无机盐工业
主管:中海油天津化工研究设计院有限公司
主办:中海油天津化工研究设计院有限公司
   中海油炼油化工科学研究院(北京)有限公司
   中国化工学会无机酸碱盐专业委员会
ISSN 1006-4990 CN 12-1069/TQ

无机盐工业 ›› 2025, Vol. 57 ›› Issue (2): 92-97.doi: 10.19964/j.issn.1006-4990.2024-0188

• 研究与开发 • 上一篇    下一篇

低温下钾盐溶解度的测定及液体肥配方研究

董南1(), 王楠1, 纪利俊1(), 盛勇2   

  1. 1.华东理工大学,上海 200237
    2.中化云龙有限公司,云南 昆明 655204
  • 收稿日期:2024-03-29 出版日期:2025-02-10 发布日期:2025-02-20
  • 通讯作者: 纪利俊(1972— ),男,副教授,研究方向为传质与分离;E-mail:jilijun@ecust.edu.cn
  • 作者简介:董南(1996— ),男,硕士研究生,研究方向为传质与分离;E-mail:13013063723@163.com

Determination of potassium salt solubility at low temperature and study of liquid fertilizer formula

DONG Nan1(), WANG Nan1, JI Lijun1(), SHENG Yong2   

  1. 1.East China of Science and Technology,Shanghai 200237,China
    2.Sinochem Yunlong Co. Ltd. ,Kunming 655204,China
  • Received:2024-03-29 Published:2025-02-10 Online:2025-02-20

摘要:

在较低温度下,高钾液体肥中钾盐的结晶析出与钾盐的溶解度密切相关。基于此,采用等温溶解平衡法测定了278.15、288.15 K下KH2PO4-KNO3-H2O和278.15 K下KH2PO4-KCl-H2O的液固相平衡数据,并基于相平衡数据绘制了相图。结果表明,两个液固体系均为简单共饱和型,无复盐或固溶体生成。两个液固体系中钾盐的溶解度随温度上升而增大,在278.15 K和288.15 K下共饱和点处的K2O含量最高。根据NY 1106—2010《含腐植酸水溶肥料》中对液体肥大量元素含量的要求,并结合KH2PO4-KNO3-H2O的液固相平衡数据,对使用KH2PO4和KNO3配制高钾液体肥的配方进行分析。结果表明,在大部分常温区和所有低温区,只使用KH2PO4和KNO3配制的液体肥的大量元素含量无法满足标准要求。通过加入聚磷酸铵,提高液体肥中大量元素含量,设计了两种低温区高钾液体肥配方,并进行实验验证。该研究可为低温下钾盐体系液体肥的配方设计提供参考。

关键词: 液固相平衡, 液体肥, 配方, 磷酸二氢钾, 硝酸钾

Abstract:

The crystallization of potassium salts in high-potassium-content liquid fertilizer at relatively low temperature is closely related to the solubility of potassium salt.In this study,the liquid-solid equilibrium data of KH2PO4-KNO3-H2O at the low temperature of 278.15 K and 288.15 K,and that of KH2PO4-KCl-H2O at 278.15 K were measured using the isothermal dissolution equilibrium method,and the data was plotted in the phase diagrams with specified crystallization regimes.The results showed that the two systems were simple co-saturated and no double salt or solid solution forms.In two systems,the solubility of potassium salts was increased with the increase of temperature,and according to phase diagrams the K2O content of co-saturated point was maximum at 278.15 K and 288.15 K.Based on the content requirement of macro-nutrition,highlighted in the NY 1106—2010 standard,the formula of the high-potassium-content liquid fertilizer was analyzed,using the solid-liquid equilibrium data.The results showed that,it was often difficult at the ambient temperature regions,and was not viable at the low temperature regions to meet the required NPK content by only using KH2PO4 and KNO3.The formulas of the liquid fertilizer were designed by adding liquid ammonium polyphosphate(APP) to increase NPK content,the results were validated by experiment.This study could provide reference for the formula design of liquid fertilizer in potassium salt system at low temperature.

Key words: liquid-solid phase equilibrium, liquid fertilizer, formula, potassium dihydrogen phosphate, potassium nitrate

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