Effects of Pb(II) on the flotation behaviour of galena with sodium humate as depressant

Abstract

In this study, the effect of Pb2+ on the flotation behaviour of galena using sodiumhumate (NaHA) as a depressant was investigated through micro-flotation tests, contact angle measurements, FTIR analysis, ICP tests and atomic force microscopic measurements. The micro-flotation test illustrated that Pb2+ could greatly enhance the depression effect of NaHA and reduce the amount of NaHA.Mechanism studies showed that Pb2+ improved the adsorption of NaHA onto the galena surface or reacted with NaHA in the solution to form the complexes of Pb2+ and NaHA, thus improving the depression effect of NaHA for galena. At pH < 9.4, Pb2+ and PbOH+ could provide adsorption sites for NaHA. Therefore, the recovery of galena was <10 %. However, at pH > 9.4, Pb(OH)2(aq) and Pb(OH)3− could not provide adsorption sites for NaHA. Therefore, the recovery of galena increased.