氨气法制备氢氧化镁的研究

以硼镁肥精制液硫酸镁为原料,通过氨气法制备花瓣状氢氧化镁.研究搅拌速度、反应温度、氨气流量等因素对氢氧化镁粒径形貌的影响.采用X射线衍射仪（XRD）、扫描电镜（SEM）和激光粒度分布仪等对MH（Mg（OH）2）粉体的晶型、粒度、形貌进行表征.实验结果表明：在大流量氨气条件下,氨气流量为8 333 mL/min时,产品的表观粒径随合成温度的升高而减小.反应温度45℃,氨气流量80 mL/min时,氢氧化镁形貌一致,分散性良好,容易过滤,其产率在80.1%左右.

Synthesis of Magnesium Hydroxide by Method of Ammonia Gas

Magnesium hydroxide with petal morphology was synthesized from self-made magnesium sulfate solution and ammonia by direct precipitation method.The influence of synthesis parameters on the morphological characteristics and sizes of magnesium hydroxide was investigated,such as stirring speed,ammonia flow rate and reaction temperature.The obtained magnesium hydroxide powders were characterized in terms of morphology,particle size and crystal habits by scanning electron microscope（SEM）,laser particle size analyzer and X-ray diffraction （XRD） techniques. The results indicated that the apparent diameter was decreased by increasing the reaction temperature at the ammonia flow rate of 8 333 mL/ min. Magnesium hydroxide powders with the advantages of regular morphology, good dispersibility and easy filter were obtained at 45 ℃ and ammonia flow rate of 80 mL/min. The yield of magnesium hydroxide was about 80. 1%.