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Synthesis of Magnesium Aluminate Spinels from Bauxites and Magnesias
Author(s) -
CunhaDuncan Flavia N.,
Bradt Richard C.
Publication year - 2002
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.2002.tb00569.x
Subject(s) - periclase , spinel , bauxite , corundum , mullite , materials science , mineralogy , magnesium , forsterite , microstructure , metallurgy , chemical engineering , geology , ceramic , engineering
The synthesis of refractory Mg‐Al spinel aggregates from bauxites and magnesias was addressed by applying the alumina–magnesia–silica ternary equilibrium phase diagram as the fundamental basis. Four different alumina sources (bauxites) and four different magnesia sources were investigated. These were fired in air through 1700°C and their reactions were monitored using X‐ray diffraction. Evolution of their microstructure was observed by scanning electron microscopy. Initially, the periclase reacts with the free corundum of the bauxite to produce Mg‐Al spinel. The periclase then reacts with the mullite in the bauxites to yield additional spinel and also some forsterite. Spinels were produced for all sixteen different raw‐material combinations.