Rutile flotation with Pb2+ ions as activator: Adsorption of Pb2+ at rutile/water interface

The adsorption of Pb2+ at the rutile/water interface has been studied for the activation of rutile flotation with salicyl hydroxamic acid (SHA) as a collector in this work. This study was performed through measurement of the zeta potential, adsorption capacity, calorimetry and X-ray photoelectron spectroscopy. The experimental results showed that the adsorption of SHA on rutile and the flotability of rutile were significantly improved by the addition of Pb2+. This improvement was attributed to the specific adsorption of Pb2+ in the form of PbOH+, which interacted with the Ti-OH at the rutile surface and formed a surface Ti-O-Pb+ complex. This adsorption followed the Langmuir model. It reversed the zeta potential sign of rutile at pH 5.5-6.8 and had a heat of adsorption of-46.71 kJ/mol, suggesting the occurrence of a chemiosorptive process. (C) 2016 Elsevier B.V. All rights reserved.