Abstract
The selective removal of lead and chlorine with minimizing zinc loss from electric arc furnace (EAF) dust is very important in the process for recovering high purity zinc from the EAF dust by high temperature metal recovery (HTMR) processes. In this study, the volatilization reaction of lead contained in the EAF dust was investigated at reaction temperatures between 973 and 1223 K in air. The main volatilization reaction equation of lead was found as follows: 2NaCl+PbO+2SiO2+Al2O3=PbCl2(g)+2NaAlSiO4In the reaction time of 90 min at 1223 K, the volatilization ratio was about 98% for both lead and chlorine, while that was about 1% for zinc. Jander rate expression was found to fit reasonably well the volatilization reaction rate over the entire temperature range. The volatilization reaction rate of lead in the EAF dust is controlled by solid-solid diffusion and has an activation energy of 175 kJ/mol (41.8 kcal/mol).
