Valorization of pre-oxidized tailings as cover material for the reclamation of an old acid-generating mining site

Laboratory column tests were conducted to assess the performance of a cover with capillary barrier effects to control acid mine drainage generation from tailings at Folldal mine site (Norway). Results showed that the pre-oxidized tailings used as the moisture retaining layer remained at a high degree of saturation (Sr > 85%) throughout the tests, thus efficiently limiting oxygen diffusion to the reactive tailings. Valorization of pre-oxidized tailings could provide an alternative to cover materials that may not be readily available at mine sites.