화학공학소재연구정보센터
Separation Science and Technology, Vol.40, No.1-3, 611-622, 2005
Cloud-point extraction for selective removal of Gd(III) and La(III) with 8-hydroxyquinoline
A less-common extraction procedure, cloud-point extraction, is used with a lipophilic chelating agent (8-hydroxyquinoline) to extract and separate lanthanum(III) and gadolinium(MD ions from an aqueous solution. Surfactant solutions are used in conjunction with 8-hydroxyquinoline to form a lanthanide complex that is extracted into the micellar phase at a temperature above the cloud-point temperature. The structure of the lipophilic part of the nonionic surfactant, the chelating agent-metal molar ratio, and the cloud-point temperature are identified as factors determining the extraction efficiency and selectivity. With Triton X-114, a selectivity higher than 30 and a decontamination factor of 50 for Gd(III) indicate that Micelle-mediated cloud-point extraction is promising for the specific separation of actinide ions from nuclear waste. Finally, a microwave procedure is proposed to decrease the duration of the experiment to less than 6 min.