Combination of CaCO3 and Ca(OH)2 as agents for treatment acid mine drainage

Abstract

Acid mine drainage (AMD) has characteristic very low pH solution and containing metal ions in high concentration. This paper presents the use of CaCO3, Ca(OH)2 and the combination of both to increase the pH and decreased the concentration of Fe and Mn ions for acid mine drainage. The research variables are the effect of reactant dosage, contact time and temperature by batch studies. The AMD before treatment has pH solution of 3.38, Fe and Mn ions concentration of 44.6 and 7.19 mg/L, respectively. The dosage of CaCO3 to increased pH solution about 7.0 was found 2400 mg/L at contact time 60 minutes and temperature 40 °C. The amount of Ca(OH)2 for the neutralization of AMD solution smaller than CaCO3 is 210 mg/L at contact time 45 minutes and temperature 40 °C. The combination dosage of CaCO3 1000 mg/L and Ca(OH)2 90 mg/L can increased the pH of AMD solution to 7.10 and reduction concentration of Fe to 3.53 and Mn to 4.51 mg/L. Therefore, the integrated of CaCO3 and Ca(OH)2 has the potential to be applied to treatment acid mine drainage.