A novel activation system for wolframite flotation by using Cu(II) ion and α-hydroxyoctyl phosphinic acid

Abstract

The flotation and adsorption mechanism of wolframite with low-toxic copper ion in the presence of α-hydroxyoctyl phosphinic acid (HPA) were investigated to reduce the use of highly toxic lead nitrate. The adsorption mechanism and flotation performance were characterized by flotation test, time-of-flight secondary-ion mass spectrometry (TOF-SIMS), zeta-potential measurement and X-ray photoelectron spectrometer (XPS). The flotation test showed that the recovery of wolframite increased from 54.9% to 69.1% after Cu(II) modification at pH 9. Meanwhile, Sodium hexametaphosphate(SHP) performed well in separating wolframite from quartz in presence of Cu(II) and HPA. The results of TOF-SIMS, Zeta-potential and XPS indicated new Cu(I), Cu(II) and Fe(III) species were traced on the wolframite surface after Cu(II) treatment. HPA was chemisorbed on the surface of wolframite through M(Fe, Cu, Mn, W)-HPA complexes.