Article

Reclamation at the Kimheden copper mine in northern Sweden included backfilling two open pits with waste rock and applying a dry cover in 1996 to mitigate acid mine drainage (AMD). Research from 2009 to 2014 assessed the impact on copper and zinc concentrations in drainage.

Results indicated a reduction in metal levels but persistent unsatisfactory water quality, suggesting ongoing sulphide oxidation. Hydrogeochemical modeling revealed that oxygen consumption rates exceed diffusion rates through the dry cover, and geophysical surveys identified sources of oxygen ingress. Recommendations for improving AMD prevention strategies are proposed based on these findings.