| Project/Area Number |
06651090
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
資源開発工学
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| Research Institution | Iwate University |
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Principal Investigator |
NAKAZAWA Hiroshi Iwate University, Department of Eng., Professor, 工学部, 教授 (00113861)
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| Project Period (FY) |
1994 – 1995
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| Project Status |
Completed (Fiscal Year 1995)
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| Budget Amount *help |
¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 1995: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1994: ¥1,300,000 (Direct Cost: ¥1,300,000)
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| Keywords | Chalcopvrite / Bacterial leaching / Thiobacillus ferrooxidans / Nitrogen fixing organism / Symbiotic relationship / Extracellular substances / Activated carbon / T.ferrooxidans |
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| Research Abstract |
Thiobacillus ferrooxidans is commonly used inthe study on the bacterial leaching of chalcopyrite. It was reported that extracellular substances from T.ferrooxidans during the bacterial leaching could affect the copper extraction from chalcopyrite. In the ecological system, some bacteria decompose or digest extracelular substances form other bacteria. In this study, I chose a acidophilic, nitrogen fixing organism Beijerinckia indica to decompose extracellular substances from T.ferrooxidans, and investigated the effect of its coexistence on the bacterial leaching of chalcopyrite by T.ferrooxidans. It is well-known that activated carbon adsorbs organic ions. Therefo, the effect of addition of activated carbon on the bioleaching of chalcopyrite was also investigated.
1. The preliminary experiment showed that optimum pH of the bacterial leaching of chalcopyrite was 1.7. In order to adapt to grow at the low pH, the culture of Beijerinckia indica was sequentially inoculated in the medium with decreasing pH of it from 3.0. Howeber, B.indica did not grow below pH3.0. A bacterial leaching test was carried out using a mixed culture with T.ferrooxidans and B.india at the initial pH 0f 3.0, but the copper extraction was not enhanced.
2. The addition of activated carbon accelerated the copper extraction in the bacterial leaching of chalcopyrite. The yield of copper after 35 days of bacterial leaching with or without lg of activated carbon were respectably 55% and 10%. The amount of copper extraced increased with decrease in the particle size of activated carbon added.
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