| 摘要 |
PURPOSE:To fix a heavy metal even when special pretreatment is not performed and an auxiliary agent is not used especially and to prevent the elution thereof by mixing a heavy metal-containing alkaline substance with dimethyldithiocarbamic acid or a salt thereof in the presence of moisture. CONSTITUTION:A heavy metal is fixed by mixing a heavy metal-containing alkaline substance with dimethyldithiocarbamic acid or a salt thereof in the presence of moisture. As the heavy metal-containing alkaline substance, fly ash, slag or contaminated soil showing alkalinity is meant. As a heavy metal, lead, chromium, cadmium, mercury, copper, zinc and the like are designated. As a salt of dimethyldithiocarbamic acid, an alkali metal salt, an alkaline earth metal salt or an ammonium salt is designated and, especially, an alkali metal salt is pref. The heavy metal-containing alkaline substnace, dimethyldithiocarbamic acid or a salt thereof and water may be sufficiently mixed and a heavy metal can be fixed immediately. |
