석탄 바닥재와 점토를 이용한 광미의 중금속 고정화와 재활용

초록

This research was performed to stabilize heavy metals in mine tailing using coal bottom ash and clay and to evaluate the recycling possibility. The coal bottom ash used in this research was mainly composed of SiO2 (53.73%), Al2O3 (33.42%), K2O (4.33%), Fe2O3 (3.24%), CaO (1.2%). SiO2 and Al2O3 composition of the clay was over 85%. And the mine tailing have high composition of SiO2 (26.91%), CaO (26.91%), Fe2O3 (26.91%). Thus, it was estimated that the coal bottom ash-clay-mine tailing might be suitable for high temperature sintering. In the analysis of Korean Standard Leaching Test, As, Pb, and Cr6+ of the mine tailing were shown in 191.3 mg/L, 425.6 mg/L, and 29.2 mg/L, respectively. As the result of SEM, the specimens with mine tailing addition showed very detailed structure than the one without mine tailing. Compressive strength of the specimens with mine tailing was highly increased to approximately 220~390 g/cm3. Compressive strength of the specimens sintered at 1,100℃ was over 100 g/cm3 better than when sintered at 1,000℃. In case of the specimen sintered at 1,100℃ with 5% mine tailing, it satisfied the first grade criterion for clay brick by KS L 4201. The specification of leaching characteristics of the sintered specimens were satisfactory at the Korean regulation standard.

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