| 摘要 |
PROBLEM TO BE SOLVED: To obtain a mixture compsn. of hydroxides which has a large specific surface area and which shows a high conversion rate to double oxides by heat treatment at a rather low temp., by mechanically mixing and pulverizing two or more kinds of hydroxides to convert the mixed hydroxides into double hydroxides to prepare the mixture compsn. which contains hydroxides and double hydroxides having a specified particle size. SOLUTION: After mixing and pulverizing, >=80 wt.% of hydroxide particles have <=500 nm particle size. The heat treatment at a rather low temp. signifies a treatment performed at <=1100 deg.C. The two kinds of hydroxides are, for example, magnesium hydroxide and aluminum hydroxide, or lithium hydroxide and manganese hydroxide. The Mg/Al ratio in the double hydroxide of Mg and Al is controlled to 1/2, 2/1 or 3/1. The double hydroxide of Mg and Al includes one to three species out of MgAl2(OH)8, Mg4Al2(OH)14.3H2O and Mg2Al(OH)10.xH2O. As for the mixing and stirring means, a medium stirring type mill is preferably used.
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