Fixation of heavy metals in municipal solid waste incinerator ash

摘要

Fly ash generated from incineration of municipal solid waste (MSW) when placed in landfills can under mild acid conditions leach lead and cadmium. A process for stabilizing lead in this fly ash is presented which involves calcining a mixture of the fly ash and certain calcium-containing compounds in the presence of an oxygen containing gas stream at a temperature greater than about 475 DEG C. and substantially less than about 800 DEG C. for times from about 30 minutes up to about 5 hours. Such treated MSW fly ash will give leachates containing lead concentrations less than the EPA regulatory limit.