关键词: 液相沉淀法, 超重力, 沉降, 氢氧化镁, 浆料

Abstract: Magnesium hydroxide nanoparticles were prepared via ordinal precipitation method, reverse precipitation method, double precipitation method and high-gravity precipitation method using magnesium chloride hexahydrate as raw material and sodium hydroxide as precipitant. The settling velocity was selected as the index to investigate the effects of different preparation methods on the settlement property of magnesium hydroxide slurry. The morphology, particle size and its distribution, and crystal phase of the samples were characterized by transmission electron microscope (TEM), laser particle size analyzer (LPSA), and X-ray diffractometer (XRD), respectively. The results showed that the settling velocity increased evidently via high-gravity precipitation method, which was 4.7 times, 12.4 times and 2.1 times of that by the ordinal precipitation method, reverse precipitation method and double precipitation method. It was also found that the samples prepared by high-gravity precipitation method were hexagonal flake-like shape with narrow particle size distribution, high purity and good dispersity.

Key words: liquid precipitation method, high gravity, sedimentation, magnesium hydroxide, slurry