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Date submitted2022-03-03
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Date accepted2022-04-27
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Date published2022-07-26
Peculiarities of rare-metal mineralization and genetic relationship of mineral associations in the eastern rim of Murzinsko-Aduysky anticlinorium (the Ural Emerald Belt)
- Authors:
- Mikhail P. Popov
The paper presents features of the location and composition, as well as a generalization of data on the age of rare-metal mineralization developed at the deposits and occurrences of rare metals and gemstones in the eastern rim of Murzinsko-Aduysky anticlinorium, within the Ural Emerald Belt, which is a classic ore and mineralogical object and has been studied for almost two hundred years. With a significant number and variety of prospecting, research and scientific works devoted mainly to emerald-bearing mica complexes and beryl mineralization, as well as rare-metal pegmatites, scientific literature has so far lacked generalizations on the formation of numerous mineral associations and ore formations that represents a uniform genetic process in this ore district. The aim of the work is a comprehensive geological-mineralogical analysis of mineral associations of the eastern rim of Murzinsko-Aduysky anticlinorium and studying their age, formation conditions and characteristic features to determine the possibility of expanding and using the mineral resource base of the Urals through developing new prognostic and prospecting criteria for rare-metal and gemstone ore formations and creating the new devices for promising objects prospecting
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Date submitted2021-06-10
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Date accepted2021-07-27
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Date published2021-10-21
Defects of diamond crystal structure as an indicator of crystallogenesis
- Authors:
- Evgeny A. Vasilev
Based on the study of a representative collections of diamonds from diamondiferous formations of the Urals and deposits of the Arkhangelsk and Yakutian diamond provinces, we established patterns of zonal and sectoral distribution of crystal structure defects in crystals of different morphological types, identified the specifics of crystals formed at different stages of crystallogenesis and performed a comprehensive analysis of constitutional and population diversity of diamonds in different formations. We identified three stages in the crystallogenesis cycle, which correspond to normal and tangential mechanisms of growth and the stage of changing crystal habit shape. At the stage of changing crystal habit shape, insufficient carbon supersaturation obstructs normal growth mechanism, and the facets develop from existing surfaces. Due to the absent stage of growth layer nucleation, formation of new {111} surfaces occurs much faster compared to tangential growth mechanism. This effect allows to explain the absence of cuboids with highly transformed nitrogen defects at the A-B 1 stage: they have all been refaceted by a regenerative mechanism. Based on the revealed patterns, a model of diamond crystallogenesis was developed, which takes into account the regularities of growth evolution, thermal history and morphological diversity of the crystals. The model implies the possibility of a multiply repetitive crystallization cycle and the existence of an intermediate chamber; it allows to explain the sequence of changes in morphology and defect-impurity composition of crystals, as well as a combination of constitutional and population diversity of diamonds from different geological formations.
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Date submitted2020-10-22
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Date accepted2021-03-02
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Date published2021-04-26
Dynamic simulation of industrial-scale gibbsite crystallization circuit
- Authors:
- Vladimir O. Golubev
- Tatyana E. Litvinova
Population balance model is crucial for improving the method of aluminum hydroxide massive crystallization and enhancing the quality of control over industrial precipitation trains. This paper presents the updated population balance model, which can be used for simulation of industrial-scale precipitation. Processes of birth-and-spread and particle breakage are considered integral parts of the precipitation process along with secondary nucleation, growth and agglomeration of particles. The conceptual difference of the proposed system of equations is its ability to reproduce the oscillatory process that occurs in precipitation circuits as a result of cyclic changes in the quality of the seed surface. It is demonstrated that self-oscillations can occur in the system without any external influence. The updated model is adjusted and verified using historical industrial data. The simulation of seed-recycle precipitation circuit showed an exact correspondence between the calculated dynamic pattern of changes in particle size distribution of aluminum hydroxide and the actual data.
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Date submitted2019-03-05
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Date accepted2019-05-03
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Date published2019-08-23
Efficiency Estimation of the Single- and Multicomponent Anti-hydrate Reagents
- Authors:
- N. A. Shostak
- E. P. Zaporozhets
Different types of technological and technical problems in the oil, gas and chemical industries are connected with the hydrate formation process and with the using of anti-hydrate chemicals. That is why, it is necessary to estimate thermobaric ranges within which reagents does not let hydrate to grow or is their dissociation. Also, to estimate anti-hydrate influence we need to determine the chemicals’ anti-hydrate efficiency and chose the best one. They make the reagents consisting of several chemical components depending on the purpose of their application – for prevention of formation and (or) elimination of hydrates. It demands calculations of the optimum concentration and expenses and also the intensity (speed) of hydrates dissociation causing with the reagents. The analytical method of the anti-hydrate chemical reagents efficiency determination containing one or several components from different classes of chemical compounds – alcohols, salts, acids, compounds of nitrogen and oxygen – is presented in this paper. With its help it is possible to define decrease in temperature of hydrate formation from reagents influence, to count key parameters of reagents anti-hydrate efficiency depending on component compositions of hydrate gas and a phase condition of a hydrate-gas system, to select types of chemical components and their quantity in multicomponent reagents, i.e., to make new compounds. The method can be used for express assessment of anti-hydrate chemical reagents efficiency on criteria sign for practical application in oil, gas and processing industry.
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Date submitted2015-07-25
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Date accepted2015-09-01
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Date published2016-02-24
The phenomenon of isothermal transition of metastable aluminate solutions into the labile area and prospects of its industrial use
- Authors:
- V. N. Brichkin
- A. Kraslawski
The paper presents theoretically based requirements for the activation of synthetic gibbsite for maximum solubility of the activated product. The article describes the methodological foundations of gibbsite thermal activation and its effectiveness evaluation in terms of aluminate solutions decomposition. It is shown that to obtain high-saturation aluminate solutions, activation should provide generation of the reagent with highly-developed surface area, which is not identical to the structure of the deposited gibbsite. As a result of high-gradient thermal activation of synthetic gibbsite, it has been found that the targeted product develops predominantly an amorphous structure with a specific surface area up to 256 m2/ g, preserving its primary particle size. Activation products were investigated using modern methods of physical and chemical analysis. The experimental results confirmed the possibility of the activated product dissolution in the aluminate solution with a metastable compound and their spontaneous decomposition with aluminum hydroxide formation, characterized by high dispersion ability. It is shown, that a significant difference in kinetics and decomposition rates of solutions is connected with the use of a seed material with different particle size composition, which leads to the development of competing mechanisms, resulting in seed recrystallization, homogeneous and heterogeneous nucleation.
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Date submitted2014-07-13
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Date accepted2014-09-13
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Date published2014-12-22
Separation and extraction of lanthanides from low concentrations of raw materials using extraction methods
- Authors:
- T. E. Litvinova
- O. V. Cheremisina
At the present time, the unique physical and chemical properties of rare earth metals (REM) mean they can find wide application in the metallurgy, mechanical engineering, avionics, petrochemical, laser and glass industries. In metallurgy, rare earth metals using for production of special grades of steel and cast iron. Adding REM can improve their mechanical properties: hardness, toughness, resistance to corrosion. REM are also used for the deoxidation of metals and alloys. The REM production technology from loparite concentrate that already exists in Russia is not enough for the metal-lurgical, oil, glass, ceramic, nuclear and military industries (just 2 % of the world’s REM are produced in Russia). REM for these industrial proposes is purchased in China, which is recog-nized as having a monopoly on the production of rare metals (96% of REM produced world-wide). If we want to supply these needs in future, we will have to produce 10 tons per year of REM, which requires processing all available resources: mono- and polymineral raw materials. One of the most acceptable source of rare earth metals and some rare metals (zirconium, niobium, hafnium) is eudialyte. The world’s biggest deposits of eudialyte are found on the Kola Peninsula in northwest Russia, near the Lovozero mining and processing plant. Eudialyte concentrate is easily decomposed by acids, which explains its layered structure and weak chemical bonds between its constituent groups. The easy leaching process is the main reason that it is processed. In our work the technological possibility of extraction and separation of lanthanides has been shown, using solutions of naphthenic and oleic acid in an inert diluent with a stoichiometric reagent consumption, without the preoxidation step of the cerium to the tetravalent state. The technological parameters and stages of the process have been established.
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Date submitted2009-09-26
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Date accepted2009-11-21
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Date published2010-06-25
The measurements of emission parameters of tungsten thermo cathodes in plasma energetic equipments
Emission parameters and coefficients of reflection of heat electrons from tungsten thermo cathodes were investigated under nontraditional for emission electronic conditions, when the surface contacts with highly ionized plasma. For measurements plasma diode electron current-magnetic field strength relations were used. Parameter Dj, which characterizes cathode heterogeneity by work function, and coefficient of reflection for policrystallic tungsten and for face 110 tungsten single crystal were measured. Proportion entering in effective reflection coefficient of electrons, reflected immediately from the surface and from potential barrier of spots field was determinate.
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Date submitted2009-08-26
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Date accepted2009-10-27
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Date published2010-02-01
Scheelites of Gavrilovskoe deposit (first find)
- Authors:
- A. E. Melnik
The Gavrilovskoe deposit (deposit of building stone) is situated in Vyborg district, Leningrad region. There was found scheelite (CaWO 4 ) in the «Northern» quarry at the Gavrilovskoe deposit in 2008. This mineral was identified exactly in the Saint Petersburg State Mining Institute (Technical University) with Raman Spectrometer Renishaw InVia Reflex. It was for the first time that scheelite was found at this place. There was researched a form of one scheelite crystal. The simple forms of this scheelite crystal were detected. It is very interesting to compare simple forms of scheelite from the Gavrilovskoe deposit to different crystals of this mineral, described in any science literature.
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Date submitted2008-10-17
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Date accepted2008-12-07
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Date published2009-12-11
Morphometry of aggregates and modeling of phase transition kinetics under metamorphism
- Authors:
- Yu. L. Gulbin
The paper discusses some general relations between the structure of metamorphic rocks and mechanisms of phase reactions. Among these relations is the influence of nucleation and growth of kinetics on the crystal size distribution. A brief overview is made of theoretical models which have been proposed to explain granulometric properties of rocks, and kinetic laws and factors on the metamorphic crystallization are considered by the example of metapelitic garnets, including the phenomenon of avalanche nucleation at finite overheating as well as the growth of porphyroblasts under diffusion-limited conditions. As a result, a new approach to modeling of native granulometric curves is presented.
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Date submitted1958-03-29
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Date accepted1958-05-29
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Date published1958-05-09
О ПРИРОДЕ ЦИРКОНА ЩЕЛОЧНЫХ ПЕГМАТИТОВ ПРИАЗОВЬЯ
- Authors:
- Unknown
Затрагивая вопрос формирования кристаллов циркона в щелочных пегматитах, автор опирается главным образом на результаты обработки материала, собранного при изучении мариуполитов — щелочных пород, развитых в Приазовской части Украины. Однако просмотр литературы показывает, что, по-видимому, природа циркона, встречающегося и в других щелочных комплексах весьма тождественна. Решение этой задачи тесно связано с расшифровкой особенностей формирования вмещающих циркон мариуполитов, поэтому ниже рассматриваются основные черты генезиса мариуполитов в таком виде, в каком они были доложены на заседаниях Федоровской сессии.
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Date submitted1958-03-16
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Date accepted1958-05-23
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Date published1958-05-09
НОВЫЙ МЕТОД ОПРОБОВАНИЯ ПО ТИПАМ РАЗРЕЗОВ
- Authors:
- Unknown
Предлагаемый метод опробования основан на закономерной зависимости между строением рудных залежей по мощности и содержанием ценного минерала. Основным объектом исследования явилось месторождение, на котором наиболее крупные рудные залежи генетически и пространственно связаны с первично хорошо расслоенным комплексом пород. Основной причиной образования расслоенного комплекса пород и рудных залежей является кристаллизационная дифференциация, которая заключалась, по-видимому, в следующем: а) движении кристаллизующегося магматического расплава; б) гравитации; в) большом скоплении элементов, дающих легколетучие соединения; г) увеличении вязкости кристаллизующегося расплава; д) неравномерном (последовательном сверху — вниз) охлаждении интрузивного тела; е) двух периодах кристаллизации расплава: первом — медленной кристаллизации главным образом лейкократовых минералов, втором — более быстрой кристаллизации всех остальных минералов магматического происхождения.
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Date submitted1951-08-16
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Date accepted1951-10-09
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Date published1952-11-20
Recrystallization and metasomatism processes in mica-bearing and ceramic pegmatites
- Authors:
- D. Nikitin
Until very recently, a common view of pegmatite genesis has not been established among a large circle of geologists studying pegmatite deposits. A. E. Fersman's theory of pegmatite formation is still widely popular. The enormous work of A. E. Fersman and his group of colleagues, aimed at collecting materials characterizing the mineral composition of pegmatites in almost all regions of the USSR, played a major positive role, attracting general attention to these deposits and thereby facilitating their rapid industrial development. This group of researchers rightly established that the formation of pegmatites is a very complex process occurring in changing physicochemical conditions and that, in accordance with changes in crystallization conditions, the paragenetic associations of the resulting minerals change. However, a number of fundamental provisions of A. E. Fersman's general theory of pegmatite genesis, as is known, have not been justified. A. E. Fersman's ideas that pegmatites are formed by means of successive crystallization in a closed system, the so-called pegmatite water-fire melt, highly enriched in volatile components, have long been met with objections.
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Date submitted1948-07-20
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Date accepted1948-09-27
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Date published1949-11-04
Genetic relationship of crystal nests with quartz veins and the origin of cavities
- Authors:
- A. E. Karyakin
In the early stages of studying the piezo-optical quartz deposits of the Northern Urals, some geologists believed that crystal nests had no genetic connection with quartz veins. Geologists came to this conclusion because at that time the bulk of piezo-optical quartz was mined not from crystal nests, but from placers, and geologists did not have enough data to correctly resolve this issue. Later, in connection with the transition to exploration of primary deposits, it was established that in most cases quartz veins and crystal nests are located in the same cracks. The asymmetrical arrangement of crystal nests in relation to quartz veins does not give reason to deny the genetic relationship of both, but only indicates a later formation of crystal nests compared to quartz veins. In all likelihood, after the formation of quartz veins, there was a fairly long intermineralization break, after which crack formation and the flow of hydrothermal solutions resumed. The duration of the intermineralization break can be judged by the sharp change in the nature of the hydrothermal solutions - from highly supersaturated with silicic acid (during the formation of quartz veins) to normal (during the formation of quartz crystals). Consequently, quartz veins and crystal nests are derivatives of a single magmatic chamber, but they were only formed in different phases of a single hydrothermal process.
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Date submitted1908-03-02
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Date accepted1908-05-24
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Date published1908-09-01
Crystals of the Mineralogical Museum
- Authors:
- Ye. S. Fedorov
Natural crystals are the most difficult object for the method of crystal-chemical analysis, and I must admit that my attempt to give the correct setting to all minerals turned out to be imperfect in many points. But it was precisely this imperfection that prompted the further development of criteria for correct installation, and pointed to the need to reconsider and individually study the crystals of many minerals.