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The authors review and systematize failure causes in wellbore areas. The present-day methods of sand control are compared with a view to substantiating their efficiency and application ranges. The recommendations on introduction of the most promising techniques are provided. The scope of the discussion encompasses treatment of a well bore area with its reinforcement with different compositions, in particular, the Polyskrep technology using nitrogen. The technology enables minimizing reduction of permeability and increasing rock strength, which enhances rock treatment efficiency.

In the design of reciprocating electromagnetic drives, the correctly selected number of turns of windings defines the required supply voltage. Using simplified mathematical models, the correlation is theoretically determined between the design factors of an electromagnetic impact drive (number of loops and wire section of winding) and the in-process dynamics (currents, coil voltage, impact energy and frequency). The analytical expressions to correlate the listed parameters are derived. Their variability is analyzed, and the recommendations to select the number of loops of windings are made. The calculation-based findings are confirmed in dynamic testing of model electromagnetic impact drives.

For many decades, most of draglines in overburden removal in open pit coal mining used analog control under Ward Leonard method. The conventional analog control is therefore digitalized to improve efficiency, reduce the power consumption and provide low-maintenance operation instead of completely replacing the dragline. Even though digitally retrofitted Ward Leonard gives more efficiency compared with analog control, there is no major change in maintenance cost or breakdown cost. This paper proposes implementing the Active Front End rectifier with DC chopper control in old analog Ward Leonard control dragline in place of digitally retrofitted Ward Leonard control. The proposed control technique is analyzed as a case study for a digitally retrofitted dragline in Indian coal mine, and a comparative study is done with the proposed system in terms of technical and economic aspects.

The current situation in copper smelting slag processing is discussed. The common method of slag processing by flotation produces secondary waste. The authors describe flotation of converter slag of the Balkhash Copper Smelter, with high mass fractions of copper, zinc, lead, iron and silver. In flotation with fractional froth removing, the times of intercycle, rougher and recleaner operations, consumptions of agents, as well as stages of milling and flotation were determined. The introduction of ammonium sulfate in slag milling improved the copper concentrate quality by means of the increase in the copper content in the concentrate from 29.54 to 37.32%. The developed flowchart produced a copper concentrate with the copper mass fraction of 32.4.8% and silver content of 204.74 g/t, and tailings with the copper mass fraction of 0.65%. It is found that tailings of the copper smelting slag processing can be used as a silicic component in manufacture of foam high-pressure steam cured concrete, which can reduce secondary waste and substantially elevate the resource value of copper smelting slag and its utilization prospects.

Aiming to separate ferrosilicon and products of dense medium separation of diamond-bearing kimberlites, and to reduce the loss of the expensive densifier-ferrosilicon, electrohydraulic treatment of ferrosilicon suspension is used. The method of conditioning of dense medium separation tailings of diamond-bearing kimberlites is developed and experimentally tested, which allows the improved quality of skimming of ferrosilicon and its loss reduction.

The mineral and chemical analyses of gold ore from one of the largest deposits in Transbaikalia are described. The main valuable component of the test oxidized gold ore type is nonuniform and coarse native gold. The uniformity of size distribution of gold in initial ore is studied. The gold ore dressability was tested using the methods of gravity separation, flotation and hydrometallurgical treatment. From the experimental results, the conclusion is drawn on the expedient applicability of an integrated technology of gold ore processing. The proposed technology of gold ore processing integrates jigging of milled ore, classification, rough-scavenging-recleaner flotation cycles with the subsequent leaching of flotation concentrate and gravity separation concentrate using a thiocyanate-based agent. Gold recovery in the proposed technology totals 96.3%, which is comparable with the recovery efficiency reached in gold cyanidation (97.5%).

This article overviews the methods of interpretation of machine learning used in image segmentation of opencast mining areas. The model checkup used the information on mining-disturbed land in the Novosibirsk Region and in some districts of Yakutia. Examples of the formation and time history of such land outlines are given. The scope of the analysis embraces various approaches to interpretation of computer vision modeling, including Grad-VAM, Saliency Maps, Feature Maps, Occlusion Sensitivity, Integrated Gradients and Counterfactual Explanations. The studies demonstrate advantages and disadvantages of each method, and imply that an increase in the number of learning iterations not always brings improvement in the model quality. The authors advise on selecting initial data interpretation techniques with regard to peculiarities of an observation target when solving certain geotechnical or geoecological problems.

The author resolves the problem connected with reliability improvement of full-scale investigation data by the method of remote productivity assessment in a hydrocarbon reservoir using records of seismic background noise on ground surface. The complication is a high-amplitude broadband interference covering half a service band. On the basis of a polyspectrum analysis, a remote oil content assessment, different from the earlier proposed method, is proposed. The procedures of statistical straggling and averaging in multi-point recording are discussed. A good agreement of the results of two independent methods increases reliability of total thickness estimates in productive intervals under a recording point. This elevates robustness of oil and gas exploration and facilitates selection of promising drilling sites. In a general case, it is possible to use half-sums of estimates of the two methods. In the areas without wells drilled, productivity maps are calculated in arbitrary units; when the thickness of productive intervals is measured in a number of wells, using a coefficient of linear regression facilitates transition from arbitrary units to units of length.

The article studies ecological observations over disturbed land in the Karabash copper ore province in the north of the South Ural using archival Landsat images taken in the period from 1989 to 2024. For the efficient evaluation of the environmental components within the limits of the Sak-Elga river watershed (basin of the Miass river), the spectral indices were used: NDVI for vegetation mantle; Fe-indices for manmade soil; AMWI for water bodies. The variation in NDVI revealed a general trend of recovery of vegetation cover in the area of 8.5 km², including reclamation sites of tailings storages. In the plain flood area of the Sak-Elga river and on the west shoulder of the Gold Mountain, some large areas with traces of pollution with sulfide-bearing waste still remain. Some prospective minerals pointed at by the spectral indices in the polluted areas are identified. The total area of contamination because of sulfide weathering presumably reduced from 10.8 to 7.5 km². The highest water pollution indexes by AMWI were revealed in the Karabash pond (0.08 in 1989 and 0.75 in 2024), Olkhovka pond (0.67 in 1989 and 0.34 in 2024) and in a hydrobotanical pond (0.24 in 2020 and 0.61 in 2024).

With a view to estimating applicability of overburden rocks of coal mining as a source of ceramics production, their quality indicators, including mineralogical and chemical compositions, hardness and dispersivity, as well as the content of components causing destructive processes and toxic gases, are analyzed. It is found that argillaceous overburden rocks experience softening and fine decomposition in dumps, which makes them better prepared for the further processing. The mineralogical and chemical compositions of argillaceous overburden is typical of natural clay. Argillaceous rocks ground to < 0.63 mm and wetted pass to a moderately plastic mass which allows shaping work pieces without defects. Baking of argillaceous rocks starts at a temperature over 900 °C, which enables manufacturing walling ceramic materials with the properties as per State Standard GOST 530-2012.