| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide soil hardener capable of reducing the elution of fluoride ions to be equal to or less than the reference value since the elution of the fluoride ions is controlled by mainly forming hardly-soluble calcium fluoride for immobilizing fluorine contained in waste water or soil; however, the environmental reference value in the elution of fluorine from the soil is specified to be ≤0.8 mg/L, and the elution of fluoride ions to be theoretically calculated from the solubility of calcium fluoride largely exceeds the reference value. <P>SOLUTION: By the coexistence of a plurality of hardly-soluble calcium compounds in inorganic wastes containing much fluorine, each calcium ion derived from each compound is eluted, and the amount of fluorine of high concentration contained much in the inorganic wastes is reduced to be ≤0.8 mg/L by the common ion effect. That is, two or more kinds of hardly-soluble calcium compounds of 1-250 pts.wt. with its solubility at 25°C being in a range of 0.001-0.400g/100 ml are added to and mixed with the inorganic wastes of 100 pts.wt. such as sludge, slag, waste gypsum, and waste soil with its fluorine content being in a range of 0.005-5.0 wt.%, and the elution of fluorine ions is specified to be ≤1.5 mg/L by the common ion effect. Further, fluorine adsorbent is added to and mixed with the mixture by 0.1-10%, and the soil hardener with its fluorine elution being ≤0.8 mg/L is acquired. <P>COPYRIGHT: (C)2013,JPO&INPIT |
