Spinel powder and spinel slurry

摘要

The invention features an MgAl2O4 spinel powder having a specific surface area of 40 m<2>/g or more and an average diameter of from 3 to 20 mu m and having uniform pores, and a slurry containing this spinel powder. The spinel powder is produced by milling (1) an MgAl2O, spinel powder obtained by synthesizing by the coprecipitation method with the use of hydroxide materials wherein the ratio of the average diameter of aluminum hydroxide "D1" to the average diameter of magnesium hydroxide "D2" satisfies the requirement 1.85≤(D1/D2) or 0.5>(D1/D2) and calcining, (2) an MgAl2O4 spinel powder obtained by drying a mixture solution containing water-soluble organic substance having a boiling point of 120 DEG C or above, converting the dried substance into a complex oxide by heating, or (3) a powder comprising as the main component an MgAl2O4 spinel powder which is obtained by mechanically mixing and milling a mixture of hydroxides for producing a spinel powder to convert into a complex hydroxide, and then heating a mixture composition containing the obtained complex hydroxide with an unconverted hydroxide to thereby convert into a complex oxide.