Cyanex 302: An extractant for Fe³⁺ from Chloride Medium

Abstract

The solvent extraction of Fe3+ from aqueous chloride solution by bis-(2,4,4-trimethylpentyl) monothiophosphinic acid (Cyanex 302, H2A2) dissolved in kerosene has been investigated over a wide range of aqueous acidity as a function of phase contact time, concentrations of Fe3+, H+ and Cl- in the aqueous phase, Cyanex 302 concentration in the organic phase and temperature. The equilibration time is 50 min. The distribution ratio is found to be independent on [Fe3+] in the aqueous phase at a constant aqueous acidity and extractant concentration. The H+, extractant and Cl- dependences are -1, 0.5 in low concentration region of extractant and -0.5, respectively; which suggest that extraction occurs via the following two parallel reactions: (i) FeCl3 + 0.5 H2A2(o) FeCl2.A(o) + H+ + Cl-; and (ii) FeCl2 + + 0.5 H2A2(o) -----FeCl2A(o) + H+. Temperature dependence data give ΔH value of 9.95 kJ/ mol. The loading capacity of Cyanex 302 towards Fe3+ is 29.41 g Fe3+/100 g Cyanex 302. The extraction equilibrium constant (Kex) is 10-0.632. Extraction ratio is found to be dependent on diluent used. Stripping of the extracted complex is found to be a difficult task, but may be made effective by a solution containing 6 M H2SO4 and 1 M Na2C2O4. Keywords: Extraction equilibrium; Fe3+ extraction; Cyanex 302; Chloride medium.DOI: http://dx.doi.org/10.3329/bjsir.v46i4.9583 BJSIR 2011; 46(4): 407-414

Factorial (25) design for the extraction of V(IV) in the V(IV)-[SO42-](H+, Na+) ? Cyanex 302-kerosene system

“…Cyanex 302 containing 78-80% R 2 PSOH, 10-12% R 3 PO, 2-3% R 2 PO 2 H, 2% R 2 PS 2 H and 8% unknown compounds (Ali et al,2011) …”

Equilibrium of the Extraction of V(IV) in the V(IV)-SO<sub>4</sub><sup>2-</sup>(H<sup>+</sup>, Na<sup>+</sup>)—Cyanex 302-Kerosene System

“…Extraction and stripping procedures are given elsewhere [19]. In both cases, two phases are agitated at O/A=1 (O = 20 mL) and 303 K (otherwise stated) for a predetermined time (20 min in extraction and 1 h in stripping).…”

“…The phase separation is quick; and the aqueous phase after equilibration is analyzed for its equilibrium pH and V(IV)-content. Then the value of extraction ratio or stripping percentage is calculated as usual [19].…”

Liquid-Liquid Extraction of V(IV) from Sulphate Medium by Cyanex 301 Dissolved in Kerosene

“…The procedure for extraction is given elsewhere [20,23]. Two phases are agitated at O/A = 1 (O = 20 mL) and 303 K (otherwise stated) for a predetermined time (15 min).…”

“…The phase separation is quick; and the aqueous phase after disengagement is analyzed for its pH (eq) and V(IV)-content. Then "D" is calculated as usual [20,23].…”