Ecological and Hydrogeological Problems of the Old Industrial Regions of the Middle Urals (Russia)

Abstract

Mining of mineral deposits leads to the formation of mining landscapes, within which specific hydrogeochemical systems arise. Following the dewatering to the depths of tens and hundreds of meters, processes of technogenic hyper-genesis and mineral formation are developing, especially in areas where the continuity of rocks is disturbed. Here, the sulfuric acid weathering crust is formed, which contains secondary minerals, including readily soluble crystalline hydrates of sulfates. The article presents the results of the analysis of the hydrochemical situation within the abandoned Levikha mine (Middle Urals). It is shown that the reason for the formation of unloading of acid mine waters on the surface during postmining is the change in the hydrodynamic conditions (cessation of the drainage and the filling of the depression cone), the dissolution of secondary minerals in the technogenic zone of hypergenesis (in the zones of collapse and displacement). The mass consumption of components at the post-operational stage is comparable to the rate of oxidative weathering of sulfides during the operation of the dewatering. The half-life of the components is about 5 years, and the formation of contaminated mine waters will last at least 50 years. These results are the basis for determining the strategy and tactics of planning work to eliminate the accumulated damage to the environment of the mining landscapes of the Middle Urals at the post-mining stage.