Removal Efficiency and Kinetics of Fe³⁺ from Phosphoric Medium by Solvent Extraction

抄録

The application of wet-process phosphoric acid in fertilizer is limited due to the excessive Fe³⁺ concentration. In this paper, a fundamental investigation on the removal of Fe³⁺ from phosphoric acid with P-15 extractant is conducted. First, effects of several parameters on the extraction rate such as extraction temperature, P-15 concentration, phase ratio O/A on Fe³⁺ extraction are carefully investigated. The composition of the extract was verified by slope method and saturation capacity method. Then, the kinetic and control mechanism of the extraction reaction is studied by constant interface cell. The extraction reaction rate equation was obtained by the initial rate method. The calculated activation energy of overall reaction is 15.4 kJ·mol⁻¹ and the change of enthalpy ∆H = −4.19 kJ·mol⁻¹ of Fe³⁺ is measured by automatic calorimeter.