182 research outputs found

    Cutting-edge industrial technology of mining tool manufacturing

    Get PDF
    Purpose. To conduct a comparative economic analysis of cermet alloys regeneration technology, to identify the most “environmentally friendly” and cost-effective processing of solid alloys waste. Methods. As a research technique, the present article considers analysis of current methods of solid tungsten cobalt alloys regeneration: pyro and hydro metallurgical, chemical (chlorine, zinc), thermochemical and the method which uses energy of blasting explosives. Findings. A comparative economic analysis of cermet alloys regeneration technologies was conducted. Originality. Fundamental way of shock wave treatment to stimulate destruction of powder product of any configuration in order to obtain a high quality powder for further formation, sintering and tool manufacturing of multiple use is demonstrated; ecologically friendly technology of hard alloys and cermet components of outdated military hardware and ammunition recycling has been developed. Practical implications. Industrial implementation of the developed technology allows to solve the following issues: – utilizing super hard metal and alloys scrap for subsequent regeneration, which ensures significant savings of strategic raw material; – the use of new technology, which excludes ineffective ways of scarce raw materials processing and manufacturing products satisfying international standards; – gradual reduction of import in favor of hard alloys cermet tools; – reduction and subsequent abandonment of strategic metals and alloys scrap export, shifting towards the export of ready products – powders and tools, which will significantly increase foreign currency earnings in the country.Мета. Провести порівняльний економічний аналіз технологій регенерації металокерамічних сплавів і вибрати найбільш “екологічно чисту” та рентабельну технологію переробки відходів твердих сплавів. Методика. В якості методики дослідження для представленої роботи було проаналізовано кілька існуючих методів регенерації відходів вольфрамом кобальтових твердих сплавів: піро- й гідрометалургійний, хімічний (хлорний, цинковий), термохімічний та із застосуванням енергії вибуху бризантних вибухових речовин. Результати. Проведено порівняльний економічний аналіз технологій регенерації металокерамічних сплавів. Наукова новизна. Показана принципова можливість використання ударно-хвильової обробки як фактора, що стимулює процеси руйнування порошкових виробів будь-якої конфігурації, з метою отримання високоякісного порошку для подальшого формування, спікання й виробництва інструменту різного призначення; запропоновано екологічно чисту технологію переробки надтвердих матеріалів, металокерамічних складових застарілої військової техніки та різних видів боєприпасів. Практична значимість. Промислове освоєння розробленої технології дозволяє вирішити наступні проблеми: – утилізацію лому надтвердих матеріалів і сплавів з їх подальшим відновленням і відповідно значною економією стратегічної сировини; – використання нової технології з виключенням вживання малоефективних способів переробки дефіцитної сировини і випуск продукції світового рівня якості; – поступова відмова від імпорту у бік твердосплавного металокерамічного інструменту; – зменшення, а потім і відмова, від експорту за межі України лому стратегічних матеріалів і сплавів, з переходом до експорту готових виробів-порошків та інструменту, що значно збільшить валютні надходження в країну.Цель. Провести сравнительный экономический анализ технологий регенерации металлокерамических сплавов и выбрать наиболее “экологически чистую” и рентабельную технологию переработки отходов твердых сплавов. Методика. В качестве методики исследования в настоящей работе были проанализированы несколько существующих методов регенерации отходов вольфрамом кобальтовых твердых сплавов: пиро- и гидрометаллургический, химический (хлорный, цинковый), термохимический и с применением энергии взрыва бризантных взрывчатых веществ. Результаты. Проведен сравнительный экономический анализ технологий регенерации металлокерамических сплавов. Научная новизна. Показана принципиальная возможность использования ударно-волновой обработки как фактора, стимулирующего процессы разрушения порошковых изделий любой конфигурации, с целью получения высококачественного порошка для дальнейшей формовки, спекания и производства инструмента различного назначения; предложена экологически чистая технология переработки сверхтвердых материалов, металлокерамических составляющих устаревшей военной техники и различных видов боеприпасов. Практическая значимость. Промышленное освоение разработанной технологии позволяет решить следующие проблемы: – утилизацию лома сверхтвердых материалов и сплавов с их последующим восстановлением и соответственно значительной экономией стратегического сырья; – использование новой технологии с исключением употребления малоэффективных способов переработки дефицитного сырья и выпуск продукции мирового уровня качества; – постепенный отказ от импорта в сторону твердосплавного металлокерамического инструмента; – уменьшение, а затем и отказ, от экспорта за пределы Украины лома стратегических материалов и сплавов, с переходом к экспорту готовых изделий – порошков и инструмента, что значительно увеличит валютные поступления в страну.Scientific work is done in the framework of complex special purpose program “Organizing collection, utilization and recycling processes of hard alloys containing tungsten, tungsten scrap, molybdenum, cobalt and their alloys”. The authors extend their thanks to Rostyslav Didyk, Professor with the Department of Mining Engineering of the National Mining University

    Silicate-sulfide liquid immiscibility in modern arc basalt (Tolbachik volcano, Kamchatka): Part I. Occurrence and compositions of sulfide melts

    Get PDF
    Silicate-sulfide liquid immiscibility plays a key role in the formation of magmatic sulfide ore deposits but incipient sulfide melts are rarely preserved in natural rocks. This study presents the distribution and compositions of olivine-hosted sulfide melt globules resulting from silicate-sulfide liquid immiscibility in primitive arc basalts. Abundant sulfide droplets entrapped in olivine from primitive basalts of the 1941 eruption and pre-historic eruptive cone “Mt. 1004” of the Tolbachik volcano, Kurile-Kamchatka arc. Inclusions range from submicron to 250 μm in size, coexist with sulfur-rich glass (≤ 1.1 wt% S), and, in some cases, with magmatic anhydrite. Saturation in sulfide occurred early in the evolution of a water- and sulfur-rich magma, moderately oxidized (QFM + 1 to +1.5), which crystallized high-Mg olivine (Fo₈₆ˍ₉₂), clinopyroxene and Cr-spinel. The process developed dense “clouds” of sulfide in relatively small volumes of magma, with highly variable abundances of chalcophile metals. The low degree of sulfide supersaturation promoted diffusive equilibration of the growing droplets with the melt in Ni and Cu, resulting in high concentrations (≈ 38 mol%) of CuS and NiS in the earliest sulfide liquids. The Tolbachik samples provide a glimpse into deep arc processes not seen elsewhere, and may show how arc magmas, despite their oxidized nature, saturate in sulfide.This study was supported by the Russian Science Foundation grant # 16-17-10145. This is CRPG contribution #253

    Platinum-group elements and gold in sulfide melts from modern arc basalt (Tolbachik volcano, Kamchatka)

    Get PDF
    Sulfide melt inclusions entrapped in primitive olivine phenocrysts can be used to understand the compositions of early sulfide melts that may ultimately contribute to magmatic sulfide ore deposits. Sulfide globules hosted in olivine (86–92 mol% Fo) from the Tolbachik basalt (the 1941 eruption) are characterized in terms of their major and trace element abundances using electron microscopy and LA–ICP–MS analysis. Distribution of major elements within individual sulfide globules varies from homogeneous to heterogeneous. Phases include monosulfide solid solution (MSS) and intermediate solid solution (ISS) intergrowths and exsolved low-temperature minerals such as pyrrhotite, pentlandite, chalcopyrite and cubanite. Trace elements (platinum-group elements — PGE, Ag, Te, Au, Pb and Bi) are also present in solid solution in sulfide phases and as micron-sized particles (“nuggets”). Such nuggets of dominantly Au, Pt, Au–Pd and Pd–Te are contained randomly within sulfide matrices or, more commonly, at phase boundaries. Nuggets are also attached to outer surfaces of sulfide globules. Concentrations of PGE in sulfides follow a log normal distribution over four orders of magnitude. The highest measured noble metal concentrations in the analyzed globules (436 ppm Au + PGE) are 13.3 ppm Au, 115 ppm Pt and 299 ppm Pd, whereas 40% of globules have < 15 ppm of noble metals. Gold and PGE concentrations correlate, suggesting these elements were concentrated by the same process(es). We propose that a number of anomalous concentrations of one or several noble metals in the analyzed globules can be best explained by entrapment of Au–PGE-rich particles (solid or liquid) from the silicate melt. Although the individual Tolbachik sulfide globules have variable PGE abundances, their mean composition resembles those of major PGE-sulfide ore deposits (e.g., Norilsk, Sudbury, Platreef and Merensky Reef).This study was supported by the Russian Science Foundation grant #16-17-1014

    Enriched, HIMU-type peridotite and depleted recycled pyroxenite in the Canary plume : a mixed-up mantle

    Get PDF
    Author Posting. © Elsevier B.V., 2009. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Earth and Planetary Science Letters 277 (2009): 514-524, doi:10.1016/j.epsl.2008.11.013.The Earth’s mantle is chemically and isotopically heterogeneous, and a component of recycled oceanic crust is generally suspected in the convecting mantle [Hofmann and White, 1982. Mantle plumes from ancient oceanic crust. Earth Planet. Sci. Lett. 57, 421-436]. Indeed, the HIMU component (high μ = 238U/204Pb), one of four isotopically distinct end-members in the Earth’s mantle, is generally attributed to relatively old (≥1-2 Ga) recycled oceanic crust in the form of eclogite/pyroxenite, e.g. [Zindler and Hart, 1986. Chemical geodynamics. Ann. Rev. Earth Planet. Sci. 14, 493-571]. Although the presence of the recycled component is generally supported by element and isotopic data, little is known about its physical state at mantle depths. Here we show that the concentrations of Ni, Mn and Ca in olivine from the Canarian shield stage lavas, which can be used to asses the physical nature of the source material (peridotite versus olivine-free pyroxenite) [Sobolev et al., 2007. The amount of recycled crust in sources of mantle-derived melts. Science 316, 412-417], correlate strongly with bulk rock Sr, Nd and Pb isotopic ratios. The most important result following from our data is that the enriched, HIMU-type (having higher 206Pb/204Pb than generally found in the other mantle endmembers) signature of the Canarian hotspot magmas was not caused by a pyroxenite/eclogite constituent of the plume but appears to have been primarily hosted by peridotite. This implies that the old (older than ~1 Ga) ocean crust, which has more evolved radiogenic isotope compositions, was stirred into/reacted with the mantle so that there is not significant eclogite left, whereas younger recycled oceanic crust with depleted MORB isotopic signature (<1 Ga) can be preserved as eclogite, which when melted can generate reaction pyroxenite.This work was supported by Wolfgang Paul Award, Alexander von Humboldt Foundation, to AVS, the Max Planck Society, DFG grants SCHM 250/64 and 82-1, HA3097/2 to HUS, KH and FH, NSF Grant EAR-9105113 to KH, Russian Basic Research Foundation and Russian Academy of Sciences

    Origin of volatiles emitted by Plinian mafic eruptions of the Chikurachki volcano, Kurile arc, Russia : trace element, boron and sulphur isotope constraints

    Get PDF
    Author Posting. © The Author(s), 2017. This is the author's version of the work. It is posted here under a nonexclusive, irrevocable, paid-up, worldwide license granted to WHOI. It is made available for personal use, not for redistribution. The definitive version was published in Chemical Geology 478 (2018): 131-147, doi:10.1016/j.chemgeo.2017.10.009.Chikurachki is a 1816-m high stratovolcano on Paramushir Island, Kurile arc, Russia, which has repeatedly produced highly explosive eruptions of mafic composition. The present work is aimed at constraining the origin of volatile components (CO2, H2O, F, S, and Cl), along with B and S isotopic compositions in a series of phenocryst-hosted melt inclusions and groundmass glasses from basaltic andesite pyroclasts of the 1853, 1986, and prehistoric Plinian eruptions of the volcano. The ranges of volatile concentrations in melt inclusions (47–1580 μg/g CO2, 0.4–4.2 wt% H2O, 399–633 μg/g F, 619–3402 μg/g S and 805–1240 μg/g Cl) imply a sudden pressure release from ~ 460 through ~ 35 MPa that corresponds to ~ 1.2–16-km-depth range of magma ascent upon decompression. We conclude that rapid ascent of the volatile-rich basaltic magmas from ~ 16-km initial depth accompanied by near-surface bubble nucleation and growth, and subsequent magma fragmentation appear to be a primary reason for the Plinian character of the Chikurachki eruptions. Significant negative correlations of S with K, Zr, Nb, Ba, La, Ce, Pr (R = − 0.8 to − 0.9), no clear relationships of S with H2O, CO2 and Cl, but strong positive correlations of S/K2O with H2O/K2O, Cl/K2O and F/K2O preclude magma degassing to be the only process affecting volatile concentrations dissolved in the melt. The δ34S values of the studied inclusion and groundmass glasses range from − 1.6 to + 12.3‰, decrease with decreasing S, show significant positive correlations with H2O/K2O, Cl/K2O and F/Zr, and negative correlations with a number of incompatible trace elements. Neither open- nor close-system magma degassing can account for the observed range of δ34S. The δ11B values of the melt inclusions range from − 7.0 to + 2.4‰ with 13–23 μg/g B. The relationships of δ11B with B/K2O and B/Nb are inconsistent with magma contamination at shallow crustal depths. Linear character of 1/S vs. δ34S relationship suggests two-component mixing. The possible mixing end-members could be the magmas having similar major and trace element compositions, but strongly contrasting volatile contents and S isotopes. Based on the behaviour of fluid-mobile vs. fluid-immobile incompatible trace elements, we conclude that the subduction component likely represents a mixture of subduction sediment-derived melt with up to 60% of slab-derived fluid. Admixture of ~ 1–8% of the inferred subduction component to the depleted mantle wedge source is required to account for the compositional range of the Chikurachki melt inclusions, and ~ 0.4–10% to constrain the composition of Kurile arc mafic magmas.This work was benefited from the NENIMF financial support of AAG during his training as a SIMS research specialist, the NSF grant EAR 0911093 to AAG, and partially from the Russian Science Foundation grant #16-17-10145 to VSK and MEZ

    Oxygen isotopes and volatile contents of the Gorgona komatiites, Colombia: A confirmation of the deep mantle origin of H2O

    Get PDF
    We report O isotopes in olivine grains (Fo89–93) and volatile contents (CO2, H2O, F, S, Cl) in olivine-hosted melt inclusions from one Gorgona picrite and five komatiites with the aim of constraining the origin of H2O in these magmas. These samples have previously been analysed for major and trace elements and volatile concentrations (H2O, S, Cl) and B isotopes in melt inclusions. A distinctive feature of the included melts is relatively high contents of volatile components and boron, which show positive anomalies in, otherwise depleted, primitive mantle normalised trace and rare earth element patterns and range in δ11B from −11.5 to 15.6‰. In this study, the olivines were systematically analysed for O isotopes (1) in the centre of grains, (2) near the grain boundaries and, (3) as close as possible to the studied melt inclusions. The majority of olivines (∼66%) are “mantle”-like, ‰‰ 4.8‰≤δ18O≤5.5‰ , with a subordinate but still significant number (∼33%) above, and only 2 grains below, this range. There is no systematic difference between the central and marginal parts of the grains. Higher than “mantle” δ18OOl values are ascribed to low-T (<300 °C) serpentinisation along inner fractures and grain boundaries of olivine phenocrysts. The measured concentrations of volatile components in the melt inclusions corrected for the effects of post-entrapment crystallisation and H2O–CO2 exsolution in inclusion shrinkage bubbles are: 286–1748 μg/g CO2, 0.2–0.86 wt.% H2O, 48–82 μg/g F, 398–699 μg/g S and 132–198 μg/g Cl. They correspond to a pressure of 86±44MPa or ∼2.5-km crustal depth of olivine crystallisation. The correlations of S and, to a lesser extent, of H2O, with highly incompatible lithophile elements and the correlation of F with Cl, but no relationships of H2O with Cl, rule out shallow depth magma degassing and/or crustal contamination. Our new δ18O olivine and volatile component data combined with the existing, highly variable δ11B values for melt inclusions also support the deep mantle origin of H2O (and probably other volatiles) in the Gorgona mafic and ultramafic magmas

    Миграция высокодоступного кластера VMware vSphere

    Get PDF
    The virtual machines platforms find frequent or regular application when designing the telecommunication infrastructures. The implementation-level virtualization system software and continuous updates of its versions remains inevitably relevant. The work focuses mainly on the reasons for virtualization and benefits of migration to an updated version of high-availability computing vSphere cluster development of VMware company using, as an example, a corporate network of one of the Moscow universities.The authors have formulated the basic benefits available with the initial introduction of a platform of the virtual machines. Among them are allocated: simplifying the network environment configuration, increasing the flexibility of using servers, their availability and quality of server infrastructure management, increasing the hardware utilization factor. In addition, reducing maintenance costs of equipment and electricity is achieved.In addition to the benefits of virtualization, a clear benefit from the update is gained, i.e. migrations of vSphere cluster to a new version using built-in capabilities meeting up-to-date network technologies. The article also concerns the preparation for migration and the upgrade process itself. An effect achieved as a result of migration is systematized and presented in the form of diagrams to reflect the quantitative evaluation of the received benefits for a number of positions. These are as follows: the reduced load on the power supplies in your server farm, increasing a share of the useful use of CPUs and RAM, reducing downtime of the virtual machines in the host failure, more economic distribution of computing load on physical servers.The article summarizes the results of migration, shows new functionality and information technology offered to the network owner resulting from the cluster upgrade. In particular, it mentions the introduction of distance learning and the creation of a corporate portal with electronic document management software.The results of this paper can be useful for specialists in virtualization and network infrastructure, who are engaged in supporting large corporate networks.Статья посвящена вопросу практической миграции ядра сетевой инфраструктуры, построенного на базе виртуального кластера VMware vSphere, на новую версию программного обеспечения. Указаны причины первоначального перехода от традиционной организации серверной платформы к платформе виртуальных машин. Отмечены достоинства технологии виртуализации. Описан процесс перехода высокодоступного кластера VMware vSphere с версии 4.0 на версию 5.1. Основное внимание уделено преимуществам миграции, касающимся разгрузки силовых цепей и повышения энергоэффективности серверной фермы, оптимизации подключения физических серверов, загрузки процессорных устройств и оперативной памяти, сокращения времени простоя виртуальных машин. Результаты работы могут быть полезны специалистам в области сетевой инфраструктуры в качестве опыта обновления платформы виртуализации крупной корпоративной сети. Актуальность работы обусловлена отсутствием универсального подхода к обновлению из-за уникальности архитектурных решений каждой корпоративной сети, что приводит к различиям в практическом осуществлении миграции. DOI: 10.7463/rdopt.0315.078963

    Oxygen isotope heterogeneity of the mantle beneath the Canary Islands : insights from olivine phenocrysts

    Get PDF
    Author Posting. © The Author(s), 2010. This is the author's version of the work. It is posted here by permission of Springer for personal use, not for redistribution. The definitive version was published in Contributions to Mineralogy and Petrology 162 (2011): 349-363, doi:10.1007/s00410-010-0600-5.A relatively narrow range of oxygen isotopic ratios (δ18O = 5.05.4‰) is preserved in olivine of mantle xenoliths, mid-ocean ridge (MORB) and most ocean island basalts (OIB). The values in excess of this range are generally attributed either to the presence of a recycled component in the Earth’s mantle or to shallow level contamination processes. A viable way forward to trace source heterogeneity is to find a link between chemical (elemental and isotopic) composition of the earlier crystallized mineral phases (olivine) and the composition of their parental magmas, then using them to reconstruct the composition of source region. The Canary hotspot is one of a few that contains ~1-2 Ga old recycled ocean crust that can be traced to the core-mantle boundary using seismic tomography and whose origin is attributed to the mixing of at least three main isotopically distinct mantle components i.e., HIMU, DMM and EM. This work reports ion microprobe and single crystal laser fluorination oxygen isotope data of 148 olivine grains also analyzed for major and minor elements in the same spot. The olivines are from 20 samples resembling the most primitive shield stage picrite through alkali basalt to basanite series erupted on Gran Canaria, Tenerife, La Gomera, La Palma and El Hierro, Canary Islands, for which shallow level contamination processes were not recognized. A broad range of δ18Oolivine values from 4.6 to 6.1‰ was obtained and explained by stable, long-term oxygen isotope heterogeneity of crystal cumulates present under different volcanoes. These cumulates are thought to have crystallized from mantle derived magmas uncontaminated at crustal depth, representing oxygen isotope heterogeneity of source region. A relationship between Ni×FeO/MgO and δ18Oolivine values found in one basanitic lava erupted on El Hierro, the westernmost island of the Canary Archipelago, was used to estimate oxygen isotope compositions of partial melts presumably originated from peridotite (HIMU-type component inherited its radiogenic isotope composition from ancient, ~12 Ga, recycled ocean crust) and pyroxenite (young, <1 Ga, recycled oceanic crust preserved as eclogite with depleted MORB-type isotopic signature) components of the Canary plume. The model calculations yield 5.2 and 5.9±0.3‰ for peridotite and pyroxenite derived melts, respectively, which appeared to correspond closely to the worldwide HIMU-type OIB and upper limit N-MORB δ18O values. This difference together with the broad range of δ18O variations found in the Canarian olivines cannot be explained by thermodynamic effects of oxygen isotopic fractionation and are believed to represent true variations in the mantle, due to oceanic crust and continental lithosphere recycling.This work was supported by the CNRS “poste rouge” grant to AG, the NSF EAR-CAREER-0844772 grant to IB and the CRPG-CNRS and at its initial stage by the DFG (grant SCHM 250/64) and the Alexander von Humboldt Foundation (Wolfgang Paul Award to A.V. Sobolev who provided access to the electron microprobe at the Max Planck Institute, Mainz, Germany)
    corecore