CAJ | 학술논문

在NaHCO3调控作用下，通过MgCl2和Na2CO3反应结晶合成了五水碳酸镁（MgCO3·5H2O）。利用SEM、XRD和TG等技术，结合反应结晶过程中镁离子浓度变化，研究了工艺参数对结晶过程和产物影响。实验结果表明，合成五水碳酸镁过程中极易生成 MgCO3·3H2O 副产物。纯 MgCO3·5H2O 制备工艺条件为：NaHCO3加入量≥3.00 g·L?1，碳酸钠加料速率2～50 ml·min?1，合成温度0～5.0℃。所合成的五水碳酸镁呈棱柱状形貌，晶体表面光滑，尺寸20～160μm。分析表明，添加碳酸氢钠促进了结晶动力学，同时3HCO?基团对三水碳酸镁晶体的形成具有位阻效应，但有利于五水碳酸镁晶体形成，产生晶型调控的协同效果。工艺参数的改变将使得结晶过程发生热力学和动力学控制的转换，影响结晶产物的晶型晶貌。
재NaHCO3조공작용하，통과MgCl2화Na2CO3반응결정합성료오수탄산미（MgCO3·5H2O）。이용SEM、XRD화TG등기술，결합반응결정과정중미리자농도변화，연구료공예삼수대결정과정화산물영향。실험결과표명，합성오수탄산미과정중겁역생성 MgCO3·3H2O 부산물。순 MgCO3·5H2O 제비공예조건위：NaHCO3가입량≥3.00 g·L?1，탄산납가료속솔2～50 ml·min?1，합성온도0～5.0℃。소합성적오수탄산미정릉주상형모，정체표면광활，척촌20～160μm。분석표명，첨가탄산경납촉진료결정동역학，동시3HCO?기단대삼수탄산미정체적형성구유위조효응，단유리우오수탄산미정체형성，산생정형조공적협동효과。공예삼수적개변장사득결정과정발생열역학화동역학공제적전환，영향결정산물적정형정모。
Lansfordite (MgCO3·5H2O) was synthesized via the reactive crystallization of MgCl2 with Na2CO3 under the regulation of NaHCO3. The effects of crystallization parameters on the crystallization process and products were experimentally investigated by means of SEM, XRD, TG techniques and taking into consideration the change of magnesium ion concentration during the crystallization process. MgCO3·3H2O was easy to generate as by-product in the synthesis process. Process conditions of pure MgCO3·5H2O preparation were as follows:NaHCO3 amount was ≥3.00 g·L?1, Na2CO3 feeding speed was 2—50 ml·min?1, reactive temperature was 0—5.0℃. The as-synthesized lansfordite crystals displayed prismatic morphology with smooth faces and a size of 20—160 μm. Analysis showed that crystallization kinetics was promoted with the addition of NaHCO3. 3HCO?group created the steric effect inhibiting nesquehonite growth but was beneficial for lansfordite crystallization. Therefore, pure lansfordite could be synthesized under the regulation of NaHCO3. Changes in process parameters could make the crystallization process shift between thermodynamic control and kinetic control, affecting crystal polymorph and morphology.