以温石棉尾矿为镁源制备碱式碳酸镁晶须

Preparation of Basic Magnesium Carbonate from Chrysotile Asbestos Tailing

温石棉尾矿煅烧活化产物经盐酸浸取后得到氯化镁溶液。以氯化镁溶液与碳酸氢铵为反应物料，采用碳化法制备碱式碳酸镁晶须。通过正交实验，研究了氯化镁与碳酸氢铵摩尔比、MgCl2溶液的浓度、碳化温度、碳化时间、陈化时间对产物的种类及其晶须形貌的影响，并对产物进行SEM、XRD和热分析。结果表明，该法制备碱式碳酸镁晶须最佳条件：氯化镁与碳酸氢铵的摩尔比为1：2，MgCl2浓度为0．8mol／L，碳化时间2h，碳化温度60℃，陈化时间为4h，在此条件下制备出碱式碳酸镁晶须样品长径比为10-40，其分子式为4MgCO3·Mg（OH）2·4H2O。

With chrysotile asbestos tailings calcined activation products, magnesium chloride solution were obtained by hydrochloric acid leaching. With magnesium chloride solution and ammonium bicarbonate as the reaction materials, magnesium carbonate whiskers were prepared by carbonation. To study the mol ratio of magnesium chloride and ammonium bicarbonate, solution concentration of MgCl2, carbonization temperature, carbonization time and aging time on the product types and morphology of the whiskers by orthogonal experimental design, The results of the SEM, XRD and thermal analysis show that the optimal preparation conditions of basic magnesium carbonate whisker： magnesium chloride and ammonium bicarbonate in a mol ratio of 1 ： 2, MgCl2 concentration of 0.8 mol/L, carbonization time of 2 h, carbonization temperature of 60 ℃, and aging time of 4 h. Under these conditions, magnesium carbonate whisker samples aspect ratio is 10 to 40, the formula is 4MgCO3· Mg（OH）2· 4H2O.