Kinetic and thermodynamic study of PbCl_2 volatilizing in air atmosphere

As for the high chlorine content of MSWI fly ash in China,the volatilization of chlorides of lead(Pb) was studied.Firstly the volatilization under air atmosphere of lead chloride(PbCl2) was modeled by Gibbs free energy criterion.Subsequently,the heating rate,that influenced the volatilization of PbCl2 was characterized on basis of experimental observations derived by means of a high temperature TG-DTA system.With the results of the thermodynamic analysis,the kinetic models of the volatilization of PbCl2 were also developed.The results show that the volatilization process of PbCl2 is mainly the phase change of PbCl2 crystal with a small quantity of lead oxide(PbO) and lead created;the volatilization curves shift with increasing heating rate towards higher temperatures,and the temperature eigenvalue increase on certain degree with increasing heating rate,but the volatilization ratio changes indistinctively;a zero-order kinetic model may describe the volatilization reaction accurately.