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Date submitted2024-05-03
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Date accepted2024-11-07
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Date published2025-04-02
Assessment of ancylite ore dressability by flotation method
For more than 50 years, most rare earth elements were extracted from carbonatite deposits, which can contain different rare earth phases, but the main extracted minerals are bastnaesite, monazite and xenotime. Many studies focused on the improvement and development of dressing circuits for ores of these minerals. However, in some carbonatite complexes, rare earth deposits are composed partly or mainly of ancylite ores. This type of rare earth ores was very poorly studied in terms of dressability – previous experiments with ancylite ores are rare and not productive enough. Ancylite is the main concentrator of rare earth elements in most carbonatite complexes of the Devonian Kola Alkaline Province (northwest Russia). Dressability of ancylite ore from the Petyayan-Vara carbonatite field in the Vuorijärvi alkaline-ultramafic complex was assessed using the flotation method. The complex is one of the most potential rare earth deposits associated with carbonatites in the Kola Region. Petrographic and mineralogical studies demonstrated the occurrence of abundant iron and barite oxide inclusions in ancylite, which imposes restrictions on physical separation of these three minerals. The study of petrogeochemical and mineralogical composition of fractions formed during mechanical grinding of ores to a size less than 2.0 mm showed that even at this stage of sample preparation, the finest-grained fractions (less than 0.071 mm) were enriched in ancylite (to 19 vol.% or more with a content of 15 vol.% in ore). Three classes of reagents were considered as collectors in flotation experiments: fatty acids, alkyl hydroxamic acids, and amino acid derivatives. The reagent from the amino acid derivative class was highly efficient. The use of such a collector in combination with sodium hexametaphosphate depressant made it possible to obtain a flotation concentrate in an open circuit with total rare earth oxides content 33.4 wt.% at 64.7 % extraction.
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Date submitted2023-07-31
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Date accepted2024-11-07
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Date published2025-02-25
Environmental assessment of biochar application for remediation of oil-contaminated soils under various economic uses
- Authors:
- Tatiana V. Minnikova
- Sergey I. Kolesnikov
Remediation is an important area of oil-contaminated soil restoration in Russia, since oil refining industry is the major one for Russia and neighbouring countries, and the issues of environmentally effective and economically profitable remediation of oil contamination have not yet been solved. Soils under various economic uses have different surface areas and degrees of soil particles envelopment with oil due to the presence or absence of cultivation, the amount of precipitation and plant litter. The introduction of various substances for remediation into oil-contaminated soils of steppes (arable land), forests, and semi-deserts, considering their differences, gives different results. Biochar is coal obtained by pyrolysis at high temperatures and in the absence of oxygen. The uniqueness of this coal lies in the combination of biostimulating and adsorbing properties. The purpose of the study is to conduct an environmental assessment of biochar application for remediation of oil-contaminated soils under various economic uses. The article compares the environmental assessments of biochar application in oil-contaminated soils with different particle size fraction. The following indicators of soil bioactivity were determined: enzymes, indicators of initial growth and development intensity of radish, microbiological indicators. We found that the most informative bioindicator correlating with residual oil content is the total bacteria count, and the most sensitive ones are the roots length (ordinary chernozem and brown forest soil) and the shoots length (brown semi-desert soil). The use of biochar on arable land and in forest soil (ordinary chernozem and brown forest soil) is less environmentally efficient than in semi-desert soil (brown semi-desert soil). The study results can serve to develop measures and managerial and technical solutions for remediation of oil-contaminated soils under various economic uses.
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Date submitted2023-08-31
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Date accepted2023-12-27
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Date published2024-11-12
Geochemical studies of rocks of the Siberian igneous province and their role in the formation theory of unique platinum-copper-nickel deposits
- Authors:
- Nadezhda А. Krivolutskaya
The Norilsk deposits, unique both in their geological structure and reserves of nickel and platinum, have attracted the attention of researchers for several decades. Several hypotheses have been proposed to explain their formation. Two of them are the most widely accepted: the model of ore formation in an intermediate chamber from picritic melt enriched in sulphides and the formation of sulphides in situ through the assimilation of sulphate-bearing sediments by tholeiitic magma as it rises to the surface. The main questions regarding the genesis of these deposits are: the composition of the parental magmas that formed the ore-bearing massifs; the relationship between intrusions and effusive rocks; and the extent and role of assimilation of host rocks by magmas. These issues are discussed in the article using a large amount of analytical data obtained by the author during the study of the magmatic rocks and geological structures in the Norilsk area. Based on these data, it was concluded that none of the proposed models could fully explain all observed geological features of the deposits as well as the appearance of the unique sulphide ores. In order to solve the problem of the genesis of the Norilsk deposits, it is necessary to analyse the evolution of P3-T1 magmatism over time in the Siberian large igneous province, especially in its eastern part, and to determine its association with ore-forming processes; and its investigating it is a priority task for understanding sulphide ore formation. Solving this task should be based not only on geophysical data but also on studies of the geochemistry of igneous rocks within the province.
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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 submitted2023-07-05
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Date accepted2024-06-03
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Date published2024-12-25
Complete extraction of conditioned ores from complex-structured blocks due to partial admixture of substandard ores
- Authors:
- Bayan R. Rakishev
The paper presents mining-technological substantiation of complete extraction of conditioned ores from complex-structured blocks of benches by mixing a layer of substandard ores of certain sizes. The relevance of the work consists in the development of innovative methods of establishing the parameters of the substandard layer of ores to be added to the conditioned ores. The main problem is to ensure complete extraction of useful components into concentrate from shipped ore with acceptable deviations from the required ones. A new typification of complex-structured ore blocks of the bench has been carried out. Analytical dependences of mining and geological characteristics of complex-structured ore blocks were obtained. Theoretical dependences for determining the main indicators of mineral processing are derived. Analytical dependences for determination of the content of useful component in shipped ore α' – mixture of conditioned ore with the content of useful component α and admixed layer of substandard ore with the content of useful component α'' are offered. For the first time in mining science, a new approach of complete extraction of conditioned ores from complex-structured blocks of benches by grabbing a certain part of substandard ores during excavation, increasing the volume of extracted ore and expanding the extraction of useful components in the concentrate has been substantiated. The increment of useful components can reach 10-15 % of the total volume of extraction, which allows predicting a significant increase in the completeness of mineral extraction from the Earth's interior.
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Date submitted2023-03-01
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Date accepted2024-06-03
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Date published2025-02-25
Lamprophyres of the Peshchernoe gold deposit, their geological position, material composition, and metasomatic alterations (Northern Urals)
The article presents the first data on biotite-hornblende lamprophyres discovered at the Peshchernoe gold deposit. We consider the geological position of lamprophyre dikes in the deposit structure and the relationship of these rocks with tectonically weakened and mineralized zones. The data on the structural position of mineralized zones, faults, dike bodies, metasomatic halos, and host volcanogenic-sedimentary rocks confirm the tectonic nature of the Peshchernoe deposit alteration system. Lamprophyre dikes are pre-ore, as evidenced by the superimposed metasomatic mineral associations. We assume that dikes of andesitic rocks, lamprophyres, and subsequently hydrothermal fluids, including ore-bearing ones, were intruded along the fault zone of northeastern strike at different geological times. The description of mineralogical and chemical transformations of lamprophyres, which occurred as a result of alteration, is given. Two stages of metasomatism are distinguished: carbon dioxide (beresitization-listvenitization) and subsequent alkaline (sodic metasomatism). During carbon dioxide metasomatism, dark-coloured minerals are replaced by chlorite, albitization and sericitization of plagioclase occur, and ferruginous dolomite is formed under the influence of a significant supply of CO2. Alkaline (sodic) metasomatism is superimposed on the mineral metasomatic paragenesis of the first stage. We consider metasomatic zoning during sodic metasomatism, manifested in one of the spessartite dikes. Chlorite and relics of magmatic dark-coloured minerals are replaced by magnesite, the supply of Na leads to the appearance of newly formed albite, and the supply of S leads to the formation of pyrite, which concentrates iron from other minerals. As a result of the sodic metasomatism, iron content in carbonates decreases in the direction from the outer metasomatic zone to the inner one. We conclude that it was the alkaline-sulphide sodium solutions that performed the ore-bearing function, and beresitization and listvenitization prepared a favourable environment for ore deposition.
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Date submitted2023-06-21
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Date accepted2023-10-25
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Date published2024-08-26
Specific action of collector from phosphoric acid alkyl esters class in flotation of apatite-nepheline ores
Increasing amount of apatite-nepheline ores with complex mineral composition involved in processing, growing content of the associated minerals in ore which are similar in their floatability to apatite lead to the necessity of using highly selective collectors. Non-frothing flotation method gave a comparative assessment of floatability of pure minerals and demonstrated a high selectivity of the action of phosphoric acid esters in relation to apatite. The effect of four reagent modes differing in the number of selective synthetic collectors was studied using the example of flotation of an apatite-nepheline ore sample containing 17.27 % apatite and 40.18 % nepheline. Mineralogical analysis of crushed ore showed that it contained two apatite varieties – coarse-grained free and finer poikilitic as inclusions in rock-forming minerals. Free apatite opens and occurs as open grains even in coarse-grained (+0.16 mm) grades. Poikilitic apatite occurs as intergrowths with different minerals, mainly with nepheline and its alteration products (natrolite, spreustein, sodalite, etc.), and pyroxene. Optical microscopy demonstrated that a growing share of reagent from the phosphoric acid oxyethylated esters class in the composition of the collector mixture allows improving the quality of the produced apatite concentrates by reducing the number of apatite intergrowths with nepheline and pyroxenes in the concentrates. In the concentrate obtained in the most selective reagent mode, the intergrowths are characterized by a 50/50 and higher ratio in favour of apatite. Concentrates of lower quality comprised intergrowths with lower apatite content, to 20/80 or less.
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Date submitted2024-04-16
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Date accepted2024-06-03
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Date published2024-07-04
Quantitative determination of sulfur forms in bottom sediments for rapid assessment of the industrial facilities impact on aquatic ecosystems
- Authors:
- Ivan P. Sverchkov
- Vladimir G. Povarov
The article describes an X-ray fluorescence method for quantitative analysis of sulfate and total sulfur in bottom sediments of watercourses and reservoirs located in the area of industrial enterprises impact. The quantitative determination of sulfur forms was carried out by analyzing the characteristic curves SKα1,2 and SKβ1,3, as well as the satellite line SKβ′ on X-ray emission spectra measured by an X-ray fluorescence spectrometer with wavelength dispersion. The study shows that these characteristic curves allow not only to determine the predominant form of sulfur, but also to separately conduct quantitative analyses of sulfates and total sulfur after fitting peaks and to separately analyze overlapping spectral lines. The results of quantitative analysis of the chemical state of sulfur by the proposed X-ray fluorescence method were compared with the results of inductively coupled plasma atomic emission spectroscopy and elemental analysis, as well as certified standard samples of soils and sediments. The results are in good agreement with each other.
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Date submitted2023-05-21
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Date accepted2024-05-02
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Date published2024-08-26
Assessment of the influence of lithofacies conditions on the distribution of organic carbon in the Upper Devonian “Domanik” deposits of the Timan-Pechora Province
The study of high-carbon formations was instigated both by the decreasing raw material base of oil as a result of its extraction, and by the progress in development of low-permeability shale strata, primarily in the USA, Australia, and China. The most valuable formations occur in traditional hydrocarbon production areas – the West Siberian, Volga-Ural and Timan-Pechora, North Pre-Caucasian and Lena-Tunguska oil and gas provinces. Specific features of the Late Devonian-Early Carboniferous high-carbon formation occurring in the eastern marginal part of the East European Platform are: heterogeneous section due to intense progradation of the carbonate platform from west to east; succession of lithofacies environments that determined the unevenness of the primary accumulation and secondary distribution of organic matter (OM); possible migration or preservation in the source strata during the subsidence stages of the moving parts of bitumides, which determined the prospects for oil and gas potential. The distribution pattern of the present OM content was investigated depending on lithofacies conditions and lithological composition of rocks in the “Domanik type” Upper Devonian-Tournaisian deposits in the Timan-Pechora Province (TPP), its transformation degree to bring it to the initial content of organic carbon and further estimation of the share of stored “mobile oil” in oil and gas source formation. The study was based on the analysis of the data set on organic carbon content in core samples and natural exposures in the Ukhta Region in the Domanik-Tournaisian part of the section including more than 5,000 determinations presented in reports and publications of VNIGRI and VNIGNI and supplemented by pyrolytic and bituminological analyses associated with the results of microtomographic, macro- and lithological studies and descriptions of thin sections made at the Saint Petersburg Mining University. For each tectonic zone of the TPP within the investigated high-carbon intervals, the content of total volumes of organic carbon was determined. The data obtained allow estimating the residual mass of mobile bitumoids in a low-permeability matrix of the high-carbon formation.
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Date submitted2023-05-31
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Date accepted2023-12-27
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Date published2024-04-25
Velocity structure of the Earth’s crust and upper mantle in the Pechenga ore region and adjacent areas in the northwestern part of the Lapland-Kola orogen by the receiver function technique
- Authors:
- Andrei G. Goev
The article presents a study of the Earth’s crust and upper mantle in the Pechenga ore region, as well as areas adjacent to it in the northwestern part of the Kola region. Applying the receiver function technique to data acquired by three broadband seismic stations, we obtained one-dimensional seismic velocity distribution models to a depth of 300 km. The stations are located in the northern parts of Finland and Norway, as well as in the Pechenga region of the Russian Federation. Despite the stations being in relatively close proximity (within 100 km of each other), the velocity models turned out to be significantly different, which indicates structural discontinuity within the lithosphere. Thus, Finland station data set revealed a gradient crust-mantle transition, which is not present in the other two models. At depths of about 150 km, a low-velocity zone was discovered, associated with mid-lithospheric discontinuity, which was not found beneath the Pechenga ore region. Furthermore, the crustal structure of the Pechenga region has an anomalously high Vp/Vs ratio to a depth of about 20 km. Considering the fact that the Pechenga (Nikel) seismic station was installed in close proximity to major copper-nickel deposits, this anomaly can be interpreted as a relic of Proterozoic plume activity.
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Date submitted2021-04-15
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Date accepted2022-09-06
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Date published2023-10-27
Gold-rare metal and associated mineralization in the western part of Bolshevik Island, Severnaya Zemlya archipelago
The presented studies are aimed to determine the formation patterns of the gold-rare metal mineralization within one of the most inaccessible Arctic islands of the Russian Federation, Bolshevik Island of the Severnaya Zemlya archipela-go. The relevance of the work is determined by the high probability of discovering a significant in terms of metal reserves deposit, which is proved by many researchers on the example of known large deposits to be a typical feature of sites with gold-rare metal formation. Obviously, only the possibility of discovering and subsequent development of a deposit of a highly liquid type of mineral, gold, can ensure the profitability of mining production on Severnaya Zemlya. It is established that the main geological, mineralogical, and geochemical features of the gold-rare metal mineralization in the Kropotkinsko-Nikitinskaya metallogenic zone of Bolshevik Island correspond to that of similar ore sites in Russia and the world. The occurrences of other formation types revealed in this metallogenic zone suggest a certain zoning in their distribution: mineralization is located in the apical parts of granitoids and in the nearest halo of hornfelses. At a distance, with an exit from the hornfelsed zone, there are occurrences of a cassiterite-sulphide formation with elevated gold and silver content at the top of the ore column, together with an increased amount of polymetallic ores. Occurrences of gold-quartz and gold-sulphide-quartz formations are localized in fault zones, as a rule, farther from granitoids. The total vertical range of gold mineralization exceeds 300 m. The assignment of all types of mineralization in the Kropotkinsko-Nikitinskaya metallogenic zone of Bolshevik Island to a single hydrothermal process is emphasized by the similar isotope composition of lead galena from heterogeneous occurrences, which determines the age of all mineralization at 200-300 Ma.
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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 submitted2022-08-22
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Date accepted2023-02-02
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Date published2023-08-28
Wodginite as an indicator mineral of tantalum-bearing pegmatites and granites
- Authors:
- Viktor I. Alekseev
In the composition of tantalum-niobates, the tin-bearing wodginite group minerals (WGM) were found: wod-ginite, titanowodginite, ferrowodginite, ferrotitanowodginite, lithiowodginite, tantalowodginite, “wolframowodginite”. We reviewed the worldwide research on WGM and created a database of 698 analyses from 55 sources including the author's data. WGM are associated with Li-F pegmatites and Li-F granites. Wodginite is the most prevalent mineral, occurring in 86.6 % of pegmatites and 78.3 % of granites. The occurrence of WGM in granites and pegmatites differs. For instance, titanowodginite and “wolframowodginite” occur three times more frequently in granites than in pegmatites, whereas lithiowodginite and tantalowodginite do not appear in granites at all. The difference between WGM in granites and pegmatites is in finer grain size, higher content of Sn, Nb, Ti, W, and Sc; lower content of Fe 3+ , Ta, Zr, Hf; higher ratio of Mn/(Mn + Fe); and lower ratio of Zr/Hf. The evolutionary series of WGM in pegmatites are as follows: ferrowodginite → ferrotitanowodginite → titanowodginite → “wolframowodginite” → wodginite → tantalowodginite; in granites: ferrowodginite → ferrotitanowodginite → “wolframowodginite” → wodginite → titanowodginite. WGM can serve as indicators of tantalum-bearing pegmatites and granites. In Russia the promising sources of tantalum are deposits of the Far Eastern belt of Li-F granites containing wodginite.
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Date submitted2022-11-02
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Date accepted2023-03-02
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Date published2023-04-25
Environmental damage from the storage of sulfide ore tailings
The mining industry is one of the most challenging in ensuring environmental safety. During the last century, the Karabash Copper Smelting Plant was processing sulfide ores and depositing the tailings into storage facilities that now occupy an area of more than 50 hectares. To date, abandoned tailings are a significant source of natural water, air, and soil pollution in the Karabash city district. The article comprehensively examines the environmental impact of the Karabashmed copper smelter, one of the oldest metallurgical enterprises in Russia. The effects of seepage from the two Karabashmed tailings facilities on water resources were assessed. We revealed that even outside the area of the direct impact of processing waste, the pH of natural water decreases to values 4-5. Further downstream, the infiltration water from the tailings pond No. 4 reduces the pH of river water to 3.0-3.5. The presented results of environmental engineering surveys are derived from sampling water and bottom sediments of the Ryzhiy Stream and the Sak-Elga River, sample preparation, and quantitative chemical analysis. The study revealed significant exceedances of the maximum permissible concentrations for a number of chemical elements in the impact zone of the copper ore processing tailings.
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Date submitted2022-10-17
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Date accepted2023-02-13
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Date published2023-04-25
Environmental geotechnology for low-grade ore mining with the creation of conditions for the concurrent disposal of mining waste
Due to the constantly deteriorating environmental situation in the regions with mining enterprises, the article considers the topical issue of disposing the maximum possible volume of waste from the mining and processing of low-grade ferrous ores through the creation of an effective underground environmental geotechnology. Traditional procedure with descending mining of reserves with a caving system does not allow waste to be disposed of in a gob. The idea is to use geotechnology based on the ascending order of mining the ore body, room excavation, leaving truncated pillars, and staggered arrangement of adjacent rooms in height, which makes it possible to form containers for waste disposal in the form of a cementless backfill. The main characteristics of the proposed procedure are investigated and compared with the traditional procedure of low-grade iron ores mining. It was established that from the point of view of the complete extraction of reserves and the unit costs for the preparatory-development operations, the processes are comparable, while in terms of the mining quality, the proposed option is much more efficient. Evaluation of environmental geotechnology by the criterion of waste disposal, performed according to the proposed methodology, showed that the combination of these technical solutions ensures the placement in the formed gob from 80 to 140% of all waste generated during the mining and beneficiation of low-grade iron ores.
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Date submitted2022-04-15
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Date accepted2022-11-17
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Date published2023-04-25
Uranium in man-made carbonates on the territory of Ufa
The paper presents the results of analyzing uranium content in man-made carbonates (scale crusts) on the territory of Ufa based on examination of 42 samples. The median uranium content in the investigated samples stands at 1.44 mg/kg, which is significantly lower than the background values (scales from the Lake Baikal water, a clarke of sedimentary carbonate rocks) and data on other settlements of the Republic of Bashkortostan. Low values of uranium content are probably associated with the effects of the three leading factors, i.e. specific subsurface geology of the territory (gypsum, limestone); types of water supply; water treatment processes for the centralized type of water supply. Spatial distribution of uranium in man-made carbonates is characterized with uniformity, which is disturbed in two cases, i.e. a change of the water supply type (from centralized to individual); and material of the vessels used for boiling the water. No significant differences were detected when comparing samples of man-made carbonates associated with different sources of water supply (the bucket and infiltration types of water intake) and the types of household filters.
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Date submitted2021-05-13
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Date accepted2022-11-28
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Date published2022-12-29
Reproduction of reservoir pressure by machine learning methods and study of its influence on the cracks formation process in hydraulic fracturing
Hydraulic fracturing is an effective way to stimulate oil production, which is currently widely used in various conditions, including complex carbonate reservoirs. In the conditions of the considered field, hydraulic fracturing leads to a significant differentiation of technological efficiency indicators, which makes it expedient to study in detail the crack formation patterns. For all affected wells, the assessment of the resulting fractures spatial orientation was performed using the developed indirect technique, the reliability of which was confirmed by geophysical methods. In the course of the analysis, it was found that in all cases the fracture is oriented in the direction of the development system element area, which is characterized by the maximum reservoir pressure. At the same time, reservoir pressure values for all wells were determined at one point in time (at the beginning of hydraulic fracturing) using machine learning methods. The reliability of the used machine learning methods is confirmed by high convergence with the actual (historical) reservoir pressures obtained during hydrodynamic studies of wells. The obtained conclusion about the influence of the formation pressure on the patterns of fracturing should be taken into account when planning hydraulic fracturing in the considered conditions.
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Date submitted2022-05-26
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Date accepted2022-11-17
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Date published2022-12-29
Renovation method of restoring well productivity using wavefields
A stagewise theoretical substantiation of the renovation vibrowave method of influencing the near-wellbore zone of reservoir for restoring well productivity is presented. The area of treatment by the proposed method covers the reservoir with a heterogeneous permeability with fractures formed by fracking. In this method a decrease in concentration of colmatants occurs due to a change in direction of contaminants migration. Under the influence of pressure pulses, they move deep into the reservoir and disperse through the proppant pack. The results of mathematical modelling of the propagation of pressure wave and velocity wave and the calculations of particles entrainment in wave motion are presented.
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Date submitted2022-08-20
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Date accepted2022-11-17
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Date published2022-12-29
Comparison of the approaches to assessing the compressibility of the pore space
- Authors:
- Vitaly S. Zhukov
- Yuri O. Kuzmin
Integral and differential approaches to determining the volumetric compression of rocks caused by changes in the stress state are considered. Changes in the volume of the pore space of rocks are analyzed with an increase in its all-round compression. Estimation of changes in the compressibility coefficients of reservoirs due to the development of fields is an urgent problem, since the spread in the values of compressibility factors reduces the adequacy of estimates of changes in the physical properties and subsidence of the earth's surface of developed fields and underground gas storages. This parameter is key in assessing the geodynamic consequences of the long-term development of hydrocarbon deposits and the operation of underground gas storage facilities. Approaches to the assessment differ in the use of cumulative (integral) or local (differential) changes in porosity with a change in effective pressure. It is shown that the coefficient of volumetric compressibility of pores calculated by the integral approach significantly exceeds its value calculated by the differential approach, which is due to the accumulative nature of pore compression with an increase in effective pressure. It is shown that the differential approach more accurately determines the value of the pore compressibility coefficient, since it takes into account in more detail the features of the change in effective pressure.
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Date submitted2022-04-13
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Date accepted2022-05-25
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Date published2022-11-03
Mineralogical and technological features and patterns of selective disintegration of ferruginous quartzites of the Mikhailovskoye deposit
The growing demand for ferrous metallurgy products necessitates the introduction of technologies that increase the efficiency of the processing of iron-bearing raw materials. A promising trend in this area is the implementation of solutions based on the possibility of selective disintegration of ores. The purpose of this work was to establish the laws of selective disintegration of ferruginous quartzites based on the results of the study of mineralogical and technological properties of raw materials. We present data on the study of mineralogical and technological features of ferruginous quartzites of the Mikhailovskoye deposit. The data were obtained using X-ray fluorescence analysis and automated mineralogical analysis. Based on studies of the nature of dissemination and the size of grains of rock-forming and ore minerals, the tasks of ore preparation are formulated. The parameters for the iron and silicon oxide distribution by grain-size classes in the grinding products were established during the study. Based on empirical dependences, the grain size of grinding was predicted, at which the most effective release of intergrowths of ore minerals and their minimum transition to the size class of –44 µm should be achieved.
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Date submitted2022-04-14
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Date accepted2022-07-21
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Date published2022-11-03
In-situ leaching of molybdenum and uranium by percarbonate and chloride-hypochlorite solutions
In-situ leaching of molybdenum and uranium is becoming an increasingly common process. The features of the material composition of ores, leading to a decrease in their filtration properties, were considered. Activation leaching with leaching solutions that have undergone electrophotochemical activation before contact with the ore mass were studied. Activation preparation of leaching solutions promotes the synthesis of clustered water molecules with collectivized protons and hydroxyl ions, as well as active forms of oxygen and hydrogen. Cell leaching of molybdenum from mature tailings of the Shakhtaminsk deposit was studied experimentally. After pre-oxidation with an active carbonate solution, a model borehole leaching was carried out with a chloride-hypochlorite solution. Molybdenum extraction on resin a was 85 % in 30 days. Experiments on the percolation leaching of uranium from the ores of the Uchkuduk and Sugraly deposits confirmed the potential possibility of a significant increase in the extraction of uranium by electrophotoactivated percarbonate solutions relative to aqueous solutions of sodium and ammonium carbonate. When leaching with carbonate solutions without an additional oxidizing agent, the extraction of uranium from the Sugraly deposit ore sample was 52 and 59 % (sodium carbonate and ammonium carbonate). The use of hydrogen peroxide as an oxidizing agent made it possible to achieve 87-88 % extraction into pregnant solutions in 21 days without pre-oxidation. The performed studies confirm the processing capability of extracting uranium and molybdenum by percolation leaching in columns and borehole leaching.
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Date submitted2022-05-10
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Date accepted2022-09-06
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Date published2022-11-03
Flotation separation of titanite concentrate from apatite-nepheline-titanite ores of anomalous zones of the Khibiny deposits
Titanium raw materials are widely used for the synthesis of various functional materials – sorbents of radionuclides and rare earth elements, various additives, filler pigments, etc. Since most of titanium concentrates are imported, in line with the import substitution program, production of titanite concentrate from apatite-nepheline ores of the Khibiny deposits is a promising trend for supplying national industry with titanium raw materials. The article presents the results of laboratory studies of flotation separation of titanite concentrate from apatite-nepheline-titanite ores extracted from the upper ore horizon of the Koashvinskoye deposit, where titanite-enriched ores are concentrated. Recovery of titanite concentrate was accomplished using two reagent modes – a mixture of alkyl hydroxamic and carboxylic acids with the addition of distilled tall oil and a mixture of tall oils with the addition of polyalkyl benzene sulfonic acids. The results of the research showed that the first flotation mode, which allows a selective recovery of titanite into the concentrate (titanite content in the concentrate was 93.5 %) is the most efficient. It was shown that flotation separation of titanite concentrate is preferable compared to the chemical method based on sulfuric acid leaching.
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Date submitted2022-05-12
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Date accepted2022-09-06
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Date published2022-11-03
Morphometric parameters of sulphide ores as a basis for selective ore dressing
To assess the possibility of selective disintegration and reduction of overgrinding of hard-to-reproduce ores, optical microscopic and X-ray microtomographic studies were carried out and quantitative characteristics of morphological parameters of disseminated and rich cuprous ore samples from Norilsk-type Oktyabrsky deposit were identified. Among quantitative morphological parameters the most informative are area, perimeter, edge roughness, sphericity, elongation and average grain spacing for disseminated copper-nickel ores; area, perimeter, edge roughness and elongation for rich cuprous ores. The studied parameters are characterized by increased values and dispersion in ore zones, which is especially important for fine-grained ores, which are difficult to diagnose by optical methods. Three-dimensional modelling of the internal structure of sulphide mineralisation samples was carried out using computed X-ray microtomography, which allows observation of quantitative parameters of grains, aggregates and their distribution in the total rock volume and interrelationship with each other. The evaluation of rock pore space by computer microtomography made it possible to compare the results obtained with the strength characteristics of rocks and ores, including those on different types of crushers. The obtained quantitative characteristics of structural-textural parameters and analysis of grain size distribution of ore minerals allow us to evaluate the possibility of applying selective crushing at various stages of ore preparation
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Date submitted2022-04-14
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Date accepted2022-07-21
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Date published2022-11-03
Technological mineralogy: development of a comprehensive assessment of titanium ores (exemplified by the Pizhemskoye deposit)
Technological mineralogy of titanium ores is the basis for assessing their complexity. It enables, from a unified standpoint, to trace the entire course of changes in mineral matter through operating procedures, including beneficiation, processing, and obtaining target industrial products. The study targets are Pizhemskoye ilmenite-leucoxene sandstones, which are distinguished by a complex polymineral composition. Along with the main ore components, there are other metals with different speciation (isomorphic admixture, independent mineral phases). The optimal set of mineralogical analysis methods for the predictive assessment of their further use is substantiated exemplified by titanium ores of the Pizhemskoye deposit, which are complex, noted for a variable content of iron oxides and contain rare earth metals. Examinations by X-ray phase analysis and scanning electron microscopy confirm that the main titanium phases of sandstones are pseudorutile and a polymineral aggregate, “leucoxene”. Considering the granulometric peculiarities of the magnetic and non-magnetic fractions of the gravity concentrate, the prospects of technologies for processing titanium raw materials are discussed. Along with the problems of obtaining high-quality raw materials, the transformations of mineral phases as a result of extreme impacts and their physicochemical properties as a consequence of isomorphic substitution of a part of Ti atoms with natural modifier agents (Fe and V) in the synthesis of titanium oxide nanostructures for industrial applications are considered (photocatalytic nanoreactor).
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Date submitted2022-01-31
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Date accepted2022-09-06
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Date published2022-11-10
Filtration studies on cores and sand packed tubes from the Urengoy field for determining the efficiency of simultaneous water and gas injection on formation when extracting condensate from low-pressure reservoirs and oil from oil rims
- Authors:
- Nikolay A. Drozdov
Oil rims as well as gas condensate reservoirs of Russia's largest Urengoy field are developed by depletion drive without formation pressure maintenance, which has led to serious complications in production of oil, gas and condensate. In addition, field development by depletion drive results in low values of oil and condensate recovery. These problems are also relevant for other oil and gas condensate fields. One of the possible solutions is simultaneous water and gas injection. Rational values of gas content in the mixture for affecting gas condensate fields and oil rims of oil and gas condensate fields should be selected using the data of filtration studies on core models. The article presents the results of filtration experiments on displacement of condensate and oil by water, gas and water-gas mixtures when simulating the conditions of the Urengoy field. Simultaneous water and gas injection showed good results in the experiments on displacement of condensate, residual gas and oil. It has been ascertained that water-gas mixtures with low gas content (10-20 %) have a better oil-displacement ability (9.5-13.5 % higher) than water. An experiment using a composite linear reservoir model from cemented core material, as regards the main characteristics of oil displacement, gave the same results as filtration experiments with sand packed tubes and demonstrated a high efficiency of simultaneous water and gas injection as a method of increasing oil recovery at oil and gas condensate fields.