Major and trace metal mobility during weathering of mine tailings: Implications for floodplain soils

► Magnitudes and mechanisms of metal mobility during tailings weathering were determined. ► By the end of the weathering experiments all leachates had pH of ∼2. ► Release of Ca, Cu, Mg, Mn and Na and retention of Al, K, Sr, Sn and Ti was observed. ► Dissolution of primary sulfides and silicates controls metal mobility. ► The release of tailings to floodplains should be severely limited or prohibited.