Effect of Initial Cell Concentration on Bio-Oxidation of Pyrite before Gold Cyanidation
Bio-oxidation of refractory sulfidic gold minerals has been applied at the commercial scale as a pre-treatment to improve gold yields and reduce chemical consumption during gold cyanidation. In this study, the effect of initial cell concentration on the oxidation of pyritic gold ore was evaluated wi...
| Main Authors: | , , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2021-07-01
|
| Series: | Minerals |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2075-163X/11/8/834 |
| _version_ | 1797522806076866560 |
|---|---|
| author | Ka Yu Cheng Caroline C. Rubina Acuña Naomi J. Boxall Jian Li David Collinson Christina Morris Chris A. du Plessis Natalia Streltsova Anna H. Kaksonen |
| author_facet | Ka Yu Cheng Caroline C. Rubina Acuña Naomi J. Boxall Jian Li David Collinson Christina Morris Chris A. du Plessis Natalia Streltsova Anna H. Kaksonen |
| author_sort | Ka Yu Cheng |
| collection | DOAJ |
| description | Bio-oxidation of refractory sulfidic gold minerals has been applied at the commercial scale as a pre-treatment to improve gold yields and reduce chemical consumption during gold cyanidation. In this study, the effect of initial cell concentration on the oxidation of pyritic gold ore was evaluated with four aerated bioreactors at 30 °C with 10% pulp density and pH maintained at 1.4 with NaOH. Results of NaOH consumption and changes in soluble Fe and S concentrations indicated that increasing the initial cell concentration from 2.3 × 10<sup>7</sup> to 2.3 × 10<sup>10</sup> cells mL<sup>−1</sup> enhanced pyrite oxidation during the first week. However, by day 18 the reactor with the lowest initial cell concentration showed profound performance enhancement based on soluble Fe and S concentrations, sulfide-S and pyrite contents in the residues, and subsequent gold leaching of the bio-oxidation residues by cyanidation. Overall, the results showed that the cell concentration was clearly beneficial during the initial stages of oxidation (first 7–8 days). |
| first_indexed | 2024-03-10T08:34:34Z |
| format | Article |
| id | doaj.art-cf7d4fd23fdb4cda85040b445151d8df |
| institution | Directory Open Access Journal |
| issn | 2075-163X |
| language | English |
| last_indexed | 2024-03-10T08:34:34Z |
| publishDate | 2021-07-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Minerals |
| spelling | doaj.art-cf7d4fd23fdb4cda85040b445151d8df2023-11-22T08:49:38ZengMDPI AGMinerals2075-163X2021-07-0111883410.3390/min11080834Effect of Initial Cell Concentration on Bio-Oxidation of Pyrite before Gold CyanidationKa Yu Cheng0Caroline C. Rubina Acuña1Naomi J. Boxall2Jian Li3David Collinson4Christina Morris5Chris A. du Plessis6Natalia Streltsova7Anna H. Kaksonen8Land and Water, Commonwealth Scientific and Industrial Research Organisation (CSIRO), Floreat, WA 6014, AustraliaLand and Water, Commonwealth Scientific and Industrial Research Organisation (CSIRO), Floreat, WA 6014, AustraliaLand and Water, Commonwealth Scientific and Industrial Research Organisation (CSIRO), Floreat, WA 6014, AustraliaCSIRO Mineral Resources, Waterford, WA 6152, AustraliaCSIRO Mineral Resources, Waterford, WA 6152, AustraliaLand and Water, Commonwealth Scientific and Industrial Research Organisation (CSIRO), Floreat, WA 6014, AustraliaLhoist, Business Innovation Centre, Rue de l’industrie 31, B-1400 Nivelles, BelgiumVintage94 Pty Ltd., Floreat, WA 6014, AustraliaLand and Water, Commonwealth Scientific and Industrial Research Organisation (CSIRO), Floreat, WA 6014, AustraliaBio-oxidation of refractory sulfidic gold minerals has been applied at the commercial scale as a pre-treatment to improve gold yields and reduce chemical consumption during gold cyanidation. In this study, the effect of initial cell concentration on the oxidation of pyritic gold ore was evaluated with four aerated bioreactors at 30 °C with 10% pulp density and pH maintained at 1.4 with NaOH. Results of NaOH consumption and changes in soluble Fe and S concentrations indicated that increasing the initial cell concentration from 2.3 × 10<sup>7</sup> to 2.3 × 10<sup>10</sup> cells mL<sup>−1</sup> enhanced pyrite oxidation during the first week. However, by day 18 the reactor with the lowest initial cell concentration showed profound performance enhancement based on soluble Fe and S concentrations, sulfide-S and pyrite contents in the residues, and subsequent gold leaching of the bio-oxidation residues by cyanidation. Overall, the results showed that the cell concentration was clearly beneficial during the initial stages of oxidation (first 7–8 days).https://www.mdpi.com/2075-163X/11/8/834bio-oxidationcell concentrationcyanidationgoldpyrite |
| spellingShingle | Ka Yu Cheng Caroline C. Rubina Acuña Naomi J. Boxall Jian Li David Collinson Christina Morris Chris A. du Plessis Natalia Streltsova Anna H. Kaksonen Effect of Initial Cell Concentration on Bio-Oxidation of Pyrite before Gold Cyanidation Minerals bio-oxidation cell concentration cyanidation gold pyrite |
| title | Effect of Initial Cell Concentration on Bio-Oxidation of Pyrite before Gold Cyanidation |
| title_full | Effect of Initial Cell Concentration on Bio-Oxidation of Pyrite before Gold Cyanidation |
| title_fullStr | Effect of Initial Cell Concentration on Bio-Oxidation of Pyrite before Gold Cyanidation |
| title_full_unstemmed | Effect of Initial Cell Concentration on Bio-Oxidation of Pyrite before Gold Cyanidation |
| title_short | Effect of Initial Cell Concentration on Bio-Oxidation of Pyrite before Gold Cyanidation |
| title_sort | effect of initial cell concentration on bio oxidation of pyrite before gold cyanidation |
| topic | bio-oxidation cell concentration cyanidation gold pyrite |
| url | https://www.mdpi.com/2075-163X/11/8/834 |
| work_keys_str_mv | AT kayucheng effectofinitialcellconcentrationonbiooxidationofpyritebeforegoldcyanidation AT carolinecrubinaacuna effectofinitialcellconcentrationonbiooxidationofpyritebeforegoldcyanidation AT naomijboxall effectofinitialcellconcentrationonbiooxidationofpyritebeforegoldcyanidation AT jianli effectofinitialcellconcentrationonbiooxidationofpyritebeforegoldcyanidation AT davidcollinson effectofinitialcellconcentrationonbiooxidationofpyritebeforegoldcyanidation AT christinamorris effectofinitialcellconcentrationonbiooxidationofpyritebeforegoldcyanidation AT chrisaduplessis effectofinitialcellconcentrationonbiooxidationofpyritebeforegoldcyanidation AT nataliastreltsova effectofinitialcellconcentrationonbiooxidationofpyritebeforegoldcyanidation AT annahkaksonen effectofinitialcellconcentrationonbiooxidationofpyritebeforegoldcyanidation |