The Swedish Acid Mine Drainage Experience: Research, Development, and Practice

Abstract

Mining has been going on in Sweden for more than 1000 years. For many centuries Sweden used to be one of the main suppliers of steel, copper, and silver to central Europe. Over the years more than 1000 sulfide mines have been mined out and left without further attention. Most of the abandoned mines were small with waste deposits of fairly high grade. Concentration by flotation started in Sweden in the 1920s making it feasible to mine large ore bodies of lower grade which has resulted in a number of large deposits of tailings and waste rock from open pit mining. In 1994, the total volume of accumulated waste from sulfide mining was estimated at 300 million tons of tailings and 200 million tons of waste rock. A national survey on mine tailings and waste rock deposits identified about 70 sites causing severe acid mine drainage (AMD) problems in 1994. Out of these, 29 sites are considered of highest priority and are supposed to be attended to within 5 years. The total cost for the reclamation program was estimated at 300 million US$ in 1995. Today, 14 sulfide mines are in operation resulting in a yearly production of 20 million tons of tailings and 17 million tons of waste rock.