Treatment of Fly Ash from Incinerators of Municipal Solid Waste

摘要

Several kinds of treatment processes for fly ashes generated from incinerators of municipal solid waste (household waste) have been developed. These fly ashes include not only toxic metals such as Pb, Cd, etc., but also PCDDs (polychlorinated dibenzodioxins). A new process has been examined in the present study. The fly ashes are formed as green pellets with some additives. They are roasted to eliminate or stabilize the toxic metals, and to decompose PCDDs. The roasted pellets become harmless through this process, and they are roasted to reuse as artificial light weight aggregates. Volatilized metals are collected as secondary fly ashes, which are recovered in the non-ferrous smelting plants. In March 2000, a new pilot plant of this process, whose capacity is approximately 100kg/hr, was installed. The several kinds of tests by using this pilot plant have been taken. The performance of roasted pellets is a very important issue. Thus the utilization of roasted pellets as aggregate has been studied. A construction company has confirmed good performances through the practical tests.