Development of Excellent Fly Ash Treatment by Employing The Non-Ferrous Metals Refining Technology

Abstract

We had developed new process to treat fly ash generated from municipal incinerators by employing the nonferrous metals refining technology. We clarified the removal mechanism of heavy metals such as lead and cadmium and optimized the conditions based on thermodynamics and metallurgical approaches. We demonstrated by the pilot plant facility with the designed capacity of 100kg/hr that harmful heavy metals like lead are safely removed to trace levels which satisfy the Japanese soil environmental standards. Furthermore, the fly ash treated by this new technology also has passed leaching tests at pH 4 simulating typical acid rain circumstances, so that it can be recycled, for example, as artificial lightweight aggregate. It was also found that volatilized metals collected as secondary ash can be recycled as smelting resources. We could verify at the same time new technology was very conformable as industrial process with developing technologies for materials and equipment. New process will be very useful to fly ash treatment and recycling in the future, as the general technology to treat many types of ashes.

Chlorination and Evaporation Behaviors of PbO-PbCl2 System in Ar-Cl2-O2 Atmosphere

“…Heavy metals removal, especially for Pb and Cd, is also an important issue in the treatment process of bottom ash or fly ash generated by municipal solid waste incineration process. [14][15][16][17][18][19][20] Chlorination-evaporation process of heavy metals with waste polyvinyl chloride is advantageous for the simultaneous waste treatment and for the repression of dioxin generation at well-controlled conditions.…”