Behavior of Lead Ions in Cassiterite Flotation Using Octanohydroxamic Acid

The effects of lead ions on the flotation performance of the cassiterite system have been investigated using microflotation tests. Adsorption experiments, X-ray photoelectron spectroscopy (XPS), contact angle measurement, and zeta (ζ)-potential measurements were conducted. Octanohydroxamic acid and lead ion solution speciation simulations were used. These were used to correlate surface properties of lead-activated with cassiterite flotation performance. Flotation results indicate that the addition of lead ions activates the cassiterite flotation. The addition of lead ions enhanced the adsorption of octanohydroxamic acid on cassiterite, and the wetting characteristic of cassiterite decreased in the presence of octanohydroxamic acid and the addition of lead ions. ζ-Potential measurements and solution chemistry analyses confirmed that flotation recovery of the cassiterite increases due to Pb(OH)+ and Pb3(OH)42+ sites on the cassiterite surface. XPS results indicated the adsorption of octanohydroxamic acid onto the cassiterite surface was through chemisorption, which combined with lead ions changed the chemical properties of the cassiterite surface.