High concentrations of heavy metals in the soil are an important environmental problem and contamination comes mainly from industrialization, often carried out without proper regulations. The mining sector is one of the major contributors to the release of dangerous substances into the environment. In Chile, this sector accounts for a major proportion of gross domestic product but has significant environmental problems linked to the risk to human health. The accumulation of waste materials, generally fine and rich in HM, takes place in large open-air deposits, called "tailing dams" and located in the vicinity of mines and processing sites. The recovery and treatment of such deposits is necessary given their increasing expansion and the resulting environmental impact.