Fired spinel complex oxide and method for preparing the same

摘要

A fired spinel complex oxide is produced by firing a mixture containing a slag by-produced in chromium refining, a reducer, and a silica-containing material, and is essentially composed of: 29 to 40 percent by weight of Fe₂O₃; 15 to 20 percent by weight of Al₂O₃; 9 to 14 percent by weight of MgO; 0 to 4 percent by weight of Na₂O; 9 to 17 percent by weight of Cr₂O₃; 14 to 20 percent by weight of SiO₂; and 2 percent by weight or less of CaO. The fired spinel complex oxide shows a Cu-Kalpha X-ray diffraction pattern in which the ratio (b/a) of the diffraction peak intensity of the silica-containing material (b) in the vicinity of 2theta=26.7° to the {113} plane diffraction peak intensity (a) in the vicinity of 2theta=36° is 0.1 or less.