Authors: J Shibata N Murayama
Publish Date: 2016/11/28
Volume: 70, Issue: 2, Pages: 471-477
Abstract
Extraction and stripping properties of Sc3+ were investigated by using a mixed extractant of Versatic Acid 10 VA10 and Trinbutyl phosphate TBP The effect of adding TBP to VA10 was considered by analyzing the binding state of VA10 and TBP by FTIR Solvent extraction of scandium from an aqueous solution of Sc3+–Ti4+–Zr4+ which simulated waste water from the titanium oxide manufacturing process the Bayers process and others was performed and the separation factor of Sc3+ over Ti4+ and Zr4+ was investigated To clarify the operating conditions of a countercurrent multistage process for Sc3+ McCabe–Thiele analysis was applied to the extraction isotherm and stripping isotherm of Sc3+ The extraction pH of Sc3+ was found to shift to higher pH and Sc3+ was stripped at a lower concentration of H2SO4 by adding TBP to VA10 Addition of TBP to VA10 suppresses the extraction of Sc3+ and promotes the stripping of Sc3+ IR spectra of the organic phase suggested that the dimeric portion of VA10 formed hydrogen bonds with TBP The extractions of Sc3+ Ti4+ and Zr4+ were 77 3 and 8 respectively The separation factors of these metal ions were βSc/Ti = 100 and βSc/Zr = 38 at pH46 on extraction with VA10 + TBP from aqueous solutionof Sc3+–Ti4+–Zr4+ Stripping efficiency of 100 8 and 22 could be achieved for Sc3+ Ti4+ and Zr4+ respectively by using 05 mol/dm3 H2SO4 From these results it was possible to separate Sc3+from impurities such as Ti4+ and Zr4+ by countercurrent multistage extraction and Sc3+ was recovered by onestage stripping with 05 mol/dm3 H2SO4 Extraction of Sc3+from the dilute aqueous solution containing 500 mg/dm3 of Sc3+reached 99 at the flow ratio A/O = 101 in the twostage countercurrent extraction and Sc3+ in the organic phase was stripped to attain a sixfold concentration by applying onestage stripping with flow ratio of O/A = 600
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