Phase equilibrium, microstructure and properties of some magnesite-chromite refractories

Serry, M. A.; Othman, A. G. M.; Girgis, L. G.; Weisweiler, Werner

doi:10.1007/bf00355880

Cited by 8 publications

(7 citation statements)

References 4 publications

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“…Recent studies 10,11 have shown that the properties of magnesia refractory products do not depend only on the precursor material and its purity, but also on other characteristics, e.g., time and temperature of calcination, structure, periclase crystal size, as well as amount, composition, and spatial distribution of the bond phases.…”

Section: Resultsmentioning

confidence: 99%

Composition of Periclase and Calcium‐Silicate Phases in Magnesia Refractories Derived from Natural Microcrystalline Magnesite

Lampropoulou

Katagas

Papamantellos

2005

Journal of the American Ceramic Society

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Mineralogical and microstructural properties of sintered and fused magnesia grains and refractory bricks derived from natural magnesite were examined. Although their CaO/SiO2 ratios can be used to approximate their mineralogical compositions, detailed X‐ray diffraction (XRD) and scanning electron microscopy (SEM) studies revealed significant deviations from the expected phase assemblages. Their microstructures vary widely in terms of proportions of direct periclase bonding, amounts and phase constitution of the siliceous bonding, and the size and composition of the periclase crystals. An exceptionally high solid solubility of CaO in periclase crystals was detected. Most of the phases of the siliceous bond exhibit nearly stoichiometric compositions and show intriguing substitutions.

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Section: Resultsmentioning

confidence: 99%

Composition of Periclase and Calcium‐Silicate Phases in Magnesia Refractories Derived from Natural Microcrystalline Magnesite

Lampropoulou

Katagas

Papamantellos

2005

Journal of the American Ceramic Society

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“…42,43 Using CaO and SiO 2 , the densities obtained at 1600°C for ~30 min were equal to those obtained without addition at 1800°C for ~30 min. The rate of grain growth is decreased because these additions restrict discontinuous grain growth.…”

Section: Liquid Phase Sintering In the Mgo-spinel Systemmentioning

confidence: 88%

Magnesia–spinel (MgAl 2 O 4 ) refractory ceramic composites

Aksel¹,

Riley²

2006

Ceramic-Matrix Composites

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“…It attracts the attention because of its unique physical and chemical properties and technological possibilities. This spinel is used in some refractories' composition [1,2], semiconductors [3], magnetic and electrical materials [4], sensors [5], catalysts [6][7][8], photocatalysts [9], pigments [10], etc. Active work on nanoceramics and nanocomposites with MgCr 2 O 4 participation [8,9,[11][12][13][14].…”

Section: Introductionmentioning

confidence: 99%

MAGNESIOCHROMITE (MgCr2O4) SYNTHESIS: EFFECT OF MECHANICAL AND MICROWAVE PRETREATMENT

Kosenko

Filatova

Egorova

2020

IVKKT

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Magnesiochromite spinel synthesis based on oxides, hydroxides and nitrates of magnesium and chromium was investigated. The precursors reactivity was compared by means of effective rate constants calculated by Ginstling-Brounshtein equation. The possibility of use of this equation was confirmed by the dependences linearity with high linear approximation coefficients. The reactivity of MgO various forms (soft-burned, or caustic magnesite, and dead-burned, or periclase) in the spinel formation was compared. Oxide precursors (especially with the periclase participation) reacted with the substantially less rate in comparison with hydroxides and salts. The influence of a preliminary mechanical activation by impact-and-attrition (planetary mill) and attrition (ball-ring mill) action as well as a microwave treatment (2.45 GHz) was analyzed. The most positive effect of a mechanical treatment in a planetary mill that was associated with an activation of Mg and Cr compounds became apparent in the field of relatively low temperatures (700-1100 °С). For example, MgCr2O4 yield at 1000 °С and the joint impact treatment of oxides was twice as much than under the simple mixing. The subsequent temperature rising lead to some decrease of a pretreatment effect so long as diffusion coefficients in these conditions grew, so the reaction run rapidly even without a preliminary mechanical treatment. It was noticed that an appreciable reduction of MgO reactivity in the spinel formation after a certain attrition in a ball-ring mill linked to the plane sliding in cubic crystals and resulted in the removing of the most disordered and defective layer from grains and the plane surface uncovering. The combined method consisting of a mechanical treatment of magnesium and chromium nitrates mixture in a planetary mill and the subsequent burning in a thermal kiln (1000 °С) was considered as the most effective as it resulted in practically single product. The microwave treatment took up an intermediate position by the effectiveness.

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Phase equilibrium, microstructure and properties of some magnesite-chromite refractories

Cited by 8 publications

References 4 publications

Composition of Periclase and Calcium‐Silicate Phases in Magnesia Refractories Derived from Natural Microcrystalline Magnesite

Composition of Periclase and Calcium‐Silicate Phases in Magnesia Refractories Derived from Natural Microcrystalline Magnesite

Magnesia–spinel (MgAl 2 O 4 ) refractory ceramic composites

MAGNESIOCHROMITE (MgCr2O4) SYNTHESIS: EFFECT OF MECHANICAL AND MICROWAVE PRETREATMENT

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