Acceleration Effect of Anionic Surfactants on Extraction Rate of Copper with Liquid Sur-Factant Membrane Containing Lix65N and Nonionic Surfactant

To investigate the effect of anionic surfactants on the extraction rate of copper with a liquid surfactant membrane containing LIX65N and a nonionic surfactant, three kinds of oil-soluble anionic surfactants were prepared: phosphoric, sulfonic and carboxylic acid surfactants having two oleyl chains. Phosphoric and sulfonic acid surfactants accelerated the extraction rate in a stirred tank where the interfacial reaction between copper and the extractant was the rate-determining step, but the carboxylic acid surfactant did not show the acceleration effect. It is considered that the acceleration effect is caused by an electrostatic interaction between copper ion and the anionic surfactants at the interface.