Application of Emulsion Liquid Membrane Technique for Uranium Extraction from Nitric Acid Solutions

摘要

The applicability of the emulsion-type liquid membrane process using tri octyl -phosphine -oxide (TOPO) as an extractant to concentrate uranium from nitric acid solutions was investigated. Span 80, kerosene and sodium carbonate were used as surfactant, diluent and internal phase in the W/O emulsion respectively. The effect of initial concentration of uranium, nitric acid concentration, percent Span 80, time and speed of mixing during extraction and emulsion breakage and ratio of (organic / internal) to external phase upon both the extraction efficiency of uranium and emulsion stability were investigated. The obtained data revealed that the extraction efficiency is directly proportional to the concentration of TOPO (mobile carrier) as well as to the initial concentration of uranium and the time and speed of mixing up to 1000 rpm during the extraction process. However, the uranium extraction efficiency is inversely proportional to the concentration of Span 80, the ratio of (organic/internal) to external phase and to the concentration of nitric acid in the external phase. A uranium extraction efficiency up to 97% was achieved under the studied conditions.