Investigation of n-Octanohydroxamate Reagent Interaction with the Surface of Oxide Copper Minerals and Copper Metal

摘要

The interaction of n-octanohydroxamate solution with the surface of copper metal and the minerals bornite, malachite and chrysocolla has been investigated. XPS, vibrational spectroscopies and electrochemical techniques were used to characterize the nature of the surface layer. Malachite, chrysocolla and bornite can form layers of hydroxamate product that can be observed using unenhanced vibrational spectroscopy. For the conditioning times in ～0.02 M n-octanohydroxamate investigated, XPS revealed that Cu hydroxamate was retained at each substrate surface after it had been rinsed with water. It was inferred that the Cu hydroxamate metal atom interacted with a N atom in an interfacial monolayer of hydroxamate which adsorbed by interaction of both of its O atoms with a substrate Cu atom. Linear scan voltammetry of a copper electrode exhibited an inhibition of copper oxidation when the n-octanohydroxamate concentration was greater than 10~(-4) M. The cupric hydroxamate observed spectroscopically on the sample surfaces was consistent with the properties measured for bulk cupric n-octanohydroxamate.