SCI和EI收录∣中国化工学会会刊

Chinese Journal of Chemical Engineering ›› 2019, Vol. 27 ›› Issue (12): 2930-2936.doi: 10.1016/j.cjche.2018.12.025

• Separation Science and Engineering • Previous Articles     Next Articles

Adsorption equilibrium, kinetics, and dynamic separation of Ca2+ and Mg2+ ions from phosphoric acid-nitric acid aqueous solution by strong acid cation resin

Rui Lü1, Qing Xi1, Tan Li1, Rui Li1, Xiaochao Zhang1, Jianxin Liu1, Caimei Fan1, Junqiang Feng2, Lingyun Zhang2, Zhihua Wang3   

  1. 1 College of Chemistry and Chemical Engineering, Taiyuan University of Technology, Taiyuan 030024, China;
    2 Shenzhen Batian Ecological Engineering Co. Ltd., Shenzhen 518057, China;
    3 Tianji Coal Chemical Group Co. Ltd., Changzhi 047507, China
  • Received:2018-10-29 Revised:2018-12-07 Online:2019-12-28 Published:2020-03-17
  • Contact: Caimei Fan E-mail:fancm@163.com
  • Supported by:
    Supported by a grant from Tianji Coal Chemical Group Co. Ltd. (Project no. 2012-1978) and Shenzhen Batian Ecological Engineering Co., Ltd. (Project no. 2013-0909).

Abstract: The separation of Ca2+ and Mg2+ ions from phosphoric acid-nitric acid aqueous solution is very significant for the neutralization process of nitrophosphate fertilizer. This paper studied the adsorption equilibrium, kinetics, and dynamic separation of Ca2+ and Mg2+ ions by strong acid cation resin, and the effects of phosphoric acid and nitric acid on the adsorption process were investigated. The results reveal that the adsorption process of Ca2+ and Mg2+ ions in pure water on resin is in good agreement with the Langmuir isotherm model and their maximal adsorption capacities are 1.86 mmol·g-1 and 1.83 mmol·g-1, respectively. The adsorption kinetics of Ca2+ and Mg2+ ions on resin fits better with the pseudo-first-order model, and the adsorption equilibrium in pure water is reached within 10 min contact time, while at the present of phosphoric acid, the adsorption rate of Ca2+ and Mg2+ ions on resin will go down. The dynamic separation experiments demonstrate that the designed column adsorption is able to undertake the separation of metal ions from the mix acids aqueous solution, but the dynamic operation should control the flow rate of mix acid solution. Besides nitric acid solution was proved to be effective to completely regenerate the spent resin and achieve the recyclable operation of separation process.

Key words: Ca2+ and Mg2+ ions, Strong acid cation resin, Adsorption equilibrium, Kinetics, Dynamic separation