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Date submitted2023-02-07
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Date accepted2023-06-20
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Date published2024-02-29
Origin of carbonate-silicate rocks of the Porya Guba (the Lapland-Kolvitsa Granulite Belt) revealed by stable isotope analysis (δ18O, δ13C)
- Authors:
- Dmitrii P. Krylov
- Ekaterina V. Klimova
Carbonate-silicate rocks of unclear origin have been observed in granulites of the Porya Guba of the Lapland-Kolvitsa Belt within the Fennoscandinavian Shield. The present work aims to reconstruct possible protoliths and conditions of metamorphic transformation of these rocks based on oxygen and carbon isotopic ratios combined with phase equilibria modeling. Isotope analysis and lithochemical reconstructions suggest that carbonate-silicate rocks of the Porya Guba represent metamorphosed sediments (possibly marls) with the isotopic composition corresponding to the Precambrian diagenetically transformed carbonates (δ18O ≈ 17.9 ‰, SMOW and δ13C ≈ –3.4 ‰, PDB). The chemical composition varies depending on the balance among the carbonate, clay, and clastic components. Significant changes of the isotopic composition during metamorphism are caused by decomposition reactions of primary carbonates (dolomite, siderite, and ankerite) producing CO2 followed by degassing. These reactions are accompanied by δ18O and δ13C decrease of calcite in isotopic equilibrium with CO2 down to 15 ‰ (SMOW) and –6 ‰ (PDB), respectively. The isotopic composition is buffered by local reactions within individual rock varieties, thus excluding any pronounced influence of magmatic and/or metasomatic processes.
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Date submitted2023-04-04
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Date accepted2023-06-20
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Date published2024-02-29
Trace elements in the silicate minerals of the Borodino Meteorite (Н5)
- Authors:
- Kristina G. Sukhanova
Major (EPMA) and trace (SIMS) element geochemistry in olivine, low-Са pyroxene and mesostasis from porphyritic and barred chondrules, as well as the pyroxene-olivine aggregate and matrix of equilibrated ordinary Borodino chondrite (Н5) is discussed. No differences in major element concentrations in the silicate minerals of the chondrules and matrix of the meteorite were found. The minerals of porphyritic olivine-pyroxene and barred chondrules display elevated trace element concentrations, indicating the rapid cooling of chondrule melt in a nebula, and are consistent with experimental data. The trace element composition of low-Са pyroxene is dependent on the position of a pyroxene grain inside a chondrule (centre, rim, matrix) and the composition of mesostasis is controlled by the type of the object (porphyritic and barred chondrules, pyroxene-olivine aggregate). The depletion in trace elements of low-Са pyroxene from the rims of chondrules in comparison with those from the centre and matrix of the meteorite was revealed. The chondrule rim is affected by interaction with surrounding gas in a nebula, possibly resulting in the exchange of moderately volatile trace elements in low-Са pyroxene and depletion in these elements relative to pyroxene from the centre of the chondrule or matrix of the meteorite. The mesostasis of barred and porphyritic olivine-pyroxene chondrules contains more trace elements than that of porphyritic olivine chondrule and pyroxene-olivine aggregate, suggesting the rapid cooling of these objects or their high liability to thermal metamorphism, which results in the recrystallization of chondrule glass into plagioclase. However, no traces of the elevated effect of thermal metamorphism on the above objects have been revealed. The results obtained indicate no traces of the equilibration of the trace element composition of silicate minerals in equilibrated chondrites.
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Date submitted2022-06-25
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Date accepted2023-06-20
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Date published2024-02-29
Determination of the accuracy of leveling route based on GNSS/leveling and Earth gravitational model data SGG-UGM-2 at some typical regions in Vietnam
- Authors:
- Bui Thi Hong Tham
- Phi Truong Thanh
This paper presents the accuracy of leveling routes determined by using GNSS/leveling at three grades and Earth gravitational model data SGG-UGM-2 in four regions of Vietnam by calculating the difference between the measured height anomalies and the model of pairs of points. The calculation is made based on the total points of three grades for four regions (99 in the Northwest, 34 in the Red River Delta, 130 in the Central Highlands, and 96 in the Mekong River Delta) with the leveling routes, connected between pair of points in each region are 189, 92, 294, and 203. The calculated results of the percentage of accuracy of the leveling routes of the four regions have shown that most of the leveling routes are satisfactory (grades I-IV, and technical leveling). The determination of the accuracy of the leveling route is completely applicable to other areas when the points have simultaneous ellipsoid and leveling heights and it also helps managers and surveyors to predict the accuracy of the height points when the above-mentioned leveling routes are connected and to take reasonable measures when implementing the project.
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Date submitted2022-05-20
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Date accepted2023-04-03
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Date published2024-02-29
Impact of carbon dioxide on the main geotechnical quality criteria and preparation cost of cemented paste backfill
There is a global upsurge in the use of cemented paste backfill (CPB) for various mining functions. However, the cost of the Portland cement binder is prohibitive, thus warranting strategies to reduce cement usage without overly diminishing the CPB quality. Since carbon dioxide is used for patented sand moulding processes, this study is premised on that physicochemical ability of CO2 to enhance the curing of consolidated inorganic materials. It evaluated the impact of carbon dioxide on the uniaxial compressive strength UCS and preparation cost of CPB standard samples (ASTM C109). The preparation cost was delimited to the purchase cost of the Portland cement. The backfill material was silica sand tailings with 4.5 wt.% Portland cement binder and a water-cement ratio of 7.6. Distilled water of pH 5.4 was used for the control samples while variable amounts of carbon dioxide were dissolved in distilled water to generate carbonated mixing water with pH values of 3.8; 4 and 4.2. The lower the carbonated water pH, the higher is the CO2 concentration. UCS tests were conducted on the samples after curing for 3, 7, 28, and 90 days. There was an observable increase in the UCSs and reduction in curing time with increasing carbon dioxide. Samples prepared with carbonated water of pH 3.8 had almost double the strength of those prepared with pure distilled water of pH 5.4, implying that more dissolved CO2 corresponds to higher CPB strength. This is supported by the trendline equations for the graphical simulation of strength on curing time. Thus, CPB with much less binder can be expected to attain the requisite UCS if carbon dioxide is incorporated. The average reduction in Portland cement consumption was 0.61 %, which translates to a cost saving of the same percentage points. If calculated over the operational life of a mine, this is a massive saving of millions of dollars.
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Date submitted2021-02-09
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Date accepted2023-09-20
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Date published2024-02-29
Analysis of experience in the use of preformed particle polymer gels in the development of high-water-cut production facilities in low-temperature oil reservoirs
- Authors:
- Sergei V. Galkin
- Yuliya A. Rozhkova
Foreign practice of oil production in high-water-cut conditions suggests using the technology of injection of preformed particle gel (PPG) suspension into injection wells. After swelling, the polymer particles become elastic and are able to penetrate through highly permeable watered intervals into the remote reservoir zone, forming a polymer “plug”. Thus far, the domestic experience of application of this technology boiled down to testing foreign compounds. We have looked into the possibilities of PPG technology application in geological and technological conditions of high-water-cut fields of Perm Krai. The paper proposes PPG reagents effective in low-temperature reservoirs (20-35 °С) and at relatively high salinity of formation water (more than 200 g/l). The world experience of PPG technology application was analyzed to identify the principal scheme of reagent injection, to establish variants of sequence of injection of PPG particles of different sizes, as well as the possibility of regulating the morphological characteristics of polymer gel particles during synthesis depending on the porosity and permeability of the reservoir. A prerequisite for the technology is the ability to remove PPG particles after treatment from the bottom-hole zone of the formation; for this purpose, tests were carried out on a breaker compound based on sodium persulfate with synergizing additives. PPG technology is effective in reservoirs with high permeability heterogeneity. Two types of high-water-cut production facilities potentially promising for PPG realization have been identified for oil fields of Perm Krai. The first type includes carbonate Tournaisian-Famennian reservoirs with pronounced macrofracturing, in which the PPGs are used for colmatation of flushed large fractures. The second type is terrigenous Visean deposits with increased oil viscosity from 5 to 100 mPa∙s and high permeability of reservoirs (> 0.5 μm2). For both types of reservoirs, areas have been selected that are promising for the implementation of PPG technology.
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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 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 submitted2023-11-27
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Date accepted2023-12-27
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Date published2024-02-29
Physico-chemical aspects and carbon footprint of hydrogen production from water and hydrocarbons
Physico-chemical aspects determine the efficiency and competitiveness of hydrogen production technologies. The indicator of water consumption is especially relevant, since water is one of the main sources of hydrogen in almost all methods of its production. The article analyzes comparative water consumption indicators for various technologies based on published research and actual data from production plants. The volume of water consumption depends on the quality of the source water, which should be taken into account when implementing hydrogen projects in order to minimize the negative impact on the environment. Based on the operating industrial plant, the material balance of hydrogen production by steam reforming was demonstrated, which made it possible to determine the proportion of hydrogen (48.88 %) obtained from water. Currently, the carbon footprint indicator is becoming more important, reflecting greenhouse gas emissions throughout the production chain. According to the results of the total greenhouse gas emissions assessment for hydrogen production by steam reforming (about 10.03 kg CO2-eq/kg H2), the carbon footprint of hydrogen from water (4.2-4.5 kg CO2-eq/kg H2) and hydrogen from methane (15.4-15.7 kg CO2-eq/kg H2) has been determined. Consequently, almost half of the hydrogen produced by steam reforming is produced from water, corresponds to the indicators of “low-carbon” hydrogen and can be considered as “renewable” hydrogen. To make management decisions, an objective assessment in terms of energy and water costs is necessary based on a system analysis by the development of hydrogen energy and the growth of global hydrogen production. The impact of these indicators on the water cycle and global water resources will increase.
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Date submitted2022-10-31
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Date accepted2023-04-21
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Date published2024-02-29
Study of the properties and action of polyelectrolytes in the treatment of the dressing plant’s discharges
The organization of intrafactory water circulation at mining and processing enterprises, when production wastes and discharges are not sent to an external tailings dump, is an urgent environmental and economic task. Returning even a part of water into the technological process after preliminary treatment will significantly reduce the volume of polluted water discharged into tailings, which will reduce energy costs for waste transportation and the negative environmental impact. One of the wastes sent to the tailings during the ore dressing wastes from the Kovdor deposit to the tailings dump is the discharge of thickeners for the preparation of apatite flotation feed. In order to choose the effective discharge cleaning regime, the authors have evaluated the action of polyacrylamide flocculants. It has been discovered that the apatite and calcite particles interact more effectively with the anionic flocculant. This fact determines its advantage for the treatment of suspended particles. The influence of the residual concentration of a flocculant on the apatite flotation, where a part of the returned treated water goes, has been assessed. Compared to flotation with recycled water, there is a decrease of P2O5 extraction into apatite concentrate of equal quality. In order to obtain the required enrichment indicators on the treated water, it is necessary to adjust the collector (tall oil fatty acids) and depressor (liquid glass) costs.
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Date submitted2023-07-07
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Date accepted2023-09-20
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Date published2024-02-29
Isotherm and kinetic adsorption of rice husk particles as a model adsorbent for solving issues in the sustainable gold mining environment from mercury leaching
One of the techniques used in extracting gold in small-scale gold mining is mercury amalgamation. However, the use of mercury presents significant health and environmental hazards, as well as suboptimal efficiency in gold extraction. This study explores the possibility of the use of rice husk as a prototype adsorbent for mercury removal from its leaching in mining environments. To support the analysis, the rice husk adsorbent was characterized by Fourier-transform infrared spectroscopy, scanning electron microscopy, electron dispersive X-ray spectroscopy, atomic absorption spectrophotometers and Brunauer − Emmett − Teller analysis. To investigate the removal of Hg from aqueous solutions, batch adsorption experiments were conducted, and the efficiency was optimized under various parameters such as contact time, rice husk dosage, and initial concentration of mercury. Kinetic and isotherm investigations were also carried out to gain a better understanding of the adsorption properties. The kinetic adsorption was analyzed using the pseudo-first-order and pseudo-second-order. Furthermore, the isotherm adsorption was analyzed using ten adsorption isotherm models (i.e., Langmuir, Freundlich, Temkin, Dubinin – Radushkevich, Flory – Huggins, Fowler – Guggenheim, Hill – de Boer, Jovanovic, Harkin – Jura, and Halsey). The amount of mercury absorption increased with increasing contact time, adsorbent mass, and initial concentration of mercury. The pseudo-second-order kinetic model is the best model that can be applied to describe the adsorption process. Analysis of the adsorption results obtained shows that the adsorption pattern is explained through the formation of a monolayer without any lateral interaction between the adsorbate and adsorbent. In addition, the formation of multilayers due to inhomogeneous pore distribution also occurs which causes a pore filling mechanism. We found that the isotherm phenomena are near the Jovanovic models with the maximum adsorption capacity) of rice husk found to be 107.299 mg/g. As a result, rice husk could be a promising option for wastewater treatment due to its fast and efficient removal capacity, as well as its affordability and eco-friendliness. The predicted thermodynamic studies using the Flory – Huggins isotherm model show that the adsorption process is endothermic, spontaneous, and physisorption. The impact shows that the utilization of rice husk can be used and fit for the current issues in the sustainable development goals (SDGs).
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Date submitted2022-09-30
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Date accepted2023-02-13
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Date published2024-02-29
Improving the efficiency of oil vapor recovery units in the commodity transport operations at oil terminals
- Authors:
- Vladimir V. Pshenin
- Gulnur S. Zakirova
In this paper the problem of losses from evaporation of light fractions of hydrocarbons during loading operations of tanker fleets vessels is considered. It was found that there is no unified approach to modeling the system “tanker – gas phase pipeline – vapor recovery units” in open sources. The absence of a generally recognized model makes it impossible to scientifically justify the application of instruments to reducing losses and the development of corresponding measures. In work it is showed that the dynamics of growth of pressure in the inner tanker capacity is described by a differential equation, considering for non-stationary essence of the process. This equation is converted to a non-dimensional form and investigated in relation to the similarity criteria of this system. This research has allowed to establish unambiguously the general character of pressure changes in the inner tanker capacity, and to predict the peak values of its growth at the initial stage of the loading operation. The obtained equations were tested on real tanker loading data and showed satisfactory convergence with the experimental data. At different stages of the loading opera-tion the component composition of vapor changes, which is shown by chromatographic analysis of the gas mixture. With the availability of a model of hydrocarbon vapor displacement from the inner of tanker, it is possible to propose measures to minimize the negative impact on the environment and return valuable vapors of the product to the technological chain of transportation.
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Date submitted2022-05-20
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Date accepted2023-06-20
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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.
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Date submitted2022-09-30
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Date accepted2023-04-03
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Date published2024-02-29
Optimization of the location of a multilateral well in a thin oil rim, complicated by the presence of an extensive gas cap
- Authors:
- Кirill О. Тomskii
- Mariya S. Ivanova
The specific share of the reserves of hard-to-recover hydrocarbon raw materials is steadily growing. The search for technologies to increase the hydrocarbon recovery factor is one of the most urgent tasks facing the oil and gas industry. One of the methods to expand the coverage of oil reserves and increase oil recovery is to use the technology of drilling multilateral wells with a fishbone trajectory. In the Russian Federation, the most branched well was drilled in the Republic of Sakha (Yakutia) at the Srednebotuobinskoye oil and gas condensate field. The main object of development is the Botuobinsky horizon (Bt reservoir). About 75 % of the geological reserves of the reservoir are concentrated in a thin oil rim with an average oil-saturated layer thickness of 10 m with an extensive gas cap. This circumstance is one of the main complicating factors in the development of the Srednebotuobinskoye oil and gas condensate field. For such complex wells, one of the most important design stages is to determine the optimal location of the fishbone well in an oil-saturated reservoir. The article shows the results of sector modeling in the conditions of the Srednebotuobinskoye field to determine the optimal location of multilateral wells using Tempest simulator.
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Date submitted2022-10-30
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Date accepted2023-09-20
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Date published2024-02-29
Combined method of phytoremediation and electrical treatment for cleaning contaminated areas of the oil complex
The scale of land pollution with oil waste necessitates the use of economical and effective methods of recultivation. Phytoremediation is one of the simplest methods, but it has a number of limitations, so additional preparation of the territory is often required before it is carried out. Preliminary electrical preparation and subsequent seeding of special phytoremediants are of interest. Passing a constant electric current through the soil volume under a low voltage removes toxicants from deep soil layers even with flooding. In addition, it reduces pollutant content in the upper layer, where the plants root system is located, which creates more favorable conditions for phytoremediants. Adequately selected types of plants will ensure additional soil cleaning, improve its structure and air exchange. The results of two research directions are presented. Experiments on the study of plant resistance to oil-contaminated soil substrate allowed establishing contamination thresholds at which it is advisable to sow a particular species, and to choose optimal phytoremediants. The study of the oil-containing soil cleaning in a monocathodocentric electrochemical installation with the fixation of main characteristics (oil products concentration, soil temperature, volt-ampere characteristics) allows us to develop technical measures to prepare territories for phytoremediation taking into account the relief features.
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Date submitted2022-07-10
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Date accepted2023-06-20
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Date published2024-02-29
Mathematical modeling of the electric field of an in-line diagnostic probe of a cathode-polarized pipeline
A mathematical model of the in-line control of the insulation resistance state for cathodically polarized main pipelines according to electrometry data is considered. The relevance of the work is caused by the opportunity to create in-line internal isolation defects indicators of the main pipelines for transported liquids that are good conductors and expand the functionality of monitoring and controlling cathodic protection systems of the main pipelines. Features of the mathematical model are: consideration of the electric conductivity of transported liquid influence on electric field distribution; consideration of the influence of external and internal insulating coating resistance; use of the electric field of an in-line diagnostic probe for quality control of internal insulation. Practical significance consists in the development of modeling methods for control subsystems of main pipeline protection against corrosion and the development of special mathematical and algorithmic support systems for monitoring and controlling the operating modes of the cathodic protection station of main pipelines.