氯化镁-白云石为原料制备氢氧化镁的研究

采用分析纯氯化镁为原材料，以白云石经煅烧、消化得到的白云灰乳为沉淀剂制备氢氧化镁。采用X射线衍射（XRD）、热重差热分析（TG-DTA）、扫描电镜（SEM）等手段对产物做了表征，考察了影响氢氧化镁质量的主要因素（如加料速率、陈化时间、反应温度、氯化镁浓度等）。结果表明，在加料速率为3 mL/min、陈化时间为1.5 h、反应温度为60 ℃、氯化镁浓度为2.0 mol/L时，可以实现钙镁的有效分离，得到高纯度的氢氧化镁产品。

Study on preparation of magnesium hydroxide with magnesium chloride-dolomite as raw materials

Magnesium hydroxide was prepared with the analytic-pure magnesium chloride as raw materials，and dolomite lime milk got from the calcination and digestion of dolomite，as the precipitating agent.The products were characterized by the X-ray diffraction（XRD），thermal gravimetric and differential thermal analysis（TG-DTA），and scanning electron microscopy（SEM） etc..The main influencing factors，such as reaction temperature，chloride magnesium concentration，feeding speed，and aging time on the quality of the magnesium hydroxide were investigated.Results showed that under the feed rate of 3 mL/min，aging time of 1.5 h，reaction temperature of 60 ℃，and magnesium chloride concentration of 2.0 mol/L，the effective separation of calcium and magnesium could be realized and high purity magnesium hydroxide products could be obtained.