The tasks of continuous optimizing production, looking for ways of increasing performance, cutting mining costs and expanding mineral resource base of a mining enterprise are becoming more relevant than ever in conditions of the current negative trends at the world market of uranium resources. Increasing enterprise competitiveness requires permanent improvement of approaches and methods for managing performance of production blocks of a mine and ensuring the necessary volumes of reserves prepared for production. In the study, a theoretical information analysis of the process flow sheet of commercial ISL uranium production was carried out. The regression relationships between the main indicators of the production process cycles were determined, and the task of controlling production blocks at the stages of acidification, active leaching, completing operation, and decommissioning was formalized. The statistical characteristics of a production block cells and the distribution of uranium reserves, obtained based on the data of ore body drilling-in, as well as the analysis of the dynamic pattern of uranium production and recovery by production block depending on time, the balance of production block productivity by pregnant and leaching solutions enabled calculating key geotechnological indicators that formed the basis for calculating regression relationships between the uranium recovery and the ratio of the leaching solution amount to the rock mass amount, as well as for estimating specific consumption of sulfuric acid and electricity depending on operation time. This approach allowed identifying the problem areas and promising ways for improving the control procedure and performance of ISL mine wellfield operation. The planned measures will allow re-estimating resource potential of a production block while simultaneously providing a reasonable forecast of the residual uranium reserves in the being exploited and drilled-in blocks, reducing costs at the main development stage, and, by providing timely decommissioning of the blocks, reducing power consumption, optimizing sulfuric acid consumption, and overall improving quality of projecting and planning the production indicators for achieving uranium production targets. The study results can be used for improving short- and medium-term planning of technical and economic indicators of main development and production based on the forecast of ore interval sizes in production blocks that contributes to strengthening resource base and increasing capitalization of a company.

One of the most problematic aspects in underground ore extraction in mining-disturbed rock masses is backfilling of man-made voids, which affect origination and redistribution of stress-strain state of the rock mass. Their existence in the earth's crust provokes subsidence/collapse of the day surface and also contributes to arising geomechanical and seismic phenomena. The purpose of the study is to substantiate environmental-friendly and resource-saving methods for backfilling of voids in underground ore mining based on revealing the features of rock integrity of the day surface and life-sustaining activity of the population living in the mining-affected area. The main negative consequences of the impact of mining on the environment and humans are high costs for conserving day surface and ensuring life-sustaining activity of the population living in the mining-affected area, as well as removing large areas of land from human activity, etc. Based on the study of a rock mass stress-strain state using geophysical and surveying methods, an environment-friendly method for backfilling of man-made voids in disturbed rock masses is proposed. It enables ensuring the integrity of the day surface and life-sustaining activity of the population living in the mining-affected area (in the vicinity of mines, dumps, sites of backfilling complexes, preconcentration and heap leaching of metals from substandard ores, tailings storage facilities, etc.). Combined geotechnologies are proposed for backfilling of voids during the development of ore deposits by underground block leaching, and scientific and methodological and technical support was provided for drilling and blasting preparation of hard ores and underground leaching of pilot blocks at the Michurinsky deposit of GP VostGOK, Ukraine. The research findings can be used in underground mining of ore deposits of complicated structure.

The paper discusses the main disadvantages of strip and underground mining methods and possibilities of eliminating the disadvantages through introducing a combined technology of coal deposit mining. Combined coal mining technology is the method comprising elements of several geotechnologies, for example, underground and strip mining, as well as, possibly, underwater mining, borehole and other techniques of deposit mining. The combined coal mining technology provides for unified layout for opening, development, production and processing of reserves for the whole LoM on the basis of general technological solutions made in advance. Such complex solutions for opening and development of deposit reserves within the opencast and underground mining contour allows minimizing the volume of openings and reducing the time for commissioning, investment costs, as well as decreasing the costs for aerage, drainage, rock mass hauling and land reclamation. Substantiation of deposit opening options should comprehensively take into account technical, organizational, and economic factors [34–37]. Analysis of the options as exemplified by the Makar’evskoe coal deposit development in Kuzbass allows to conclude that the combined method is promising and promotes increasing optimal volumes of coal production, while reducing the deposit development time by about 15 %, and increase the net present value compared to underground and opencast mining options more than 5 times.

The paper is devoted to studying issues of machinery thermal state monitoring using generalized approach to objectives of electromechanical system (EMS) diagnostics based on current temperature values. Generalized mathematical model of EMS (a homogeneous body or a multi-weight estimated heat balance diagram) for various operation conditions of a facility allows to identify diagnostic indicators (criteria) for taking specific measures to stabilize its operation. Increasing efficiency of the facility thermal state monitoring can be achieved using noncontact measuring instruments to determine temperature distribution over the facility surface. Temperature distribution over an EMS facility surface enables concluding on maintenance necessity. For effective application of noncontact thermal-imaging equipment for diagnostics of EMS on the basis of the provisions presented in the paper, training program for specialists in thermometering of industrial facilities has been developed.

For analyzing the dependence of face equipment failure on its length, two groups of elements are commonly considered. The first group includes all elements of shearer-loaders: conveyor drives, elements of pumping stations of powered supports, supports of face junctions with strikes and others. The second group includes all elements of powered support sections, linear sections of pan lines and scrapers of face scraper conveyors, electric cables of shearer-loaders, main pipelines of powered supports, etc. It is noted that the constancy of number of the first group elements linear variability of number of the second group elements do not uniquely determine the constancy or variability of the failure factor of the aggregate of the same type elements of the first or the second groups [1]. The plot of mean-time-between-failures (MTBF) of SL-500S stoping complex as function of face length is presented. Besides, the curve of the face (complex) length-dependence of average recovery) time (after failure of the SL-500S stoping complex time is shown. Analyzing the dependence of availability factor of stoping complexes on the face length showed that the length of stoping complexes is not a factor determining decrease in the MTBF and increase in the average recovery time. The plot of recovery time (after failure) of the SL-500S stoping complex as function of face length is shown. A formula is presented for assessing the cumulative effect, on the MTBF of SL500S stoping complex, of its length and potash ore cuttability. The plot of correlation between the MTBF of SL500S stoping complex and the face length/the potash ore cuttability is presented, which demonstrates that the complex length followed by the thickness of the extracted layer produce the greatest effect on the MTBF. The plot of the number of failures per day as a function of the maintenance factor of the SL-500C shearer-loader is presented. The plot demonstrates that the average number of failures of the SL-500C shearer-loader per day reaches a minimum and practically stabilize at values of the maintenance factor of 0.9–1.0, which correspond to three-shift production with one 6-hour maintenance shift per day.

It is known that conveyor operates in chemically aggressive and abrasive environments; for this reason the drive drum of belt conveyor wears out rather rapidly. It is noted that the lining of the conveyor drum increases coefficient of friction between the conveyor drum and the conveyor belt, reduces the belt wear rate, and also protects against corrosion and abrasive wear. The plot of the PU-60 polyurethane wear rate as function of load when rolling on steel is presented. It is noted that increasing the load increases the strength of adhesive junction between steel and polyurethane rollers; friction wear causes fatigue failure of surface layers of the materials. Besides, the plot of the PU-80 polyurethane wear rate as function of load when rolling on steel is presented. The plot of the polyurethanes wear rate as function of hardness of polyurethane is presented, which shows that the lowest wear rate is demonstrated by the hardest polyurethane, PU-80. The bar chart of static friction coefficient for PU-60 and PU-80 polyurethanes demonstrates that the optimal material for lining the drive drum of a conveyor belt is PU-80. The plot of the rubber wear rate as function of load at a speed of 1 m/s is presented. The plot shows that the wear rate increases with increasing the load. This is due to the effect of two factors: growing contact deformations of the surface layer of the rubber and increasing the contact area of mating parts. It is noted that IRP-1347 rubber is less susceptible to wear than "REMAGRIP" rubber. This allows using IRP-1347 rubber in aggressive environments. The bar chart of static friction coefficient for the rubber presented in the paper shows that the investigated IRP-1347 and REMAGRIP rubber grades have the required value of static friction coefficient for use as lining material for the drive drum. The plot of the wear rate as function of the rubber hardness and as function of the polyurethane hardness is presented. In practice, it is proved that the best material for lining the drive drum is PU-80.

The article describes the algorithm for seismic imaging data processing that enables detecting and evaluating geological anomalies based on the system of specific criteria. Employing the algorithm we can complete the process of profile record, amplitude and velocity spectra computation, filtering and imaging of T-X curves. Subsequently computation and statistical processing of kinematic and dynamic parameters are made in the selected velocity windows. The main procedures for the algorithm include tomographic recovery of wavefield parameters in the plane of extraction panel, detection and interpretation of anomalous zones based on the prediction criteria to determine type of the discontinuity. There is a good reason that tomography in the plane of extraction panel shall be made in velocity windows of the dedicated wavetrains step by step for the main informative parameters. Analysis of the velocity distribution for the amplitude module maximum provides high accuracy when it comes to detect anomalous zones. This parameter is marked by relative independence on chance factors. Analysis of typical wavetrain frequency shift is determining factor indicative not only of the discontinuity but also of its type. Recording of wavetrain amplitude distribution is characterized by high accuracy in terms of anomalous zone detection. However, recording is complicated by dependence on a host of chance factors. The other parameters have much lesser quality and can be used as auxiliary. The algorithm is implemented into software capable to computerize most time-consuming operations. Use of this algorithm is illustrated as a case study for the results of data analysis and interpretation for seismic exploration at 37К10-В longwall panel section in Kuzembaev Mine (Kazakhstan).

Some non-destructive methods for controlling the internal structure of rocks are described and examples of their use are given. Examples of the use of X-ray and neural tomography, scanning electron and acoustic microscopy are also given. It is shown that the method of laser-ultrasound struktroskopii is promising. Two examples of the use of the latter are given: measuring the local porosity of samples of geomaterials and monitoring changes in the internal structure as a result of electromagnetic exposure.

In order to create a more effective dialkyldithiophosphate collector used in combination with potassium butylxanthate in flotation of silver ores (m. Dukat), the effect of a number of dialkyldithiophosphate collectors was studied depending on their surface-active properties and hydrophobic ability. It is shown that their collective strength, with close hydrophobic ability, increases as their surfaceactive properties increase and reaches a maximum at a surface tension of 42-45.3 mN/m, and then begins to decrease. The reduction of the hydrophobic ability, even with their high surface-active properties, for example, for hydrolyzed samples, significantly reduces the recovery of silver. Taking into account the studied influence of surface activity and the hydrophobic ability of the reagents, a more efficient dialkyldithiophosphate collector has been developed, increasing silver recovery compared with the standard reagent by 1.8-3.4 %, depending on the ore enrichment. Improving the extraction of silver without reducing the selectivity of the process also contributes to the optimal cost ratio of the proposed dialkyldithiophosphate collector and xanthate.

The work examines the ways of estimating the smooth wall blasting quality when excavating mine workings. One of the main criteria is to achieve “smooth” mine working contour. It is shown that the mine working contour line represents a fractal object; its geometry is properly estimated by fractional fractal dimension. The definition of fractal dimension is based on the Richardson’s law, which connects the length of infinitely broken line and measurement interval. The calculation algorithm of fractal dimension in computer program is introduced. The analysis of real mine working contours which are formed in the process of drilling and blasting operations, allowed to determine statistically reliable connection of roughness coefficient of the mine working surface and the value of its fractal dimension. Quality criterion for smooth wall blasting is suggested – fractal coefficient of mine working shape. Its value represents the relation of equivalent cross-section area of a mine working to its perimeter, which is determined by fractal dimension of a contour. Obtained ratios allow to reliably estimate the quality of smooth wall blasting when excavating mine workings.