Phase Equilibria in the K_۲SO_۴-NiSO_۴-H_۲O System

Given the important role of the micronutrient nickel in plant metabolism, the use of nickel-containing substances as fertilizer components is considered to be of significant scientific and practical importance. To ensure the presence of a sufficient amount of solid phases in mixtures of nickel sulfate and potassium sulfate, the solubility of the salts was investigated at ۲۵ ℃ under constant temperature and continuous stirring conditions using the isothermal method. Based on the obtained results, an isothermal diagram of the K۲SO۴-NiSO۴-H۲O system at ۲۵ ℃ was constructed. The results of the isothermal solubility diagram study showed that, in the K۲SO۴-NiSO۴-H۲O system, the formation region of the double compound K۲SO۴·NiSO۴·۶H۲O lies within the concentration ranges of ۰.۳۳-۲۳.۰۹% nickel sulfate and ۶.۸۲-۱۱.۱۶% potassium sulfate. Based on the obtained results, the feasibility of producing stable liquid chlorine-free potassium fertilizers crystallizing at ۲۵ ℃ and containing ۰.۳% nickel and ۱۱-۱۲% potassium was substantiated. The findings of this study are of significant importance for the development of highly efficient micronutrient-containing fertilizers, particularly for the scientific design of liquid fertilizer compositions intended for drip irrigation technologies. The formed compound was isolated from the crystallization field of the phase diagram and confirmed by modern physicochemical analysis methods, including EDS, XRD, IR spectroscopy, and thermal analysis.

کلیدواژه ها:

Nickel sulfate ، Potassium sulfate ، solubility diagram ، phase equilibrium ، micronutrient fertilizer ، K۲SO۴&middot ، NiSO۴&middot ، ۶H۲O