Home – Home – Jornals – Chemistry for Sustainable Development 2019 number 5

Processes occurring in the dumps of sulphide-bearing rocks had drawn the researchers' attention for a long time. Environmental hazards connected with the activity of mining industry facilities under the conditions of climate change can be estimated by modeling. Modeling was performed in the water-rock-atmosphere systems (software suite Selector), where rock is an average mineral composition of rocks from the Allarechensky Deposit Dumps of copper-nickel ores. The conditions for the carryover of different components during weathering of rocks in the dump were determined, and the effect of climatic factors on the formation of new phases was evaluated. It was demonstrated that abrupt temperature changes promote rock weathering. In addition to copper and nickel, potassium and aluminium will pass into solution during the cold period. Gibbsite and aluminium silicates will be formed during the warm period. Comparison of modeling results with field studies revealed the adequacy of the model and high degree of the interaction of rocks and atmospheric precipitation in the dumps. Evaporation gives rise to more acid solutions, increased transfer of nickel, copper, iron and sulphates into solutions. The basic premise is that the destruction of wastes mineral matrix occurs practically all the year round under the regional climatic conditions, due to the formation of highly mineralized solutions inside the dump body and on its surface. Atmospheric precipitation, filtered through rock fragments with high sulphide content, affects the hydrosphere causing an increase in the concentration of all the major ions (Clˉ, SO₄²ˉ, HCO₃ˉ, Na⁺, K⁺, Ca²⁺, Mg²⁺) by a factor of several units, compared to pure natural waters.