Liquid Membrane Extraction of Uranium from Dilute Sulfuric Acid Leach Liquors Using DEHPA Carrier

Abstract

The recovery of uranium from dilute sulfuric acid leach liquors is an important process in hydrometallurgical operations for improving resource utilization and reducing environmental impacts associated with uranium mining and processing. The present study investigates the liquid membrane extraction of uranium using di-(2-ethylhexyl) phosphoric acid (DEHPA) as a carrier under controlled operational conditions. The research focuses on evaluating uranium transport efficiency, extraction selectivity, membrane stability, and process optimization associated with liquid membrane separation systems. Experimental analysis was conducted to examine the influence of feed solution acidity, DEHPA concentration, stripping agent composition, stirring speed, membrane phase composition, and contact time on uranium extraction and transport behavior. Results demonstrate that DEHPA-based liquid membrane systems effectively facilitate selective uranium transfer through carrier-mediated extraction and stripping mechanisms, resulting in enhanced uranium recovery from dilute leach solutions. The study further reveals that optimized membrane composition and operating conditions significantly improve extraction kinetics, uranium flux, and separation efficiency while minimizing membrane instability and carrier loss. Increased carrier concentration and controlled pH conditions contributed to enhanced uranium complexation and transport performance. Comparative assessment with conventional solvent extraction methods confirms the advantages of liquid membrane technology, including lower reagent consumption, simultaneous extraction and stripping capability, and reduced secondary waste generation.