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G. I. Antonov - One of the best experts on this subject based on the ideXlab platform.
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Chromite-Periclase roof articles
Refractories and Industrial Ceramics, 1996Co-Authors: G. I. Antonov, V. P. NedosvitiiAbstract:An investigation of the technology for chromite-Periclase roof articles is presented. With a scarcity of Periclase powders compositions with 25–30% granular chromium ore and 35% finely milled mixture of Periclase and chromite seem a suitable material for chromite-Periclase roof linings. It is possible to use charges with 65% scrap. Specifications have been developed, experimental batches produced and tested, and industrial-scale production begun.
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Magnesia refractories from Slovakian Periclase
Refractories, 1996Co-Authors: Yu. D. Gerashchuk, G. I. Antonov, N. V. Il’chenko, L. K. Poltavets, G. N. Shcherbenko, Zh. A. GrivakovaAbstract:The Nikitovsk Dolomite Plant has produced an experimental industrial batch of magnesia articles based on Slovakian Periclase. Results have shown that the articles made of Slovakian Periclase correspond to the requirements of GOST 10888-76 for Periclase-chromite refractories and GOST 4689-74 for Periclase refractories.
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Production of an experimental batch of stabilized dolomite-Periclase refractories
Refractories, 1996Co-Authors: Yu. D. Gerashchuk, G. I. Antonov, L. K. Poltavets, V. P. Nedosvitii, I. V. Il'chenko, Zh. A. GrivakovaAbstract:Briquets based on dolomite and waste from chrome ore concentration have been used for producing an experimental batch of environmentally safe stabilized dolomite-Periclase refractories with operational properties comparable to chromite-Periclase counterparts. A special technological run including preparation and roasting of clinker will be required for commercial production.
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Periclase refractories from imported powders
Refractories, 1995Co-Authors: G. I. Antonov, G. N. Shcherbenko, L. M. YakobchukAbstract:Ten charges with different compositions were obtained from Periclase refractories and used to investigate the parameters of Periclase articles. The properties of articles of industrial size prepared from imported powders did not differ from those prepared from Satkinsky Periclase.
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Production of refractories from Chinese Periclase
Refractories, 1995Co-Authors: N. P. Borovik, G. I. Antonov, L. V. Pererva, V. I. Koroteeva, G. N. ShcherbenkoAbstract:Periclase refractories from Chinese Periclase are produced by the Chasovo-Yarsky Refractory Plant. The refractories have been tested with positive results at a number of metallurgical works, and specifications have been established for articles.
R. Abart - One of the best experts on this subject based on the ideXlab platform.
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Reaction-induced fracturing in a hot pressed calcite-Periclase aggregate
Journal of Structural Geology, 2017Co-Authors: H. Kuleci, E. Rybacki, Ole Ivar Ulven, B. Wunder, R. AbartAbstract:Abstract The chemo-mechanical feedbacks associated with hydration of Periclase immersed in a calcite matrix were investigated experimentally. Dense calcite-Periclase aggregates with
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Hydration of Periclase at 350 ^∘ C to 620 ^∘ C and 200 MPa: experimental calibration of reaction rate
Mineralogy and Petrology, 2016Co-Authors: H. Kuleci, C. Schmidt, E. Rybacki, E. Petrishcheva, R. AbartAbstract:The hydration of Periclase to brucite was investigated experimentally. Single crystals of Periclase machined to millimeter sized cubes with (100) surfaces were reacted with distilled water at temperatures of 350 to 620 ^∘C and a pressure of 200 MPa for run durations of 5 to 40 minutes. Hydration produced a layer of brucite covering the surface of Periclase. While the shrinking Periclase largely retained its cube shape a surface roughness developed on the μ m scale and eventually outward pointing spikes bounded by (111) faces emerged on the retreating faces of the Periclase due to kinetic selection of less reactive (111) and (110) surfaces. The Periclase to brucite conversion followed a linear rate law, where the reaction rate increased from 350 to 530 ^∘C and then decreased towards higher temperature and finally vanished at about 630 ^∘C, where Periclase, brucite, and water are in equilibrium at 200 MPa. The overall kinetics of the hydration reaction is conveniently described in terms of a phenomenological interface mobility. Measuring the velocity of the hydration front relative to the lattice of the reactant Periclase, the temperature dependence of its mobility is described by an Arrhenius relation with pre-exponential factor 1.7.10^−12 m ^4/s.J and activation energy of E _ A =55 kJ/mol.
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hydration of Periclase at 350 c to 620 c and 200 mpa experimental calibration of reaction rate
Mineralogy and Petrology, 2016Co-Authors: H. Kuleci, C. Schmidt, E. Rybacki, E. Petrishcheva, R. AbartAbstract:The hydration of Periclase to brucite was investigated experimentally. Single crystals of Periclase machined to millimeter sized cubes with (100) surfaces were reacted with distilled water at temperatures of 350 to 620 ∘C and a pressure of 200 MPa for run durations of 5 to 40 minutes. Hydration produced a layer of brucite covering the surface of Periclase. While the shrinking Periclase largely retained its cube shape a surface roughness developed on the μm scale and eventually outward pointing spikes bounded by (111) faces emerged on the retreating faces of the Periclase due to kinetic selection of less reactive (111) and (110) surfaces. The Periclase to brucite conversion followed a linear rate law, where the reaction rate increased from 350 to 530 ∘C and then decreased towards higher temperature and finally vanished at about 630 ∘C, where Periclase, brucite, and water are in equilibrium at 200 MPa. The overall kinetics of the hydration reaction is conveniently described in terms of a phenomenological interface mobility. Measuring the velocity of the hydration front relative to the lattice of the reactant Periclase, the temperature dependence of its mobility is described by an Arrhenius relation with pre-exponential factor 1.7.10−12 m 4/s.J and activation energy of EA=55 kJ/mol.
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Hydration of Periclase at 350 ∘ C to 620 ∘ C and 200 MPa: experimental calibration of reaction rate
Mineralogy and Petrology, 2015Co-Authors: H. Kuleci, C. Schmidt, E. Rybacki, E. Petrishcheva, R. AbartAbstract:The hydration of Periclase to brucite was investigated experimentally. Single crystals of Periclase machined to millimeter sized cubes with (100) surfaces were reacted with distilled water at temperatures of 350 to 620 ∘C and a pressure of 200 MPa for run durations of 5 to 40 minutes. Hydration produced a layer of brucite covering the surface of Periclase. While the shrinking Periclase largely retained its cube shape a surface roughness developed on the μm scale and eventually outward pointing spikes bounded by (111) faces emerged on the retreating faces of the Periclase due to kinetic selection of less reactive (111) and (110) surfaces. The Periclase to brucite conversion followed a linear rate law, where the reaction rate increased from 350 to 530 ∘C and then decreased towards higher temperature and finally vanished at about 630 ∘C, where Periclase, brucite, and water are in equilibrium at 200 MPa. The overall kinetics of the hydration reaction is conveniently described in terms of a phenomenological interface mobility. Measuring the velocity of the hydration front relative to the lattice of the reactant Periclase, the temperature dependence of its mobility is described by an Arrhenius relation with pre-exponential factor 1.7.10−12 m 4/s.J and activation energy of EA=55 kJ/mol.
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microstructure and texture evolution during growth of magnesio aluminate spinel at corundum Periclase interfaces under uniaxial load the effect of stress concentration on reaction progress
American Journal of Science, 2014Co-Authors: E. Rybacki, R. Abart, Je P Abek, Gerlinde HablerAbstract:Reaction rims of magnesio-aluminate spinel were grown at the contacts between Periclase and corundum at temperatures of 1250 °C to 1350 °C and under uniaxial load of 0.026 and 0.26 kN per 9 mm2 of initial contact area. Single crystals of Periclase with [100] and of corundum with [0001] perpendicular to the polished reaction interface as well as polycrystalline corundum were used as starting materials. Immediate application of the load before heating resulted in deformation twinning and fracturing of corundum introducing stress concentration and lateral variations in the quality of physical contact at the reaction interface. The tight contacts are characterized by enhanced reaction progress which together with the positive volume change of the reaction and limits on plasticity of the studied phases led to the opening of void spaces along the reaction interface and large lateral variations in rim thickness occur. Spinel shows strong topotactic relations to the reactant phases including full topotaxy between spinel and Periclase, partial topotaxy with (111)spi‖(0001)cor and {101}spi‖{10-10}cor, and axiotaxy with (111)spi‖(0001)cor between spinel and corundum. Oriented nucleation and selective growth were the main mechanism of texture formation. Stress concentrations and tight physical contacts across the reaction interface may enhance nucleation of topotactic grains. The respective spinel–Periclase and spinel–corundum reaction interfaces are mostly semi-coherent with sets of line dislocations accounting for the lattice misfit. The systematic occurrence of porosity along the semi-coherent and its absence along the incoherent sections of the spinel–Periclase interface reflect the different capacities of the (semi)-coherent and incoherent interface sections for annihilating the vacancies that were emitted from the advancing spinel–Periclase reaction interface.
Daisuke Yamazaki - One of the best experts on this subject based on the ideXlab platform.
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interconnection of ferro Periclase controls subducted slab morphology at the top of the lower mantle
Earth and Planetary Science Letters, 2014Co-Authors: Daisuke Yamazaki, Takashi Yoshino, Tomoeki NakakukiAbstract:Abstract The electrical conductivity of mantle rocks during phase transformation from ringwoodite to silicate perovskite and ferro-Periclase was measured at 25 GPa and various temperatures ranging from 1300 to 1900 K. The electrical conductivity was high at the initial stage of annealing, suggesting that ferro-Periclase forms interconnected layers in aggregates of silicate perovskite and ferro-Periclase that are representative of lower mantle rock. At 1900 K the electrical conductivity quickly decreased and reached that of silicate perovskite, suggesting the cut-off of the interconnected ferro-Periclase because of rounding of crystals. Below 1700 K, the high conductivity values were maintained for experimental duration. The interconnection of ferro-Periclase, which has a lower viscosity than silicate perovskite, can be maintained in a cold descending slab over geological time scales (∼1 My), indicating that a colder slab is less viscous than the warmer mantle surrounding it. The low-viscosity slab can be prevented from penetrating into the deeper part of the lower mantle by the high viscosities encountered at a depth of ∼1000 km, referred to as the “viscosity hill”, that cause stagnation at this depth as observed by seismic tomography.
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texture of mg fe sio3 perovskite and ferro Periclase aggregate implications for rheology of the lower mantle
Physics of the Earth and Planetary Interiors, 2009Co-Authors: Daisuke Yamazaki, Takashi Yoshino, Tomoo Katsura, Takuya Matsuzaki, Akira YonedaAbstract:Abstract Rheology of the lower mantle characterizes the dynamics of the earth's interior and it is often controlled by the textures of the constituting material which are (Mg,Fe)SiO3 perovskite and ferro-Periclase aggregate. We conducted high-pressure experiments to synthesize the (Mg,Fe)SiO3 perovskite and ferro-Periclase aggregates and measured two important textures of “grain size” and “dihedral angle”. The grain growth rates of perovskite and (ferro-)Periclase in two phase aggregates were influenced by the iron content and increased with factors of ∼1.5 in iron-rich system. This difference in grain growth rates indicates that the viscosity of aggregates of iron-rich system is only a few times greater than that of iron-poor system for likely diffusion creep in the lower mantle. In contrast, the change of the dihedral angle of perovskite – Periclase – perovskite at triple grain junction with variation of iron content was not observed systematically, but the dihedral angle decreases from ∼110° to ∼105° with an increase of temperature from 1673 to 2273 K. The dihedral angle of 105–110° would imply the interconnected network spatially of ferro-Periclase in the aggregates and the connectivity increases with temperature. As a result, at higher temperature, ferro-Periclase plays more important role for understanding the rheology of the lower mantle because ferro-Periclase is a few order of magnitude softer than (Mg,Fe)SiO3 perovskite.
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no interconnection of ferro Periclase in post spinel phase inferred from conductivity measurement
Geophysical Research Letters, 2008Co-Authors: Takashi Yoshino, Daisuke Yamazaki, Eiji Ito, Tomoo KatsuraAbstract:[1] Electrical conductivities of post-spinel, which are thought to be a dominant assembly in the lower mantle, were investigated at the conditions of the uppermost lower mantle (25 GPa and temperatures ranging from 300 to 2000K) in a Kawai-type multi-anvil apparatus. Post-spinel phases with a bulk composition of ((Mg,Fe)2SiO4: XFe = 0.09) were measured to constrain the bulk conductivity of the lower mantle. To investigate interconnectivity of ferro-Periclase in silicate perovskite matrix, a single phase composed of magnesium silicate perovskite ((Mg,Fe)SiO3: XFe = 0.1) and ferro-Periclase ((Mg,Fe)O: XFe = 0.13) were also measured. The conductivity values of the silicate perovskite are distinctly lower than those for the coexisting ferro-pericalse. Both absolute values and change in activation enthalpy for the conductivity of the post-spinel phases are similar to those for the silicate perovskite. These observations suggest that ferro-Periclase in post-spinel are isolated in silicate perovskite matrix.
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some mineral physics constraints on the rheology and geothermal structure of earth s lower mantle
American Mineralogist, 2001Co-Authors: Daisuke Yamazaki, Shunichiro KaratoAbstract:We explore the implications of recent mineral physics measurements of diffusion coefficients and melting temperatures of lower mantle materials on the rheological and geothermal structure of Earth’s lower mantle. We show that MgSiO3 perovskite is significantly stronger than MgO Periclase and therefore the rheology of the lower mantle depends strongly on the geometry of a weaker phase, Periclase. We calculate viscosities of the lower mantle for two cases: (1) where Periclase occurs as isolated grains and (2) where Periclase occurs as continuous films, using mineral physics data and models of two-phase rheology. We find that the effective viscosity for the former is about ~10–1000 times higher than the latter. We therefore suggest that the rheology of the lower mantle is structure- and hence strain-dependent, leading to weakening at large strains due to the formation of continuous films of Periclase. Overall depth variation of viscosity depends not only on the pressure dependence of creep but also on the geothermal gradient. Both MgSiO3 perovskite and Periclase have relatively small activation energies ( E * = g R T m with g = 10–14, where R is the gas constant and T m is melting temperature), and therefore the depth variation of viscosity is rather small, even for a nearly adiabatic temperature gradient. However, the geothermal gradients consistent with the geodynamical inference of nearly depth-independent viscosity are sensitive to the pressure dependence of viscosity which is only poorly understood. A superadiabatic gradient of up to ~0.6 K/km is also consistent with mineral physics and geodynamical observations.
D. R. Mel’nikova - One of the best experts on this subject based on the ideXlab platform.
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Two Challenges to the System of Periclase Quality Evaluation
Journal of Materials Science Research, 2015Co-Authors: L. M. Axelrod, I. G. Maryasev, A. A. Platonov, D. R. Mel’nikovaAbstract:A new method of estimating the fused Periclase quality – the revision of international standards. Quality and service life of refractories on the basis of fused Periclase depend to a large extent upon the size of Periclase crystals and its mineralogical composition. During fusion of Periclase it is impossible to obtain completely homogeneous material with identical crystals size. That is why it is generally accepted to evaluate quality of fused Periclase by the average crystals size. Measurements of this item are usually done with the help of generally adopted method of chords, which was developed in the last century and has a number of drawbacks. Magnezit Group developed a new objective method of digital analysis during microscopic examination of structural elements of fused Periclase. It allows to considerably improve objectivity of obtained data. The main feature of the new method is application of the system of images analysis, which allows to carry out in automatic mode measurements on the preliminary created digital model of the whole area of the polished section. With the help of the digital model it is possible to calculate average size of fused Periclase crystals taking into account number of crystals as well as percentage of the area occupied by them. Does CaO/SiO 2 ratio influence service life of refractories? New view of old rules. Till today it was considered that one of the characteristics of fused Periclase quality is coefficient of basicity – CaO/SiO 2 , ratio, which should be more than 2. Magnezit Group carried out investigations of coarse-crystalline fused Periclase with MgO >97.5 % content and with various CaO/SiO 2 ratios. We present in this report the main study results: if the impurities content is low in the fused Periclase with MgO >97.5 %, then coefficient of basicity exerts limited influence onto the service life of Periclase-carbon bricks.
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Improvement of Methods for Determining Fuzed Periclase Crystal Size
Refractories and Industrial Ceramics, 2015Co-Authors: L. M. Aksel’rod, I. G. Maryasev, A. A. Platonov, D. R. Mel’nikovaAbstract:A new digital analysis procedure is developed for microstructural study of fuzed Periclase structural elements aimed at objectivity. The main parameters are presented distinguishing the proposed method from a normal linear method by means of chords. An example is provided of crystal sizes for fuzed Periclase produced by the Magnezit Group and other producers, measured by old and new methods. Checking fuzed Periclase with an MgO content of more than 97.5% with a different CaO/SiO2 ratio in Periclase-carbon refractories did not reveal the effect of this parameter on life in a steel-pouring ladle lining.
Ya. L. Kats - One of the best experts on this subject based on the ideXlab platform.
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Plasma Heating of Periclase-Carbonaceous Refractory for Lining of Steel Ladles
Metallurgist, 2019Co-Authors: Ya. L. Kats, M. V. Krasnyanskii, D. I. Yusupov, A. S. Tyuftyaev, M. Kh. Gadzhiev, M. A. KhromovAbstract:The paper presents the experimental results on plasma heating of fired Periclase-carbonaceous refractory material. A high heating rate of more than 1000^∘C/h was achieved. The thermophysical properties of the fired refractory were refined. It was shown that fired Periclase-carbon has a lower thermal conductivity than unfired (9.5 and 25 W/(m·K), respectively), as well as higher emissivity (0.6 and 0.3, respectively). Using the obtained data, the parameters of the CFD model of the plasma heating process of Periclase-carbonaceous refractory were refined, which will enable a more accurate simulation of this process in the future.
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Plasma-ARC Heating of Periclase-Carbonaceous Refractory
Metallurgist, 2017Co-Authors: M. V. Krasnyanskii, Ya. L. Kats, A. S. Tyuftyaev, M. Kh. Gadzhiev, M. A. Sargsyan, D. I. YusupovAbstract:Plasma-arc heating of Periclase-carbonaceous refractory was experimentally tested. A high heating rate of 600°C/h was achieved. The experimental results were used to correct the thermal characteristics of raw refractory and to determine the energy characteristics of the arc discharge. Raw Periclase-carbonaceous refractory has high heat conductivity (25 W/(m·K)) and low emissivity (0.3). The radiated power (130 kW) of the discharge is calculated from spectral measurements of an argon plasma arc with a current of 1000 A and an arc voltage of 150 V. The obtained data are used to specify the parameters of the CFD-model of plasma-arc heating of Periclase-carbonaceous refractory.
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Determination of the Integral Emissivity of a Periclase-Carbon Lining
Metallurgist, 2014Co-Authors: M. V. Krasnyanskii, Ya. L. KatsAbstract:Experimental values have been determined for the integral emissivity (blackness) of Periclase-carbon refractories used in the working layer of the lining of steel-pouring ladles. The values were found for the range 500–900°C. It was established that the emissivity of Periclase-carbon refractories is considerably higher than that of Periclase refractories. Use of the data which were obtained is making it possible to more accurately measure the temperature of such linings by the pyrometric method.