无机盐工业
主管:中海油天津化工研究设计院有限公司
主办:中海油天津化工研究设计院有限公司
   中海油炼油化工科学研究院(北京)有限公司
   中国化工学会无机酸碱盐专业委员会
ISSN 1006-4990 CN 12-1069/TQ

无机盐工业 ›› 2025, Vol. 57 ›› Issue (5): 26-31.doi: 10.19964/j.issn.1006-4990.2024-0410

• 镁资源高值化利用 • 上一篇    下一篇

CO2矿化硫酸镁制备三水合碳酸镁的形貌调控研究

马楚璇1(), 成怀刚1,2(), 程文婷1, 马卓慧1   

  1. 1.山西大学资源与环境工程研究所,CO2减排与资源化利用教育部工程研究中心,山西 太原 030006
    2.青海大学化工学院,青海 西宁 810016
  • 收稿日期:2024-07-18 出版日期:2025-05-10 发布日期:2025-06-05
  • 通讯作者: 成怀刚(1978— ),男,教授,博士生导师,主要研究方向为无机盐资源循环工程;E-mail:chenghg@sxu.edu.cn
  • 作者简介:马楚璇(1998— ),女,硕士研究生,主要研究方向为盐湖资源综合利用;E-mail:1242710163@qq.com
  • 基金资助:
    国家自然科学基金联合重点项目(U20A20149);青海省基础研究计划项目(2023-ZJ-920M);山西大学交叉学科建设项目;国家自然科学基金青年项目(22208198)

Study on morphology control of magnesium carbonate trihydrate prepared by CO2 mineralization of magnesium sulfate

MA Chuxuan1(), CHENG Huaigang1,2(), CHENG Wenting1, MA Zhuohui1   

  1. 1. Institute of Resources and Environmental Engineering,Shanxi University,Engineering Research Center for CO2 Emission Reduction and Resource Utilization,Ministry of Education,Taiyuan 030006,China
    2. College of Chemical Engineering,Qinghai University,Xining 810016,China
  • Received:2024-07-18 Published:2025-05-10 Online:2025-06-05

摘要:

盐湖镁资源的主要加工途径之一是通过氯化镁矿化制备碳酸镁产品,而以硫酸镁为镁源时的矿化工艺经验尚少,且存在形貌和粒度难调控的问题。针对上述问题,采用以MgSO4·7H2O为镁源矿化CO2的方法制备MgCO3·3H2O晶体,开展了工艺优化的实验研究。通过X射线衍射仪、扫描电子显微镜等手段对产物进行表征,探究了反应条件与晶体组成及形貌间的关联规律,并分析了CO2矿化历程。结果表明,当反应温度为50 ℃、MgSO4初始浓度为0.6 mol/L、NH3·H2O浓度为4.0 mol/L时,能够获得结晶良好、表面光滑、形貌规则的MgCO3·3H2O晶体。以MgSO4·7H2O为镁源时,MgCO3·3H2O发生碱式转化的相变温度达到80 ℃,且获取优质MgCO3·3H2O晶体所需的MgSO4初始浓度达0.6 mol/L,工艺条件比MgCl2·6H2O为镁源时更为苛刻。以MgSO4·7H2O为镁源制备的MgCO3·3H2O是直径为1~3 μm的棒状晶体,有别于以MgCl2·6H2O为镁源时的晶须和晶棒型产品。以MgSO4·7H2O为镁源矿化CO2的反应历程主要由3个阶段构成,分别是Mg(OH)2的形成、Mg(OH)2的溶解和MgCO3·3H2O的形成。

关键词: 镁资源, 碳酸镁水合物, 晶体形貌, CO2矿化, 硫酸镁

Abstract:

One of the reprocessing ways of magnesium resources in salt lake is to prepare magnesium carbonate products by mineralization of magnesium chloride,but the mineralization process experience is still limited when magnesium source is magnesium sulfate,and the morphology and particle size are difficult to control.To solve the above problems,MgCO3·3H2O crystals were prepared by mineralizing CO2 with MgSO4·7H2O as magnesium source,and the experimental study on process optimization was carried out. The products were characterized by X-ray diffractometer and scanning electron microscope.The correlation between reaction conditions and crystal composition and morphology was investigated.The process of CO2 mineralization was also analyzed.The results showed that when the reaction temperature was 50 ℃,the initial concentration of MgSO4 was 0.6 mol/L,and the concentration of NH3·H2O was 4.0 mol/L,MgCO3·3H2O crystals with good crystallization,smooth surface and regular morphology could be obtained.When MgSO4·7H2O was used as magnesium source,the basic transformation temperature of MgCO3·3H2O was up to 80 ℃,and the initial concentration of MgSO4 required for obtaining high⁃quality MgCO3·3H2O crystals was up to 0.6 mol/L.The process conditions were more severe when MgCl2·6H2O was magnesium source.MgCO3·3H2O prepared with MgSO4·7H2O as magnesium source was a rod⁃like crystal with a diameter of 1~3 μm,which was different from the whisker and rod products of MgCl2·6H2O as magnesium source.The reaction process of mineralized CO2 with MgSO4·7H2O as magnesium source was mainly composed of three stages,namely,the formation of Mg(OH)2,the dissolution of Mg(OH)2 and the formation of MgCO3·3H2O.

Key words: magnesium resources, magnesium carbonate hydrate, crystal morphology, CO2 mineralization, magnesium sulfate

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