Acid mine drainage from Folldal mine tailings : geochemical characterization and simulation

The mining of certain minerals, such as copper and zinc is commonly connected with acid mine drainage (AMD) problems that can have serious impact on human health and cause ecological destruction. The Folldal mining area was intensively mined for copper, sulphur and zinc for about 200 years from 1747 to 1968. The main objectives of this research work were to predict the acid producing capacity of Folldal mine tailings by using static and kinetic tests and to develop geochemical models to quantify leachate composition. The static tests were carried out for 19 topsoil samples collected from different parts of the mining area. Humidity cell (small column) tests (kinetic tests) and large column test were performed to assess the sulphate and heavy metals leaching rates from the soil samples. Inverse geochemical modelling using PHREEQC codes was applied to explain possible mass transfer processes between column leachates of mine tailings and rainwater.