Extraction of Chromium (VI) From Mineral Acid Solutions by Tri-n-Octyl amine Oxide

Chromium is an important non-ferrous metal with high corrosion resistance finding its application in electroplating, tannery, chloral kali industries etc. Out of the two most stable forms of Chromium hexavalent one considered as a serious health hazard and it has attracted attention as a pollutant in natural waters. In view of this the separation and determination of chromium has been receiving considerable attention. Solvent extraction of Chromium (VI) from hydrochloric, sulphuric, and nitric acid solutions with Tri-n-Octyl amine oxide (TOAO) in benzene has been studied. The optimum conditions for extraction were established from the study of the effect of several variables like concentration of extractant, metal ion, acidity etc.  The extractions are nearly quantitative with hydrochloric and sulphuric acid & are partial from nitric acid solutions. The extracted species are also identified. The method has been applied for the recovery and determination of chromium in synthetic as well as stainless steel samples.