Fixation and utilization of ash residue from the incineration of municipal solid waste

摘要

Municipal solid waste ash is utilized in the manufacture of an aggregate and is processed to form a cold bonded pellet which, when tested by means of TCLP leaching extraction tests using TCLP No. 2 extraction fluid, does not exceed the 1990 limits for the RCRA priority heavy metals. The pellets may be surface coated with defined agents to seal the pellet or to provide properties which enhance the use of the pellet in either asphaltic or cement concrete mixes. A method of utilizing MSW ash includes the steps of collecting the bottom ash and fly ash components, processing the bottom ash component to remove unprocessible material and crushing the crushable component to a desired size, magnetically separating the magnetic material from at least the processed bottom ash component, treating at least the fly ash component of the ash with alkali silicate to fix the heavy metals, and utilizing the processed ash such as by adding cement or other binders in a mix to form pellets having an early strength sufficient to permit handling after 24 hours. Pellets may be treated with selective components and coatings to enhance the pellet's use as an aggregate in asphaltic or cement concrete mixes.