Application of Copper Mining Waste in Radionuclide and Heavy Metal Immobilization

Abstract

Copper slag flotation tailings (CSFT), as the end waste from copper mining, are evaluated for radionuclide and heavy metal immobilization. Characterization of CSFT based on grain size and mineral composition, surface functional groups, pH and electrical conductivity in aqueous media, thermogravimetric analysis (TGA), determination of characteristic temperatures in sample melting process, leachability, and toxicity tests is conducted. The screening sorption of Mn(II), Co(II), Ni(II), Zn(II), Cd(II), and Pb(II) inactive isotopes from single-component solutions is performed. The Cd(II) ions show better sorption potential than other ions, with a sorption capacity of 0.08 mmol g−1 at the highest initial concentration. Sorption decreases in the sequence Cd(II) > Pb(II) > Zn(II) > Mn(II) > Ni(II) > Co(II) at all initial concentrations. Although CSFT shows lower sorption capability than synthetic sorbents based on fayalite and magnetite, its inexpensiveness and substantial accessible amount represent great advantages in wider utilization.