高纯纳米晶氢氧化镁粉体制备及表征

Preparation and Characterization of High-Purity Nano-Crystal Mg(OH)2 Powder

摘要:

以自制的高纯硫酸镁和由氨水、氢氧化钠组成的复合碱液为原料制备高纯纳米氢氧化镁粉体。考察几种关键因素对镁沉淀率和产物平均粒度的影响。结果表明，随着溶液中Mg2+初始浓度和反应温度的提高，镁沉淀率提高，产物平均粒度先降低后提高；延长反应时间和陈化时间，镁沉淀率和产物平均粒度都提高；提高搅拌速度，镁回收率提高不大，但产物平均粒度减小。当Mg2+初始浓度2.0 mol×L-1，反应温度50 ℃，反应时间60 min，搅拌速度900 r×min-1，陈化时间90 min时，Mg沉淀率为95.4 %，得到的氢氧化镁粉体为六方片状颗粒，粒度在50~140 nm，且粒度分布均匀，分散性好，纯度很高。

Abstract:

High-purity nano-crystal Mg(OH)2 powder was prepared, using self-made high-purity MgSO4 and mixed alkali solution of ammonia water and NaOH liquor as starting materials. The effects of several key factors on precipitation rate of Mg and average particle size of powder were studied. The results show that with increasing of initial concentration of Mg2+ and reaction temperature, the precipitation rate of Mg increases, while the average particle size of powder decreases at first, and then increases; if prolong the reaction time and ageing time, the precipitation rate of Mg and the average particle size of powder both increase; if increase stirring rate, the precipitation rate of Mg does not increase obviously, but the average particle size of powder decreases. When the initial concentration of Mg2+ is 2.0 mol×L-1, reaction temperature is 50 oC, reaction time is 60 min, stirring rate is 900 r×min-1, and ageing time 90 min, the precipitation rate of Mg is 95.4%; meanwhile the morphology of obtained Mg(OH)2 particles is hexagonal flake, the size of them is between 50 nm and 140 nm, the granularity distribution is uniform, the dispersibility is good, and the purity is high.