Study of the multicomponent system wet process phosphoric acid–methyl isobutyl ketone at 40 °C phase equilibria and extraction performances

✍ Scribed by M. Feki; M. Stambouli; D. Pareau; H.F. Ayedi

• Book ID: 104427091
• Publisher: Elsevier Science
• Year: 2002
• Tongue: English
• Weight: 168 KB
• Volume: 88
• Category: Article
• ISSN: 1385-8947
• DOI: 10.1016/s1385-8947(01)00246-7

✦ Synopsis

This work concerns the purification of wet process phosphoric acid (WPA) by solvent extraction with methyl isobutyl ketone (MIBK) at 40 • C. For this purpose, an exhaustive study of the multicomponent extraction system WPA-MIBK was carried out. In a first step, the distribution of the main components (H 3 PO 4 , H 2 O, MIBK) and the major impurities of WPA (Ca 2+ , Mg 2+ , Al 3+ , Fe 3+ , SO 4 2-, F -) between the conjugated phases was systematically studied. Then, expression of phase compositions in terms of H 3 PO 4 , H 2 O and MIBK on an impurity-free basis enabled us to compute the characteristics of the H 3 PO 4 countercurrent multistage extraction using the Mac Cabe-Thiele method. Both as-received and water-saturated MIBK were considered as solvent. From graphical results, optimum conditions to conduct the extraction of H 3 PO 4 from concentrated WPAs (53.5-58% P 2 O 5 ) were determined. To validate experimentally the obtained results, continuous countercurrent extractions were performed on a laboratory-scale mixer-settler unit. A good agreement was observed.