Abstract
Adsorption of ethylxanthate on sphalerite in an alkaline medium, after activation with Pb 2+ from the solution was investigated. The activation was performed respectively at pH=5.0 to 6.0 and at pH=8.0 to 9.0 in order to determine the effect of the activation pH on the adsorption data. Internal reflection spectroscopy (ATR-IR) was used for monitoring the change resulting on the sphalerite surface. This was correlated with zeta-potential measurements and flotation data. Lead from the solution increases the natural floatability of sphalerite in an alkaline medium. The addition of lead ions before sphalerite flotation with xanthate also causes a marked increase in sphalerite floatability compared with its flotation at the same KEX concentration but without any activator. IR data do always confirm the activating effect of Pb 2+ dissolved ions on KEX adsorption in an alkaline medium whether activation was performed in an acid or an alkaline medium. They indicate, however, variations in the kinetics of activation, depending on pH. The longer activation time (40 min) necessary to reach a near-equilibrium condition in an alkaline medium, compared with that required in an acid medium, is due to a different mechanism of activation, depending on pH. These results are in agreement with the suggested mechanisms for acid and alkaline media given in the literature.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call