| Project/Area Number |
10650919
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
資源開発工学
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| Research Institution | Waseda University |
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Principal Investigator |
SASAKI Hiroshi Waseda University, School of Science and Engineering, Professor, 理工学部, 教授 (50006037)
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| Project Period (FY) |
1998 – 1999
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| Project Status |
Completed (Fiscal Year 1999)
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| Budget Amount *help |
¥2,600,000 (Direct Cost: ¥2,600,000)
Fiscal Year 1999: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1998: ¥2,000,000 (Direct Cost: ¥2,000,000)
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| Keywords | Formation of Magnetite Precipitate / Mine Drainage / High concentrated sludge / Sludge recycling method / Optimum neutrilization method / 抗廃水処理 / マグネタイト法 / 殿物繰り返し法 / 殿物容積 / 共存イオン / 微粒子分離 / ゼータ電位 / 殿物密度 |
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| Research Abstract |
Neutralization and sedimentation method has been conventionally adopted for long time. Neutralizing chemicals such as slaked lime are added to mine waste water after treated by oxidation process to convert ferrous to ferric ions, to adjust pH value within neutral zone. The sludge return and neutralization method is the alternation of neutralization and sedimentation method, and it is characterized by returning a part of sediment to the neutralization process. Recently, it was developed in our laboratory that a novel and optimum neutralization process that generate stable and compact magnetite precipitation from comparative low concentrated ferrous sulfate solution without oxidation at room temperature.
In this research, the effect of co-existing ion on magnetite formation was examined and sludge recycling method was applied to artificial acid mine water treatment to get high concentrated solid sludge. The influence of aluminum ion and soluble silica, which are expected to prevent the formation of magnetite from mine water, was investigated in laboratory scale. In the case of aluminum, aluminum hydroxide precipitation disturbed the magnetite crystalline.
Soluble and polymerized silica that adsorbed intermediate precipitate had a harmful effect on the magnetite formation.
The ratio of the solid content of sludge vs. recycling time decreased gradually with increasing co-existing concentration. This optimum neutralization method was applied to Komaki and Osarizawa mine water, and was revealed that approximately 4 times high concentrated solid sludge were formed compared to conventional method in Komagi mine water. For Osarizawa mine water, 1.4 times higher densities sludge were formed after 30 times recycling.
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Report
(3 results)
Research Products
(3 results)
