危险废物水泥窑共处置过程Pb的热力学平衡?  

Equilibrium Analysis of Lead in Hazardous Waste During Co-Processing with Cement Kiln

作　　者：王雷[1] 金宜英[2] 李润东[1] 聂永丰[2] 

机构地区：[1]沈阳航空航天大学辽宁省清洁能源重点实验室,沈阳110036 [2]清华大学环境学院,北京100084

出　　处：《燃烧科学与技术》2011年第3期224-230,共7页Journal of Combustion Science and Technology

基　　金：国家科技支撑计划资助项目(2009BAC64B06);辽宁省创新团队资助项目(2008T150)

摘　　要：采用热力学平衡分析的方法对比研究了水泥窑煅烧条件下重金属Pb的迁移特性,并与焚烧炉焚烧条件下Pb的迁移特性进行了对比.采用CHEMKIN计算软件根据系统吉布斯自由能最小的原理进行计算.结果表明,Cl和SiO2都对重金属Pb的热力学行为有重要影响,Cl促进Pb的挥发,而SiO2有利于Pb的固定.在焚烧炉内,在温度高于900 K的条件下氯几乎全部以HCl的形式存在.在水泥窑中,温度低于1 450 K,HCl占氯的比例低于50%,HCl在约1 800 K时所占的比例最大,约为80%.由于水泥生料的主要成分为CaCO3,煅烧后分解产生大量的CaO,使水泥窑内呈现碱性气氛,抑制了HCl气体的生成.水泥窑煅烧过程Pb的固定率为45%,远高于焚烧炉焚烧过程Pb的固定率11%.An equilibrium analysis was performed to determine the migration characteristics of lead under the condi-tions of sintering in cement kiln and municipal solid waste（MSW）incineration.Using the thermodynamic equilibrium software CHEMKIN,the Gibbs free energy of the reaction system was minimized according to chemical potentials combined with atom population constraints.The results indicate that both chloride and SiO2 have great effect on the thermodynamic behavior of lead.Chlorides promote the evaporation of lead,while SiO2 stabilizes lead into silicate.When the incineration temperature in incinerator is higher than 900 K,chlorides mainly exist as HCl.When the sin-tering temperature is lower than 1 450 K,the ratio of HCl to chloride is lower than 50%,and the highest ratio of HCl to total chloride occurs at about 1800 K which is about 80%.Because the main component of cement raw materials is CaCO3,which generates a large amount of CaO after decomposition,an alkaline atmosphere is generated and the generation of HCl is inhibited.The stabilized rate of lead is 45% in the sintering process in cement kiln,which is much higher than that in the incineration process in incinerator which is only 11%.

关 键 词：危险废物 水泥 铅 化学形态 热力学 

分 类 号：X705[环境科学与工程—环境工程]