Abstract:Arsenic compounds in different chemical forms were added to cement raw materials to produce clinkers. Thermogravimetric analysis, clinker sintering and clinker digestion were conducted to investigate the volatilization characteristics of arsenic related to time under isothermal conditions and possible reactions during co-processing of hazardous wastes in cement kilns. The results indicate that the volatile law varies with different chemical forms. The volatility of arsenic in sodium arsenate is small within the temperature range producing clinker. The volatilization proportion of arsenic in orpiment during co-processing increases with time, and after 25min, it does nearly not increase. And the volatilization proportion of arsenic in orpiment increases as temperature increases at temperatures below 1000℃, but decreases as temperature increases at temperatures above 1000℃. The volatile law of arsenic in sodium arsenite at temperatures above 1000℃ is similar to orpiment, that is the volatilization proportion decreases with the increase of temperature, and after 25min it does nearly not increase. The volatilization kinetics equation of arsenic in orpiment which indicates the relation between the volatilization proportion and temperature and time was obtained: α=1-exp[-1.77exp (-3158/T)t]. Through the calculation of theoretical values of arsenic volatilization at different temperatures over different time periods, the feeding quantities of arsenic wastes can be controlled to avoid environmental pollutions.
崔敬轩, 闫大海, 李丽, 王琪. 水泥窑共处置过程中砷挥发特性及动力学研究[J]. 中国环境科学, 2014, 34(6): 1498-1504.
CUI Jing-Xuan, YAN Da-Hai, LI Li, WANG Qi. Volatilization characteristics and dynamics research on arsenic during co-processing in cement kilns. CHINA ENVIRONMENTAL SCIENCECE, 2014, 34(6): 1498-1504.