Decomposition of sulfides and carbonaceous matters in double refractory gold ores by fungal-released enzymes
| Project/Area Number |
18J10835
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| Research Category |
Grant-in-Aid for JSPS Fellows
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| Allocation Type | Single-year Grants |
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| Section | 国内 |
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| Research Field |
Earth system and resources engineering
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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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| Project Status |
Completed (Fiscal Year 2019)
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| Budget Amount *help |
¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 2019: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 2018: ¥1,000,000 (Direct Cost: ¥1,000,000)
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| Keywords | Gold recovery / Carbonaceous gold ore / Enzymes / Acidianus brierleyi / QEMSCAN / Phanerochaete chrysosporium / Peroxidase enzymes |
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| Outline of Annual Research Achievements |
Double refractory gold ore containing gold-bearing sulfides and carbonaceous matter was sequentially treated with iron and sulfur oxidising archaea Acidianus brierleyi and lignin-degrading enzymes from Phanerochaete chrysosporium. This treatment resulted in an increase in gold recovery from 24% to 92%. Biooxidation of the sulfide minerals is already known, and therefore, the secondary focus, after improving the gold recovery, was characterising the carbonaceous matter. The transformation of the carbonaceous matter during the sequential treatment was investigated using QEMSCAN analysis, Raman and 3D fluorescence spectroscopy. The results show that the carbonaceous matter was initially hosted in illite, a silicate mineral, and the amount of carbon to illite affected the texture of the carbonaceous illite mineral. The enzymatic decomposition of the carbonaceous matter was found to be accelerated if the sample had undergone a prior treatment to decompose sulfide minerals. This is because the enzymes are susceptible to arsenic poisoning and therefore, the oxidative dissolution of arsenopyrite aided the enzymatic reaction. The lignin-degrading enzymes preferentially attacked the defects in the graphitic structure of carbonaceous matter and in the process, produced humic-like substances. The humic-like substances that are produced by the enzyme treatment acted as one of the binding agents in the agglomeration of the carbonaceous aluminosilicate residue (C-Si-Al). This new C-Si-Al was partially removed by alkaline washing step to improve gold recovery from DAC from 76% to 92%.
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| Research Progress Status |
令和元年度が最終年度であるため、記入しない。
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| Strategy for Future Research Activity |
令和元年度が最終年度であるため、記入しない。
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Report
(2 results)
Research Products
(7 results)
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[Presentation] Sequential biotreatment of carbonaceous silva ore2019
Author(s)
Flores, D., M., M., Konadu, K., T., Sakai, R., Sasaki, K.,
Organizer
International Symposium on Earth Science and Technology
Related Report
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[Presentation] Eff ect of carbonaceous matter on bioleaching of Cu from carbonaceous chalcopyrite ore2019
Author(s)
Konadu, K.T., Sakai, R., Flores, D., M., M., Harrison, S.T., Osseo-Asare, K., Sasaki, K.
Organizer
International Biohydrometallurgy Symposium
Related Report
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