Novel multiple ligand metal-group collectors assembled from benzohydroxamic acid and cupferron

Abstract

Pb–BHA (lead complexes of benzohydroxamic acid) as metal-group collectors have been recently used for mineral flotation collector. This complex possessed high selectivity but low flotation efficiency due to extensive dosage. To improve the flotation performance of Pb–BHA, we designed a novel multiple ligand complex collector assembled from Pb2+, BHA, and cupferron (CPF) (i.e., Pb–BHA–CPF). The flotation performance of Pb–BHA–CPF was studied through the flotation test. The structure of Pb–BHA–CPF was analyzed by Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS), and the adsorption mechanism of Pb–BHA–CPF at the solid–liquid interface was investigated and discussed through the zeta potential, FTIR, XPS, and crystal chemistry analyses. Based on the results, Pb–BHA–CPF exhibited stronger collecting ability and selectivity than Pb–BHA at a lower reagent dosage. Structural analysis revealed that BHA and CPF could coordinate with Pb2+ to form novel multiple ligand complexes with lead groups, and CPF may replace BHA to form the molecular structure of Pb(L1)n(L2)m (HL1 = BHA, NH4L2 = CPF, n > m). The adsorption mechanism analysis indicated that Pb–BHA–CPF had stronger electrostatic attraction than Pb–BHA and showed stronger chemical adsorption strength with the active oxygen atoms on the mineral surface. This study proposed a method for designing and assembling a multiple ligand metal-group collector.