Effect of grinding on synthesis of MgAl2O4 spinel from a powder mixture ofMg(OH)(2) and Al(OH)(3)

Dry grinding of the powder mixture composed of magnesium hydroxide and gibb site using a planetary ball mill followed by its heating was conducted to p repare MgAl2O4 spinel. Both the starting materials are easily converted to amorphous phase by intensive grinding within 60 min. The monolithic MgAl2O4 spinel phase can be obtained from the mixtures ground over 15 min by calci nation at 900 degreesC. The reactivity of the mixtures ground over 30 min i s not improved. Prolonged finding promotes the aggregation of ground fine p articles, but the aggregates deflocculate into fragments after calcination. (C) 2000 Elsevier Science B.V. All rights reserved.