| Project/Area Number |
60550465
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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 |
金属精錬・金属化学
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| Research Institution | TOHOKU UNIVERSITY |
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Principal Investigator |
AZAKAMI Takeshi Faculty of Engineering, Tohoku University, Professor., 工学部, 教授 (50006029)
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| Co-Investigator(Kenkyū-buntansha) |
ITOH Satoshi Faculty of Engineering, Tohoku University, Instructor, 工学部, 助手 (70133048)
HINO Mitsuhisa Faculty of Engineering, Tohoku University, Instructor, 工学部, 助手 (40005335)
NAKAZAWA Shigeatsu Faculty of Engineering, Tohoku University, Associate Prof., 工学部, 助教授 (70006055)
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| Project Period (FY) |
1985 – 1986
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| Project Status |
Completed (Fiscal Year 1986)
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| Budget Amount *help |
¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 1986: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1985: ¥1,300,000 (Direct Cost: ¥1,300,000)
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| Keywords | copper smelting / matte / vacuum refining / impurity removal / arsenic / antimony / ビスマス / 鉛 |
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| Research Abstract |
The levels of several impurities such as arsenic and antimony in copper concentrates have been increasing in recent years. Elimination of these impurities is important during the copper smelting process, because the Va elements present serious problems for electrical and mechanical properties of copper. In this study, a vacuum refining was applied for <Cu_2> S・FeS copper mattes which contain 1 mass percent impurities of arsenic, antimony, bismuth and lead at 1150゜C as one of the elimination techniques of an impurity from copper matte.
By the present study, the following conclusions were obtained;
1) The concentrations of the impurities in the matte decrease with decreasing pressure of treatment and increasing processing time, although evaporation of impurity elements from the matte was almost not recognized at an atmospheric pressure of nitrogen.
2) Nearly all amount of lead and bismuth were removed from the copper matte at the pressure of 1mmHg.
3) The antimony content decreased from 1 mass% to 0.08 in the matte by the vacuum refining after 2 hours at 1mmHg pressure. An arsenic content also decreased to 0.5 mass% in the matte under the same conditon for antimony, its removal being insufficient.
4) Lead removal from the low grade copper matte was faster than that from the high grade matte. It seems that the evaporation rate may correlate with sulfur pressures over the mattes, because, in the present condition, lead sulfide was estimated thermodynamically a predominant gas species of lead over the molten matte, and the sulfur pressure equilibrated with the low grade copper matte is higher than the pressure over the high grade matte.
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