title: Liquid-liquid extraction, separation recovery and transport of tantalum by crown-ether.
abstract: A solvent extraction, separation, preconcentration method and recovery of tantalum is reported. Tantalum is extracted with dibenzo-18-crown-6 (DB18C6) in dichloromethane in presence of niobium from 4 M hydrochloric acid. The transport of tantalum(V) ions through a supported liquid membrane containing DB18C6 has been studied. The influence of molarity of acid, carrier concentration, temperature and kinetics of transport is discussed. Tantalum-DB18C6 extract was directly inserted in the plasma for ICP-AES measurement which enhances the sensitivity to 20-folds with the detection limit 1 ng. The mixed compelxes of tantalum-DB18C6 with methyl violet and thiocyanate have also been studied. Tantalum was recovered from tin scrap and determined in standard and sea water samples.
authors.affiliation: Chemistry Department, School of Sciences, Gujarat University, Ahmedabad 380 009, India.
authors.forename: Y K
authors.initials: YK
authors.lastname: Agrawal