An investigation on the solid–liquid phase equilibrium of the quaternary system KH 2 PO 4 –H 3 PO 4 –CH 2 OHCH 2 OH–H 2 O

Thermodynamic Modeling the Solid–Liquid Phase Equilibrium of a Water–Methanol–Potassium Dihydrogen Phosphate Ternary System with a Mixed-Solvent Electrolyte (MSE) Model

“…MKP can be dissolved in solution, mainly in the form of K + and H 2 PO 4 – . In the H 2 O–CH 3 OH–MKP system, the following dissociation reactions mainly exist , …”

“…It is applied in the industry, feed, agriculture, food, pharmaceutical, and other fields. , Especially in agriculture, MKP is an important fertilizer, which is an efficient chlorine-free phosphorus potassium compound fertilizer and has the advantages of high nutrient composition (including K 2 O 35%, P 2 O 5 52%), good fertilizer efficiency, good water solubility, and easy to be absorbed by plants. − In recent years, with the development of water-soluble fertilizers, the demand for MKP in agriculture increases. At present, the relatively mature production method of MKP is the neutralization method with thermal process phosphonic acid as the raw material, but the raw materials of this method are expensive; therefore, this method is not suitable for the production of MKP for practical use in agriculture. − Therefore, potassium chloride and wet phosphoric acid are used as raw materials to reduce the production cost. The key part of this process is the crystallization section, usually using evaporation concentration and cooling crystallization, but this method has high energy consumption and the product quality is not of good quality; therefore, the salting-out crystallization method is used, which has good crystallization efficiency, can be carried out at a low temperature, and has low energy consumption.…”

“…Cao et al used ethanol as an antisolvent to measure the phase equilibrium and physical property data of the KCl–KH 2 PO 4 –C 2 H 5 OH–H 2 O system at 298.15 K by the isothermal solution saturation method and moist residues. Yang et al proposed the method of introducing ethylene glycol to reduce the solubility of MKP. The effects of the mass fraction of phosphate, the mass fraction of ethylene glycol, and temperature on the solubility of MKP were studied by the isothermal solution saturation method.…”

Continuous and simultaneous conversion of Moroccan phosphogypsum waste to Na2SO4, and K2SO4 using the quaternary system Na+, K+ // Cl-, SO42- - H2O at 25°C

“…Xie et al shows that solid-liquid phase equilibria can greatly improve the efficiency of manufacturing and application of liquid fertilizers [39]. Based on the solubility data and phase diagram of the quaternary system KH2PO4-H3PO4-CH2OHCH2OH-H2O, Yang et al proposed a design of the crystallization process of KH2PO4 from the solution of ethylene glycol -KH2PO4 -H3PO4 [40]. Cheng at al.…”

Measurement and Correlation of Solid–Liquid Equilibria of Quaternary System KCl–KH2PO4–(NH2)2CO–H2O and Its Ternary Subsystem KH2PO4–(NH2)2CO–H2O at 303.15 K

“…Solubility Data of Quaternary System KCl−KH calculated with eqs 9−12,44 and the calculation results are shown in Table4.In Figure4, points A, B, and C represent the cosaturated points of KCl−KH 2 PO 4 −H 2 O, KH 2 PO 4 −(NH 2 ) 2 CO−H 2 O, and KCl−(NH 2 ) 2 CO−H 2 O, respectively. Three univariate curves AE 2 , BE 2 , and CE 2 represent the cosaturated solubility curves of KCl−KH 2 PO 4 , KH 2 PO 4 −(NH 2 ) 2 CO, and KCl− (NH 2 ) 2…”