2014 Volume 5 Issue 3 Pages 183-190
Recently, incineration ash has attracted attention as a cement material. However, the ash contains dioxins, heavy metals and chlorines. Therefore, this ash recycling needs an appropriate disposal method like preventing elution of heavy metals. As an effective prevention method, there is the hydration reaction mechanism of cement. In this study, we evaluated the ability of preventing elution of lead compounds by the Availability Test and the Ministry of Environment Notification No.46 Test (No.46 Test) using eight samples: a raw fly ash (FA) and seven different cements solidified by the hydration reaction made from incinerated ash. All samples excluding FA showed validity to suppress lead elution levels in both leaching tests. And, in the No.46 test, seven cement samples did not exceed the reference values. In addition, we analyzed the existent form of lead in solidified incinerated ash by Powder X-ray diffraction. We used three types solidified cement samples: Normal (no addition), contained 1% lead dinitrate, contained 1% lead dichloride. As a result, the sample to which lead was added showed the existence of a lead sulfide. It showed that this cement solidified method can be made into an existent form which cannot elute lead easily. We checked the difference in quantity of lead elution between two types of lead addition samples by the leaching tests. Therefore, we concluded that the existence form of lead is an important factor concerning elution of lead by solidification of incineration ashes.