Reaction Chemistry and Microstructure Development of MgO-C Refractories Containing Metal Antioxidants
Phase formation and their stability during firing MgO-C refractories with minor additions of Al-metal were studied at temperature between 600° and 1200°C in an atmosphere of argon. The phases formed at different stages of the reaction process were identified by powder x-ray diffraction and scanning electron microscopy. At the initial stages of the reaction process, a liquid phase containing al and Mg, was formed at a temperature below the melting point of Al-metal (660°C). The liquid, once formed, coexists with MgO and C at temperatures up to 850°C and then slowly dissociates to molten al reacted with C to yield Al4C3 in the form of thin platelets, whereas, the Mg-gas combined with the oxygen present in the furnace to yield MgO in the form of whiskers on the cold-face of the refractories. At temperatures above 1000°C, Al4C3 reacts with MgO to form spined, MgAl2O4. Since MgAl2O4 is compatible with both MgO and C, no further reaction occurred in the refractories.
J. P. Guha and J. D. Smith, "Reaction Chemistry and Microstructure Development of MgO-C Refractories Containing Metal Antioxidants," Proceedings of the Unified International Technical Conference on Refractories 2005, American Ceramic Society, Jan 2006.
Materials Science and Engineering
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Article - Conference proceedings
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