LIU Jiayi1,WANG Yulian1,2,SHI Tianjiao1,XU Hao1,ZHANG Xiaxiang3,LI Chuang1,YUAN Zhigang1
(1.College of Materials Science and Engineering,Shenyang Ligong University,Shenyang 110159,China;2.State Key Laboratory of Mineral Processing,Beijing 100160,China;3.College of Materials Science and Engineering,Hunan University,Changsha 410082,China)
Abstract：Basic magnesium carbonate crystals (4MgCO3·Mg(OH)2·4H2O) were prepared from magnesite with the aid of anhydrous ethanol through hydration,carbonization,pyrolysis and other processes at a low temperature (55 ℃).The phase structure and microstructure of the products were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM).The effects of pyrolysis time,addition amount of anhydrous ethanol,pH of precursor solution and addition time of anhydrous ethanol on phase composition and morphology of products were studied.The growth mechanism of basic magnesium carbonate assisted by anhydrous ethanol was investigated.The results show that the microstructure and size of 4MgCO3·Mg(OH)2·4H2O are regulated by pyrolysis time,amount of anhydrous ethanol,pH of precursor solution and time of anhydrous ethanol addition.The optimum conditions for the preparation of 4MgCO3·Mg(OH)2·4H2O with the mean diameter of 2.3 μm and the morphology of rose bract are as follows:pyrolysis time of 105 min,volume ratio of anhydrous ethanol to Mg(HCO3)2 solution of 1∶2,and pH value of the precursor solution of 10±0.05.At this time,the addition amount of anhydrous ethanol has no significant effect on the crystal.The addition of anhydrous ethanol to assist the growth process of basic magnesium carbonate can not only reduce the energy required by the reaction,but also form a dense double electric protective film which can be adsorbed on the crystal surface,promote the formation of new nucleus and accelerate the conversion rate of MgCO3·3H2O to 4MgCO3·Mg(OH)2·4H2O.
Keywords：anhydrous ethanol; magnesite; basic magnesium carbonate crystal; low temperature direct method
中图分类号：TQ132.2
文献标志码：A
文章编号：1008-5548(2021)01-0041-09
DOI：10.13732/j.issn.1008-5548.2021.01.005
收稿日期：2020-06-26，修回日期：2020-09-21，在线出版时间：2020-11-02 10:42。
基金项目：国家自然科学基金,编号:51804200;辽宁省教育厅高校科研基金,编号:LG201927; 矿物加工科学与技术国家重点实验室开放基金资助项目,编号:BGRIMM-KJSKL-2019-14;辽宁省科技厅博士启动基金项目,编号:20180540104。
第一作者简介：刘珈伊(1995—),男(满族),硕士研究生,研究方向为菱镁矿法制备微纳米碳酸镁系化合物基础研究。E-mail:liujiayizz07@163.com。
通信作者简介：王余莲(1986—),女,博士,副教授,硕士生导师,研究方向为矿物材料的制备及应用研究。E-mail:xinxinwyl@163.com。
