Application of liquid emulsion membrane (LEM) process for enrichment of molybdenum from aqueous solutions

A comprehensive study pertaining to liquid emulsion membrane (LEM) extraction process to enrich dilute aqueous solutions of molybdenum salt is presented here. The liquid membrane is made up of Aliquat 336 as a carrier, organic diluent and an emulsifying agent. The selection of extractant, Aliquat 336 was made on the basis of conventional liquid–liquid extraction studies. The role of pH is very important in the LEM process for extraction of molybdenum. The important variables affecting the LEM permeation process, including the residence time for LEM extraction, membrane viscosity (surfactant concentration), extractant concentration, internal strip phase concentration, organic solvents, level of agitation and the phase ratio between emulsion phase (Vm) and feed phase (Vl) were systematically investigated. When the strip phase concentration was 0.5 M (NaOH) and dodecane was used as a diluent, better extraction of molybdenum was obtained. Higher Vm/Vl gave higher extraction of molybdenum.