Bio-reduction of pyrite investigated in a gas lift loop reactor

A. Hol, R.D. van der Weijden, G. van Weert, P. Kondos, C.J.N. Buisman

Research output: Contribution to journalArticleAcademicpeer-review

12 Citations (Scopus)


To liberate gold from refractory pyrite, oxidative destruction techniques that consume lots of energy and generate acidic waste streams are custom. As an alternative the “bio-reduction” of pyrite is proposed and investigated in this study. Bio-reduction is an anaerobic process based on sulfate/sulfur reducing bacteria which are thought to be able to use pyrite-sulfur as a possible electron acceptor. The conversion of pyrite-sulfur into hydrogen sulfide is advantageous because energy is saved and the generation of an acidic waste stream is prevented. In addition, the generated H2S can be used to produce elemental sulfur, or even gold lixiviants such as thiosulfate or bisulfide. Batch experiments under anaerobic conditions showed that two effects can inhibit bio-reduction; methane formation and sulfide accumulation. In a gas lift loop reactor operated at pH 5, temperature of 35 °C, and with continuous sulfide removal no evidence of pyrite bio-reduction was found. Though the sulfate reducing bacteria survived, they did not utilize pyrite-sulfur as an electron acceptor under the chosen conditions.
Original languageEnglish
Pages (from-to)140-146
JournalInternational Journal of Mineral Processing
Issue number3-4
Publication statusPublished - 2010


  • bearing arsenian pyrite
  • gold
  • oxidation
  • bioreactor
  • minerals
  • progress
  • part


Dive into the research topics of 'Bio-reduction of pyrite investigated in a gas lift loop reactor'. Together they form a unique fingerprint.

Cite this