Synergistic solidification/stabilization of electrolytic manganese residue and carbide slag.

Electrolytic manganese residue (EMR) contains high concentrations of NH and heavy metals, such as Mn, Zn, Cu, Pb, Ni and Co, while carbide slag (CS) contains high amount of OH and CO, both posing a serious threat to the ecosystem. In this study, EMR and CS synergistic stabilization/solidification (S/S) was discussed science CS could stabilize or solidify EMR and simultaneously reduce its corrosive. The results showed that after the synergistic S/S for 24 h when liquid-solid ratio was 17.5% and CS dosage was 7%, Mn and NH leaching concentrations of the S/S EMR were below the detection limits (0.02 mg/L and 0.10 mg/L) with a pH value of 8.8, meeting the requirements of the Chinese integrated wastewater discharge standard (GB 8978-1996). Mn was stabilized as MnFeO, MnSiO, CaMnSiO, and NH escaped as NH. Zn, Cu, Pb, Ni and Co in EMR can also be stabilized/solidified because of the react with OH and CO in CS. Chemical cost was only $ 0.54 for per ton of EMR synergistic harmless treatment with CS. This study provided a new idea for EMR cost-effective and environment-friendly harmless treatment.