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Date submitted2024-05-03
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Date accepted2024-09-05
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Date published2024-11-12
Platinum group elements as geochemical indicators in the study of oil polygenesis
This study examines elements of the platinum group (PGE), primarily platinum and palladium, as geochemical indicators in the investigation of oil polygenesis. It has been found that, like other trace elements such as nickel, vanadium, and cobalt, platinum group elements and gold can occur in oil fields at both background levels and in elevated or even anomalously high concentrations. The objective of this research is to analyze PGE and trace elements as geochemical markers to identify the geological factors, including endogenous processes, responsible for these unusually high concentrations in oil. A comprehensive review of the literature on this subject was conducted, along with new data on the presence of precious metals in oils from Russia and globally. The study explores the geological mechanisms behind elevated PGE concentrations in oils, utilizing atomic absorption spectroscopy with atomization in the HGA-500 graphite furnace to measure PGE content. Previously, the tellurium co-deposition method (ISO 10478:1994) was used to isolate noble metals from associated elements. Possible geological origins of abnormally high concentrations of platinum metals in oils have been identified. These include endogenous factors such as the spatial proximity of oil fields to ultrabasic rock massifs, the effects of contact-metasomatic processes, and influences from mantle dynamics. Moreover, data concerning mantle elements can serve as indicators of the depth origins of certain hydrocarbon fluids, thus contributing to the study of oil polygenesis.
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Date submitted2022-03-31
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Date accepted2022-05-11
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Date published2022-07-26
Carbonatite complexes of the South Urals: geochemical features, ore mineralization, and geodynamic settings
- Authors:
- Irina L. Nedosekova
The article presents the results of study of the Ilmeno-Vishnevogorsky and Buldym carbonatite complexes in the Urals. It has been established that the carbonatites of the Ilmeno-Vishnevogorsky complex are represented by high-temperature calciocarbonatites (sövites I and II) with pyrochlore ore mineralization. U-Ta-rich populations of uranium pyrochlores (I) and fluorocalciopyrochlores (II) crystallize in miaskite-pegmatites and sövites I; fluorocalciopyrochlores (III) and Sr-REE-pyrochlores (IV) of late populations form in sövites II. In the Buldym complex, along with high-temperature calciocarbonatites containing fluorocalciopyrochlore (III), medium-temperature varieties of magnesiocarbonatites with REE-Nb mineralization (monazite, niobo-aeschynite, columbite, etc.) are widespread. Miaskites and carbonatites of the Urals are characterized by high contents of LILE (Sr, Ba, K, Rb) and HFSE (Nb, Ta, Zr, Hf, Ti), which are close to the contents in rift-related carbonatite complexes of intraplate settings and significantly differ from synorogenic collisional carbonatite complexes. The Ural carbonatite complexes formed on continental rift margins during the opening of the Ural Ocean at the time of transition from extensional to compressional tectonics. Later on, they were captured and deformed in the suture zone as a result of collision. Plastic and brittle deformations, anatexis, recrystallization of rocks and ores of carbonatite complexes in the Urals are associated with orogenic and post-collision settings.
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Date submitted2020-06-11
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Date accepted2021-03-30
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Date published2021-06-24
Crystal morphology of spherical viruses
- Authors:
- Yury L. Voytekhovsky
The article discusses modern views on the structure of spherical virus capsids, which have the shape of icosahedrons (icosahedral viruses). Each face of icosahedron is composed of a single-layer closest packing of protein globules, which can have different orientation relative to the edges of icosahedron. If the lines of globules are parallel to the edges of icosahedron, then the capsid has a point symmetry group I h (with symmetry planes), if they are not parallel – the symmetry group I (without planes). From a mathematical point of view, in both symmetry groups there are series that unite equally (up to similarity) arranged capsids. They are connected pairwise by transitions to dual forms (homologous series). A hypothesis is formulated that the largest spherical viruses can have even more diverse and complex capsid structures. Along with icosahedron, their basic forms can be any simple shapes, allowed in I h and I symmetry groups (8 in total). A suggestion is made that transitions within similarity series and between homologous series have a phylogenetic significance. There are known spherical viruses of both symmetry groups. For example, the SARS-CoV-2 coronavirus has a symmetry group I h and belongs to a well-known series. The crystallographic approach allows to construct a strict morphological classification of spherical viruses. This is important for their early recognition and separate examination. The article demonstrates practical application of crystal morphology in the study of viral systems – an urgent problem of geoecology and life protection.
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Date submitted2020-09-10
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Date accepted2020-11-25
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Date published2021-06-24
Formation conditions of noble metal mineralization in sulfide cobalt-copper-nickel ores of Kamchatka (on the example of Annabergitovaya Schel ore occurrence)
The authors present research results, the purpose of which is to study the specifics of noble metal mineralization and its genesis in sulfide cobalt-copper-nickel ores of the Kamchatka nickel-bearing province. The paper is dedicated to one of its many ore occurrences called Annabergitovaya Schel (Annabergite Gap). The material composition of platinoid, silver, gold, bismuth and tellurium minerals, as well as sulfarsenides in the ores of this occurrence was investigated. Based on the data of mineral formation sequence and the use of geosensors, conclusions were drawn regarding the genesis of noble metal mineralization. Formation of platinoid minerals, silver and gold at the Annabergitovaya Schel ore occurrence is mainly associated with the epigenetic effect of post-ore granitoids on ore-bearing intrusion rocks of the Dukuk complex of the cortlandite-norite formation and on syngenetic ores. An early association of noble metal minerals is represented by sperrylite, irarsite, and rare unnamed phases of Pt + Ir + Te. Irarsite and Pt + Ir + Te phases were formed at the contact-metasomatic stage. Sperrylite can be assumed to be of magmatic origin. Silver sulfides and tellurides, silver and palladium bismuth tellurides, and native gold were formed at the late, hydrothermal-metasomatic, stage. The occurrence conditions of mineral parageneses, associated with noble metal mineralization, correspond to the formation of shallow-depth metasomatic rocks (≤5 km). Sub-developed quartz-feldspar metasomatites, associated with the formation of early platinoid arsenides and sulfarsenides, are in equilibrium with circumneutral solutions (pH of 4.5-6.5) at temperatures of 350-600 °C. Late hydrothermal association with Pd, Ag and Au minerals is close to propylites and was formed at pH values of 4.5-6.5 and temperature of 150-350 °C.
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Date submitted2020-04-15
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Date accepted2020-05-13
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Date published2020-10-08
Processing of platinum group metal ores in Russia and South Africa: current state and prospects
- Authors:
- Tatyana N. Aleksandrova
- Cyril О’Connor
The presented study is devoted to a comparative review of the mineral raw material base of platinum group metals (PGMs) and technologies of their processing in South Africa and Russia, the largest PGM producers. Mineralogical and geochemical classification and industrial value of iron-platinum and platinum-bearing deposits are presented in this work. The paper also reviews types of PGM ore body occurrences, ore processing methods (with a special focus on flotation processes), as well as difficulties encountered by enterprises at the processing stage, as they increase recovery of the valuable components. Data on mineralogical features of PGM deposits, including the distribution of elements in the ores, are provided. The main lines of research on mineralogical features and processing of raw materials of various genesis are identified and validated. Sulfide deposits are found to be of the highest industrial value in both countries. Such unconventional PGM sources, as black shale, dunites, chromite, low-sulfide, chromium and titanomagnetite ores, anthropogenic raw materials, etc. are considered. The main lines of research that would bring into processing non-conventional metal sources are substantiated. Analysis of new processing and metallurgical methods of PGM recovery from non-conventional and industrial raw materials is conducted; the review of existing processing technologies for platinum-bearing raw materials is carried out. Technologies that utilize modern equipment for ultrafine grinding are considered, as well as existing reagents for flotation recovery; evaluation of their selectivity in relation to platinum minerals is presented. Basing on the analysis of main technological processes of PGM ore treatment, the most efficient schemes are identified, i.e.,gravity and flotation treatment with subsequent metallurgical processing.
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Date submitted2019-10-17
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Date accepted2020-01-24
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Date published2020-04-24
Composition and probable ore igneous rocks source of columbite from alluvial deposits of Mayoko district (Republic of the Congo)
The article presents the results of optical, electron microscopic and electron microprobe studies of columbite group minerals, collected during heavy mineral concentrate sampling of alluvial deposits in the Mayoko region (Republic of the Congo). The aim of the study is revealing tantalum niobates ore body in this region. We found that these minerals in loose deposits are represented by two grain-size groups: less than 1.6 mm (fine fraction) and 1.6-15 mm (coarse fraction). The grains of both fractions belong mainly to columbite-(Fe), less often to columbite-(Mn), tantalite-(Mn) and tantalite-(Fe), contain impurities of Sc, Ti, and W. The crystals have micro-scaled zoning (zones varies slightly in the Ta/Nb ratio values) and contains a lot of mineral inclusions and veins represented by zircon, pyrochlore supergroup minerals and others. Columbite-(Fe) and columbite-(Mn) are characterized by an increased content of Ta 2 O 5 up to the transition to tantalite-(Fe) and tantalite-(Mn). This allows us to exclude the formation of subalkaline rare-metal granites, their metasomatites (albitites and greisenes) and carbonatites, from the list of possible columbite ore rocks source in the Mayoko district. Thus, beryl type and complex spodumene subtype rare-element pegmatites of the mixed petrogenetic family LCT-NYF (according to P.Černý) should be considered as a probable root source. The results of the research should be taken into account when developing the methodology for prospecting in this area.
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Date submitted2019-05-12
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Date accepted2019-07-22
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Date published2019-10-23
A Modern View of Anomalies in the Metal Groups of the Periodic System of D.I.Mendeleev
The article is devoted to the 150 th anniversary of the Periodic Table of Chemical Elements by D.I.Mendeleev. The fundamental law of nature, discovered by D.I.Mendeleev has anomalies and paradoxes associated with certain groups of metals. When studying the physical and chemical properties of complex metal compounds, many discrepancies can be found, namely, the location of elements in groups, which primarily relate to metals with different valences. By studying the approaches and methods for predicting the arrangement of chemical elements, it can be established that D.I.Mendeleev eliminated many differences for some metals during the formation of the Periodic system of chemical elements. D.I.Mendeleev developed a principle that excludes such errors when finding and discovering new elements. Analytical studies conducted by a Russian scientist helped to calculate the atomic masses and describe the properties of three elements not known at that time – «eka-boron», «eka-silicon», «eka-aluminum», the existence of which was proved and confirmed by subsequent discoveries of scandium, germanium, boron, and gallium. The paper provides a significant assessment of the forecasting of metals in various groups of the periodic system. Changes in the properties of some metals significantly influenced their location in the table of D.I.Mendeleev.
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Date submitted2018-07-22
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Date accepted2018-09-07
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Date published2018-12-21
Game theory model of state in-vestment into territories of advanced development in the regions of mineral resources specialization
- Authors:
- A. V. Kozlov
- A. B. Teslya
- S. A. Chernogorskii
Historically developed and non-compliant with modern conditions, the structure of industry placement and related inequality in economic development of certain territories are additional negative factors that hinder economic development of the country. Hence, the search for new organizational forms and methods of territorial development, facilitation of industrial growth in regions with mineral resources specialization become more and more relevant. Another no less important issue is justification of economic feasibility of using such tools and assessment of critical consequences of their application. Suggested by the authors, game theory model of state investment into territories of advanced development describes the method of limited resources distribution and becomes an instrument to assess the feasibility of investment into creation of advanced development territories under the conditions of insufficient information and actions of specific interest groups. Application of the suggested game theory model of state investment into creation of advanced development territories allows to forecast behavior of program participants, to model consequences of management decisions both for government structures and separate program participants.
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Date submitted2018-01-06
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Date accepted2018-02-26
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Date published2018-06-22
Extraction of platinum metals during procssing of chromium ores from dunnite deposits
- Authors:
- G. V. Petrov
- Ya. M. Shneerson
- Yu. V. Andreev
Currently, the main raw materials sources of platinum group metals in Russia are complex sulfide copper-nickel ores of the Taimyr region and placer deposits. However, in view of the inevitable loss of platinum metals during the metallurgical processing of initial ores and the deterioration of the quality of ore raw materials, along with a decrease in the share of platinum mining from placers, there is a need to look for new non-traditional sources of platinum group metals. Dunnites of the Middle Urals are promising platinum-bearing raw materials. The use of the gravitational-magnetic processing of chromium ores of dunnite deposits makes it possible to identify a magnetic platinum-bearing concentrate with a high content of magnetite and platinum-iron alloys, they can be refined using chemical-metallurgical methods. This article presents the results of research of identifying peculiarities of technological behavior of chromium, iron and noble metals during mechanical processing of ledge chromium ore. The kinetic regularities of the sulfuric acid decomposition of magnetite are determined. Optimum technological parameters of sulfuric acid leaching of iron from magnetic products of chromium ore dressing are established. Based on the conducted studies, the PDF and PID for the complex processing of chromium ores of dunnite deposits is proposed, which ensures the production of a rich platinum-bearing concentrate and a high-quality chromite concentrate that meets the requirements of chemical production.
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Date submitted2015-12-01
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Date accepted2016-02-29
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Date published2016-12-23
Simulation of diesel engine energy conversion processes
- Authors:
- A. S. Afanasev
- A. A. Tretyakov
In order to keep diesel engines in good working order the troubleshooting methods shall be improved. For their further improvement by parameters of associated processes a need has arisen to develop a diesel engine troubleshooting method based on time parameters of operating cycle. For such method to be developed a computational experiment involving simulation of diesel engine energy conversion processes has been carried out. The simulation was based on the basic mathematical model of reciprocating internal combustion engines, representing a closed system of equations and relationships. The said model has been supplemented with the engine torque dynamics taking into account the current values of in-cylinder processes with different amounts of fuel injected, including zero feed. The torque values obtained by the in-cylinder pressure conversion does not account for mechanical losses, which is why the base simulation program has been supplemented with calculations for the friction and pumping forces. In order to determine the indicator diagram of idle cylinder a transition to zero fuel feed mode and exclusion of the combustion process from calculation have been provisioned.
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Date submitted2015-08-17
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Date accepted2015-10-18
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Date published2016-04-22
Platinum specialization of supergene nickel deposits on ultramafic massifs of the Urals
- Authors:
- I. V. Talovina
This paper presents an analysis of geochemical data obtained as a result of persistent research of the Buruktal, Ufalei, Elov and others supergene nickel deposits of the Urals on the content of precious metals. Content and distribution of platinum group elements, gold and silver in oxide–silicate nickel ores are compared with their content in initial dunite-harzburgite bedrock. It was revealed that all the PGE accumulate in supergene nickel deposits. Geochemical specialization of PGE mineralization of supergene nickel deposits is determined by palladium and platinum, while in dunite-harzburgite substrate of primary ophiolitic massifs major platinoids are ruthenium, osmium and iridium. Pt/Pd ratio is generally less than 1, i.e. palladium is dominating in them with some exceptions.