Bentonite clays enjoy wide application in mining, metallurgy, petrochemistry and in manufacture of building materials. A feature of natural bentonites, representing high dispersion layered aluminosilicates, is their ability to structure polymeric composites and to improve thereby their mechanical and service properties. The comparative analysis of the composition and properties of clays from the Kangalas coal mine in the Republic of Sakha (Yakutia), purified using the developed method, with bentonites from a Khakassia deposit was conducted. The introduction of ECH-based aluminosilicates into rubbers demonstrated a positive effect on the physical and mechanical properties of the latter. However, the tensile strength and breaking elongation of rubbers containing Khakassia bentonites exceed those of rubbers filled with kaolinite clays from the Kangalas open pit. At dosages of up to 3 parts by weight of minerals, the rubber properties in both cases are positive. This effect of modifiers on ECH-based rubbers is confirmed by the existing scientific data on the mechanisms by which various minerals influence rubber properties. The plasticity number calculation places the Kangalas clay in the category of high-plasticity materials. This type of clay forms well, without cracks, has a wide range of moisture content at the preserved plasticity, and contains a large quantity of clayey minerals. Testing of clays from the Kangalas open-pit mine as a modifier for elastomeric sealing composites, which are intended for the use in mining equipment in the Republic of Sakha (Yakutia), allows a conclusion on the promising nature of this research area.

During blasting, it is critical to ensure safety of facilities in close vicinity of an open pit mine. One of the factors which affect guarded buildings and constructions is vibrations from the blasting-induced seismic effect. The blasting-induced seismic hazard criterion is PPV at the bottom of an object. It is experimentally proved that this parameter is less variable in case of variable geology and better correlates with the mass of an explosive charge, distance between the blast and measurement point and with the onset of initiation of damages in constructions than other parameters such as the amplitude of displacement, or the acceleration and period of vibrations. This study selected a guarded object representing an industrial building of a main stepdown substation on a high foundation frame. The scope of the control embraced the change in the crack openings in the structure of the building under the impact of loading generated by blasting operations in an open pit mine, and by other factors, in particular, weather. The comparative analysis of the effects generated by weather and blasting in the open pit was performed. The layouts of strain-gauge transducers to measure the change in the crack openings, and their attachment at the structures of the building are presented. Transducers nos. 1, 2 and 6 were placed in the transformer hall inside the building, and transducers nos. 3, 4 and 5 were arranged in the unheated and ventilated underfloor space. The obtained results prove that the blasting-induced deformations are much lower than deformations induced by soil vibrations because of the weather factors.

The article discusses the teamwork results achieved by the specialists of Polymetal and Blast Maker in adapting Blast Maker’s automated blast design system to the specific geological conditions of the Nezhdaninka deposit situated in the permafrost area in the Republic of Sakha, Yakutia. The deposit is developed using selective blasting of blocks in overburden rocks and in ore bodies. In view of a great number of blocks and due to the tight schedule of their preparation, there are some issues connected with the manual blast pattern design, which prevents from reaching the desired effect of minimized loss and dilution. It has become necessary to have a digital system to ensure the high accuracy and agility of blasting pattern design and blast performance simulation with regard to actual nonuniformity of rock and ore properties. The pilot trials of the automated blast design system proved efficiency of the system performance in the specific geological and geotechnical conditions of the Nezhdaninka deposit. The comparison of the model blast scenario with the laser survey results made it possible to obtain a detail estimate of the detachment zone. The comparison results show that the main causes of disagreement between the prognostic and actual scenarios of blasting are: the values of the scaling factors included in the crushing energy calculation and the presence of the structural damages in rock mass. Improvement of the program has succeeded to multiply enhance its functional, which allows designing blasting operations in conformity with the local variations in the geomechanical characteristics of rock mas, down to every blasthole. This promotes enhancement of blast quality, agreement between the designed and actual perimeters of blasting in blocks and, as a consequence, higher total performance of blasting.

The implemented analysis of ground support systems in modern mines reveals the growing use of the yielding steel frame supports. This is governed by higher deformation of rock mass at great depths of the present-day mining operations. As a consequence, it has become necessary to improve the design of the yielding steel frame supports and to duly assess their basic performance: load-bearing capacity, and horizontal and vertical yield. Special bench testing of frames is the most informative technique. The governing factor here is the active loading diagram. In particular, the direction of the applied active forces should be in parallel to the longitudinal axis of the frame and should be preserved for the whole period of the frame yield testing. To observe all requirements imposed on testing the basic parameters of frames, a special test bench is developed. Its key feature is the loading mechanism using a sliding pair. In this case, the capping loading assembly placed on a slider is moved in parallel to the longitudinal axis of the frame. The slider movement is provided by a coaxially arranged cylinder. The loading assembly design allows in-plane change of the point of the force application to the frame capping. Interaction with the capping involves a pair of rollers arranged at the ends of a twoshoulder lever. The adopted design of the force application circuit of the test bench ensures the force action on the frame in the unchangeable direction independent of the capping deformation.

The article examines the key trends of technological process automation and robotization in open stoping as the basis of safe ore drawing and haulage. Employment of remote control and, moreover, autonomous load–haul–dump machines in underground mines necessitates the development of new theoretical approaches to safety of entry and operation of the equipment in stopes. A loading–hauling system can represent a single communication system involving load–haul–dumpers machines working in stopes, technical devices for monitoring stoping space, assessing dynamics of ore draw, detecting hazardous events and processes in stopes, and means for eliminating threats to the troublefree operation of the equipment. The concept of coordinated operation of the autonomous load–haul–dump machines and monitoring devices, integrated into a unified information system, is presented as a diagram of the organization of ore draw and loading operations in a stope, and a basic block diagram of information exchange between the technical devices. As they are implemented, the proposed concept and method for controlling the face oredraw process make it possible, in near-real time, to predict and eliminate hazards, to timely withdraw load–haul–dump machines from stopes, to ensure control of ore draw and haulage, and to achieve full extraction of the valuable mineral.The study was supported by the Russian Science Foundation, Grant No. 25-17-00345, https://rscf.ru/project/25-17-00345/.

Recent decade enjoys a steadily increasing trend in consumption of products of the mining industry. At the same time, the mining industry faces continuous complication of geotechnical and ecological conditions of production. It is possible to overcome the difficulties by means of building up the productive capacity of mines, with the backup provided by the advancement and improvement of geotechnologies and mining machinery and equipment. Extraction of thick ore deposits with low contents of useful components needs technological tools capable to ensure multiple reduction in the cost of mining operations. The most critical strategical task is to create in less than no time a machinebuilding industry in Russia, capable of manufacturing reliable and high-productive equipment in series and in required number.

The paper presents 3D numerical stress–strain modeling of rock mass to forecast rockburst hazard in the promising Gakman block of the Yukspor deposit, Khibiny Massif. The research addresses the vital task of mining safety at mineral deposits liable to dynamic rock pressure manifestations. The numerical modeling was carried out using the finite element method and SigmaGT software with regard to the geological structure of the Gakman block, physical and mechanical properties of rocks and the in-situ tectonic stress field. Background values and orientations of the principal stress vectors are determined. Potentially hazardous compression concentrations in the abutment pressure zones under overlying rocks of the Yukspor deposit are identified as the sites that create the risk of dynamic rock pressure events. Significant tensile stress zones are revealed in overlying rock mass, which are expected to promote systematic rock falls as mining is advanced in the Gakman block. Local-scale modeling results proved the impact exerted by the diagonal orientation of the maximum principal stress vector relative to the ore body strike on the stress concentration at the roof–wall junction. This effect must be taken into account when planning support operations and designing destress drilling patterns. The obtained results provide a scientific basis for enhancing mining safety through early identification of potential rockburst-hazardous zones, stoping design optimization, as well as sequencing of extraction and support operations in underground openings in the Gakman block.

The article describes the experience of the comprehensive scientific and technological supervision of potassium salt production and applied research for EuroChem Mineral and Chemical Company’s entities, namely: integrated geomechanical monitoring and supervision of mining operations, mathematical modeling of geomechanical processes, development of input data and recommendations for underground mining design, as well as revision of earlier procedural rules of potassium salt production. Implementation of managerial decisions on cultivation of in-house scientific and technological supervision skills in geology, hydrogeology and geomechanics, as well as close cooperation with leading specialized organizations in applied problem solving allowed tuning up and improving teamwork in handling urgent production problems toward promotion of long-term challenging areas of activities as a potential framework for the future growth (elaboration of new strategic alternatives, revision of the available and potential points of growth, though not immediately profitable). Such approach reduces the time of decision-making on the need of investigations with regard to development prospects and designing needs, enables fast recommendations on mining design and operation thanks to availability of in-house specialists and equipment, and allows introduction of innovations available on the market and applicable for optimizing all processes and satisfying all needs of the Company. As a result, the strategic lines of research on design and production are determined, their implementation is planned, including with the help of leading specialized organizations; the scientific and technological supervision develops and improves at the Company, and the package of the made and introduced corporate decisions on automation of project and operation information processing finds implementation.

The relevance of the problem of power quality maintenance in power supply systems in the mineral mining sector, including joint operation of centralized and autonomous power sources, is substantiated. The prospects of using the multifunction filter compensating devices based on active converters to ensure power quality in combined power systems are shown. The analysis of the efficiency of power quality maintenance by the multifunction filter compensating devices based on several active converters in the combined power supply systems of mines was carried out. The universal power quality regulator based on parallel and serial active converters is considered as the multifunction filter compensating device. The main function of the parallel active converter is to eliminate current harmonics and current reactive components. The main function of the serial active converter is to eliminate voltage harmonics, as well as voltage deviations and dips. The simulation model of the combined power supply system with linear and nonlinear loads, as well as the multifunction filter compensating device based on parallel and serial active converters, is developed. Based on the modeling results, the regularities are identified, that reflect the influence of the internal reactance of power supply on the efficiency of correction of power quality indicators by the proposed multifunction filter compensating device with the serial active converter equipped with the output passive filters of various configurations. The obtained regularities make it possible to properly configure the passive filters installed at the output of the serial active converter as a part of the multifunction filter compensating device to improve efficiency of power quality maintenance in the combined power supply systems for the given set of standardized and non-standardized indicators, including the level of voltage and current harmonics, voltage deviations and the level of the reactive component of current, with regard to power supply parameters.

Risk evaluation and control is one of the top priorities. There is yet no uniform understanding and general notion of a risk. Mining practices undergo impact of various risks: economic, financial, social, ecological, technological etc. The authors propose their own notion of a geomechanical risk. The article describes a geomechanical risk evaluation and control procedure. The procedure involves machine learning algorithms for the prediction of critical parameters (horizontal displacements) as estimates of stability of load-bearing components (pillars) in a salt mining system. In the capacity of a tool of pillar safety planning and decision-making, the authors propose a model—‘heat map’—built using adaptation of machine learning results and convergence threshold parameters.