TYPICAL PROPERTIES OF MA SPINEL
As will be discussed in Section V, spinel can be synthesized using different raw
materials and via different processes; therefore, the properties of synthesized
spinels vary. Table 2, as an example, lists some typical properties of dense, sintered,
stoichiometric spinel (4). Spinel has a higher melting temperature (21358C)
than Al2O3 (20548C) but lower than MgO (28508C). Its thermal expansion coefficient
(_8.4 _ 1026/K) is close to that of alumina (_8.8 _ 1026/K), but much
lower than MgO (_13.5 _ 1026/K). Furthermore, it has superior hydration
resistance than periclase and thus can be used in water-based castable systems