白云石碳化制备碱式碳酸镁的新钙镁分离方法

以白云石碳化法为基本方法,在碳化过程中加入添加剂乙酰丙酮,并控制体系的pH值,得到了一种改良的钙镁分离方法,制备出高纯碱式碳酸镁。通过单因素实验,研究了煅白消化条件、精镁乳液碳化条件对消化、碳化效率和产品纯度的影响。结果表明,最佳的实验条件为:消化时间40min、消化温度50℃、消化液固比50∶1;碳化至pH值为10时加入添加剂乙酰丙酮(HAA),且加入量为0.005~0.020mol/L,抽滤pH值为8.5。得到的碱式碳酸镁产品的化学成分为:MgO41.00%,CaO0.63%,Fe≤0.05%。

Novel Method of Calcium and Magnesium Separation in Preparation of Basic Magnesium Carbonate with Dolomite by Carbonation

High-purity basic magnesium carbonate was prepared by a novel carbonation method with dolomite,for which acetyl acetone was added and the pH value of the system was monitored.The influences of digestion and carbonation conditions of fine emulsion of magnesium on the process of digestion and carbonation,as well as on the purity of the product,were well studied through single factor experiment.The results indicate that the optimized condition is confined as follows:calcinations time is 40 min,digestion temperature is 50℃,and liquid-solid ratio is 50∶ 1;0.005～0.020mol/L HAA is added to the mixture at pH 10,and filtrated at pH 8.5.The content of the basic magnesium carbonate is MgO of more than 41.00wt％,CaO of less than 0.63wt％ and Fe of 0.05wt％.