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Date submitted2022-11-29
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Date accepted2023-03-02
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Date published2023-10-27
New data on the composition of growth medium of fibrous diamonds from the placers of the Western Urals
This article presents the results of studying microinclusions of fluids/melts in diamonds from the placers of the Krasnovishersky District (western slope of the Middle/Northern Urals), which make it possible to establish the evolution of diamond-forming media in the subcontinental lithospheric mantle of the eastern margin of the East European craton. Impurity composition of the studied crystals reveals three different types of diamonds, the formation of which was associated with separated metasomatic events. Microinclusions in B-type diamonds containing A and B nitrogen defects reflect an older metasomatic stage characterized by the leading role of silicic and low-Mg carbonatitic fluids/melts. The second stage is associated with the growth of A-type diamonds containing nitrogen exclusively in the form of A-centers. At this stage, the formation of diamonds was related with low-Mg carbonatitic media, more enriched in MgO, CaO, CO2, and Na2O compared to B-type diamonds. The third stage probably preceded the eruption of the transporting mantle melt and led to the formation of C-type diamond containing A and C nitrogen defect centers and microinclusions of silicic to low-Mg carbonatitic composition. The recorded trend in the evolution of diamond-forming fluids/melts is directed towards more carbonatitic compositions. Fluids/melts are probably sourced from eclogitic and pyroxenitic mantle substrates.
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Date submitted2018-08-29
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Date accepted2018-10-25
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Date published2019-02-22
The study of the effect of temperature on the ability of metals to accumulate energy during their plastic deformation
The subject of research is the surface layer of highly loaded parts, friction units of mining machines and equipment. The article presents a theoretical analysis of the factors that determine the ability of the material of the surface layer of parts to accumulate energy in the process of plastic deformation. It is suggested that the activation character of the accumulation of energy by metals. Based on the theory of diffusion, it was shown that the mobility of atoms, as well as the accumulated energy, are determined by the ratio of the test temperature to the melting temperature.
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Date submitted2017-11-20
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Date accepted2018-01-09
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Date published2018-04-24
Sulfidization of silver-polymetallic ores of «Goltsovoe» deposit for decreasing loss of silver in mill tailings
- Authors:
- L. V. Shumilova
- O. S. Kostikova
The results of laboratory studies of flotation concentration of silver-polymetallic ores of the Goltsovoe deposit at the Omsukchansk concentrator are presented. The results of sieve analysis of mill tailings of the experimental sample of MTP N 101 (N 7577-i) are described. They indicate that a large amount of silver (123 g/t) is lost in the size class – 0.040 mm (yield 50.25 %). According to the results of mineralogical analysis, it is established that the major losses of noble metal are associated with its fine impregnation in oxides, sulfides and silicate rocks. The main silver-bearing minerals are acanthite, polybasite and kustelite (class – 0.040 mm). Experimental studies were carried out in two stages. The purpose of the first stage is to determine the influence of grinding fineness in flotation feed (for a finished class content of 0.074 mm in the range of 60-95 %) for silver recovery at different amounts of butyl potassium xanthate (50, 150, 300 g/t). The purpose of the second stage is to evaluate the effectiveness of sulfidization at different consumption of sodium sulfide Na 2 S·9H 2 O (50, 150, 200, 450, 750 g/t – 1 % aqueous solution) under the conditions of the optimal reagent mode established in the first stage of the study. The results of experiments to determine the optimum grinding fineness and studies on the enrichment of silver-polymetallic ore with the use of sodium sulfide as a sulfidizer are presented. The efficiency of the sulfidization process is estimated. The following experimental dependencies of silver recovery are established: on the degree of grinding and consumption of butyl potassium xanthate; on variations of grinding fineness and the consumption of sodium sulphide (with a consumption of butyl xanthate 150 g/t); and on grinding fineness at optimum consumption of sodium sulfide 150 g/t and butyl potassium xanthate 300 g/t. A comparative evaluation of dependence of silver recovery index from the degree of grinding fineness before and after introduction of sodium sulphide (collecting agent consumption of 150 g/t) is given. T\
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Date submitted2014-11-19
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Date accepted2015-01-12
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Date published2015-10-26
Scientific heritage of academician Nikolay Semenovich Kurnakov
- Authors:
- O. A. Dubovikov
Once N.V.Lipin, a professor of mathematics at the Leningrad Mining Institute, told N.S.Kurnakov that M.V.Lomonosov had complained about his lack of familiarity with mathematics. The outstanding scientist replied «That’s absolutely true, and I have already told you about it: we all need mathematics, and the more chemistry develops, the more it needs a mathematical justification». According to one scenario of the international nongovernmental organization, the Club of Rome, there will be a three-fold decrease in the world’s raw materials resources and multifold volume reduction in industrial production by the middle of the 21st century. Another scenario claims that raw materials will reduce only by one third, and the volume of industrial production will remain at the level of the beginning of the century. Not only the first scenario, but also the second one forecasts industrial stagnation. It is unacceptable for dynamic and sustainable development of the technological civilization. Intensively developing economies in China, India, Brazil and Russia defy the forecast of the Club of Rome, as it has not taken into account the possibility of scientific and technological progress in reducing energy consumption and using alternative sources, as well as the increased technological potential of the humanity. Due to depletion of the main sources of energy (oil and gas), many experts link the future of the world’s power industry with the possible use of solid energy resources. From the environmental point of view solid fuel gasification technology is the most preferable. As the calorific value of producer gas is relatively low in comparison with natural gas, some research of possible use of producer gas (as an alternative to natural gas which is available not in all regions) at Russian industrial enterprises has been conducted.