LIQUID MEMBRANE PROCESSES FOR GALLIUM RECOVERY FROM ALKALINE-SOLUTIONS

In this paper, we examine the possibility of using membrane extraction and supported liquid membranes to recover gallium from alkaline solut ions. Membrane extraction proves to be an alternative process to recov er gallium from such liquors. In order to maximize mass transfer, high ly hydrophilic membranes should be used in both the membrane extractio n and stripping processes. The optimum composition of the membrane ext ractant is 10-15% Kelex 100, 10% n-decanol, 5% Versatic 10, and kerose ne (vol %). The highest gallium permeability was obtained when the fee d solution contained about 1.5 mol/L sodium hydroxide. The supported l iquid membrane used failed to transport gallium because of instability . The dominant mechanisms for failure are considered to be spontaneous formation of a water-in-oil emulsion and formation of precipitates, c ausing membrane pore obstruction.