Recovery of heavy metals from municipal incinerator fly ash by extraction and electrolysis

摘要

In this investigation, the extracted heavy metals from a municipal incinerator fly ash (MIFA S) were recovered by electrowinning using an electrolytic cell of the fludized-bed type. NaOAc (pH=3) having 0.1N in concentration was selected as the sole extractant for the extraction of heavy metals from MIFA S specimen. For the study of electrolytic recovery, the experiments were carried out based on a 2~(3-1) fractioanl factorial design using current density, initial pH, and operating temperature as the experimental factors. It was determined that current density was important to electrolytic recovery of Pb and Cu, but with an opposite effect. The other two experimental factors were insignificant in this regard. Using a fludized-bed electrolytic cell with nonconductive glass beads as the bed medium, 96.70percent of Pb and 93.69percent of Cu were recovered from the leachate of MIFA S when 0.4Amp-hr of electrical charge was applied. Based on the results obtained in this study, a treatment train of solvent extractiona nd electrolytic recovery of heavy metals was found to be technically feasible.