著者

辰本 拓也 綱澤 有輝 小板 丈敏 高谷 雄太郎 小山 恵史 所 千晴

出版者

一般社団法人 資源・素材学会

雑誌

Journal of MMIJ (ISSN:18816118)

巻号頁・発行日

vol.139, no.11_12, pp.52-62, 2023-12-29 (Released:2023-12-27)

参考文献数

18

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To clarify the mechanism of liberation in the comminution process of electronic scrap (e-scrap), we attempted to express the degree of liberation by first-order kinetic equation related to impact energy. Breakage energy measurements, comminution experiments, and discrete element method (DEM) simulations were conducted on two types of e-scrap with relatively simple structures. The mechanism of the liberation was estimated from the observation of the fractions in the comminution experiments. The results of the breakage energy measurements and DEM simulations supported the mechanism in terms of impact energy. The results of fitting first-order kinetic equations based on the cumulative specific impact energy from the DEM simulations and the degree of liberation in the experiments showed a high correlation. The fitting parameters of the firstorder kinetic equations were compared confirmed to be consistent with the mechanism of liberation and the breakage energy measurements, suggesting the numerical validity of the equations. In conclusion, it was shown that for e-scrap with relatively simple structures, the first-order kinetic equations of the cumulative specific impact energy calculated by DEM simulations can be used to evaluate the degree of liberation.

著者

綱澤 有輝 古作 吉宏 坂入 義隆 塚田 浩二 斉藤 瑞稀 蛭子 陽介 三觜 幸平 陳 友晴 所 千晴

出版者

一般社団法人 資源・素材学会

雑誌

Journal of MMIJ (ISSN:18816118)

巻号頁・発行日

vol.138, no.6, pp.95-102, 2022-06-30 (Released:2022-06-30)

参考文献数

14

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The high-pressure grinding roll (HPGR) has been known to achieve a high mineral liberation with relatively low energy consumption. However, quantitative methods for evaluating the effect of HPGR grinding on the promotion of the mineral liberation of copper ores have not been fully established. This study aims to establish a quantitative evaluation of promoting the liberation ratio of copper minerals by HPGR grinding. We performed clack observation using the combination of the paint penetration method and the mineral liberation analyzer (MLA). Direct clack observation reveals that HPGR grinding can promote the formation of cracks in the product particles. The liberation ratio of copper minerals is related to the percentage of cracks in the product particles. Besides, the grinding tests using a laboratory ultra-small scale showed that the liberation ratio of copper minerals became larger than that of the ball milling alone. In all conditions where HPGR grinding was conducted before ball milling, the ball milling time became almost half that of the ball milling alone. The grinding kinetic constant of the HPGR milling product in ball milling is also determined. The grinding kinetic constants for 80% passing particle size in HPGR grinding products are larger than that in feed ores, and they are consistent with the trend of ball milling time. This might be because the HPGR milling causes cracks in the particles, which are more easily ground in the subsequent ball milling. Consequently, this study demonstrates that the ratio of clacks and the grinding kinetic constant in the ball milling process after HPGR milling can be used as an index to quantitatively evaluate the effect of HPGR milling on promoting the liberation of copper minerals.