During waste incineration

PbO (difficult to volatilize) can be chlorinated to PbCl2 (easy to volatilize) by the interaction of NaCl and Si/Al in ash at high temperature. The mechanisms of this transformation were investigated by analyzing the release of chlorine and lead in the view of indirect and direct chlorination during the tube furnace incineration at rising temperature. During the indirect chlorination initialized at 700-800℃

oxygen containing water vapor was found more favorable to reaction than oxygen without water vapor

while Al2O3 was more favorable than SiO2. NaCl was found as vapor to participate indirect chlorination. During the direct chlorination through SiO2

PbO reacted with SiO2 first to form silicate at about 500℃

and then reacted with NaCl vapor produced initially at about 650℃. During the direct chlorination through Al2O3

PbO reacted with Al2O3 first to form aluminate at 700-800℃

and then reacted with NaCl. When Al2O3 was mixed with SiO2

the direct chlorination properties turned from SiO2 matrix type to Al2O3 matrix type

and the initial chlorination temperature increased from about 650℃ to 700-800℃.