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.

著者

松岡 秀和 三觜 幸平 河田 真伸 高谷 雄太郎 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.2, pp.12-18, 2022-02-28 (Released:2022-02-10)

参考文献数

31

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Copper sulfide minerals are the major raw materials for copper products. Copper sulfide minerals are mined at copper mines and concentrated by flotation process. In recent years, the mining of refractory copper ores, which is difficult to concentrate by flotation due to their fine grain size, presence of multiple copper mineral species, and fluctuation of the content ratio of these minerals in feed ore. In addition, the hydrophilization of copper mineral surfaces due to oxidation and the mineral content variation of ore result in poor and unpredictable performance of flotation operation. In this study, therefore, we focused on the activation of the copper mineral surfaces using sodium hydrosulfide (NaHS) to render the surfaces hydrophobic and tried to quantify the effect of the fluctuation of mineral content ratio by using a new flotation kinetic model. Two samples showing different content ratios of chalcocite, bornite, and chalcopyrite and having fully oxidized surface were used in the flotation tests. We established a new flotation kinetic model by considering the reaction between the copper mineral surface and NaHS and the depression of floatability by adsorption of hydrogen sulfide ions onto the copper mineral surface. As a result, a good relation was confirmed between the model and the flotation test results for both ore samples. This result showed that our model can accurately predict the flotation results of refractory copper ores and will encourage the further usage of these refractory copper ores in the future.