It is confirmed in this study that silica can be activated with lead (II) ion and floated with potassium amyl xanthate in the alkaline region as evidenced from micro-flotation experiments. This conclusion is complimented with the results from electrophoresis experiments and by solution chemistry analysis. The PbOH+ and Pb(OH)(2(aq)) species which are believed to be responsible for silica activation were found to precipitate at the silica surface. These island-like precipitate structures were clearly observed using AFM and SEM imaging. With amyl xanthate addition, lead amyl xanthate was formed as revealed by FTIR. Contact angle measurements further confirmed the nature of lead activation in silica flotation with amyl xanthate collector. (C) 2016 Elsevier B.V. All rights reserved.