2005 Fiscal Year Final Research Report Summary
Recovery of metal values from secondary volatilized fly ash by acid leaching and precipitation separation method.
| Project/Area Number |
16560715
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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 |
Recycling engineering
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| Research Institution | Kumamoto University |
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Principal Investigator |
KAWAHARA Masayasu Kumamoto University, Graduate School of Science and Technology, Professor, 大学院・自然科学研究科, 教授 (60145282)
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| Project Period (FY) |
2004 – 2005
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| Keywords | Secondary fly ash / Dechlorination / Sulfuric acid leaching / Selective leaching / Precipitation separation / Lead sulfate |
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| Research Abstract |
Acid leaching and precipitation separation was conducted to recover metal values from secondary volatilized fly ash. Some of results obtained are follows.
The leaching of secondary volatilized fly ash with sulfuric acid and hydrochloric acid has been conducted, and leaching properties of ash were investigated. Zn, Pb, Cu and Fe were leached from secondary volatilized fly ash by hydrochloric acid solution, but Pb was not leached from the ash by sulfuric acid solution. For leaching the ash containing high amount of alkali content, a large quantity of acid was needed. By sulfuric acid leaching after washing of the ash, separation of lead and zinc can be accelerated.
Cu was recovered from the leaching solution after sulfuric acid leaching by cementation. Fe and Zn were recovered from the solution after cementation by pH control. Pb was leached from the residue after sulfuric acid leaching by sodium acetate solution.
97% of zinc and 93% of lead can be recovered from the secondary volatilized fly. Washing treatment of the ash before leaching prevents dissolution of lead from the final residue.
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