SCI和EI收录∣中国化工学会会刊

Chinese Journal of Chemical Engineering ›› 2023, Vol. 60 ›› Issue (8): 131-142.DOI: 10.1016/j.cjche.2023.04.008

Previous Articles     Next Articles

Solid-liquid phase equilibrium for the system ammonium polyphosphate-urea ammonium nitrate-potassium chloride-water at 273.2 K

Xingjuan Liang, Dehua Xu, Zhengjuan Yan, Jingxu Yang, Xinlong Wang, Zhiye Zhang, Jingli Wu, Honggang Zhen   

  1. Ministry of Education Research Center for Comprehensive Utilization and Clean Processing Engineering of Phosphorus Resources, College of Chemical Engineering, Sichuan University, Chengdu 610065, China
  • Received:2022-06-18 Revised:2023-04-04 Online:2023-10-28 Published:2023-08-28
  • Contact: Zhengjuan Yan,E-mail:zjyan@scu.edu.cn
  • Supported by:
    The authors greatly acknowledge the fund supported by the National Natural Science Foundation of China (32172677).

Solid-liquid phase equilibrium for the system ammonium polyphosphate-urea ammonium nitrate-potassium chloride-water at 273.2 K

Xingjuan Liang, Dehua Xu, Zhengjuan Yan, Jingxu Yang, Xinlong Wang, Zhiye Zhang, Jingli Wu, Honggang Zhen   

  1. Ministry of Education Research Center for Comprehensive Utilization and Clean Processing Engineering of Phosphorus Resources, College of Chemical Engineering, Sichuan University, Chengdu 610065, China
  • 通讯作者: Zhengjuan Yan,E-mail:zjyan@scu.edu.cn
  • 基金资助:
    The authors greatly acknowledge the fund supported by the National Natural Science Foundation of China (32172677).

Abstract: Based on the dynamic method, a quaternary system of ammonium polyphosphate (APP)-urea ammonium nitrate (UAN, CO(NH2)2-NH4NO3)-potassium chloride (KCl)-H2O and its subsystems (APP-[CO(NH2)2-NH4NO3]-H2O, KCl-[CO(NH2)2-NH4NO3]-H2O and APP-KCl-H2O) were systematically investigated at the temperature of 273.2 K. Each ternary phase diagram contains one invariant point and three crystallization regions. The crystallization regions are: (1) (NH4)3HP2O7, (NH4)4P2O7 and ((NH4)3HP2O7 + (NH4)4P2O7) for APP-[CO(NH2)2-NH4NO3]-H2O diagram; (2) KCl, KNO3 and (KCl + KNO3) for KCl-[CO(NH2)2-NH4NO3]-H2O diagram and (3) (NH4)3HP2O7, KCl and ((NH4)3HP2O7 + KCl) for APP-KCl-H2O diagram. The quaternary phase diagram of APP-[CO(NH2)2-NH4NO3]-KCl-H2O has no quaternary invariant point but includes four solid phase crystallization regions, i.e., (NH4)3HP2O7, (NH4)4P2O7, KNO3 and KCl, in which the KNO3 region occupies the largest area. The maximum total nutrient content (N + P2O5 + K2O) existing as ionic forms in the APP-[CO(NH2)2-NH4NO3]-H2O, KCl-[CO(NH2)2-NH4NO3]-H2O, APP-KCl-H2O and quaternary systems is 44.70%, 32.86%, 45.56% and 46.23% (mass), respectively, indicating that the maximum nutrient content can be reached using raw materials of the corresponding systems to prepare liquid fertilizer. In the quaternary system, the content of ascends with the increase of the total nutrient content, while the contents of and CO(NH2)2-N increase with elevated total N. This work can help optimize the operating parameters for the production, storage and transportation of liquid fertilizers.

Key words: Water-soluble ammonium polyphosphate, Urea ammonium nitrate (UAN), Phase equilibria, Solubility, Thermodynamics

摘要: Based on the dynamic method, a quaternary system of ammonium polyphosphate (APP)-urea ammonium nitrate (UAN, CO(NH2)2-NH4NO3)-potassium chloride (KCl)-H2O and its subsystems (APP-[CO(NH2)2-NH4NO3]-H2O, KCl-[CO(NH2)2-NH4NO3]-H2O and APP-KCl-H2O) were systematically investigated at the temperature of 273.2 K. Each ternary phase diagram contains one invariant point and three crystallization regions. The crystallization regions are: (1) (NH4)3HP2O7, (NH4)4P2O7 and ((NH4)3HP2O7 + (NH4)4P2O7) for APP-[CO(NH2)2-NH4NO3]-H2O diagram; (2) KCl, KNO3 and (KCl + KNO3) for KCl-[CO(NH2)2-NH4NO3]-H2O diagram and (3) (NH4)3HP2O7, KCl and ((NH4)3HP2O7 + KCl) for APP-KCl-H2O diagram. The quaternary phase diagram of APP-[CO(NH2)2-NH4NO3]-KCl-H2O has no quaternary invariant point but includes four solid phase crystallization regions, i.e., (NH4)3HP2O7, (NH4)4P2O7, KNO3 and KCl, in which the KNO3 region occupies the largest area. The maximum total nutrient content (N + P2O5 + K2O) existing as ionic forms in the APP-[CO(NH2)2-NH4NO3]-H2O, KCl-[CO(NH2)2-NH4NO3]-H2O, APP-KCl-H2O and quaternary systems is 44.70%, 32.86%, 45.56% and 46.23% (mass), respectively, indicating that the maximum nutrient content can be reached using raw materials of the corresponding systems to prepare liquid fertilizer. In the quaternary system, the content of ascends with the increase of the total nutrient content, while the contents of and CO(NH2)2-N increase with elevated total N. This work can help optimize the operating parameters for the production, storage and transportation of liquid fertilizers.

关键词: Water-soluble ammonium polyphosphate, Urea ammonium nitrate (UAN), Phase equilibria, Solubility, Thermodynamics