高等学校化学学报 ›› 2023, Vol. 44 ›› Issue (6): 20230074.doi: 10.7503/cjcu20230074

• 物理化学 • 上一篇    下一篇

诱导期测定法对碳酸锂成核动力学的研究

程文婷(), 李倩倩, 成怀刚, 程芳琴()   

  1. 山西大学资源与环境工程研究所, 太原 030031
  • 收稿日期:2023-02-20 出版日期:2023-06-10 发布日期:2023-04-14
  • 通讯作者: 程文婷,程芳琴 E-mail:wtcheng@sxu.edu.cn;cfangqin@sxu.edu.cn
  • 基金资助:
    国家自然科学基金(22208198);国家重点研发计划项目(2022YFC3901305)

Determination of the Nucleation Kinetics of Lithium Carbonate by Induction Period Measurement

CHENG Wenting(), LI Qianqian, CHENG Huaigang, CHENG Fangqin()   

  1. Institute of Resources and Environmental Engineering,Shanxi University,Taiyuan 030031,China
  • Received:2023-02-20 Online:2023-06-10 Published:2023-04-14
  • Contact: CHENG Wenting, CHENG Fangqin E-mail:wtcheng@sxu.edu.cn;cfangqin@sxu.edu.cn
  • Supported by:
    the National Natural Science Foundation of China(22208198);the National Key Research and Development Program of China(2022YFC3901305)

摘要:

在288.15~323.15 K温度范围内, 采用诱导期测定法研究了碳酸锂(Li2CO3) 在有无添加NaCl的 LiCl-Na2CO3过饱和溶液中的成核动力学. 通过OLI电解质与水化学物性分析软件内嵌的全组分模型严格计算Li2CO3在溶液中的过饱和度, 研究了温度、 过饱和度和NaCl的添加量对Li2CO3成核诱导期的影响, 并结合经典初级成核理论计算了活化能、 固-液界面张力和接触角等成核动力学参数. 结果显示, 在相同的过饱和度下, NaCl的添加使得Li2CO3的成核诱导期增长; 添加NaCl后Li2CO3成核反应的活化能从63.69 kJ/mol(溶液中Cl的超额含量Y=0)增加到72.85 kJ/mol(溶液中Cl的超额含量Y=0.5), 表明NaCl的添加抑制了Li2CO3的成核. 采用经典初级成核理论研究了Li2CO3的两种成核机制(均相成核和非均相成核), 计算结果表明, 在同一温度下, 均相成核时的固-液界面张力始终大于非均相成核时的固-液界面张力, 温度的变化以及NaCl的添加对固-液界面张力的影响均可忽略.

关键词: 碳酸锂, 成核, 动力学, 诱导期, 界面张力

Abstract:

Nucleation kinetics was investigated by induction period measurement for supersaturated solutions of lithium carbonate(Li2CO3) in the LiCl-Na2CO3 system with and without NaCl over the temperature range of 288.15—323.15 K. The supersaturation of Li2CO3 was rigorously determined by full speciation model through OLI stream analyzer software. The effects of temperature, supersaturation and presence of NaCl on the nucleation induction period of Li2CO3 were studied experimentally. The nucleation kinetic parameters such as activation energy, interfacial tension and contact angle were calculated according to the classical theory of primary nucleation. The induction period was prolonged by adding NaCl in solutions at a constant supersaturation. The activation energy of Li2CO3 nucleation reaction increased from 63.69 kJ/mol(the excess of Cl ions Y=0) to 72.85 kJ/mol(the excess of Cl ions Y=0.5) after the addition of NaCl, indicating that the addition of NaCl inhibited the nucleation of Li2CO3. Classical theory of primary nucleation was used to study the homogeneous and heterogeneous nucleation mechanism of Li2CO3. The interfacial tension of homogeneous nucleation was higher than that of heterogeneous nucleation. Both interfacial tensions of homogeneous and heterogeneous nucleation had no significant dependence on temperature, and were not obviously influenced by the presence of NaCl.

Key words: Lithium carbonate, Nucleation, Kinetics, Induction period, Interfacial tension

中图分类号: 

TrendMD: