Recovery of rare earths from phosphate ores through supported liquid membrane using N,N,N′,N′-tetraoctyl diglycol amide

The rare earth elements (REEs) such as lanthanum, cerium, praseodymium, and neodymium were successfully recovered from the leaching solutions of phosphate ores through a Supported Liquid Membrane (SLM). The extractant, N,N,N',N'-tetraoctyl diglycol amide (TODGA), was employed as novel carrier for REEs transport. Permeation rate was observed to be significantly fast and more than 95.0% of REE3+ was collected using 0.10 M TODGA as carrier. The mechanism of transport was investigated by studying various parameters, such as feed HNO3 and NaNO3 concentration, TODGA concentration in the membrane and the stirring rate etc. In view of practical application to the collection of REEs from the phosphate ore leaching liquor, the stability of the membrane was also studied. The result shows that the membrane was highly selective for lanthanides. This research would provide a new environmentally friendly and new sustainable green approach for the recovery of REE with SLM technique.