卤水-石灰乳法制备纳米氢氧化镁新工艺研究

Study on new preparation technology of nano-sized magnesium hydroxide by lime-brine method

以天然盐湖卤块为原料，采用石灰乳为沉淀剂，控制温度在40～90℃，采用特殊的除钙技术，使产品中氢氧化镁质量分数大于98％，氧化钙质量分数小于0．2％，分解温度396．93℃，热质量损失30．96％。利用扫描电子显微镜对产品形貌进行表征，结果显示制得的氢氧化镁产品粒径在80nm左右，粒子呈片状晶体结构。制得的氢氧化镁产品比表面积为39．2m^2／g。此生产工艺简单，生产成本低，是一种比较清洁的合成工艺路线。新工艺生产的产品质量不仅达到国家行业标准，而且达到国外企业标准，可望进行工业性生产。

A new preparation technology for nano - sized magnesium hydroxide has been developed which takes the natural brine from salt lakes as raw material, lime milk as precipitator, adopts special calcium- removing technique and controls the temperature at 40 - 90 ℃ during the reaction. With this technology, the Mg （ OH ） 2 content of the product was more than 98% ,the CaO content was less than 0.2% ,decomposition temperature was 396.93℃ and the thermal mass loss was 30.96%. The topography of the product has been characterized by SEM. Results showed that the mean particle size of the magnesium hydroxide was about 80 nm and the particles were lamellar grains. The specific surface area was 39. 2 m^2/g. This technology has the advantages of simple process and low cost and it is a cleaner synthesis route. The quality of the product not only reaches the National Standard ,but also gets to the foreign enterprise standard. Therefore, the industrial production was being expected.