent. The optimum conditions of the dry slaking can be obtained by the research of the influences of dry slaking technology on the structure and desulfurized property of desulfurization agent. And then, it can help to enhance desulfurization ratio during flue gas desulfurization.This paper investigated the influences of factors, such as water/solid ratio, initial temperature of hydrating-water, agitation rate, and hydration time, on the structure and desulfurized property of dusulfurization agent by the methods of orthogonal experimental design and single factor experimental design. Thermodynamics and kinetics of this process were studied by methods of mass balance and enthalpy balance. The dry slaking velocity of quick lime and chemical-physical properties of desulfurization agent were studied on by adding additives such as silicon dioxide, ferric oxide, alumina, and magnesia, into the process with different species and amounts of additives.In this research, specific surface area and porosity were used as characteristic parameters of white lime. Experimental results indicated that the influence of these factors arranged in a decreasing order is hydration time, water/solid ratio, agitation rate and initial temperature of hydrating-water. Accordingly, the optimal values of the procedure factors obtained from this system are 5 min¹0 min of slaking time, 1.3:1¹.6:1 of water/solid ratio, 300 r/min⁴00 r/min of agitation rate, and 25℃⁴5℃of initial temperature of hydration water. Thermodynamic calculations show that in the range of the optimum water-cement ratio, the equilibrium constant of lime digestion was large, lime water content was moderate, with the best physical and chemical properties and consistent with the experimental results. Dynamics calculations show that the dry lime diffusion controlled the digestion process, lime carter equation could basically describe the reaction mechanism of dry digestion process. Different amounts of impurities added in lime had different effect on the digestive process. Impurities in a certain range were contribute to digestion. They can improve the structural performance of desulfurization agent, and improve the desulfurization performance. When SiO₂ content was in the 6.0 %⁸.0 %, MgO was about 1.0 %, Fe₂O₃ was 2.0 %³.0 % and Al₂O₃ was 1.0 %, the digestion products obtained better performance of the physical structure.更多还原