SCI和EI收录∣中国化工学会会刊

›› 2017, Vol. 25 ›› Issue (2): 211-215.DOI: 10.1016/j.cjche.2016.06.009

• Chemical Engineering Thermodynamics • 上一篇    下一篇

Effects of temperature and phosphoric acid addition on the solubility of iron phosphate dihydrate in aqueous solutions

Tongbao Zhang, Yangcheng Lu, Guangsheng Luo   

  1. State Key Laboratory of Chemical Engineering, Department of Chemical Engineering, Tsinghua University, Beijing 100084, China
  • 收稿日期:2016-03-30 修回日期:2016-06-28 出版日期:2017-02-28 发布日期:2017-03-14
  • 通讯作者: Yangcheng Lu
  • 基金资助:
    Supported by the National Natural Science Foundation of China (21176136, 21422603) and the National Basic Research Program of China (2007CB714302).

Effects of temperature and phosphoric acid addition on the solubility of iron phosphate dihydrate in aqueous solutions

Tongbao Zhang, Yangcheng Lu, Guangsheng Luo   

  1. State Key Laboratory of Chemical Engineering, Department of Chemical Engineering, Tsinghua University, Beijing 100084, China
  • Received:2016-03-30 Revised:2016-06-28 Online:2017-02-28 Published:2017-03-14
  • Supported by:
    Supported by the National Natural Science Foundation of China (21176136, 21422603) and the National Basic Research Program of China (2007CB714302).

摘要: As important controlling factors for the synthesis of iron phosphate materials by liquid-phase precipitation, the solubilities of iron phosphate dihydrate were systematically measured at H3PO4 concentrations from 1.13 wt% to 10.7 wt%, temperature from 298.15 to 363.15 K, and atmosphere pressure in this work. The solubility was found to increase 5 orders of magnitude or more with increasing the concentration of phosphoric acid, and decrease 1 to 2 orders of magnitude with increasing the equilibrium temperature. The phosphoric acid addition and temperature were found to affect the solubility of iron phosphate dihydrate by the formation or dissociation of coordination species, which could further accelerate the phase transformation from the amorphous iron phosphate dihydrate to orthorhombic iron phosphate dehydrate by dissolution-recrystallization mechanism. The high dependences of the solubility of iron phosphate materials on H3PO4 concentration and temperature were also well predicted by calibration equations, which are meaningful for quantitatively understanding the precipitation process and sequential crystalline structure transformation and pursuing a rational strategy for synthesizing specific iron phosphate materials.

关键词: Iron phosphate, Solubility, Aqueous solution, Phosphoric acid, Temperature

Abstract: As important controlling factors for the synthesis of iron phosphate materials by liquid-phase precipitation, the solubilities of iron phosphate dihydrate were systematically measured at H3PO4 concentrations from 1.13 wt% to 10.7 wt%, temperature from 298.15 to 363.15 K, and atmosphere pressure in this work. The solubility was found to increase 5 orders of magnitude or more with increasing the concentration of phosphoric acid, and decrease 1 to 2 orders of magnitude with increasing the equilibrium temperature. The phosphoric acid addition and temperature were found to affect the solubility of iron phosphate dihydrate by the formation or dissociation of coordination species, which could further accelerate the phase transformation from the amorphous iron phosphate dihydrate to orthorhombic iron phosphate dehydrate by dissolution-recrystallization mechanism. The high dependences of the solubility of iron phosphate materials on H3PO4 concentration and temperature were also well predicted by calibration equations, which are meaningful for quantitatively understanding the precipitation process and sequential crystalline structure transformation and pursuing a rational strategy for synthesizing specific iron phosphate materials.

Key words: Iron phosphate, Solubility, Aqueous solution, Phosphoric acid, Temperature