PURIFICATION OF TRI-n-OCTYL PHOSPHINE OXIDE BY EXTRACTION AND PRECIPITATION. EXTRACTION OF Zn, Mo AND Fe IN ACID MEDIUM
LALDJA MEDDOUR, MOHAMED A. DIDI* TLEMCEN UNIVERSITY, FACULTY OF SCIENCES, DEPARTMENT OF CHEMISTRY, LABORATORY OF CATALYSIS AND SYNTHESIS IN ORGANIC CHEMISTRY, BOX 119, TLEMCEN, ALGERIA. *CORRESPONDING AUTHOR: MADIDI13@YAHOO.FR
The aim of this work was a process of purification of tri-n-octyl phosphine oxide (TOPO) based on extractability properties. In this context, the extraction parameters (acid concentration, volume ratio of the phases, mixing time) were optimized. The extraction operation was followed by the precipitation of the formed complex. This purification technique made it possible to increase the TOPO purity from 27.8% to 92%. The liquid–liquid extraction of Zn, Mo and Fe was carried out using the purified TOPO, starting from the aqueous solutions of hydrochloric acid. It was carried out under various operating conditions including the variation of the HCl concentration, the molar ratio [TOPO]/[Zn], the volume ratio of the phases (organic/aqueous) and the contact time between phases. The best extraction yields were obtained for the concentrations of HCl varying between 3 – 7 mol/L, for the contact times varying from 5 – 20 minutes and the volume ratios of phases between 1 and 4, according to studied metal. For a molar ratio [TOPO]/[Zn] > 10, the value of extraction yield of Zn by TOPO is doubled.
