Feasibility of lead and copper recovery from MSWI fly ash by combining acid leaching and electrodeposition treatment

Abstract

This research is the first to investigate acid leaching treatment of municipal solid waste incineration (MSWI) fly ash and handling of the fresh leachate using the electrodeposition (ED) technique. The purpose of this research was to evaluate the feasibility of acid leaching to extract Pb and Cu from fly ash and the recovery of Pb and Cu from the fresh leachate. Acid leaching fly ash at a fixed liquid–solid (L/S) ratio of 20/1 with a 0.5 N HNO3 solution has a loss mass of ∼68.6%, and the leaching percentages of Cl, Pb, and Cu are 87.6, 59.4, and 77.0%, respectively. As for the sequential extraction analyses, acid leaching can yield Pb and Cu from fly ash transformed into a comparatively steady fraction. Electrodeposition at an electric current of 10 A can recover 25.7% Pb and 59.8% Cu. This article also presents a solution for combining acid leaching treatment and the ED technique to handle MSWI fly ash. © 2012 American Institute of Chemical Engineers Environ Prog, 32: 1074–1081, 2013