| 摘要 |
PURPOSE:To provide an energy saving method for solidifying a material containing heavy metals which reduces the treatment cost remarkably without generating noxious gas by incorporating water, carbon dioxide, and bivalent iron into the material containing heavy metals and heating the mixture with stirring. CONSTITUTION:Ashes from a dust collector 9 containing heavy metals are introduced from a fly ash hopper 10 to a 1 ton reactor, for example. The heavy metal-containing ashes is mixed with bivalent iron from a tank 2, for example, a 20% aqueous solution of ferrous sulfate in a weight ratio of 15%. Exhaust gas containing 10% carbon dioxide from a flue 11 is introduced into the mixture in a rate of 10l/min. per 1kg of the dry mixture, and the temperature of the mixture is kept, for example, at 70 deg.C with continued stirring with an agitator 6. The results of the elution test of the mixture after the treatment for one hour, which was done according to Notice No. 13 of the Environment Agency, conform to the ocean disposal standards for all heavy metals. |
