Abstract
A method to harden incineration ash using binder materials that have calcium and silica as the main components is proposed in this paper. Incineration ash is burnt at a relatively low temperature of 800 degrees. This form of ash includes many harmful heavy metals. A large amount of metallic aluminum is contained in the incineration ash of municipal waste. Considerable expansion is caused by the generation of hydrogen gas through the response of metallic aluminum and calcium hydroxide as a result of the hydration of cement. In this paper, a method to control the expansion with this hydrogen gas and to restrain the leaching of heavy metals is proposed. The final volume of the solidified body is almost the same as that of the untreated incineration ash. The leaching concentration of lead from the final solidification is 1/2500 of that from incineration ash. In this paper, the safety of the solidified body was evaluated using a bioassay and a tank leaching test with lead.
