Abstract
In this study, mine tailings obtained in a region near to Youngwol Sangdong(Korea) was used to investigate the contamination of heavy metal ions. Some amount of mine tailings and lignin(AE agent) were added in the general cement pastes, of which the compressive strength and leaching rate were investigated. X-ray fluorescence analysis shows that the major constituents of mine tailings are 56.9wt% of SiO2, 10.8wt% of Fe2O3, 11.2wt% of CaO and 11.4wt% of Al2O3, and the major phases are quartz and calcite. In the content of heavy metal ions, the concentration of As ion is the highest as 257.261mg/ℓ. When mine tailings and lignin were added in cement pastes, the compressive strength was higher in the cement pastes adding only lignin. Lignin addition significantly improved the compressive strength of cement pastes by approximately 15% when being cured in distilled water. The compressive strength was lower in the cement pastes adding mine tailings than in the cement pastes not adding. The leaching rates of Cr, Pb and As ion in distilled water were decreased in the cement pastes adding lignin, compared to in the cement pastes not adding. The leaching rates of all heavy metal ions in the cement pastes curing for 28 days were within the maximum permitted limits in KSLT and EPT method. Therefore, it is thought that mine tailings can be used as an ecological material.
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