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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 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 submitted2022-08-10
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Date accepted2023-02-28
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Date published2024-02-29
Selection of the required number of circulating subs in a special assembly and investigation of their performance during drilling of radial branching channels by sectional positive displacement motors
The task of sludge removal to the surface during construction of directional and horizontal wells and strongly curved radial channels is relevant. For stable operation of technical system “Perfobore”, it is proposed to use a circulating sub that ensures efficient cleaning of channel wellbore from the drilled rock. Two schemes of technical system “Perfobore” are considered, consisting of two seven-meter coiled tubing, a positive displacement motor, a bit and one circulating sub in the first scheme and two subs in the second scheme. For each of the schemes CFD modeling was implemented to determine values of pressure and speed. It was found out that the use of two circulating subs in the assembly is more efficient. In order to confirm the numerical experiment, bench tests were carried out. It was determined that the designed circulating sub can eject up to 25 % of pumped drilling fluid. The bench tests of full-size technical system “Perfobore” for drilling 14-meter channels with two circulating subs showed that the axial load on positive displacement motor produced by hydraulic loader was 3000 N and pressure drop depending on flow rate was 1.5-2.0 MPa. This allows the motor to operate at maximum power.
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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 submitted2020-05-16
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Date accepted2021-03-02
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Date published2021-04-26
Study of drive currents for lifting bridge cranes of metallurgical enterprises for early diagnosis of load excess weight
The article discusses an approach based on the analysis of the drive motor currents to create an additional means of protection against emergency situations during the operation of bridge cranes associated with lifting a load with a mass exceeding the permissible one . A mathematical model of an overhead crane drive is described, as well as the results of computer simulation. It is shown that in the process of lifting up, before the stage of lifting the load, the stator current of the drive electric motor does not depend of the load mass, but when the load is detached, already for several periods of the mains voltage after the rope is pulled, when the mass of the load is exceeded, a measurable excess of the amplitude value of the current is recorded. This pattern has been confirmed for a number of cranes of various lifting capacities used at metallurgical enterprises. The possibility of diagnosing excess weight of the lifted load with a higher speed than existing mechanical methods of overload control is demonstrated, at the same time it is not required to make changes to the structural elements of overhead cranes.
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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 submitted2020-02-19
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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 submitted2019-10-30
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Date accepted2019-11-23
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Date published2020-02-25
Methodology for determining the parameters of drilling mode for directional straight sections of well using screw downhole motors
- Authors:
- Vladimir S. Litvinenko
- M. V. Dvoinikov
Article presents results of study on possibility of increasing the efficiency of drilling directional straight sections of wells using screw downhole motors (SDM) with a combined method of drilling with rotation of drilling string (DS). Goal is to ensure steady-state operation of SDM with simultaneous rotation of DS by reducing the amplitude of oscillations with adjusting the parameters of drilling mode on the basis of mathematical modeling for SDM – DS system. Results of experimental study on determination of extrema distribution of lateral and axial oscillations of SDM frame depending on geometrical parameters of gerotor mechanism and modes ensuring stable operation are presented. Approaches to development of a mathematical model and methodology are conceptually outlined that allow determining the range of self-oscillations for SDM – DS system and boundaries of rotational and translational wave perturbations for a heterogeneous rod with an installed SDM at drilling directional straight sections of well. This mathematical model of SDM – DS system's dynamics makes it possible to predict optimal parameters of directional drilling mode that ensure stable operation of borehole assembly.
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Date submitted2019-07-07
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Date accepted2019-09-13
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Date published2019-12-24
Installation for experimental research of multiphase electromechanical systems
- Authors:
- V. M. Tereshkin
- D. A. Grishin
- I. A. Makulov
The subject of this study is an installation for experimental research designed to study the characteristics and control algorithms of multiphase motors with the number of working phases from 3 to 8, connected by a star, a triangle, or in another way, allowing phase currents to flow, creating a rotating electromagnetic field. The installation consists of two separate independent units: a controller, or a human-machine control interface, and a power inverter module (converter). The controller is connected to the converter by a two-wire half-duplex interface (RS485) via the Modbus RTU communication protocol. The installation also includes synchronous motors with the number of phases 3, 5, 7. Using the developed installation for experimental research, it is possible to carry out experimental studies of multiphase motors when implementing various control algorithms for a converter that implements pulse-width vector modulation. The time required to implement control algorithms is minimal. According to the results of the experiments, it is possible to carry out a comparative analysis of multiphase motors in terms of energy efficiency, in terms of vibration of electromagnetic origin, in dynamic parameters. An experimental assessment of the load of the converter keys is possible. The created installation is an effective tool for checking the reliability of the results of theoretical studies of electromechanical systems based on multiphase motors.
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Date submitted2019-07-10
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Date accepted2019-08-30
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Date published2019-12-24
Methodology for calculating technical efficiency of power sections in small-sized screw downhole motors for the «Perfobur» system
With an increase in the share of old and low-yield wells and for the efficient exploitation of fields, it is necessary to include low-capacity formations into production. There are many wells where sidetracking and hydraulic fracturing are difficult due to the close proximity of the gas cap and underlying water caused by geological and technological reasons, and the use of existing secondary drilling-in technologies is not effective due to the extensive colmatated zone or annular circulation. Relevance of radial drilling technologies is growing, which allows drilling-in of the formation with a network of extended channels to establish high-quality hydraulic communication between the formation and the well without affecting the permeability of the formation. In contrast to radial drilling technologies using hydraulic washing, technical system (TS) «Perfobur» uses small-sized screw downhole motors (SDM) and rock cutting tools for channel construction. For efficient milling of production casing and destruction of rock, the hydraulic downhole motor must have high torque, and for the possibility of drilling with a high rate of angle gain, it must have short power section. Existing Russian and foreign SDM have limited number of standard sizes and do not meet the requirements specified for the development of the downhole module of TS «Perfobur». The paper discusses the development of universal small-sized sectional screw downhole motors for milling casing strings and drilling a network of branched channels of super-small diameter and radius of curvature as a part of the TS «Perfobur». Methodology proposed in the article for selecting optimal configuration of the SDM power sections allows constructing small-sized sectional downhole motor that meets the technical requirements and has improved characteristics compared to standard SDM.
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Date submitted2019-05-05
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Date accepted2019-07-03
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Date published2019-10-23
Scraper Face Conveyors Dynamic Load Control
- Authors:
- E. K. Eshchin
The task of controlling the dynamic loading of scraper face conveyors (SC) is considered and the unsatisfactory state of loading of mechanical and electrical components of the SC is recorded. The possibility of the appearance of a self-oscillatory nature of the entire system load due to the peculiarities of the movement of the traction chain along the lattice frame of the SC is indicated. The property of the system is noted – the cyclic nature of the loading of the circuit during movement, which causes energy exchange processes between the mechanical and electromotive components of the conveyor (when using the head and tail electric drives) through the common cable network of the power supply system of the SC. A high level of dynamic loading of the electromechanical system causes the problem of eliminating the self-oscillating operating mode of the SC that generates it which is proposed to be solved by changing the angular rotation speeds of the SC drive sprockets. Angular speeds can be changed by applying frequency control of asynchronous electric motors. The efficiency of setting the frequency of electric motor stator currents of the head and tail drives of the conveyor is established in proportion to the frequency of rotors rotation to eliminate self- oscillating modes of operation in the main operating mode. The possibility of reducing the starting shock values of the electromagnetic moments of electric motors is considered. The results of the calculation of the start-up and liquidation of the self-oscillating operating mode are presented on the example of the scraper face conveyor Anzhera-34. The results of calculations of the start-up modes and the main operational transportation of coal in an uncontrolled mode of operation and after the introduction of control are compared, based on which it is concluded that it is advisable to use active control of the dynamic loading ofSC.
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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 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 submitted2019-03-21
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Date accepted2019-05-05
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Date published2019-08-23
Stimulation of the Drilling Process with the Top Driven Screw Downhole Motor
- Authors:
- S. L. Simonyants
- M. Al Taee
Paper considers application of the top driven screw downhole motor during drilling of directional wells. The advantages and disadvantages of the rotation-sliding technology with implementation of top drive together with screw downhole motor are shown. It has been proven that the use of a screw downhole motor with simultaneous rotation of drilling pipes using the drilling rig's top drive allows increasing the bit rotation frequency without additional loading of the drilling string. Field data for the work out of one-type PDC bits in identical geological and technical conditions with different types of drives during the construction of three directed wells at the Rumaila oil field of the Republic of Iraq were obtained. A regular increase in the mechanical penetration rate, which is explained by an increase in the bit rotation frequency, has been proved. According to the data obtained, a comparative analysis of the drilling indices was carried out, as a result of which the feasibility of joint use of top power drive with screw downhole motor at drilling oil and gas wells was proved.
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Date submitted2018-09-07
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Date accepted2018-11-10
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Date published2019-02-22
Justification of the technological parameters choice for well drilling by rotary steerable systems
- Authors:
- Vladimir S. Litvinenko
- M. V. Dvoinikov
Paper presents the analysis of the investigation results of vibrational accelerations and beating amplitudes of the downhole drilling motor, which help to define the ranges of optimum energy characteristics of the gerotor mechanism, ensuring its stable operation. Dependencies describing the operation of the «drilling bit – rotary steerable system with power screw section – drilling string» system and the values of the self-oscillation boundaries and the onset of system resonance when it is used jointly, were defined as a result of computational and full-scale experimental research. A mathematical model is proposed, which allows determining the optimal range of technological parameters for well drilling, reducing the extreme vibration accelerations of the bottomhole assembly by controlling the torque-power and frequency characteristics of the drilling string, taking into account the energy characteristics of the power screw section of the rotary steerable system. Recommendations on the choice of drilling mode parameters were given.