Extraction of Heavy Metals from the Ash Using Hydrochloric Acid

This study aims to develop a methodology for analysis of extraction of heavy metals from air pollution control (APC) ash using hydrochloric acid. In this work, the ash was firstly characterized and then hydrochloric acid was used to extract Ni, Zn, Pb and Cu out from the ash. In addition, influence of hydrochloric acid concentration on removal ratio of the four heavy metals was studied. It was found that removal ratio followed the decreasing sequence of Pb > Zn > Cd > Cu for acid extraction using hydrochloric acid. The optimal acid concentration was 4 mol/L, which resulted in a removal ratio of 91% for Pb, 84% for Zn, around 53% for Cd and around 41% for Cu.