-
Date submitted2024-03-20
-
Date accepted2024-11-07
-
Date published2025-02-27
Analysis of the stress state of rocks transformation near a horizontal well during acid treatment based on numerical simulation
The article presents an overview of the assessment and modelling of the stress state of rocks in the near-wellbore zone of horizontal wells during acid stimulation of the formation for improving the efficiency of oil and gas field development. A numerical finite element model of near-wellbore zone of the reservoir drilled by a horizontal section was compiled using one of oil fields in the Perm Territory as an example. The distribution of physical and mechanical properties of the terrigenous reservoir near the well was determined considering transformation under the action of mud acid for different time periods of its injection. Multivariate numerical simulation was performed and the distribution of horizontal and vertical stresses in near-wellbore zone was determined with regard for different values of pressure drawdown and changes in stress-strain properties depending on the area of mud acid infiltration. It was found that a change in elastic modulus and Poisson's ratio under the influence of acid led to a decrease in stresses in near-wellbore zone. Analysis of the stress distribution field based on the Coulomb – Mohr criterion showed that the minimum safety factor of rock even after the effect of mud acid was 1.5; thus, under the considered conditions of horizontal well modelling, the reservoir rock remained stable, and no zones of rock destruction appeared.
-
Date submitted2023-06-25
-
Date accepted2024-11-07
-
Date published2025-02-25
Study of wormhole channel formation resulting from hydrochloric acid treatment in complex-type reservoirs using filtration and X-ray computed tomography methods
- Authors:
- Andrei A. Аbrosimov
The primary function of hydrochloric acid treatment (HAT) is to create the maximum number of high-conductivity channels in the near-wellbore zone of the reservoir to restore its permeability and enhance hydraulic connectivity between the undisturbed part of the formation and the well. The objective of this study is to physically model HAT on core samples from the Orenburg oil and gas condensate field and to research the impact of such treatment on the structure of the pore space of rocks related to complex-type reservoirs. The complexity of the rock's pore space and the low permeability of the formations are distinguishing features of the study object. For this reason, HAT is a widely applied method for production intensification, necessitating the verification of acid injection rates, where the success criterion is the formation of high-conductivity filtration channels (wormholes) in the near-wellbore zone. These channels significantly expand the drainage area of wells, thereby bringing additional reservoir sections into development. The study examined the characteristics of filtration channel development resulting from acid treatment. Their structure was characterized and analyzed using X-ray computed tomography. The complex study confirmed the accuracy of the selected injection rate and provided practical recommendations for enhancing the efficiency of HAT.
-
Date submitted2023-12-15
-
Date accepted2024-06-13
-
Date published2025-02-25
Development of equipment and improvement of technology for inertial thickening of backfill hydraulic mixtures at the final stages of transportation
The results of the study of the functioning of the developed thickening equipment as part of the stowing complex for the formation of a flow of high-concentration hydromixture are presented. To explain the operation of the hydrotransport system of the stowing complex, equipped with a thickener of the developed design, its basic diagram is presented. A mathematical model has been created that describes the mechanism of inertial sedimentation of a solid component of a hydraulic mixture in a working chamber equipped with hydrodynamic profiles. Interaction with the profile leads to flow stratification due to a change in the trajectory of movement and a decrease in speed. The interval of rational velocity of primary pulp entering the input of the working chamber of the inertial thickener is substantiated. The synthesis of solutions of the thickening process model is performed in the COMSOL Multiphysics and Ansys Fluent programs. This made it possible to eliminate physical contradictions in the operation of the equipment and justify the overall dimensions of its main elements, ensuring the implementation of the mechanism of inertial sedimentation of the slurry. It was found that the concentration of the thickened flow at the outlet branch pipe of the thickener working chamber is determined by the level of the primary hydraulic fluid velocity, the characteristic length of the section of interaction with the deflecting profile, and the ratio of the flow and attack angles. A nomogram of the dynamics of the change in the hydraulic fluid concentration in the section of the outlet branch pipe depending on the ratios of the overall dimensions of the deflecting profile of the working chamber was compiled. The results of the study allowed formulating recommendations for selecting the dimensions of the thickener's deflecting hydrodynamic profile to form a flow of hydraulic mixture with a concentration of about 50 % by weight. The developed equipment can be used in a stowage complex and will increase the range of supply of the stowage mixture. This is due to the fact that a flow of primary slurry with a low concentration, due to lower pressure losses, can be moved in a pipeline system over a greater distance than a flow with a high filler content. The use of a thickener at the final stage of transportation is intended to increase the concentration of the hydraulic mixture immediately before production.
-
Date submitted2024-05-28
-
Date accepted2024-11-07
-
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.
-
Date submitted2023-09-08
-
Date accepted2024-06-03
-
Date published2024-12-25
Modern approaches to barium ore benefication
Barite is one of the critically important minerals in several industries, including the fuel and energy, nuclear, and medical sectors. For decades, its extraction did not require any complex techniques; however, with the depletion of rich barite-bearing veins around the world, the circumstances have changed. While the demand for barite is growing widely, it is necessary to optimize and improve the existing methods for benefication of barite and barite-containing ores, and create new approaches to extracting this mineral, as well as develop technogenic barite deposits accumulated in large quantities during the previous ore production. Dumps and tailings often demonstrate high barite content, while new mining technologies make its extraction cost-efficient. Russian and foreign papers of the last 14 years provide data on the current state of primary and technogenic deposits, areas of barite use and the approaches employed for its benefication. Considering the expansion of the range of barite applications, the growing need for the mineral in the oil and gas industry and the difficulties in developing new barite deposits in Russia, the importance of new approaches to the enrichment of ore tailings in polymetallic deposits is revealed.
-
Date submitted2023-06-01
-
Date accepted2024-03-05
-
Date published2024-08-26
Analyzing friction bolts load bearing capacity in varying rock masses: an experimental study in Anti Atlas Imiter silver mining region, Morocco
This study analyzes how key factors impact friction rock bolt capacity using standard pull-out tests, focusing on 39 mm diameter, 180 cm long split-tube bolts. We investigate bolt performance dependence on rock mass rating (RMR), time after installation, schistosity orientation, surface roughness, and installation quality. The aim is optimizing bolt design and implementation for enhanced underground stability and safety. Results show RMR strongly exponentially correlates with pull-out resistance; higher quality rock masses increase capacity. Anchorage capacity significantly rises over time, especially for RMR above 70. Increasing angle between bolt axis and rock foliation from 0 to 90° boosts pull-out response. Reducing borehole diameter below bolt diameter grows bolt-ground friction. Empirical models estimate load capacity based on RMR, time, orientation, diameter, roughness and installation quality. These reliably predict bolt performance from site conditions, significantly improving on basic RMR methods. Experiments provide practical friction bolt behavior insights for typical rock masses. The data-driven analysis ensures models are applicable to actual underground scenarios. This enables tailored optimization of bolting configurations and supports. Methodologies presented should improve safety, efficiency and cost-effectiveness of reinforced mining and tunneling. Overall, this study fundamentally furthers friction bolt performance understanding, enabling superior underground support design.
-
Date submitted2024-04-08
-
Date accepted2024-06-13
-
Date published2024-12-25
Analysing the problems of reproducing the mineral resource base of scarce strategic minerals
The results of studying the scarcity of strategic minerals in the Russian Federation are presented, domestic consumption of which is largely provided by forced imports and/or stored reserves. Relevance of the work is due to aggravation of the geopolitical situation and a growing necessity to meet the demand of national economy for raw materials from own sources. Analysis of the state of mineral resource base of scarce minerals in the Russian Federation was accomplished, problems were identified and prospects for its development were outlined taking into account the domestic demand for scarce minerals, their application areas and the main consumers. Reducing the deficit through the import of foreign raw materials and the development of foreign deposits does not ensure the reproduction of the domestic mineral resource base, independence of the country from imported raw materials as well as additional competitive advantages, economic stability and security. It was ascertained that a major factor holding back the development of the mineral resource base is insufficient implementation of new technological solutions for the use of low-quality ore. Improving the technologies in the industry is relevant for all types of scarce minerals to solve the problem of reproducing their resource base. Taking into account the prospects for the development of the resource base for the minerals under consideration (manganese, uranium, chromium, fluorspar, zirconium, titanium, graphite) requires a set of legal and economic measures aimed at increasing the investment attractiveness of geological exploration for subsoil users at their own expense without attracting public funding. The proposed measures, taking into account the analysis of positive experience of foreign countries, include the development of junior businesses with expansion of the “declarative” principle, the venture capital market, various tax incentives, preferential loans as well as conditions for the development of infrastructure in remote regions. The proposed solution to the problem of scarcity of strategic minerals will make it possible in future to present measures to eliminate the scarcity of certain types of strategic minerals taking into account their specificity.
-
Date submitted2024-04-10
-
Date accepted2024-06-03
-
Date published2024-07-19
Combined method for processing spent acid etching solution obtained during manufacturing of titanium products
Possessing high strength, low density and significant chemical resistance, titanium has found wide application in various fields of the national economy – the chemical industry, aviation and rocket technology, mechanical engineering, medicine, etc. The production of titanium products is hampered by a fairly strong oxide film covering its surface. Removal of the oxide film from the surface of titanium workpieces is carried out by etching in solutions of mineral acids of various compositions. A spent acid etching solution (SAES) is formed, containing titanium salt and the remainder of unreacted acids. Almost all etching solutions contain HF and one of the strong acids. This is H2SO4, HCl or HNO3. Thus, the SAES includes ions of titanium, fluorine or chlorine, orsulfate, or nitrate. SAES is quite toxic and must be diluted or cleaned several times before being discharged into a reservoir. Most of the methods used to extract impurities contained in SAES lead to a decrease in their content. As a result of such purification, there is a loss of substances contained in SAES in significant quantities and of interest for further use. The work presents experimental results obtained from the combined processing of SAES containing titanium fluoride, hydrofluoric and hydrochloric acids. At the first stage, SAES is treated with sodium hydroxide. The resulting titanium hydroxide precipitate is filtered off. At the second stage, the filtrate containing sodium fluoride and chloride is processed in a membrane electrolyzer. In this case, not only the extraction of sodium salts from the filtrate occurs, but also the production of sodium hydroxide and a mixture of hydrofluoric and hydrochloric acids. Sodium hydroxide can be used for processing SAES, and a mixture of acids for etching titanium workpieces.
-
Date submitted2023-07-25
-
Date accepted2024-05-02
-
Date published2024-08-26
Finite element analysis of slope failure in Ouenza open-pit iron mine, NE Algeria: causes and lessons for stability control
Slope failures in mining engineering pose significant risks to slope stability control, necessitating a thorough investigation into their root causes. This paper focuses on a back analysis of a slope failure in the Zerga section of the Ouenza – Algeria open-pit iron mine. The primary objectives are to identify the causes of slope failure, propose preventive measures, and suggest techniques to enhance stability, thereby providing crucial insights for monitoring slope stability during mining operations. The study commenced with a reconstruction of the slopes in the affected zones, followed by a numerical analysis utilizing the Shear strength reduction method within the Finite element method (SSR-FE). This approach enables the examination of slope stability under both static and dynamic loads. The dynamic load assessment incorporated an evaluation of the vibrations induced by the blasting process during excavation, introducing seismic loading into the finite element analysis. The findings reveal that the primary triggering factor for the landslide was the vibration generated by the blasting process. Furthermore, the slope stability was found to be critically compromised under static loads, highlighting a failure to adhere to exploitation operation norms. The challenging geology, particularly the presence of marl layers where maximum shear strain occurs, contributed to the formation of the landslide surface. The study not only identifies the causes of slope failure but also provides valuable lessons for effective slope stability management in mining operations.
-
Date submitted2023-04-10
-
Date accepted2024-12-27
-
Date published2024-04-25
Optimization of specific energy consumption for rock crushing by explosion at deposits with complex geological structure
The selection of efficient drilling and blasting technology to achieve the required particle size distribution of blasted rock mass and reduce ore dilution is directly related to the accurate definition of rock mass properties. The zoning of the rock massif by its hardness, drillability and blastability does not consider the variability of the geological structure of the block for blasting, resulting in an overestimated specific consumption of explosives. The decision of this task is particularly urgent for enterprises developing deposits with a high degree of variability of geological structure, for example, at alluvial deposits. Explosives overconsumption causes non-optimal granulometric composition of the blasted rock mass for the given conditions and mining technology. It is required to define physical and mechanical properties of rocks at deposits with complex geological structure at each block prepared for blasting. The correlation between the physical and mechanical properties of these rocks and drilling parameters should be used for calculation. The relation determined by the developed method was verified in industrial conditions, and the granulometric composition of the blasted rock mass was measured by an indirect method based on excavator productivity. The results demonstrated an increase in excavation productivity, thus indicating the accuracy of given approach to the task of identifying the rocks of the blasted block.
-
Date submitted2022-09-05
-
Date accepted2023-09-20
-
Date published2024-04-25
Modeling the efficiency of seasonal cooling devices when changing the statistical distribution of weather conditions
The climatic factor of warming, which is evidenced by a significant number of scientists and research teams in Russia and the world, has a significant impact on the cryogenic state of permafrost soil, the preservation of which is one of the most common principles of construction in the North. The influence of projected climatic changes in planning up to 2050 on the efficiency of seasonal cooling devices, the principle of operation of which is based on seasonal soil freezing, is considered. The conducted modeling has shown that in a situation of stable climate, the preservation of the cryogenic state of permafrost soil is realized without the use of additional measures. With warming with a trend of 0.1 °C per year, seasonal cooling devices do not ensure the preservation of the current level of the cryogenic state of the soil and additional measures are required to increase their efficiency in the summer. In the case of more extreme warming with a rate of 0.25 °C per year, the modeling results show that seasonal cooling devices do not significantly affect the rate of soil thawing and the solution to the problem should be its complete replacement with systems with year-round action.
-
Date submitted2022-05-20
-
Date accepted2023-06-20
-
Date published2024-02-29
Increasing the quality of zeolite-bearing rocks from Eastern Transbaikalia by applying directed energy
This paper presents the use of accelerated electrons to treat zeolite-bearing rocks from Eastern Transbaikalia to increase the efficiency of separating zeolites from rock-forming minerals via electromagnetic separation. The effectiveness of the liberation of zeolite minerals using accelerated electrons was analyzed. The results of dry electromagnetic separation of zeolite-bearing rocks are presented. The dependence of the extraction of iron-bearing minerals from zeolite-bearing rocks by electromagnetic separation on the magnetic field intensity for different particle sizes has been established. The main methods of zeolite-bearing rock enrichment and ore preparation were determined. A technological scheme for processing zeolite-bearing rocks, based on the use of accelerated electron treatment at the ore preparation stage, is presented, significantly improving the zeolite production quality.
-
Date submitted2023-08-16
-
Date accepted2023-10-24
-
Date published2023-10-27
Results of complex experimental studies at Vostok station in Antarctica
Scientific research in the area close to the Russian Antarctic station Vostok has been carried out since its founding on December 16, 1957. The relevance of work to study the region is steadily increasing, which is confirmed by the Strategy for the Development of Activities of the Russian Federation in the Antarctica until 2030. As part of the Strategy implementation, Saint Petersburg Mining University solves the comprehensive study issues of the Vostok station area, including the subglacial Lake Vostok, related to the development of modern technologies and technical means for drilling glaciers and underlying rocks, opening subglacial reservoirs, sampling water and bottom sediments, as well as carrying out comprehensive geological and geophysical research. For the successful implementation of the Strategy, at each stage of the work it is necessary to identify and develop interdisciplinary connections while complying with the requirements for minimizing the impact on the environment. During the season of the 68th Russian Antarctic Expedition, the staff of the Mining University, along with the current research works , began research of the dynamic interactions between the forces of the Earth, from the deepest depths to the surface glacier. Drilling and research programs have been completed. The drilling program was implemented jointly with colleagues from the Arctic and Antarctic Research Institute at the drilling complex of the 5G well. The research program included: shallow seismic studies, core drilling of snow-firn strata, study of the snow-firn strata petrostructural features, studies of cuttings collection filters effectiveness when drilling snow-firn strata and the process of ice destruction in a reciprocating rotational method, bench testing of an acoustic scanner. As a result of drilling in 5G well at the depth range of 3453.37-3534.43 m, an ice core more than 1 million years old was obtained.
-
Date submitted2023-03-10
-
Date accepted2023-06-20
-
Date published2023-07-19
Enhancement of energy efficiency of the vacuum oil distillation unit using pinch analysis
- Authors:
- Еkaterina А. Yushkova
- Vladimir A. Lebedev
The actual task of the state is to increase the energy efficiency of the oil refinery. The object of research is a vacuum distillation unit, including a preheating unit for raw materials and a furnace for heating fuel oil before the column. Pinch analysis allows to analyze and optimize a large number of heat flows. In this study the analysis and enhancement of efficiency of the research object is carried out by enthalpy pinch analysis. In order to reduce the heat load of the furnaces, the additional flows were introduced into the heat exchange system of the oil heating unit. Parametric optimization of the new heat exchange system was carried out. The minimum needs of the heat exchange system in external energy carriers are determined. An enthalpy cascade of the heat exchange system has been constructed, which clearly shows the distribution of heat between each heat flow of the system. In the analysis of the energy efficiency of a furnace, an important point is the determination of the optimal heat capacity of the combustion products. In this work, we have determined the optimal flow heat capacity, at which the heat loss with the exhaust gases is minimal. As a result of the studies carried out, the efficiency of the fuel oil preheating unit has been increased by maximizing heat recovery, and the cost of external energy carriers has been minimized. By reducing heat loss with flue gases, it was possible to increase the efficiency of the furnace.
-
Date submitted2021-10-31
-
Date accepted2023-03-02
-
Date published2023-12-25
Improvement of technological schemes of mining of coal seams prone to spontaneous combustion and rock bumps
On the example of the Alardinskaya mine, the problem of underground mining of seams prone to spontaneous combustion and rock bumps in the conditions of the Kondomsky geological and economic region of the Kuznetsk coal basin is considered. The contradictions in the requirements of regulatory documents for the width of the inter-panel coal pillars in the mining of seams with longwalls in conditions of endogenous fire hazard and in the mining of seams that are dangerous due to geodynamical phenomena are discussed. These contradictions impede the safe mining of seams using traditionally used layouts with the danger of spontaneous combustion of coal and rock bumps. A mining-geomechanical model is presented, which is used for numerical three-dimensional simulation of the stress-strain state of a rock mass with various layouts for longwall panels using the finite element method. The results of the numerical analysis of the stress state of the rock mass immediately before the rock bump are presented, and the main factors that contributed to its occurrence during the mining of the seam are established. A dangerous degree of stress concentration in the coal seam near the leading diagonal entries is shown, especially in conditions of application of abutment pressure from the edge of panels’ gob. The analysis of the features of stress distribution in the inter-panel pillar at different widths is carried out. Recommendations for improving the layout for the development and mining of coal seams that are prone to spontaneous combustion and dangerous in terms of rock bumps in the conditions of Alardiskaya mine have been developed. The need for further studies of the influence of pillars for various purposes, formed during the mining of adjacent seams, on the stress-strain state of previously overmined and undermined seams is shown.
-
Date submitted2022-10-24
-
Date accepted2023-03-03
-
Date published2023-04-25
Use of clay-containing waste as pozzolanic additives
Growing productivity of mining and processing enterprises entails an increase in the volumes of liquid tailings impoundments and upstream impoundments of ore processing waste. Enterprises face the challenge of minimizing the environmental impact of waste and guaranteeing the sanitary and epidemiological safety of population. The article presents a possibility of recycling one type of such waste (clay-containing concentration tailings of apatite-nepheline and sylvinite ores, coal beneficiation tailings) by using them after preliminary thermochemical treatment as pozzolanic additives to cements and concretes, including concrete mixtures used for soil stabilization, development of territories, reclamation of mine workings, as a component of the insulating layer of landfills for the disposal of municipal solid waste. An analysis of the phase changes of kaolinite, one of the main minerals that make up clay-containing waste, in the temperature range of 200-1,000 °С showed that a change in its mineral form during heat treatment is the main factor in changing its pozzolanic activity. The effect of heat treatment of clay minerals at temperature of 700-800 °C on their pozzolanic activity, estimated by the ability to absorb calcium hydroxide (0.7 g Ca(OH) 2 per 1 g of modified kaolinite), is considered. It is shown that the addition of heat-treated samples (20 % by weight) improves the quality of cement increasing its activity by 15 %, in comparison with the use of unmodified clay minerals. It was proved experimentally that partial replacement of Portland cement with thermally modified kaolinite increases the strength of consolidating stowing mixture by up to 15 %. This approach to processing of ores containing layered silicates, which provides for thermochemical modification of run-of-mine ore, intensifies the processes of tailings thickening and filtering.
-
Date submitted2022-11-11
-
Date accepted2023-01-19
-
Date published2023-12-25
Evaluation of the efficiency of sorbents for accidental oil spill response in the Arctic waters
The development and operation of new oil fields on the Arctic shelf increases the risks of oil spills, which require the use of oil spill response tools and materials that are efficient in harsh climatic conditions. The question of actual efficiency of sorbents for reducing the level of oil pollution in the conditions of the Arctic and subarctic waters is relevant. The work is aimed at a comparative study of the efficiency of sorbents of mineral and organic origin used by coastal enterprises in the Kola Bay as well as a sorbent based on chitin in model systems simulating real conditions in sea waters. The characteristics of sorption agents were determined applying ASTM F716-18 procedure. Sorption capacity was evaluated in respect of ARCO grade oil, diesel fuel and marine oil. The efficiency of sorbents was estimated in model systems “sea water – oil” at water temperature corresponding to the average annual surface temperature in the Barents Sea. Actual data on sorption capacity of commercial sorbents “Lessorb”, “Novosorb”, a sorbent based on vermiculite and chitin sorbent in relation to potential pollutants of waters were obtained. The dynamics of sea water saturation with oil products at –0.5 (±1) and 10 (±1) °С was determined. It is shown that at higher temperature the concentration of oil products in sea water column (in the presence of an oil film on the surface) is on average four times higher than at low temperature. Kinetic dependences were obtained that describe the content of oil products in water column and near-surface layer of sea water in the presence of the studied sorbents at 5 (±1) °C, corresponding to the average annual temperature in the Kola Bay of the Barents Sea. A method is proposed for evaluating the efficiency of sorbents from the values of regression coefficients characterizing the dependence of oil products content in sea water on the character of sorbent and duration of its action.
-
Date submitted2022-10-19
-
Date accepted2023-02-14
-
Date published2023-04-25
Electric steelmaking dust as a raw material for coagulant production
The paper describes the issues associated with waste generated during steel production and processing, in particular the dust from electric arc furnaces (EAF). An effective solution for the disposal of such waste is its involvement in processing to obtain valuable products. This paper studies the physical and chemical properties of EAF dust produced during the smelting of metallized pellets and captured by the dust and gas cleaning system of the steel-smelting shop at the Oskol Electrometallurgical Combine, Belgorod Region. The results obtained in the study of the chemical and disperse compositions of dust, the microstructure of the surface made it possible to propose the use of dust as a raw material for coagulant production. The conditions of acid-thermal treatment of dust are determined, contributing to the partial dissolution of iron (II), (III), and aluminium compounds, which ensure the coagulation processes during wastewater treatment. Model solutions show high efficiency (> 95 %) of water treatment from heavy metal ions by modified EAF dust.
-
Date submitted2021-12-15
-
Date accepted2022-09-12
-
Date published2023-08-28
Substantiation and selection of the design parameters of the hydroficated equipment complex for obtaining backfill mixtures from current enrichment tailings
The issue of the influence of the concentration of the solid phase on the reduction of energy costs and specific energy consumption during pulp transportation is considered. The procedure for preparing slurry from the current enrichment tailings is shown. A scheme is given and the operation of a hydroficated unit for thickening and hydraulic transport of backfill mixtures is described. A diagram of the movement of solid particles in one of the units of the complex – a lamellar thickener is shown. The summary table shows the main design parameters and characteristics of the lamellar thickener. A general view of the laboratory setup used for experimental studies with slurry at various concentrations is given. An example of calculating productivity, density and specific load is presented. The dependence of the shear stress on the velocity gradient was determined for various pulp concentrations. Experimental studies of the process of thickening the production of slurry from the current enrichment tailings have been carried out. It was found that the geometric dimensions of the thickener depend on the concentration of the solid phase in the transported mixture. It is concluded that the flow rate of the slurry and the head loss are functions of the rheological characteristics of the viscoplastic slurry and can be calculated from the derived calculated dependencies.
-
Date submitted2022-07-15
-
Date accepted2022-12-13
-
Date published2023-02-27
Assessment of the efficiency of occupational safety culture management in fuel and energy companies
The results of development, testing and implementation of the process of occupational safety culture management in a fuel and energy company including the assessment of current state, assessment of deviation, formation of control action and its implementation are presented. Using the methods of mathematical analysis, the components of occupational safety culture and criteria for their evaluation were developed. As a control action, a procedure for conducting behavioural safety audit was elaborated and implemented. Proceeding from the results of analysing average ratings of safety culture components among the employees prior to and after the introduction of behavioural safety audit, it was concluded that there was a statistically significant increase in the average values of 12 out of 16 ratings of safety culture components. Analysis of the results of 1,011 audits showed the absence of an “alarm area” at the enterprise. Introduction of the developed process management model promotes an increase in the efficiency of attaining a high level of occupational safety culture in fuel and energy companies.
-
Date submitted2022-05-23
-
Date accepted2022-07-21
-
Date published2023-02-27
Alluvial tin mining by spray-suction borehole method: a case study on remaining alluvial tin reserves in Bangka Belitung, Indonesia
The area of the Bangka Belitung Islands, which is a potential area for alluvial tin deposits in Indonesia, has been affected by the destruction of tin reserves on the mainland due to rampant artisanal mining, which has left remnants of small-dimensional reserves. The remnants of these reserves can no longer be mined using the hydraulic mining of open pit method due to the small dimensions of the deposits. The hypothesis is that such sedimentary conditions can only be mined by the borehole method. This research aimed to design tools and perform test mining using the borehole method with a spray-suction mechanism. This research produced a novelty, namely, a method and parameters for alluvial tin deposits mining using borehole mining methods, such as the excavation capacity, excavation radius, mining recovery, and dilution factor. The benefit of this research is expected to provide an opportunity to increase the amount of onshore alluvial tin reserves to support tin production.
-
Date submitted2022-10-10
-
Date accepted2023-01-19
-
Date published2023-12-25
Assessment of the possibility of using leucoxene-quartz concentrate as raw material for production of aluminium and magnesium titanates
Leucoxene-quartz concentrate is a large-tonnage by-product of development of the Timan oil-titanium field (oil-saturated sandstones) which is not commercially used at present. High content of titanium compounds (to 50 % by weight) and lack of industrial, cost-effective, and safe technologies for its processing determine a high relevance of the work. Conventional processing technologies allow increasing the concentration of TiO2, but they are only a preparation for complex and hazardous selective chlorination. The process of pyrometallurgical conversion of leucoxene-quartz concentrate into aluminium and magnesium titanates was investigated. It was ascertained that the temperature of solid-phase reaction in Al2O3-TiO2-SiO2 system necessary for the synthesis of aluminium titanate (Al2TiO5) is 1,558 °С, and for MgO-TiO2-SiO2 system – 1,372 °С. Scaling up the process made it possible to synthesize a significant number of samples of titanate-containing products, the phase composition of which was studied by X-ray phase analysis. Two main phases were identified in the products: 30 % aluminium/magnesium titanate and 40 % silicon dioxide. In products of pyrometallurgical processing in the presence of aluminium, phases of pseudobrookite (3.5 %) and titanite (0.5 %) were also found. It was ascertained that in magnesium-containing system the formation of three magnesium titanates is possible: MgTiO3 – 25, Mg2TiO4 – 35, MgTi2O5 – 40 %. Experiments on sulphuric acid leaching of samples demonstrated a higher degree of titanium compounds extraction during sulphuric acid processing. An integrated conceptual scheme for processing leucoxene-quartz concentrate to produce a wide range of potential products (coagulants, catalysts, materials for ceramic industry) was proposed.
-
Date submitted2022-01-16
-
Date accepted2022-04-06
-
Date published2023-04-25
Production of biodiesel fuel from vegetable raw materials
One way to reduce the amount of harmful emissions from diesel fuel could be the replacement of part of the fuel with biofuel. Research is related to the production of biodiesel fuel in three ways: transesterification of vegetable oils; esterification of fat acids extracted from vegetable oil; and hydroprocessing of vegetable oils using catalysts in the diesel hydrotreatment process. Food and non-food oils, monatomic and diatomic alcohols were used to produce biodiesel fuel. Optimal parameters of vegetable oil transesterification have been determined: temperature; raw material ratio (oil/alcohol); mixing speed; time; type of process catalyst. The characteristics of the obtained biodiesel fuel samples were studied and compared with each other as well as with the requirements of EN 14214 “Automotive fuels. Fat acid methyl ethers for diesel engines. General technical requirements” and EN 590:2009 “EURO diesel fuel. Technical specifications”. With regard to the physical and chemical characteristics of biodiesel fuel, the best way to produce it is by transesterification of vegetable oils. However, all fuels can be used as components of a blended environmentally friendly diesel fuel.
-
Date submitted2022-05-31
-
Date accepted2022-11-17
-
Date published2022-12-29
Estimation of the influence of fracture parameters uncertainty on the dynamics of technological development indicators of the Tournaisian-Famennian oil reservoir in Sukharev oil field
Issues related to the influence of reservoir properties uncertainty on oil field development modelling are considered. To increase the reliability of geological-hydrodynamic mathematical model in the course of multivariate matching, the influence of reservoir properties uncertainty on the design technological parameters of development was estimated, and their mutual influence was determined. The optimal conditions for the development of the deposit were determined, and multivariate forecasts were made. The described approach of history matching and calculation of the forecast of technological development indicators allows to obtain a more reliable and a less subjective history match as well as to increase the reliability of long-term and short-term forecasts.
-
Date submitted2022-06-09
-
Date accepted2022-11-17
-
Date published2022-12-29
Drilling of deep and ultra-deep wells for prospecting and exploration of new raw mineral fields
Scientific and technological progress over the last century has led to an enormous increase in the consumption of minerals, including energy resources. Most of the exploited oil and gas fields are already considerably depleted, so it is necessary to search for new hydrocarbon resources, particularly at great depths. Deep drilling plays a special role in solving this problem. The article considers the world and Russian experience of ultra-deep wells drilling. The methods and technologies used in the construction of wells, as well as complications and accidents occurring during their drilling were analyzed. The analysis revealed that the existing limitations for drilling parameters of deep and ultra-deep wells are caused by the technical characteristics of surface and bottomhole drilling equipment, which do not meet the extreme drilling conditions. The directions for development of deep and ultra-deep well drilling machinery and technologies are suggested. The notion of extreme rock and geological drilling conditions is introduced, which describes drilling in conditions of hydrostatic pressure of flushing fluid column and high bottomhole temperature both at stable and unstable wellbore conditions, coming close to the upper limit of operating technical characteristics of bottomhole assembly, the drill string and flushing fluid.