Kinetic Conditions of Extraction of RE (III) with a New Emulsion Liquid Membrane.

The electron layer structure and physical chemical properties of rare earth elements are very similar, rare earths are difficult to separaterare. Therefore, the extraction of rare earth is always research hot issue in rare earth metallurgy. A new emulsion extractant was prepared with 6%D2EHPA as the flow carrier, 5 % Tl 54 as the surfactant, 3.0 mol/L HCl solution as the inner water phase, sulfonated kerosene as the membrane solvent and control R_oi of 1.5. By using the emulsion extractor to extract La³⁺, Ce³⁺, Sm³⁺, Eu³⁺, Ho³⁺ and Er3+ in sulfuric acid system, the optimal kinetic conditions for the extraction of RE (III) by emulsion film method (ELM) were determined. The results show that under optimal kinetic conditions of emulsification time of 5 min, extraction time of 6 min, emulsion to water ratio (R_ew) of 0.5, extraction temperature of 25 °C, the outer water phase is rare earth element aqueous solution, the highest extraction rate of La³⁺ is 99.92%, the maximum enrichment ratio is 3.33, and the mass transfer rate k = 9. 35 X 10^-10 m/s. The ELM shows excellent extraction performance and enrichment effect for low concentration La³⁺ solution. [ABSTRACT FROM AUTHOR]