Abstract:Manganese slag was leached by way of overturn with quicklime as additive. Types and concentration of pollutants in lixivium were analyzed. Effects of additive amount of quicklime, moisture content of manganese slag, and pre-reaction time on harmless treatment were analyzed. The results show that water-soluble Mn2 and NH4 -N are key pollutants with excessive concentration. Quicklime has hydration reaction with water to form good alkaline environment. Hydration reaction realizes good harmless treatment effect by physical inclusion, adsorption, and precipitation. Concentration of water-soluble Mn2 and NH4 -N is 2.60 mg/L and 19.53 mg/L respectively with removal ratio of manganese and NH4 -N of 99.8% and 97.0% respectively under the optimum conditions including additive amount of quicklime of 10%, moisture content of manganese slag of 27%, pre-mixing time of 40 min, and pre-reaction time of 72 h.