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Date submitted2024-05-28
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Date accepted2024-11-07
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Date published2024-12-25
Methods of intensification of pipeline transportation of hydraulic mixtures when backfilling mined-out spaces
The paper presents an analysis of the advantages and limitations of additional measures to intensify the transportation of the backfill hydraulic mixture flow. The results of the analysis of the conditions for using pumping equipment to move flows with different rheological properties are shown. Generalizations of the methods for influencing the internal resistance of backfill hydraulic mixtures by means of mechanical activation, as well as increasing fluidity due to the use of chemical additives are given. The article presents the results of studies confirming the feasibility of using pipes with polymer lining, which has proven its efficiency in pumping flows of hydraulic mixtures with different filler concentrations. An analytical model of hydraulic mixture movement in the pipeline of the stowage complex has been developed. The trends in pressure change required to ensure the movement of hydraulic mixture in pipelines of different diameters are exponential, provided that the flow properties are constant. The effect of particle size on the motion mode of the formed heterogeneous flow, as well as on the distribution of flow density over the cross-section, characterizing the stratification and change in the rheological properties of the backfill hydraulic mixture, is assessed. An analytical model of centralized migration of the dispersed phase of the hydraulic mixture flow is formulated, describing the effect of turbulent mixing of the flow on the behavior of solid particles. An assessment of the secondary dispersion of the solid fraction of the hydraulic mixture, which causes a change in the consistency of the flow, was performed. The studies of the influence of the coefficient of consistency of the flow revealed that overgrinding of the fractions of the filler of the hydraulic mixture contributes to an increase in the required pressure in the pipeline system.
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Date submitted2024-04-12
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Date accepted2024-09-05
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Date published2024-11-12
Promising reagents for the extraction of strategic metals from difficult-to-enrich mineral raw materials
The need of the mining and processing industry for new types of directional reagents is due to the deterioration of the material composition of the processed ores. Low Au content (less than 0.5-1.0 g/t), finely dispersed Au inclusions (0.1-10.0 microns) in the ore, similar properties of the separated minerals have an extremely negative effect on flotation performance when using traditional reagents, which leads to significant losses of valuable metal with enrichment tailings. Expanding the range of domestic flotation reagents based on the latest achievements of fundamental research and their targeted application at mining and processing companies will compensate for the negative impact of the mineral composition of raw materials and ensure maximum extraction of strategic metals from difficult-to-enrich ores. The use of modern research methods (scanning electron and laser microscopy, UV spectrophotometry, XRF and chemical analysis) made it possible to visualize the adsorption layer of new reagents-collectors of a number of dithiocarbamates with different structures of a hydrocarbon radical and an organic modifier on the surface of gold-containing sulfides. The amount of adsorbed reagents on the surface of minerals has been experimentally determined. The specific features of the fixation of reagents on minerals of various compositions led to optimal correlations of their consumption in the flotation process. Scientifically based reagent regimes ensured an increase in the gold content in the concentrate and a decrease in the loss of gold with tailings by 5-6 % during flotation enrichment of the refractory ore of the Malinovskoe deposit.
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Date submitted2024-10-29
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Date accepted2024-10-29
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Date published2024-11-12
Study of thermodynamic processes of the Earth from the position of the genesis of hydrocarbons at great depths
In the context of significant depletion of traditional proven oil reserves in the Russian Federation and the inevitability of searching for new directions of study and expansion of the raw material base of hydrocarbon raw materials in hard-to-reach regions and on the Arctic shelf, a scientific search is underway for accumulations in complex geological conditions and in manifestations that differ significantly from traditional ones, which include the processes of oil and gas formation and preservation of oil and gas in low-permeability “shale” strata and in heterogeneous reservoirs at great and super-great depths. Within the oil and gas provinces of the world, drilling of a number of deep and super-deep wells has revealed deposits at great depths, established connections between hydrocarbon deposits and “traces” of hydrocarbon migration left in the core of deep wells, which has made it possible to significantly re-evaluate theoretical ideas on the issue of oil and gas formation conditions and the search for technologies aimed at solving applied problems. Modern geochemical, chromatographic, bituminological, coal petrographic and pyrolytic methods of studying oil and bitumoids extracted from the host rocks of deep well cores give a hope for identifying correlations in the oil-source system, revealing processes that determine the possibility of hydrocarbon formation and accumulation, and defining predictive criteria for oil and gas potential at great depths.
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Date submitted2023-07-05
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Date accepted2024-06-03
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Date published2024-12-25
Complete extraction of conditioned ores from complex-structured blocks due to partial admixture of substandard ores
- Authors:
- Bayan R. Rakishev
The paper presents mining-technological substantiation of complete extraction of conditioned ores from complex-structured blocks of benches by mixing a layer of substandard ores of certain sizes. The relevance of the work consists in the development of innovative methods of establishing the parameters of the substandard layer of ores to be added to the conditioned ores. The main problem is to ensure complete extraction of useful components into concentrate from shipped ore with acceptable deviations from the required ones. A new typification of complex-structured ore blocks of the bench has been carried out. Analytical dependences of mining and geological characteristics of complex-structured ore blocks were obtained. Theoretical dependences for determining the main indicators of mineral processing are derived. Analytical dependences for determination of the content of useful component in shipped ore α' – mixture of conditioned ore with the content of useful component α and admixed layer of substandard ore with the content of useful component α'' are offered. For the first time in mining science, a new approach of complete extraction of conditioned ores from complex-structured blocks of benches by grabbing a certain part of substandard ores during excavation, increasing the volume of extracted ore and expanding the extraction of useful components in the concentrate has been substantiated. The increment of useful components can reach 10-15 % of the total volume of extraction, which allows predicting a significant increase in the completeness of mineral extraction from the Earth's interior.
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Date submitted2023-01-16
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Date accepted2023-06-20
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Date published2024-04-25
Study on the thin layer drying and diffusion mechanism of low rank coal in Inner Mongolia and Yunnan
Coal is one of the world's most important energy substances. China is rich in coal resources, accounting for more than 90 % of all ascertained fossil energy reserves. The consumption share of coal energy reaches 56.5 % in 2021. Due to the high moisture content of low-rank coal, it is easy to cause equipment blockage in the dry sorting process. This paper considers low-rank coal coming from Inner Mongolia (NM samples) and Yunnan (YN samples). The weight loss performance of the samples was analyzed using thermogravimetric experiments to determine the appropriate temperature for drying experiments. Thin-layer drying experiments were carried out at different temperature conditions. The drying characteristics of low-rank coal were that the higher the drying temperature, the shorter the drying completion time; the smaller the particle size, the shorter the drying completion time. The effective moisture diffusion coefficient was fitted using the Arrhenius equation. The effective water diffusion coefficient of NM samples was 5.07·10–11 - 9.58·10–11 m2/s. The effective water diffusion coefficients of the three different particle sizes of YN samples were 1.89·10–11 - 4.92·10–11 (–1 mm), 1.38·10–10 - 4.13·10–10 (1-3 mm), 5.26·10–10 - 1.49·10–9 (3-6 mm). The activation energy of Inner Mongolia lignite was 10.97 kJ/mol (–1 mm). The activation energies of Yunnan lignite with different particle sizes were 17.97 kJ/mol (–1 mm), 33.52 kJ/mol (1-3 mm), and 38.64 kJ/mol (3-6 mm). The drying process was simulated using empirical and semi-empirical formulas. The optimal model for Inner Mongolia samples was the Two-term diffusion model, and Yunnan samples were the Hii equation was used.
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Date submitted2022-05-17
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Date accepted2023-04-03
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Date published2024-02-29
Improvement of concentrate quality in flotation of low-rank coal
- Authors:
- Sergei A. Kondratev
- Tatyana A. Khamzina
Percentage of high-rank coal with low content of ash, moisture, and sulfur in total coal production output is low. Most of the produced coal has a low quality (lignite, bituminous coal: long-flame and fiery). Under increasing requirements for ecological cleanness of coal, the efficient use of coal products is only possible after improvement of their processing properties. The authors discuss the enhancement of flotation efficiency of low-rank coal using the mechanism of physisorption of a collecting agent in particle – bubble attachment. It is explained why the yield of concentrate with low ash content increases as a result of combination of collectors having different physical properties. It is shown that the surface activity of a heteropolar agent relative to the gas – liquid interface and the adsorption density of the agent govern its collecting properties. Based on the recovery – surface activity relationship, the correlation is found between the collecting activity of a chemical compound and the structure of its molecules. The combination of the collectors with different surface activity enables adjusting collectability and selectivity of the blend. The physisorption mechanism of collectors can be a framework for developing recommendations on modification of concentrate yield and ash content, and on selection of optimized ratios of surface activities of miscible collectors relative to the gas – liquid interface.
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Date submitted2023-03-14
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Date accepted2023-06-20
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Date published2023-07-19
A reliability study of the traction drive system in haul trucks based on failure analysis of their functional parts
The efficiency of a mining and processing plant depends on the level of complex mechanization of the production process. In mineral extraction, haulage is a major cost category, with haul trucks being the key component of the mining transportation system. To improve production performance, mining operations can increase their haulage turnover and reduce transportation costs, which necessitates making haul trucks more reliable. This can be done by improving their mean time to first failure (MTFF) indicators. This article analyzes the reliability status of the traction drive system inhaul trucks operating in the mineral resources sector. It provides a quantitative assessment of traction drive system failures resulting from part defects and discusses the associated repair costs. By examining failure data from 2018 to 2022 and the results of vibration tests performed on a diesel generator, the study reveals that the most expensive failures are associated with defects in the synchronous generator, which are primarily caused by elevated external vibrations. Based on basic vibration tests and vibration spectra tests at different operating modes, recommendations have been formulated concerning the generator’s robustness to external mechanical forces and the ways to increase the generator’s protection grade to prevent dust intrusion. The study also identifies the frequency range that poses the greatest risk of damage to the windings.
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Date submitted2022-10-28
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Date accepted2023-03-02
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Date published2023-04-25
Assessment of the possibility of using iron-magnesium production waste for wastewater treatment from heavy metals (Cd2+, Zn2+, Co2+, Cu2+)
Relevant problems associated with treatment of industrial wastewater from heavy metal ions are considered. Due to industrial development, the amount of wastewater increases as well as the risks of heavy metals getting into surface and groundwater, accumulating in water bodies and becoming aggressive environmental pollutants, which affect the animal and human organisms. To assess the possibility of extracting metal ions (Cd 2+ , Zn 2+ , Co 2+ , Cu 2+ ) from industrial wastewater and their further treatment, studies were carried out on redistribution of heavy metals in the “wastewater – waste” system using iron-magnesium production waste. Samples of the investigated waste weighing 0.1; 0.2; 0.5; 1; 1.5; 2 g were taken for wastewater volume of 50 ml per each subsample. Contact time varied from 5 to 180 min, waste fraction was 1 mm. The interaction process showed that the waste efficiently removes metal ions (Cd 2+ , Zn 2+ , Co 2+ , Cu 2+ ) from industrial wastewater. The efficiency of removing a pollutant from the solution depends on the weight of the waste subsample, initial concentration of metal ions, and contact time.
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Date submitted2022-02-22
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Date accepted2022-05-11
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Date published2022-11-03
Scientific substantiation and development of innovative processes for the extraction of zirconium and rare earth elements in the deep and comprehensive treatment of eudialyte concentrate
- Authors:
- Valentin A. Chanturiya
Based on a package of modern analysis methods, the influence of various acids and energy effects on the morphology, elemental composition, structural and chemical transformations of the mineral surface, and the efficiency of eudialyte concentrate leaching was studied. The mechanism and the optimal conditions and specific features of the destruction of eudialyte and rock minerals and the extraction of zirconium and REE under the influence of various acids, powerful nanosecond pulses, dielectric barrier discharge, electrochemical processing, mechanochemical activation and ultrasound were revealed. The mechanism of formation and the optimal conditions for the dispersion of silica gel, depending on the methods and parameters of energy effects, was theoretically and experimentally substantiated. A combined three-stage circuit of nitric acid leaching of eudialyte concentrate with ultrasonic treatment of the suspension, providing 97.1 % extraction of zirconium and 94.5 % REE, were scientifically substantiated and tested. The conditions for the selective deposition of zirconium and REE were theoretically and experimentally substantiated.
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Date submitted2021-06-08
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Date accepted2021-11-30
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Date published2021-12-27
Management of groundwater resources in transboundary territories (on the example of the Russian Federation and the Republic of Estonia)
Groundwater, as a source of water supply, the most important mineral and geopolitical resource, , is often the only source of high-quality drinking water that is protected from pollution under conditions of increasing deterioration of surface water quality. Transboundary groundwaters are the focus of hydrogeological researchers for a number of reasons, including the reduction and pollution of water resources as a result of economic activities. The increased controversy between states over transboundary water issues has necessitated the development of international legal documents on issues related to water conflict prevention and the sustainable use of fresh water. As part of the analysis of the problem of legal regulation of groundwater extraction from transboundary aquifers and complexes, it is proposed to consider this aspect on the example of Russia. The problems of regulation of rational use and protection of fresh water in the bilateral treaties of the Russian Federation were revealed; a methodology for the management of groundwater extraction in the territory of the transboundary aquifer was developed, the size, parameters, and factors influencing the formation of the transboundary zone have been determined (based on research and analysis of water intake activities in the border areas of the Russian Federation and the Republic of Estonia) were determined.
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Date submitted2020-09-15
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Date accepted2021-11-30
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Date published2021-12-27
Evaluating the effectiveness of fine gold extraction technologies on the example of titanomagnetite beach placers of the western coast of Kamchatka
- Authors:
- Valentina E. Kungurova
The material on the gold content of coastal-marine deposits of the western coast of Kamchatka is analyzed and the resource potential is briefly characterized. A review of gold technological estimates obtained from the study of gold-bearing samples taken in promising areas of the coastal-marine strip, from the Bolshaya Vorovskaya River in the north to Cape Levashova in the south, is presented. Stock materials supplemented by our studies were used. Gold-bearing deposits with very fine (0.05-0.1 mm) and fine (0.1-1.0 mm) gold amounting to 94.6 % were tested, as well as samples with gold up to 2 mm and more in addition to fine gold The content of freely recoverable gold reached 91.9 %. In the case of significant gold reserves in placers, prospects for their commercial development open up. experiments on the enrichment of gold-bearing coastal-marine deposits of Western Kamchatka indicate the possibility of extraction of free gold and other valuable components from them. Gravity technologies and modern equipment developed by ОАО Irgiredmet and JSC ITOMAK are the most effective for their extraction. enrichment of gold-bearing formations with simultaneous extraction of several useful components from them, which is possible with the use of fluoride technology, can also become economically advantageous.
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Date submitted2021-06-15
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Date accepted2021-10-18
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Date published2021-12-16
Study on hydrometallurgical recovery of copper and rhenium in processing of substandard copper concentrates
- Authors:
- Denis S. Lutskiy
- Aleksander S. Ignatovich
Over the past decade, there has been a steady growth in demand for rare metals, with rhenium being one of the most highly demanded, but also one of the most expensive and difficult to obtain. The high demand for rhenium is due to its use as a key component of metallurgical alloys or as a component of catalysts used in the oil refining industry. The aggregate of facts causes profitability of processing of the rhenium-containing mineral resources, which also are the copper substandard concentrates obtained at processing of the Zhezkazgan sandstones. The study focuses on the processes of extraction of copper and sorption recovery of rhenium from solutions of ammonia leaching of copper substandard concentrates. Model solutions similar in the elemental composition to solutions of ammonia leaching solutions of copper substandard concentrates obtained during the processing of Zhezkazgan sandstones were used as an object of the study. The paper estimates extraction characteristics of copper recovery using LIX 84-I solution in kerosene, as well as sorption characteristics of the rhenium recovery process using the Purolite PPA100 anion exchanger. Based on the obtained characteristics the possibility of hydrometallurgical processing of ammonia leaching solutions of substandard copper-sulfide concentrates, and recovery of the obtained commercial products is shown.
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Date submitted2021-02-20
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Date accepted2021-10-18
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Date published2021-12-16
Thermal protection implementation of the contact overheadline based on bay controllers of electric transport traction substations in the mining industry
The article presents the principle of thermal protection of the contact overheadlineand substantiates the possibility of practical implementation of this principle for rail electric transport in the mining industry. The algorithm for the implementation of modern digital protection of the contact overhead line as one of the functions of the controller is described. A mathematical model of thermal protection is proposed, which follows from the solution of the heat balance equation. The model takes into account the coefficient of the electrical networktopology, as well as the coefficient of consumption of the current-carrying core of the cable, which determines the reduction in the conducting section from contact erosion and the growth of oxide films. Corrections for air flows are introduced when receiving data from an external anemometer, via telemechanics protocol. The mathematical model was tested by writing a real thermal protection program in the C programming language for the bay controller, based on the circuitry of which is the STM32F407IGT6 microcontroller for the microcontroller unit. Verification tests were carried out on a serial bay controller in 2020. The graphs for comparing the calculated and actual values of temperatures, with different flow rates of the current-carrying conductor of the DC cable, are given. To obtain data, telemechanics protocols IEC 60870-104 and Modbus TCP, PLC Segnetics SMH4 were used.
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Date submitted2020-05-18
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Date accepted2020-06-16
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Date published2021-04-26
Traction asynchronous electric drive of mine electric locomotivesimulation model structure improvement
The article discusses the solution to the problem of underground railway transport slipping in dynamic modes, which occurs when there is a significant difference in the speeds of the driving and driven pairs of wheels. The state of the rail surfaces largely determines the coefficient of adhesion, therefore, using a mathematical model, the condition for the dependence of the magnitude of slipping and tractive effort is selected. For effective acceleration and deceleration of an electric locomotive, it is necessary to control the coefficient of adhesion at a certain level. A simulation model of rolling stock has been created, which for the first time takes into account a mechanical system with distributed parameters. In the structural diagram of the automatic control system of traction electric drives with frequency regulation, such factors as the volume of goods being moved, rolling friction, slope (rise) levels and the state of the rail track are taken into account. The simulation results show the features of the movement and stops of the freight train not only by the diagrams of speed and forces in the modes of acceleration-deceleration and uniform movement, but also the positions of the plungers and tractive forces on the couplings of the electric locomotive and all trolleys involved in the movement of goods. The practical application of the proposed method lies in the possibility of starting a heavily laden train from its place on the ascent section in conditions of insufficient adhesion coefficient with contaminated roads.
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Date submitted2020-05-16
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Date accepted2020-07-30
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Date published2020-12-29
Results of the study of kinetic parameters of spontaneous combustion of coal dust
The article is devoted to the study of the problem of spontaneous combustion of energy grades of coal not only during storage, but also during transportation. As the main samples for the study, the energy grades of SS and Zh coals were selected. The main task of the scientific research was to study the rate of cooling and heating of coal depending on their thermophysical parameters and environmental parameters. To solve this problem, the authors used both the author's installations designed to study the thermophysical parameters of the spontaneous combustion process (the Ya.S.Kiselev method), and the NETZSCH STA 449 F3 Jupiter synchronous thermal analysis device, the NETZSCH Proteus Termal Analysis software package. On the basis of a complex study of the spontaneous combustion process, the authors of the article obtained the kinetic characteristics of the spontaneous heating process (activation energy and pre-exponential multiplier). Nomograms of the permissible size of coal density of different types and shapes of accumulation depending on the ambient temperature are presented, practical recommendations for the prevention (avoidance) of spontaneous combustion of coal fuel are given.
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Date submitted2020-02-19
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Date accepted2020-04-17
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Date published2020-10-08
Decrease in coal losses during mining of contiguous seams in the near-bottom part at Vorkuta deposit
- Authors:
- Oleg I. Kazanin
- Valeriy V. Yaroshenko
The problem of formation of extended zones with high rock pressure (HRP) from safety pillars at the boundaries of extraction pillars formed due to the mine layout of complex geometry is considered at the example of JSC Vorkutaugol mines. A detailed analysis of the remaining reserves of the near-bottom part of the deposit was carried out to estimate losses and the impact of HRP zones from the Chetvertyi protective seam to mining operations on the Troinoi upper seam along with the possibilities for the reduction of sizes of HRP zones at the account of expanding the underworked space. Due to research on the near-bottom part of the Vorkuta deposit, within the framework of the accepted layout, a zone at the Komsomolskaya mine and two zones at the Zapolyarnaya-2 mine were singled out, at which losses at the boundaries of the extraction pillars amount up to 13-22 % of the total resources of the mine field. The high volume of losses in these pillars indicates the relevance of research on the priority extraction impact of protective seams on the efficiency and safety of mining operations in the working area of underworked and HRP zones. Based on the analysis of foreign and Russian experience in the pillar cleaning-up at the boundaries of working areas and the methodical guidelines and instructions, a technological scheme was developed that allows increasing the coal mining recovery factor in the near-bottom part of the Vorkuta deposit from 0.75 to 0.9 without fundamental changing of the ventilation and transport networks and also without purchasing any additional mining equipment. The conducted economic calculations confirmed the effectiveness of implementing the new technological scheme for cleaning-up reserves at the boundaries of extraction districts. The economic effect is from 0.079 to1.381 billion rubles of additional profit from coaxial extraction pillars, depending on the mining and geological conditions and the size of the pillars.
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Date submitted2019-06-06
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Date accepted2019-08-09
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Date published2020-04-24
Studies of enrichment of sulfide and oxidized ores of gold deposits of the Aldan shield
The paper presents the analysis of studies of the enrichment of sulfide and oxidized ores in Yakutia deposits. The ore of the deposit is a mixture of primary, mixed and oxidized ores. The main useful component of the studied ore samples is gold with a content of 1.5 to 2.8 g/t, the silver content is low – 5-17 g/t. Ore minerals are represented by sulfides, among which pyrite predominates. The total sulfide content does not exceed 3-5 %. The presence in the ore of free and associated gold with a grain size from fractions of a micron to 1.5 mm. Gold is represented by nuggets in intergrowth with sulfides and also forms independent inclusions. Ores are classified as easily cyanidable. It was found that the content of amalgamable gold is 10-49, the share of cyanidable gold ranges from 66.67-91, the share of refractory gold is 9.0-33.33 %, which in absolute amount equals to 0.24-0.8 g/t. The extraction of gold in gravitation concentrate varies depending on the gold content in the ore and the yield of concentrate and for ores with a gold content of 1.5-2.8 g/t from 40 to 60 %. The direct cyanidation of all studied ore samples established the possibility of extracting gold into solution up to 86.7-92.9 %, the gold content in cyanidation cakes is 0.2-0.3 g/t. Investigations of the gravitation concentrate by the method of intensive cyanidation showed that with an initial gold content of ~ 500 g/t, up to 98.9 % is extracted into the solution. The gold content in intensive cyanide cakes will be 6-15 g/t. A set of studies carried out by the authors of the article at various institutes showed that it is advisable to process ore from the deposit using cyanidation technology with preliminary gravitational extraction of gold.
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Date submitted2019-07-11
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Date accepted2019-09-11
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Date published2020-04-24
Research of lithium sorption by KU-2-8 cation exchanger from model solutions simulating geothermal fluids in the dynamic mode
- Authors:
- Tatiana P. Belova
- Tatiana I. Ratchina
The extraction of chemical compounds from hydromineral raw materials is currently a promising objective. The geothermal deposits in the Kamchatka Territory should be considered as possible sources of lithium, boron and other chemical compounds. Their economic efficiency is justified by the complexity of the use of resources of geothermal fluids. The article presents data obtained as a result of experimental studies of lithium sorption by KU-2-8 cation exchanger from model solutions that simulate geothermal fluids in the dynamic mode. It was shown that in the first phase of sorption, ion exchange results in the absorption of lithium and sodium ions by the hydrogen form of cation exchanger up to the degree of cation exchanger saturation by 78 %. After that, the displacement of lithium ions by sodium ions is observed. The intermediate solutions were obtained in which the molar ratio of Li/Na is 80 times higher than in the initial solution. To separate sodium and lithium, it is proposed to use the lithium form of cation exchanger obtained using a portion of lithium chloride concentrate. The separation occurs due to the displacement of lithium ions by sodium ions. The effluent has a molar ratio of Li/Na = 10.4. The regeneration is carried out with 1 n hydrochloric acid, while the concentration coefficient of sodium chloride equals three.
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Date submitted2019-05-26
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Date accepted2019-07-23
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Date published2019-10-23
Ensuring Stability of Undermining Inclined Drainage Holes During Intensive Development of Multiple Gas-Bearing Coal Layers
At high rates of production face advance, requirements towards reliable operation of undermining drainage holes get raised. The issue of maintaining high intensity of gaseous seams development under naturally increasing gas content, mining depth and capacity of production equipment poses a problem. The greatest threat comes from the loss of hole stability in the bearing pressure affected zone (in front of the face) and in the intensive shift area of overhanging rock corbels (behind the face). Intensification of air leaks due to deformation of borehole channel leads to impoverishment of removed methane-air mixture and an increasing risk to disturb safe aerogas regime in the mining area. The paper describes a mechanism of how coal-face operations affect the state of underground holes and formation of overhanging rock corbels. A typification of basic kinds of borehole deformations is presented. Authors point out critical disadvantages of the most widely-used technological schemes of gaseous seams development under high load on the production face, which hinder normal operation of a gas drainage system. As a result of research, a dependency of shot hole number, as well as the distance between shot hole axes and the borehole, on the stress state of the borehole outline has been defined more precisely. Basing on that, a formula to calculate drilling parameters of the discharge hole system has been suggested. Implementation of these measures will allow to increase the efficiency of underground gas drainage and to maintain growing intensity of gaseous coal seam development.
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Date submitted2019-05-24
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Date accepted2019-07-15
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Date published2019-10-23
Effective Power and Speed of Mining Dump Trucks in Fuel Economy Mode
- Authors:
- V. I. Alexandrov
- M. A. Vasileva
- V. Y. Koptev
Existing methods for determining the effective power, based on the calculation of the average indicator operation of the engine during the piston stroke, do not take into account the change in thermodynamic parameters and the polytropic operation of the engine, the value of which depends on the polytropic efficiency of the duty cycle. This is the reason that the calculation of the effective power leads to some error – the margin of the engine features. The identification of this stock allows us to review the entire line of dump trucks in the direction of increasing their pass- port effective capacity, which will lead to a reduction in capital purchase costs due to the choice of a previously un- derestimated and cheaper option, as well as a reduction in current operating costs due to a decrease in the specific fuel consumption rate. Taking into account the stochastic nature of the transport process and assessing the influence of all external and internal factors when calculating the rational mode of operation of a mining truck can further reduce specific fuel consumption by choosing the rational speed of its movement in loaded and empty directions.
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Date submitted2018-10-28
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Date accepted2018-12-30
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Date published2019-04-23
Development and research of formation technologies on specialized presses with subsequent sintering of high-density details from iron-based powders
- Authors:
- A. M. Dmitriev
- N. V. Korobov
- A. Zh. Badalyan
Creating shifts of the lyaers in a deforming workpieces improves the quality of the product produced by pressure treatment. qual-channel angular pressing and precipitations of a cylindrical billet with a rotating turnaround were developed by specialists earlier and became basic for scientists engaged in nanotechnology. One of the most modern schemes for creating nanostructures by processing on presses is the «Cyclic Extrusion Compression» scheme (in Russia – «Hourglass»), which has significant drawbacks. To date, research on the creation of layer shifts in compacted metal powders is substantially less than in compaction of compact blanks. The article developed compaction schemes for presses of blanks from iron-based powders that have a certain analogy with the «Hourglass», while lacking the disadvantages inherent in the named scheme and implemented on the created samples of specialized hydraulic presses. The results of the studies of density, strength and microhardness before sintering the samples molded from a number of domestic and imported powders on iron base, including those doped with carbon and other alloying components, are described. It has been established that with the use of the formation schemes for powders providing large shifts between particles, the density of the preforms increases on average by 10-12 %. With an average stress (16.32 MPa) of the transverse section of the molded specimen prior to its sintering, molding with shifts between particles increases this stress by 78 %. The strength after sintering of samples made using the compaction schemes developed by the authors of the article increases approximately by 2 times. Magnetic pulse treatment (MPT) of a molded sample prior to its sintering increases its resistance to shearing before sintering, regardless of the molding pattern. When MPT of both the powder and the molded sample is executed, the most uniform distribution of microhardness in the sample is achieved, and after subsequent sintering, the most uniform distribution of the mechanical characteristics of the product. The results of all studies are described by regression equations.
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Date submitted2018-09-10
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Date accepted2018-11-06
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Date published2019-02-22
Comparative analysis of zincand tin oxidation with acids at room temperatures
- Authors:
- S. D. Pozhidaeva
- L. S. Ageeva
- A. M. Ivanov
The paper analyses the parameters of deep oxidation of zinc and tin by copper (II) compounds and molecular iodine in the presence of molecular oxygen and hydrogen peroxide, as second oxidizers working synchronously with them in various media (aqueous, aqueous-organic and organic) with the participation of mineral and carboxylic acids close to room temperature. The contribution of the reactivity of the metal to its rate of consumption, especially the average, is often much less than the contribution associated with the release characteristics of the working surface, determined by the rates of accumulation of surface deposits of metal oxidation products, their strength and adhesion characteristics their destruction and shifting into the bulk phase.
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Date submitted2018-05-05
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Date accepted2018-07-18
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Date published2018-10-24
Calculations of dynamic operating modes of electric drives self-propelled mining machines
- Authors:
- E. K. Eshchin
The task of improving the calculations of the dynamic modes of electric drives of self-propelled mining machines, particulary, tunneling machines, is considered. Attention is drawn to the possibility to opearte in dynamic modes of a spatial change in the an asynchronous electric motor stator housing position, included in the electric drive, around the axis of its rotor due to the ultimate rigidity of the supports of the mining machine. In connection to this, it is possible to change the absolute angular velocity of rotation of the electromagnetic field of the stator of this electric motor. The necessity of introducing into existing mathematical models that determine the state and behavior of asynchronous electric motors, additional differential and algebraic relations for calculating the absolute speed of the electromagnetic field of the stator and the nature of the motion of the stator housing of the electric motor as part of the mining machine is noted. The results of calculations of the idle start mode of the electric motor of the executive body of the mining combine are shown, showing the difference in the nature of its electromagnetic moment variation, rotor rotation speed, as well as efforts in individual reducer elements of the driving body driving the stator body from similar calculation results without taking into account the stator body movement. The conclusion is made about the possible discrepancy between the calculated and experimental results in the study of the dynamic modes of self-propelled mining machines.
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Date submitted2018-05-16
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Date accepted2018-07-22
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Date published2018-10-24
Extraction of copper, cobalt and nickel ions from aqueous solutions by extractant CYANEX 272
- Authors:
- L. A. Voropanova
- V. P. Pukhova
The extractant CYANEX 272, which active component is di(2,4,4-trimethylpentyl)-phosphinic acid (C 8 H 17 ) 2 POOH, is effective for extraction of copper (II), cobalt (II) and nickel (II) ions. The extraction of metal ions using di(2,4,4-trimethylpentyl)-phosphinic acid as an extractant is carried out due to the formation of an organophosphorus complex with wide pH range: copper at pH > 2, cobalt at pH > 3, and nickel at pH > 5. They are extracted with an organic phase: copper at pH = 3-7, cobalt at pH = 4-7, and nickel at pH = 6-9, and precipitate in the organophosphorus compound: copper at pH > 7, cobalt at pH ≥ 8, and nickel at pH ≥ 10. The possibility of separation of copper (II) and cobalt (II) is insignificant, the stripping of copper (II) and nickel (II) happens at pH = 4-6, and the stripping of cobalt (II) and any of nickel (II) – at pH = 5-6. The obtained results of ion extraction of the investigated metals can be used not only for processing of technological solutions, but also for purification of effluents from industrial enterprises and mine waters, heap and underground leaching solutions, etc. from the ions of studied metal ions.
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Date submitted2018-01-02
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Date accepted2018-03-14
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Date published2018-06-22
Analysis of the options of modernization of roller-bit drilling machines with a submersible steamer
- Authors:
- D. A. Yungmeister
- I. Krupenskii
- S. A. Lavrenko
The designs of submersible hammers and dampers protected by patents for reducing the vibration of the drilling rig of roller drill machines are proposed. The variants of modernizing drilling rigs for drilling hard rocks and faces of complex structures are considered. Particular attention is paid to the joint work of submersible shockers and pneumatic shock absorbers, the preferred schemes for the arrangement of these devices by drilling rigs are indicated. The results of experimental tests of machines with pneumatic hammers are presented to determine the vibration performance and drilling speeds. The pneumatic hammer allows increasing the speed of drilling process to the intensification of the destruction of the plain face by the shock load and the cleavage of the protrusions of the unevenness of the face, the better fitting of the bit to the face and the release of the blades or the bit pins from the drill bit. The choice of a particular type of damper or shock absorber depends on its design scheme and the possibility of changing the design of the drill string. With the complexity of installing a damping device in the mast (with significant dimensions of shock absorbers and drilling of strong heterogeneous rocks), it is advisable to use a set of tools to reduce hydraulic pulsations in the mains and cylinders of the hydraulic system by installing chokes in the oil plants and pneumatic shock absorbers. It is proposed to use the device for the development of pneumatic hammers by a patent-pending drilling method with a hollow piston filled with magnetically active heavy liquid, which will allow controlling the frequency and size of the shock pulses and partially compensating for the drill string fluctuations arising from the uneven immersion of the bit in the array . It is noted that the proposed solutions increase the drilling speed by an average of 15%.