著者

石田 毅 直井 誠 陳 友晴 奈良 禎太

出版者

京都大学

雑誌

基盤研究(A)

巻号頁・発行日

2013-04-01

---

地球温暖化の速効的対策であるCO2(二酸化炭素)地中貯留では,大量のCO2を地下深部に圧入するが, CO2は地下深部ではさらさらとして粘度が小さい超臨界状態となるため周辺地層に与える影響を検討して必要がある.本研究では,現場の岩盤に超臨界CO2の圧入しその際の微小な破壊音であるAEを測定した.その結果,超臨界CO2は水の圧入に比べてAEの震源が広く分布するが,圧入位置での亀裂造成後時間が経過すると亀裂閉合によると思われるAEが観測された.このようなAEは岩盤の破壊ではなくガス抜けよるものと思われ,例えAEの震源分布が広がっても周辺地層に安定性に与える影響は小さいと思われた.

著者

杉山 博信 陳 友晴

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.135, no.10, pp.89-93, 2019-10-31 (Released:2019-10-31)

参考文献数

24

---

12CaO・7Al2O3 electride is one of the outstanding materials expected to be applied in various fields such as electronics and catalyst, and generally fabricated by sintering high purity CaCO3 and Al2O3. We attempted to fabricate 12CaO・7Al2O3 electride using limestone as a raw material instead of using high purity CaCO3 aiming at further industrial use, and investigated the gas adsorption properties of the fabricated samples. Three samples, two from limestone and one from high purity CaCO3, were prepared and exposed to the atmosphere for about 9 hours, and then the gas adsorption properties of them were analyzed by Py-GC/MS. As a result, desorption of N2 and O2 which are abundant in the atmosphere was not observed by heating the samples exposed to the atmosphere up to 700℃, while desorption of CO and CH4 was identified. It is implied that the desorbed CO originates from CO2 in the atmosphere. This result indicates these samples might selectively adsorb CO2 and CH4 as compared with N2 and O2. Furthermore, for the limestone derived samples, the selectivity of CO2 and CH4 adsorption was improved and this result indicated the possibility that the CO2 adsorption capacity of these samples is higher than that made from high purity CaCO3. One reason of this phenomena is inferred the changes in the electronic state of material surfaces due to the doping of impurities contained in limestones, such as Mg, Sr, and Cu, into the Ca sites of the cage-like structure in 12CaO・7Al2O3 electride.

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

---

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.