1988 Fiscal Year Final Research Report Summary
Production of highly pure fine coal powder by ultrafine grinding and separation by surface engineering
| Project/Area Number |
62302052
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| Research Category |
Grant-in-Aid for Co-operative Research (A)
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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 | TOHOKU UNIVERSITY |
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Principal Investigator |
YASHIMA Saburo Professor of Research Institute of Mineral Dressing and Metallurgy, Tohoku University, 選鉱製錬研究所, 教授 (90006966)
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| Co-Investigator(Kenkyū-buntansha) |
HASHIMOTO Hitoshi Research Associate of Faculty of Engineering, Tohoku University, 工学部, 助手 (90156290)
SANO Shigeru Associate Professor of Ichinoseki Technical College, 助教授 (20042195)
KANDA Yoshiteru Professor of Faculty of Engineering, Yamagata University, 工学部, 教授 (40007034)
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| Project Period (FY) |
1987 – 1988
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| Keywords | Effective fine grinding of coal / Grinding additives / Ultrafine grinding of coal / Grinding characteristics of coal / Crushing behavior of fine Particle / 微小粒子の破壊挙動 / 界面工学的分離法 |
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| Research Abstract |
(1) Grinding additives Grinding mechanism of a laboratory Hardgrove mill was analyzed by means of a dead space model. As a result, poor flowability of fine coal powder was found to cause a decrease in grinding rate or efficiency. This result suggests that reagents which can improve the flowability of fine coal powder are effective for fine grinding by the hardgrove mill. Grinding tests on 40 kinds of reagents or more were conducted to select effective additives for fine grinding of coal by the Hardgrove mill. As a result, carbon black, calcium stearate, methanol, etc. were found to be very effective. Action mechanism of these effective additives were analyzed by means of the dead space model.
(2) Grinding characteristics of coal relations among grindability, mechanical properties and rank properties of coal were investigated. As a result, the higher rank coal was found to be more elastic and to have lower strength and higher grindability. Moreover, the mechanical behavior of fine coal perticles was investigated. As a result, the mechanical behavior changes from elastic to plastic under several microns.
(3) Development of ultrafine grinding system Effective ultrafine grinding system for coal was investigated. As a result, attrition grinding was found to be more effective then impact grinding.
(4) Separation by surface engineering The applicability of selective coagulation followed by column flotation to the demineralization of ultrafine coal powder was investigated. As a result, it was found to be necessary to disperse coal particles perfectly before coagulation to accomplish the effective demineralization.
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