Liquid Membrane Process for the Selective Recovery of Uranium from Industrial Leach Solutions

Abstract

Leach liquor of uranium concentrates are generated at Uranium Corporation of India Limited (UCIL), Jaduguda, India. Application of the emulsion liquid membrane (ELM) technique was tested for the efficient recovery of uranium from the leach liquor, in the presence of metal ions such as Fe, Ca, Mg, and Mn. The liquid membrane employed consisted of a diluent (light and heavy paraffin), a surfactant (Span 80), and an extractant (Alamine 336), and sodium carbonate was used as the stripping solution. Initially, the ELM process parameters were optimized by using synthetic leach liquor as the feed phase. The role of the acidic feed-phase pH, which enhances the cotransport of H+ ions along with uranium inside the emulsion globules, was found to be significant, as it helped in achieving the complete extraction and stripping of uranium. The best optimized parameters were directly used for the separation and concentration of uranium from industrial leach solutions. In one step, in the presence of various metal ions, the selective permeation of uranyl ions through the liquid membrane was observed to be greater than 90%, and the concentration of uranium inside the strip phase was observed to be nearly 7 times higher. Separation factors of uranium with respect to Fe, Mg, Ca, and Mn were experimentally found to be 129, 781, 43, and 1462, respectively, in 12 min. Finally, application of the process in uranium ore processing is demonstrated.

A Novel Liquid Emulsion Membrane Containing TODGA as the Carrier Extractant for Am Recovery from Acidic Wastes

“…Additionally, simultaneous extraction and stripping make the liquid membrane based separation method an attractive proposition as third phase formation becomes a distant possibility. Out of the liquid membrane based separation methods, liquid emulsion membranes (LEM) have been particularly attractive due to faster mass transfer rates and there are several reports on the separation of transition metal ions (18)(19)(20)(21), toxic metal ions (22)(23)(24)(25)(26), and even actinide ions (27,28), though literature on actinide separations is very limited. In case of LEM methods also, the limitations of solvent extraction appear to be alleviated due to lower metal ion loading which is a consequence of simultaneous stripping.…”

Emulsion ionic liquid membranes (EILMs) for removal of Pb(ii) from aqueous solutions

“…The solute can be recovered again by breaking of the emulsion membrane. 13 However, from the preparation of the emulsion membrane to the driving force for the metal ion to diffuse, there are certain parameters (e.g. speed of agitation, surfactant and extractant concentration, treat ratio, and feed phase pH), which affect the performance of the ELM process.…”

Recovery of 4-chlorophenol from an aqueous solution by ELM: stability of the membrane, modeling, and optimization of the extraction using experimental designs

“…Several works have emerged since then, as the extraction of heavy metals [4][5][6] or precious metals [7], the separation of hydrocarbons [8,9], the recovery of organic compounds from aqueous solution like 2-chlorophenol [10], the extraction of heteropolyanion complexes [11] etc. Extractions of different metals have being reported and compared when using ELM extraction processes in the presence of different extractants, surfactants, and feed solutions [12].…”