化工学报 ›› 2017, Vol. 68 ›› Issue (2): 702-707.DOI: 10.11949/j.issn.0438-1157.20161259

• 分离工程 • 上一篇    下一篇

杂质离子对MgCl2和CO2反应-萃取-醇析耦合过程的影响

陈贵兰, 宋兴福, 于建国   

  1. 化学工程联合国家重点实验室, 华东理工大学国家盐湖资源综合利用工程技术研究中心, 上海 200237
  • 收稿日期:2016-09-08 修回日期:2017-01-04 出版日期:2017-02-05 发布日期:2017-02-05
  • 通讯作者: 于建国
  • 基金资助:

    青海省科技厅项目(2015-GX-Q19A)。

Effects of impurity ions on coupled reaction-extraction-alcohol precipitation process of MgCl2 and CO2

CHEN Guilan, SONG Xingfu, YU Jianguo   

  1. State Key Laboratory of Chemical Engineering, National Engineering Research Center for Integrated Utilization of Salt Lake Resources, East China University of Science and Technology, Shanghai 200237, China
  • Received:2016-09-08 Revised:2017-01-04 Online:2017-02-05 Published:2017-02-05
  • Supported by:

    supported by the Science and Technology Department Program of Qinghai Province (2015-GX-Q19A).

摘要:

通过反应-萃取-醇析耦合过程,将MgCl2和CO2制备成碳酸镁和氯化氢气体是盐湖老卤资源化利用的有效途径。系统地研究了老卤中Na+、K+、Ca2+对MgCl2和CO2反应-萃取-醇析耦合过程得到的固体产物晶型晶貌的影响。结果表明,Na+和K+对耦合过程的影响相似,固体产物均为高纯棒状三水碳酸镁(MgCO3·3H2O),且Na+和K+均能选择性吸附在MgCO3·3H2O晶体的轴面(101),阻碍该晶面的生长,使得棒状MgCO3·3H2O直径变小;Ca2+对反应-萃取-醇析耦合过程有不利的影响,由于CaCl2能参与反应,生成球状无定形纳米钙镁碳酸盐,使得三水碳酸镁纯度降低。

关键词: 盐湖老卤, 反应-萃取-醇析耦合, 三水碳酸镁, 杂质离子, 形貌

Abstract:

The preparation of nesquehonite (MgCO3·3H2O) and hydrogen chloride by MgCl2 and CO2 based on a coupled reaction-extraction-alcohol precipitation process is an effective way for the comprehensive utilization of brine. The effects of impurity ions Na+, K+ and Ca2+ in brine on the morphology of the solid product obtained in the coupled reaction-extraction-alcohol precipitation process are investigated systematically. The results indicate that Na+ and K+ have a similar influence on the coupled process. The products are rod-like high purity MgCO3·3H2O when Na+ and K+ are added. Moreover, Na+ and K+ can be selectively absorbed onto the axial face (101) of MgCO3·3H2O, that will hinder the growth along the (1 0 1) direction and resulting a decrease in the diameter of MgCO3·3H2O. Ca2+ shows a negative effect on the coupled process. The added impurity CaCl2 can react with CO2 and form spherical amorphous nano Mg/Ca-carbonate, which will decrease the purity of the solid products.

Key words: brine, coupled reaction-extraction-alcohol precipitation process, nesquehonite, impurity ions, morphology

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