| 摘要 |
<p>PROBLEM TO BE SOLVED: To promote the elution of lead compounds in ash dust which has been considered to be difficult so far and to recycle treated ash dust solids as a cement raw material, and the like, by adding a specified amount of the ash dust into a calcium chloride aqueous solution of a specified concentration, promoting the elution of lead contained in the ash dust, and performing solid- liquid separation. SOLUTION: When lead components contained in ash generated in a burning furnace and a combustion furnace, which are used in the production of industrial products, raw materials, and the like, or dust in exhaust gas after combustion (ash dust including the ash and the dust) are removed, 1 ps.wt. of the ash dust is added to 4-50 pts.wt. of a calcium chloride aqueous solution of 0.2-2.5 mol/liter in concentration, the elution of lead contained in the ash dust is promoted, and solid-liquid separation is performed. Although the method of the separation is not limited in particular, filtration can respond to the separation as a relatively simple method. The liquid obtained by the separation is used repeatedly as the calcium chloride aqueous solution for eluting lead. The solids obtained by the separation is dewatered/dried to be used as a raw material for cement.</p> |
