RECYCLING STABILIZED FLY ASH FROM MUNICIPAL SOLID WASTE INCINERATION FACILITY IN ROAD HYDRAULIC MATERIALS

摘要

In France, purification of gazes produced by incineration of household waste generates more than 300 000 tons a year of solid residues. Considered as ultimate and hazardous waste they must therefore be stored in a specific so-called Class I confined landfill after stabilization with hydraulic binders. The cost of this solution incites some companies to investigate different processes to entrap the potential toxic substances, such as heavy metals, available in municipal solid waste incineration fly ashes (MSWFA) to make their storage cheaper or even their re-use possible. This paper presents some results obtained within the project Revasol leaded by Solvay company which has developed such a process, NOVOSOL®, for minerals residues stabilization. After a brief description of the process, which mainly consists in a washing step, followed by the addition of phosphoric acid and a thermal treatment, the paper presents a laboratory study where so-treated MSWFA were introduced as replacement of fine particles in well-graded hydraulic materials dedicated to road bedding courses. The interest on the mechanical point of view of such a replacement is confirmed on two 30-meter long road sections incorporating graded-aggregate treated with an hydraulic binder, one with treated MSWFA and the second without.