甲醇-水体系中碱式氯化镁纤维的制备工艺研究

在甲醇-水的复合溶剂中，以MgCl2·6H2O和NH3·H2O为原料制备碱式氯化镁纤维。研究了甲醇浓度、氯化镁与NH3·H2O物质的量比、氯化镁浓度、反应温度、陈化温度等对碱式氯化镁产率及形貌的影响规律，以正交实验进行优化，并采用XRD、SEM、TG/DTG等对产品进行分析。实验结果表明，甲醇体积分数为25.0%、n（氯化镁）∶ n（NH3·H2O）=3.0∶1、氯化镁浓度为4.0 mol/L、反应温度为25 ℃、陈化温度为50 ℃时，碱式氯化镁一次产率为13.13%，长径比大于100，XRD和TG/DTG结果证实产品组成为Mg2（OH）3Cl·4H2O。产率比水相中产率提高了近 1倍，表明甲醇-水体系是制备高产率碱式氯化镁的有效方法之一。

Preparation of basic magnesium chloride fiber in methanol-water solvent system

In the mixed solvent of methanol and water，MgCl2·6H2O and NH3·H2O were used as raw materials to prepare basic magnesium chloride fiber.The effects of methanol concentration，amount-of-substance ratio of MgCl2 to ammonia， concentration of MgCl2，reaction temperature，and aging temperature on morphology and yield of basic magnesium chloride were investigated.The experiment conditions were optimized by orthogonal test and the products were analyzed by XRD， SEM，and TG/DTG.Results showed，when methanol′s volume fraction was 25.0%，n（MgCl2）:n（NH3·H2O）=3.0:1，c（MgCl2）=4.0 mol/L，reaction temperature was 25 ℃，and aging temperature was 50 ℃，the one-time yield of basic magnesium chloride was 13.13%，and slenderness ratio of product was more than 100.The results of XRD and TG/DTG showed that the product was Mg2（OH）3Cl·4H2O.The yield nearly doubled than reaction in water phase.Methanol and water system was one of effective methods for increasing yield of basic magnesium chloride.