Lead and copper activation of pyrite in the presence of thiol collectors was examined by means of cyclic voltammetry and microflotation techniques. Di-isobutyl dithiophosphinate (Aerophine 3418A) and alkyl thionocarbamate (AFRO 3894) were employed as collector of lead and copper, respectively. Otherwise, isopropyl xanthate (IPX) was also used as a collector of both: lead and copper. The results revealed that in the presence of non-conventional collectors, the increase in pyrite recovery due to the activation by copper and lead species, was noticeably smaller than that exhibited when xanthate (IPX) was used. The electrochemical response of pyrite indicates that lead activation favors the formation of dixanthogen. In non-xanthate systems, the voltammograms of pyrite remained unaffected regardless of the activation by lead or copper species. (c) 2005 Elsevier Ltd. All rights reserved.