将模拟浓海水和NaOH直接沉淀制备的Mg(OH)2水热处理得到Mg(OH)2阻燃剂粉体，考察了矿化剂和温度对其晶体形貌、结晶性及分散性的影响. 结果表明，在实验温度范围内，碱类矿化剂对晶体形貌的改善优于氯盐矿化剂；矿化剂浓度和水热温度越高，对晶体形貌改善越好，晶体粒径及厚度增加越快，且可减小晶体极性和微观内应变，提高结晶度和分散性. 在水热时间8 h、温度200℃、4.0 mol/L NaOH溶液为矿化剂条件下，可制备出粒度分布均匀、平均粒径约为0.250 mm、厚度约61 nm、团聚指数约为10.95的阻燃型Mg(OH)2.

Flame retardant magnesium hydroxide powder was prepared by hydrothermal modification method with magnesium hydroxide powder as raw material that was synthesized by precipitation of simulated concentrated seawater and sodium hydroxide. The effects of mineralizers and temperature on the morphology, crystalline structure and dispersion properties of hydrothermal products were examined. The magnesium hydroxide powder was characterized. The results show that alkali salts are superior to chlorine salts as mineralizers. In the experimental ranges, the higher the mineralizer concentration and temperature, the better the improved crystalline properties of product, such as more regular morphology, larger crystal size, greater plate thickness, less microstrain, superior crystallizability and dispersibility. Magnesium hydroxide particles as flame retardant with primary particle size about 0.250 mm, thickness of 61 nm and agglomeration number 10.95 can be obtained using 4.0 mol/L NaOH as mineralizer under the hydrothermal temperature of 200℃ and hydrothermal time of 8 h.