## 1 Introduction  
The study of the consequences of the exploitation of mineral deposits in permafrost conditions is especially important for countries with large polar and highly mountainous regions. The majority of active research is carried out in Russia, Canada, the USA, Italy, and the countries of northern Europe [1, 2, 3], as well as China and the countries of Central Asia containing high mountain regions with low-temperature conditions and permafrost similar to those in Russia [4]. In all climates, mine reclamation is a major challenge for mining companies, especially when mine tailings can lead to the formation of acidic drainage solutions. Previous studies [5, 6] have reviewed the principal parameters and processes that influence the quality of mine drainage, in addition to the performance of passive treatment of mine drainage in cold climates. Review [7] discusses the significant knowledge gaps currently associated with the release of toxic rare earth elements (REEs) from mining waste to the environment, as well as developing waste management strategies. However, traditional methods of mine reclamation are challenging to apply to areas located in the arctic conditions due to their remoteness, severe climatic conditions, the degradation of permafrost, and the effects of climate change. It is, therefore, necessary to design and develop new approaches for effective mine reclamation in Arctic climate conditions. Such approaches are of particular importance, as mining operations should be optimized so that their profitability is maintained in changing market conditions and to meet increasing societal and environmental demands. Study [8] presents an overview of the interplay between mining and the surrounding socio-ecological systems in the Arctic region and investigated the mining activities from four perspectives, examining (1) environmental, (2) economic, (3) social, and (4) legal dimensions, covering three life-cycle stages: (1) pre-mining, (2) mining, and (3) post-mining. The degradation of permafrost, melting, and reduction of rocky glaciers all have impacts on the quality of surface waters. Recent studies have shown that climate change is impacting the inorganic chemical characteristics of surface fresh water in permafrost areas and affecting aquatic ecosystems. In addition, thickening of the active layer and melting of near-surface ground ice can influence inorganic chemical fluxes from permafrost into surface water. Permafrost degradation may also modify trace element contents in surface water [9]. However, information on the dominant geochemical reactions occurring in various cryospheric conditions and how these reactions change during the ice-free period is currently extremely limited. Chemical weathering under cryospheric conditions is typically more intense, with a strong seasonal increase in water mineralization [10]. Tailing dumps from mining and mineral processing enterprises have a number of environmental consequences. These include the oxidation of finely crushed tailings, enrichment of ore with atmospheric oxygen, and formation of mineralized drainage waters, which migrate outside the tailing dumps, leading to the pollution of surface and ground waters of the surrounding area [11; 12; 13; 14]. When tailings containing sulfides are thawed, a highly mineralized acidic drainage solution is formed [15], which interacts with rock in an exothermic reaction. Interactions of water with tailings in areas in the Far North often lead to the thawing of permafrost soils, formation of man-made talks, and leakage of man-made waters. In the case of the development of fault zones in these areas, acidic solutions are often filtered outside the tailing dump, promoting further development of filtration channels and more intense leakage of acidic solutions. Temperatures below freezing will slow down this process but will not eliminate oxygen consumption. To remedy this issue, thermal covers have been widely adopted for freeze encapsulation of potentially reactive mine waste rock and tailings.