Physicochemical Modeling of Drainage Water Formation in Waste of the Krasnorechenskaya Concentrating Mill (Russian Far East)

The processes of drainage water formation during the oxidation of tailings from sulfide-containing ores at the Krashorechenskaya concentrating mill (Dalnegorsk region of the Russian Far East) to a depth of up to 1.5 m at 25°C have been simulated for the first time using Selektor software. The qualitative and quantitative compositions of the resulting solutions have been determined, and crystallization of hypergene and technogenic minerals has been traced. The acidity of solutions and the concentrations of sulfide ore (As, Pb, Zn, S) and host rock elements (Ca, Mg) have been found to increase with depth. The total mineralization of the solutions increases by a factor of 2.7 and reached 1.32 g/L. The occurrence of intensive hypergene processes at all horizons has been confirmed by the crystallization of hypergene and technogenic minerals such as calcite, goethite, and fibroferrite, and the weight of the latter increased with depth. It has been shown that drainage waters of the tailings make a negative contribution to the chemical composition of the surface and ground waters of the region, which leads to their pollution.