| 摘要 |
The high purity magnesium hydroxide is produced by (a) treating a debrominated magnesium chloride hydrate (MgCl26H2O) soln. with an ammonia soln., and removing precipitates, (b) treating the supernatant with lime, and removing gypsum-precipitates, (c) heat-concentrating the supernatant, and removing the precipate, (d) cooling the supernatant, and separating and removing the crystal, (e) concentrating the supernatant at 134 deg.C, and separating and dehydrating the magnesium chloride crystal to obtain a high purity magnesium chloride, (f) heating and hydrolyzing it at 600 deg.C to obtain magnesia, and (g) keeping it in 15 % ammonium hydroxide soln. for at least 1 hr. The magnesia useful as fine ceramics is obtained by roasting the high purity magnesium hydroxide.
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