Chemical Passivity of Pb in Ore Soil by Using Improved Red-Mud Materials

Red mud can use as remediation material to remediation for metal contaminated soil. On the basis, the particles were made and added in the soil from lead-zinc district. Through the five-step sequential extracting, different phases of lead have been extracted and determined. Effectiveness of remediation was measured by residue phase lead increased and other phases decreased. Experimental results show that red mud-based particles have significant effect on fixation of Pb in long-term contaminated soil. The largest increase ratio of residue phase was 81.26% and the concentration of carbonate phase, iron-manganese oxide phase and organic phase were lower than blank samples. Comparing application of particles to red-mud powder, the rising trend of pH relieved.