The importance of strategic mine planning to ensure the long-term viability of mining projects has increased significantly because of the limited availability of high-grade ore deposits. Given its high-dimensional and combinatorial nature, developing a precise mathematical optimization technique to solve the entire problem remains challenging, particularly for real-size block models. The primary objective of this study was to propose a method that combines a nested pit strategy with integer programming (IP) models to overcome computational limitations by reducing the problem’s complexity, decreasing solution times, and providing insights into alternative production schedules for large-scale open-pit mines. The proposed algorithm strategically fixes the decision variables based on parametric analysis of the ultimate pit limit to simplify the IP model. The approach was applied to various block models from MineLib, and the results were compared with standard IP solutions and findings from related studies using alternative algorithms. Applying the proposed method demonstrated significant reductions in the solution time (up to 95%) and the ability to solve intractable models.

At many quarries for the extraction of building stone there is a problem of increased output of fines after all stages of crushing and grinding, which leads to a decrease in the economic performance of mining enterprises. The fine fraction is formed by the crushing / grinding of prefractured rock mass. Reducing the intensity and size of the prefracture zones will lead to a solution to the problem at hand. To determine the effect of explosive detonation properties on the degree of structural weakening of a rock mass, studies were conducted to measure the detonation velocity, stresses generated by a blast in the rock mass, as well as laboratory studies of microfracturing by X-ray computer microtomography. The size of the prefracture zones increases from 33 to 77 charge radii with increasing the detonation velocity from 2 to 5.2 km/s. The dependence of the number of microdefects (microfractures) generated by a blast on the velocity of explosive detonation takes the form of an exponent for the near zone and is linear for the distances far from the blast. According to the data of the experiments conducted at short distances (10R), the density of induced microfracturing N is within ≈5 thousand pcs/cm³, and with increasing the detonation velocity it increases to ≈13.8 thousand pcs/cm³. At medium (40R) and long (70R) distances, N increases from ≈750 to ≈2,400 pcs/cm³ and from 0 to ≈200 pcs/cm³, respectively. Using explosives with a reduced detonation velocity allows reducing the “surplus” impact on a rock mass and thus reducing the intensity of prefracture in the zone of controlled crushing during a blast. The study allowed obtaining quantitative parameters of the intensity and size of the prefracture zones, which compose the supplement to findings of historical studies on qualitative determination of prefracture.

Block stone excavation is a key aspect of the building materials industry, important for providing construction with durable materials and when giving aesthetic solutions to various structures and design elements. However, when excavating stone (using drilling and blasting), it is necessary to maintain its integrity for further processing and use. The conditions required for applying the method of blasting separation (split off) of stone blocks from hard rock mass were considered, which is important for improving the quality of blasted stone blocks. The rational parameters of stone block blasting with Granilen elastic tubular charges (Granilen ETCs) are presented. An approach to the preliminary assessment of stone block fracturing zone under various explosive loading regimes was determined. The relationship between the consumption of explosives and fracturing of stone blocks at possible blasthole spacing was considered. The mechanism of creating an extended rupture plane in a rock mass was studied. The decisive role of stress waves in the formation of an extended main rupture along the line of blasthole charges was established. It was shown that it is possible to localize the zone of induced fracturing by regulating the conditions for the interaction of stress waves. The results of numerical modeling of stress fields at blasting a single charge and a two-charge Granilen ETC system are presented, which made it possible to assess zones of induced fracturing and the conditionsfor the formation of a main rupture. Blasting effectiveness increases significantly due to the orientation of the expected stone block separation line parallel to the plane of the best rupture, taking into account the anisotropy of the physical and mechanical properties of granites. The study confirms the feasibility of increasing the yield of commodity blocks when selecting rational blasting parameters.

The presented research is carried out in continuation of the works connected with studying the nature of radioactivity of drainage waters of quarries of Novosibirsk region, performed by the Laboratory of Hydrogeology of Sedimentary Basins of Siberia, INGG SB RAS, which showed that the waters of granite quarries are characterized by significantly higher radioactivity, than waters of other host rocks. The results of detailed mineralogical and geochemical studies of granitoids of the Ob-Zaisan region within the Kolyvan-Tom folded system are presented for the first time. The relevance of the present study is determined by the previously obtained data on high concentrations of uranium, thorium, and radon in drainage water of quarries developed in this territory. The granitoids of the Priobsky (Obsky and Novosibirsk massifs) and Barlak complexes were studied. It was established that the rocks of the complexes differ significantly in the spectrum of accessory minerals, which acted as the concentrators of natural radioactive and rare-earth elements: in the Barlak, in addition to apatite, sphene, and zircon, typical for all phases of the intrusion, fluorite, topaz, rutile, and minerals enriched with rare-earth elements are found: monazite, xenotime, bastnesite, parisite, less often uraninite. It was shown that a wide range of mineral-concentrators of radioactive and rare-earth elements determines higher concentrations of radionuclides in groundwater of the Barlak granitoid complex. Maximum uranium concentrations are one order of magnitude and those of thorium are two orders of magnitude higher in the groundwater of the Barlak granitoid complex compared to those of the Priobsky granitoid complex. The following peak concentrations, mg/dm³, were established in the groundwater of the studied granitoid complexes: ²³⁸U up to 1.40 and ²³²Th up to 2.16 · 10^–3. One can predict a high background of radionuclides in the groundwater of the Barlak and Priobsky granitoid complexes, within the ranges, mg/dm³: ²³⁸U from 0.1 · 10^–3 to 1.40 and ²³²Th from 1 · 10^–6 to 2.16 · 10^–3. Radon ²²²Rn activity in the groundwater ranges 1–50 Bq/dm³ in the contact zones of granitoids with different-aged sedimentary rocks to 600–5,000 Bq/dm³ in the areas of granitoids occurrence.

The anisotropy in the deformational behavior of blocky rock masses has been comprehensively investigated. The uniaxial deformation modulus was selected as the key parameter. This modulus is generally anisotropic and depends on the loading direction, as well as on the properties of the intact rock, joints, and joint setting. Representative volumes of blocky rock masses were numerically simulated using the discrete element method and were loaded uniaxially in various directions. Subsequently, the failure mode and the deformation modulus were studied for different loading directions and various relative joint settings. A new nonlinear, stress- dependent stiffness matrix for joints was introduced, incorporating the surface conditions of the joints in terms of the Joint Roughness Coefficient (JRC) and the properties of the intact rock materials in terms of the Uniaxial Compressive Strength (UCS). The results of the assessments are presented in the form of rose diagrams, showing variations in the deformation modulus of the blocky rock mass that depend on the joint’s JRC, the intact rock’s UCS, and the structure of the rock mass in term of the relative joint angle. Also, the expected degree of anisotropy for various joint surface conditions and uniaxial compressive strengths of intact rock were introduced. In the Geological Strength Index (GSI) table, results are classified such that assigning a value to the JRC for each class of joint surface conditions allows for the corresponding deformation modulus and degree of anisotropy. According to this chart, it is deduced that the effect of joint roughness on the deformation modulus of blocky rock masses is greater than that of the intact rock UCS. The results support the hypothesis that a blocky rock mass has a critical strain that is independent of the loading angle (θ) and the orientation of the third joint set (α).

Along with the introduction of new froth separation sections at new and existing enterprises, the basis for increasing the output of small diamonds is the reduction of their losses at the existing froth separation sections. The results of the studies of diamond surface composition under conditions of technogenic hydrophilization made it possible to establish the influence of the effects of crystallization of carbonate and silicate mineral films and the fixation of sludge fractions on the hydrophobicity and floatability of diamonds. It was proposed to use combined regimes of conditioning of ore and recycled water to increase floatability of diamonds, providing removal of hydrophilizing coatings and restoration of natural hydrophobicity of diamonds. The application of methods of acoustic, thermal, electrochemical, and reagent treatment of water-mineral disperse systems, as well as their combinations to increase floatability and reduce losses of hydrophilic diamonds in the process of froth separation was considered and substantiated.

Based on the study of the effect of the temperature factor in the preparation and froth separation processes, the optimal temperature regime of froth separation cycle operations was substantiated, providing the use of the heat consumed for thermal treatment of the initial diamond-containing material at a temperature of 85–90°С to maintain the required temperature in the conditioning operations with a collector and immediately in the froth separation and flotation operations.

It was shown that the regulation of phase composition of an apolar collector by additives of low- and medium- molecular fractions provides increase of its collecting ability due to transition of asphaltene-resin fraction into adhesion-active form and occurrence of processes of the collector autodispergating in aqueous phase. On the basis of the statistical analysis of froth separation process indicators depending on changing the share of recycled water in the processes the reason for worsening the indicators (performance) was determined, which consisted in a significant increase in the concentration of sludges. The optimum degree of recycled water use (85%) was determined, which ensures decreasing the used collector consumption by 8% without decreasing diamond recovery and concentrate quality.

Flotation beneficiation plays a leading role in the processing most ores. The efficiency of this process is ensured by the correct selection of operating modes, which involves choosing the most selective reagents and determining their optimal consumption. Despite the significance of this issue, the classic approach to determining beneficiation parameters involves testing followed by the processing of the results obtained and the determination of the reagent consumption. However, such studies do not reveal the essence of the physicochemical processes occurring within the pulp, and the results of testing one sample may not correspond to the optimum when the properties of the sample change.

The purpose of this work is to develop and implement a methodological approach to the study of ore flotation beneficiation using ionometry methods. The data obtained from ion-selective sensors significantly deepen our insight into the transformations occurring during the flotation process and allow for consideration of possible adverse factors that hinder effective process progression.

To achieve this goal, a comparative analysis of two approaches to flotation beneficiation testing was performed using complex sulfide ores as examples. In the first stage, a flotation beneficiation study was conducted through D-optimal factor testing, which included 20 individual tests to determine the optimal consumption of modifying reagents, yielding qualitative indicators. In the second stage, flotation tests were conducted using electrochemical monitoring with pH, Ag2S, Pt, and membrane electrodes. A universal flowchart for flotation studies with ion-selective sensors has been developed, facilitating the application of this approach to various ores. The implementation of the results from this comparative analysis has led to a 7.8% increase in beneficiation efficiency while reducing reagent consumption. Additionally, the insights gained into the electrochemical processes occurring allowed for assumptions about the adverse factors affecting flotation outcomes. In conclusion, a model for the potential application of this approach at existing enterprises was proposed, including the implementation of an “intelligent assistant” for flotation operators based on the developed electrochemical models.

The use of dry methods of processing and beneficiation of mineral raw materials is one of the promising areas, as this approach to concentrate production is less energy-consuming, less labor-intensive, and economically beneficial. The paper presents experimental studies on preliminary dry separation of Arkachan deposit ores to determine the quality of beneficiation of the separation products. The studies on dressability were carried out on pilot plants for dry ore processing and beneficiation: combined impact crusher DKD-300, centrifugal mill TsMVU-800, pneumatic separator POS-2000. Processing of the obtained separation products by pneumatic separation and screening according to the sequential flow chart of crushing and grinding was carried out in laboratory conditions at a gravity concentration table SKO-0.5. The GRG test was performed at an ITOMAK-0.1 centrifugal concentrator using a sequential grinding circuit. The GRG test showed that for more efficient gravity separation of gold, up to total gold recovery of 73.91%, the degree of grinding up to 80% passing 0.071 mm was required, allowing obtaining a gravity concentrate graded at 70.28 g/t gold.

The problems of geoenvironmental consequences of mining operations are especially acute in the arctic and subarctic regions, where the spread of permafrost significantly reduces the buffering capacity of landscapes. The article presents data on the content of heavy metals in the soil cover of the transient zone between the middle taiga and north taiga landscapes of Western Yakutia under the conditions of mining operations and assesses the resistance of different types of soils to heavy metals pollution. Field and laboratory works were carried out in August 2022. The heavy metals content was determined by atomic absorption spectrometry. Specialized software was used for analysis, such as MS Excel 2013, Statistica 12.0, and QGis 3.26.1. Calculation of organic forms of heavy metals in soil solutions was performed using the NICA-Donnan model. In the course of studies, the structure of the soil cover in the Nakyn kimberlite field in the conditions of the mining industrial complex operation was determined and a sketch map of the soil cover of the territory was compiled. The geochemical series of the studied heavy metals is as follows according to the degree of concentration of heavy metals in cryolithic soils: Pb > Zn > Ni > Cu > Cd > As > Hg. Positive correlations between humus and Cd, Pb, Zn, as well as the occurrence of synergism in the Pb–Cd, Zn–Pb, Zn–Cu pairs were revealed. The soils organic matter enhances migration of heavy metals. The man-made input of Ni and Zn in cryolithic soils will lead to increase of mobile fraction. Cd is more mobile in pale-yellow carbonate and cryogenic soils. The regional background level of heavy metals for these types of soils was calculated, which can be used in future works when the intensity of mining operations increases.

In the field of designing power supply systems of open pits an important role is attributed to the problems of components reliability analysis, which can be solved by integrated application of different analysis methods for individual types of electrical equipment and network devices in power supply systems. The purpose of the work is to establish optimal parameters for an open-pit mine power supply at mining and processing complexes, and to conduct research that allows a technical and economic model of the system to be created. It has been established that mathematical statistics provides a number of methods for establishing the homogeneity (or heterogeneity) of the population of random variable values. When analyzing the data of failure statistics of electrical equipment, the method of comparative estimate of two sample averages (compared to the method of comparing the empirical distribution with the normal distribution or the moving average method) is the most acceptable. The paper presents accident rates of electrical equipment of open-pit substations and network devices of the quarry processed on the basis of data, also presents the relationship between the reliability of the circuit and its elements and shows the influence of protection reliability on the reliability of the circuit. Methods of optimizing open-pit power supply systems are presented, which consist in the use of first-order gradient methods, second-order methods or the so-called quadratic optimization methods, and random search methods. A group of gradient methods is the most widespread for solving nonlinear programming problems, among which the method of steepest descent should be considered primarily. The combination of random search with the penalty function method makes it possible to determine conditional extrema for the problem of optimizing the electrical grid and system operation mode. The method of random descent, which consists in determining the minimum of the target function according to an appropriate algorithm, is also considered, in which the direction of motion is generally given by a random vector uniformly distributed over a hyposphere.