Extraction of copper(II) and nickel(II) by cyclic trioximes and cyclic furazan oximes

The extraction properties of 1,2,3-cyclopentanetrione trioxime (H3CPT) and its furazan, and of 4-t-butyl-1,2,6-cyclohexanetrione trioxime (H3BHT) and its furazan are described. H3CPT was found to be too soluble in water and was therefore of no use in extraction but H3BHT was satisfactory. The extracted copper and nickel chelates of H3BHT precipitate by agglomeration caused by intermolecular hydrogen bonding and/or coordination of the third oxime group. This precipitation blocked back extraction. The furazan oximes derived from these trioximes did not form copper or nickel chelates under extraction conditions