In the Kola Subarctic, a mining industry has developed, which is a source of environmental pollution with heavy metals. The objects of study were the tailings of three large mining enterprises in the region: apatite-nepheline, complex and loparite ores. The geotechnical characteristics were studied, and the granulometric composition of the samples was established. The main minerals that make up the material of ore dressing tailings have been determined. Using inductively coupled plasma mass spectrometry, the content of trace elements, in particular heavy metals and rare earth elements, has been established. The enrichment factor, the geoaccumulation indexes, the potential ecological risk index factor and the potential environmental hazard index have been calculated. Priority pollutants characteristics for specific objects have been identified. It is noted that the finely dispersed material of the tailings of loparite and complex ores is 1.5–3 times enriched in heavy and rare earth metals in comparison with the total material of the tailings. In laboratory conditions, experiments were carried out to simulate the process of interaction of dust particles with soil solutions containing different amounts of dissolved organic matter and at average seasonal temperatures. It was found that a decrease in the pH of the solution and an increase in the amount of organic carbon and temperature lead to the mobilization of heavy and rare earth metals from the tailings.

One of the main sources of non-ferrous and precious metals is sulfide ores. This paper presents a review of the existing literature on the electrochemical properties of some of the most common industrial sulfides, such as pentlandite, chalcopyrite, sphalerite, galena, pyrrhotite, pyrite, etc. The study results of the surface redox transformations of minerals, galvanic effect, cathodic oxygen reduction reaction on the surface of sulfides are presented. The electrochemical properties of sulfide minerals are manifested both in the industrial processes of flotation and hydrometallurgy and in the natural geological setting or during the storage of sulfide-containing mining, mineral processing, and metallurgical industry waste.

An extended study of the chemical composition of surface waters and lakes bottom sediments, which are affected to varying degrees by an enterprise that mines and processes rare metal ores in the Lovozero tundra, was carried out. Using inductively coupled plasma mass spectrometry, the content of trace elements and rare earth elements was established. Elevated concentrations of trace elements and rare earth elements were revealed in samples of water and bottom sediments of lakes receiving wastewater from the enterprise and polluted due to dusting in the tailings of the processing plant. Thus, the average content of the total REEs in the surface layers of the SR Ilma and Lovozero (at the mouth of the Sergevan River) reaches 561 and 736 mg/kg, respectively, while for the SR of Lake Krivoe this indicator was 74 mg/kg. The enrichment factor (EF_i), geoaccumulation index (I_geo), potential ecological risk index factor (E_ir) and potential ecological hazard index (RI) were calculated. Assessing the total pollution with trace elements and rare earth elements of bottom sediments of lakes Ilma and Lovozero at the mouth of the Sergevan River, the value of potential ecological risk reaches values corresponding to the level of moderate ecological risk pollution (RI_lma = 174, RI_Lovozero = 186). The conducted correlation analysis made it possible to establish some of the main phases containing trace elements and rare earth elements in the bottom sediments of lakes Ilma and Lovozero.

The increase in demand for rare earth metals and the depletion of natural resources inevitably causes the need to search for alternative unconventional sources of rare metal raw materials. The article presents the results of a study of the composition and properties of the beneficiation tailings of currently produced loparite ores. Sieve, mineralogical, chemical, and radionuclide analyses were carried out. The average content of loparite in tailings was determined. Using scanning electron microscopy, minerals-concentrators of rare earth elements in the loparite ore beneficiation tailings were diagnosed. The distribution of valuable components and thorium in the tailings was determined depending on the particle size class. The radium-thorium nature of radioactivity was established, the values of the effective specific activity of the samples were calculated. We concluded that it is necessary to develop an integrated technology for processing the beneficiation tailings of loparite ore, due to the complex and heterogeneous mineral and chemical composition of the tailings material.

The article presents a study of the environmental impact of dusting tailing dumps of rare-metal ore dressing in the Murmansk region of Russia. The purpose of the study was to establish patterns in the atmochemical halo migration of the dust pollution of loparite ore dressing tailings. The geotechnical characteristics and material composition of the tailings material have been investigated. Potentially dusty areas identified. Models of dispersion of inorganic dust under different meteorological scenarios are constructed: at low wind load, normal and unfavorable meteorological conditions. The modeling of the spread of pollutants in the area exposed to dust at the storage site was carried out in the program for modeling atmospheric pollution Ecolog-4.60. Calculation of the dispersion of inorganic dust containing 20–70% SiO₂ showed that the atmochemical halo of tailings dust pollution spreads over tens of kilometers, and already at a wind speed of about 8 m/s, the concentration of suspended solids at the border of the enterprise sanitary protection zone exceeds the maximum one-time maximum permissible concentration is 3–3.3 times, and under unfavorable meteorological conditions—Dusting reaches the boundaries of the residential area (inhabited locality Revda), located in the north-west of the enterprise, and exceeds the MPCm.o. 1.5 times.

This paper presents the results of wastewater treatment at a mining enterprise developing a complex ore deposit in the Murmansk region, Russia. The main pollutants are sulfate, manganese, and strontium. For this complex wastewater treatment, a two-stage scheme was proposed and tested using two sorbents (at a pH of 6): an aminated peat biosorbent to remove sulfate and a commercial sorbent based on the mineral brucite to remove metals. Optimal conditions were established for purifying the wastewater of sulfate and manganese and strontium ions to the level of maximum available concentrations in water bodies for fishery purposes.