Investigating the Electrochemical Interaction of a Thiol Collector with Chalcopyrite and Galena in the Presence of a Mixed Microbial Community

Ngoni Mhonde*, Mariette Smart, Kirsten Corin, Nora Schreithofer

*Corresponding author for this work

Research output: Contribution to journalArticleScientificpeer-review

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Abstract

High microbial cell counts have been recorded in sewage waters employed as process water in mineral beneficiation plants across the world. The presence of these microbes can negatively impact flotation performance through mineral passivation, although some microbes improve flotation performance as investigated in various bio-flotation studies. The current study aims to understand the electrochemical behaviour of minerals in the presence of a sodium ethyl xanthate (SEX) collector and microbes originating from a sulphide ore processing plant in South Africa. The electrochemical response was correlated to observe flotation performance. Mixed potential measurements were conducted in parallel to microflotation tests, to assess the hydrophilicity or hydrophobicity induced on sulphide minerals adapted to microbe-laden synthetic plant water. Sulphide minerals' mixed potentials and interactions of SEX with sulphide minerals were dramatically reduced in the presence of the mixed microbial community (MMC). The observations were correlated with poor flotation efficacy noted in microflotation tests. These fundamental results shed light on how the adsorption of thiol collectors on sulphide minerals is adversely affected by microbes, prompting a discussion on flotation process monitoring when mineral beneficiation is conducted using microbe-laden water.

Original languageEnglish
Article number553
Number of pages16
JournalMinerals
Volume10
Issue number6
DOIs
Publication statusPublished - Jun 2020
MoE publication typeA1 Journal article-refereed

Keywords

  • electrochemistry
  • microbes
  • microflotation
  • recovery
  • adhesion
  • zeta potential
  • PLATINUM-GROUP MINERALS
  • WATER-BORNE BACTERIA
  • THIOBACILLUS-FERROOXIDANS
  • FLOTATION BEHAVIOR
  • ETHYL XANTHATE
  • PAENIBACILLUS-POLYMYXA
  • PYRITE
  • IMPACT
  • MECHANISM
  • ADHESION

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