Uranium(VI) extraction by emulsion liquid membrane from acidic wastes using tri-n-octylphosphine oxide (TOPO) and sodium carbonate

Acidic wastes containing low concentration of uranium are generated during uranium purification and processing. An emulsion liquid membrane (ELM) process for selective separation and recovery of uranium from such wastes was investigated using tri-n-octylphosphine oxide (TOPO) in paraffin as a carrier and sodium carbonate as a stripping agent. The composition of waste was nearly 500 ppm U(VI), 400 ppm Fe(III), 300ppm Ca(II), 100ppm Al(III), 5000ppm Na(I) and 150ppm Mg(II) at an acidity of 1.2 M HNO3 of the feed phase. Various factors that affect the emulsion stability as well as percentage extraction of uranium have been optimized in order to obtain maximum extraction. In presence of various metal ions, selective permeation of uranyl ions through liquid membrane was observed to be more than 75%. The results show that the U(VI) concentration in the final raffinate can be lowered to below 100 ppm.

کلیدواژه ها:

Acidic waste ، Uranium(VI) recovery ، Emulsion liquid membrane ، Tri-n-octylphosphine oxide (TOPO) ، Sodium carbonate