METAL-ION EXTRACTION

Metal ion extraction through complexation with an organic soluble liga nd is a process widely used in the hydrometallurgy industry for the se paration, purification and recovery of many metals. It is now being ap plied to environmental problems to reduce emissions of heavy metals su ch as chromium from tanning and chrome plating processing plants. Sign ificant developments in this area include the use of micelle systems t o simulate the oil/water interface, NMR studies to ascertain the site of ligand solubilisation, ATR techniques to study kinetics at the liqu id/liquid interface, and the use of membrane reactors to limit the los s of organic solvent in the rafinate and so allow the application of t his technology to lower concentration feeds.