水泥窑协同处置危险废物过程中铅-镉的挥发动力学研究

为了考察含重金属类危险废物在水泥窑协同处置过程中,铅、镉随时间和温度变化的挥发特性,本研究选择铅、镉两种重金属元素的氯化物和硫化物开展挥发动力学实验.通过热重实验、水泥熟料煅烧及熟料消解实验,得到了重金属挥发率随时间及温度的变化规律.结果表明,两种重金属元素的挥发率在实验温度区间内均随温度的升高、时间的增加而增大;根据等温动力学及阿累尼乌斯方程对Pb、Cd的挥发率随温度和时间变化的规律进行动力学模拟,得到了较好的线性拟合效果,并得出了以氯化物和硫化物形态存在的铅和镉元素在水泥窑协同处置过程中的动力学方程.本实验结果可为预测水泥窑协同处置过程中重金属的挥发量提供支持.

Volatilization kinetics of lead and cadmium during hazardous waste co-processing in cement kilns

Volatilization characteristics of Pb and Cd in the forms of chlorides and sulfides at different temperatures over different time periods dur-ing co-processing with cement raw materials were studied by thermogravimetric analysis,clinker sintering and clinker digestion.The volatili-zation of Pb and Cd increases with temperature and time within the temperature range in the test.According to isothermal kinetics and Arrhen-ius equation,kinetics simulation was utilized to describe the relationship between the volatilization proportions of Pb and Cd,temperature and time.Good linear fitting results and volatilization kinetics equations of Pb and Cd in the forms of chlorides and sulfides during co-processing with cement raw materials were obtained.These results provide support for predicting the volatilization of Pb and Cd during the process.