Separation of Steel Slag From Landfill Waste for the Purpose of Decontamination Using a Superconducting Magnetic Separation System

Superconducting magnetic separation has been applied on a soil remediation. Huge amount of steel slag has been dumped into a landfill site and mixed with covering soil. The soil-steel slag mixture is hazardous material and needs to be treated because steel slag has heavy metals, which can be leached out. Two types of soil sample from the landfill site, i.e., plain soil and soil sample after the soil-washing process, have been sampled and tested with the superconducting magnetic separation system. Variable magnetic force (0.5-4 T) was applied, and the separated portion was increased as the magnetic field increased. The separated and passed through soil was analyzed for iron and heavy metal species. The concentration of these species was obtained by the magnetic separation, and the concentration was 1.1-2.2 times depending on the metal species, and the concentrating effect were higher in the soil sample pretreated with the soil-washing process. In comparing the concentration effect of the analyzed metal species by the magnetic separation, the concentration factor is in order of Fe ≥ Zn ≥ Cu ≥ Pb.