Abstract: Research is made on the process conditions for preparing magnesium hydroxide by hydration method with the magnesium oxide product of a salt lake in Qinghai as the raw material in the campaign of the comprehensive utilization of the resource of salt lakes.Single factor conditional tests are made on the effect of the reaction parameters such as the reaction time, reaction temperature, ratio of solid to liquid of the raw material, etc.on the conversion rate and product particle size, and to explore the mechanism of preparing magnesium hydroxide by hydration method.It has been preliminary determined that the optimal conditions for the preparation include the reaction temperature between180~200℃, the reaction time between 5~7h and the ratio of solid to liquid of the raw material of 1∶4, on which conditions, a flaky magnesium hydroxide product with d₅₀ of about 20μm , uniform size and good crystallization can be obtained.

Key words: Magnesium oxide, Magnesium hydroxide, Hydration method