SCI和EI收录∣中国化工学会会刊

中国化学工程学报 ›› 2020, Vol. 28 ›› Issue (1): 208-215.DOI: 10.1016/j.cjche.2019.08.006

• Chemical Engineering Thermodynamics • 上一篇    下一篇

Leaching calcium from phosphogypsum desulfurization slag by using ammonium chloride solution: Thermodynamics and kinetics study

Yanjun Zhong, Ting Shi, Qiuge Chen, Xiushan Yang, Dehua Xu, Zhiye Zhang, Xinlong Wang, Benhe Zhon   

  1. School of Chemical Engineering, Engineering Research Center of Comprehensive Utilization and Clean Processing of Phosphorus Resources of Ministry of Education, Sichuan University, Chengdu 610065, China
  • 收稿日期:2018-12-28 修回日期:2019-08-13 出版日期:2020-01-28 发布日期:2020-03-31
  • 通讯作者: Xinlong Wang
  • 基金资助:
    Supported by Young Teachers Scientific Research Foundation Project of Sichuan University (2014SCU11020), National Key Research Project (2017YFB0307504), and Sichuan Science and Technology Planning Project (2019YFH0149).

Leaching calcium from phosphogypsum desulfurization slag by using ammonium chloride solution: Thermodynamics and kinetics study

Yanjun Zhong, Ting Shi, Qiuge Chen, Xiushan Yang, Dehua Xu, Zhiye Zhang, Xinlong Wang, Benhe Zhon   

  1. School of Chemical Engineering, Engineering Research Center of Comprehensive Utilization and Clean Processing of Phosphorus Resources of Ministry of Education, Sichuan University, Chengdu 610065, China
  • Received:2018-12-28 Revised:2019-08-13 Online:2020-01-28 Published:2020-03-31
  • Contact: Xinlong Wang
  • Supported by:
    Supported by Young Teachers Scientific Research Foundation Project of Sichuan University (2014SCU11020), National Key Research Project (2017YFB0307504), and Sichuan Science and Technology Planning Project (2019YFH0149).

摘要: Phosphogypsum (PG) desulfurization slag is a calcium-rich residue from reductive decomposition of PG using sulfur as the reductant. We proposed a technology of preparation light calcium carbonate with PG desulfurization slag, which mainly contains two steps:leaching and carbonizing. In this work, we concentrated on the former, in which ammonium chloride aqueous solution was utilized as leaching agent to extract calcium from the slag, and conducted thermodynamics and kinetics study on it. FactSage software was employed to do thermodynamic and phase equilibrium diagram calculations. The influence of leaching conditions including agitation speed, initial concentration of leaching solution, reaction temperature, and liquid/solid ratio on the calcium leaching rate was discussed in detail by means of experiment optimal design. A kinetic model developed from the shrinking core model was given to describe the leaching process. The apparent kinetic activation energy (Ea) of the leaching reaction was calculated to be 10.58 kJ·mol-1.

关键词: PG desulfurization slag, Leaching process, Thermodynamics, Kinetic model

Abstract: Phosphogypsum (PG) desulfurization slag is a calcium-rich residue from reductive decomposition of PG using sulfur as the reductant. We proposed a technology of preparation light calcium carbonate with PG desulfurization slag, which mainly contains two steps:leaching and carbonizing. In this work, we concentrated on the former, in which ammonium chloride aqueous solution was utilized as leaching agent to extract calcium from the slag, and conducted thermodynamics and kinetics study on it. FactSage software was employed to do thermodynamic and phase equilibrium diagram calculations. The influence of leaching conditions including agitation speed, initial concentration of leaching solution, reaction temperature, and liquid/solid ratio on the calcium leaching rate was discussed in detail by means of experiment optimal design. A kinetic model developed from the shrinking core model was given to describe the leaching process. The apparent kinetic activation energy (Ea) of the leaching reaction was calculated to be 10.58 kJ·mol-1.

Key words: PG desulfurization slag, Leaching process, Thermodynamics, Kinetic model