Solvent Extraction Separation of Zirconium (iv) With Anberlite LA - 1 From Citrate Solutions

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Abstract
Zirconium was quantitatively extracted with 8 × 10−2 M of Amberlite LA-1 or LA-2 xylene from 0.001 M citric acid at pH 3.5 and it was stripped from the organic phase with 2 M hydrochloric acid and was determined spectrophotometrically at 665 nm as its complex with arsenazo III. Zirconium was separated from binary as well as tertiary mixtures by exploiting the difference in the distribution coefficient or by selective extraction or selective stripping. The method was applied for the analysis of zircon. Zirconium was extracted as its anionic complex with various mineral acids by liquid anion exchanger. The chlorocomplex of zirconium was extracted from 6–10 M hydrochloric acid with trioctylamine1–5, triisooctylamine6 or Aliquat 33657. The sulphotocomplex of zirconium was extracted with Aliquat 33658, Primine JMT9, Alamine 33610. The nitratocomplex was less extensively utilised for the extractive separation of zirconium11, 12. Zirconium was extracted quantitatively from oxalate13, 14 and malonate media15. These extractions were carried out at low pH and separated zirconium from large number of associated elements. The ion exchange chromatographic behaviour of zirconium on column with cation exchange16–17 or with anion exchange18 resin with citric acid as eluent were utilised but extraction studies from citrate solutions were never attempted. From the critical study of existing methods it was observed that zirconium was extracted at narrow pH range; with high concentration of complexing ligand for extraction with liquid anion exchangers and long period of equilibration for extraction as well as stripping. So also such extractions were possible mostly at milligram concentrations involving use of hazardous diluents like benzene. In order to circumvent these difficulties an attempt was made to develop a better method for the solvent extraction separation of zirconium by ion pair formation. Therefore this paper presents systematic investigations on the solvent extraction separation of zirconium from citrate media with liquid anion exchangers. From the study of various factors. The optimum conditions for the extraction and the separation of zirconium from associated elements are evaluated. The method has been extended for the analysis of zirconium from zircon.