2018 Fiscal Year Annual Research Report
Decomposition of sulfides and carbonaceous matters in double refractory gold ores by fungal-released enzymes
| Project/Area Number |
18J10835
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| Research Institution | Kyushu University |
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Principal Investigator |
KONADU KOJO Twum 九州大学, 工学府, 特別研究員(DC2)
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| Project Period (FY) |
2018-04-25 – 2020-03-31
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| Keywords | Gold recovery / Carbonaceous gold ore / Peroxidase enzymes / Acidianus brierleyi / QEMSCAN |
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| Outline of Annual Research Achievements |
This work aimed to increase the gold recovery from double refractory gold ore by oxidising the sulfide minerals and carbonaceous matter sequentially before cyanidation. The pre-treatment utilised the iron oxidiser Acidianus brierleyi and peroxidase enzymes form the fungus Phanerochaete chrysosporium. After a combined period of 29 days of pre-treatment, the gold recovery increased from 24% to 92%. Also, the mineralogical analysis found that the decomposition of the carbonaceous matter by the fungal treatment aided in the formation of large aluminosilicate particles which interfered with the gold recovery. This research shows that this sequential treatment method can be a viable route for recovering gold from very refractory ore types.
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| Current Status of Research Progress |
Current Status of Research Progress
1: Research has progressed more than it was originally planned.
Reason
The progress of this research has been as expected. A key part to achieving our desired result was a collaboration with Prof. Sue Harrison of the University of Cape Town to use their Quantitative Evaluation of Materials by Scanning Electron Microscopy (QEMSCAN) machine. This collaboration is effect now, and due to this, I have not experienced any undue delays in achieving my goal of applying the sequential pre-treatment to the gold ore and assessing the changes in both gold recovery and ore mineralogy.
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| Strategy for Future Research Activity |
I have three objectives for my future work. (1) Applying the sequential treatment to the treatment of double refractory gold ore from the Pogo gold mine (Alaska) which has been previously operated by Sumitomo Metal Mining Co. Ltd., (2) Characterising the large aluminosilicate particles formed as a result of the fungal treatment using through a collaboration with researchers at the Commonwealth Scientific and Industrial Research Organization (CSIRO) in Australia, and (3) Determining how viable this bio-treatment system is with other types of refractory types ores like a carbonaceous copper ore found in Zambia.
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