Abstract
A brand-new utilization technology for combustion residues such as MSW incineration ash and coal flyash which are expected to be promoted for recycling has been being researched and developed. Its principle is a hydrothermal treatment for the combustion residues mixed with organic wastes using boiler steam as unutilized energy in which not only mineralogical reaction but also interaction of mineral substances with organic ones could give effective stabilization of the residue. Preliminary exprimental studies were performed which included a lab-scale treatment for 1 hour with saturated steam of 200 centigrade, some analyses for raw samples and treated ones such as an elementary analysis, a gas constituent analysis and a pH stat leaching test. In results, we observed a carbonation reaction, a hydrolysis reaction as well as a hydrogasification reaction. However Reduction effect of toxic metal leachability has not yet observed according to the result of pH stat leaching test. Addition of an ageing process could be necessary for the long-term stabilization.
