Separation of Te(IV) and Se(IV) by Extraction with Cyanex 925

Abstract

Liquid–liquid extraction of tellurium(IV) and selenium(IV) with Cyanex 925 in toluene from aqueous hydrochloric acid media was studied separately, under the influence of variables such as: hydrochloric acid concentration, reagent concentration, equilibration time, diverse ions, stripping agents, and temperature. The difference in extractability of these metal ions in hydrochloric acid media toward Cyanex 925 facilitates their separation. The temperature dependence of extraction equilibriums were examined by the temperature variation method to estimate apparent thermodynamic function, ΔH. From the temperature study, the extraction reaction for Te(IV) was found to be exothermic in nature, while that of Se(IV) endothermic.

Keywords:

• Extraction
• Tellurium(IV)
• Selenium(IV)
• Separation
• Temperature
• Cyanex 925

Acknowledgment

The authors are thankful to Cytec Canada Inc., Canada, for supplying the Cyanex 925 gift sample.