산성광산배수 처리에서 CO2 탈기와 pH 제어가 슬러지 발생에 미치는 영향 = Effects of CO2 Degassing and pH Control on Sludge Formation in Acid Mine Drainage Treatment

다국어 초록 (Multilingual Abstract)

Acid mine drainage from the (Samma)taejung coal mine was examined using water-quality analysis, degassing and neutralization trials, and geochemical modeling. The mine water was highly acidic (pH 3.34) and contained elevated levels of dissolved Fe, Al, Mn, Mg, SiO2, CO2, and SO4 2–. Stoichiometric calculations estimated approximately 393 kg/day of precipitation, with secondary minerals derived from CO2, SO4 2–, Ca, and Mg exceeding contaminant mass. Neutralization modeling showed that calcite precipitates around pH 6.5, while Mn(OH)2, brucite, and gypsum form sequentially above pH 9. Dissolved CO2 was removed within 20 min of degassing, which controlled calcite precipitation. At pH > 9, gypsum and brucite formation were identified as the main cause of sludge generation. These findings suggest that combining CO2 degassing with maintaining the neutralization reactor below pH 9 can reduce lime consumption and minimize sludge production.