2024 Volume 70 Issue 3 Pages 141-150
To evaluate the effects of adding half-burnt dolomite and phosphate compounds as immobilizers for reducing the leaching of heavy metals from Zn leaching residues in Kabwe town, Zambia, batch leaching and immobilization tests were conducted. The results showed that the dolomite significantly reduced Cd, Cu, and Zn leaching. The immobilization was greatly influenced by pH. That is, the leaching concentrations of heavy metals decreased with pH. The Pb concentration in the leachate was significantly reduced by mixing the dolomite with phosphate compound to produce Ca5(PO4)3(OH), which might be further precipitated as Pb5(PO4)3(OH), resulting in a significant decrease in the leaching concentration of Pb. This study implies the effectiveness of half-burnt dolomite and mixing of the dolomite and phosphate compound for immobilizing heavy metals in mine residue.
