著者

高橋 良尭 山口 耕太郎 笹岡 孝司 濱中 晃弘 島田 英樹 一ノ瀬 政友 久保田 士郎 佐分利 禎

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.94-100, 2019-10-31 (Released:2019-10-31)

参考文献数

19

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Rock blasting is one of the most common techniques for rock breakage in the open-pit mining excavation. On the other hand, the application of the technique has been restricted by law since it may cause a serious impact on surrounding environment, such as flyrock, ground vibration and noise. According to the statistics, more than 70% of accidents relating to the usage of explosives is flyrock. This accident may cause serious damage to buildings, human beings, and objects in the surrounding area. However, a detailed guideline for prevention of flyrock has not been developed yet. From these points of views, a series of field experiments was conducted and initial velocity and flying direction of fragmented rock were discussed by considering blasting standard and rock mass conditions such as strength, fractures/cracks and joints. The result shows that powder factor and burden have strong influence on the initial velocity of fragmented rock. Not only blasting designs but also rock mass conditions, cracks/joints strongly effect on the initial velocity. In addition, it was also made clear that the existence of fractures/cracks/joints in the blasting face have an obvious impact on the direction of fragmented rock.

著者

古川 博文 松井 紀久男 島田 英樹

出版者

一般社団法人 資源・素材学会

雑誌

資源と素材 (ISSN:09161740)

巻号頁・発行日

vol.121, no.9, pp.446-455, 2005 (Released:2007-02-24)

参考文献数

6

被引用文献数

1 3

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India is the third largest coal producer in the world and has substantial coal reserves. It produced about 340 million tons of coal in 2002-2003. Open cast production accounts for 80% of the total output and the remaining 20% is from underground. The share of the underground output in the total production is expected to remain at the current level through 2010 even as the coal production increases. Despite its huge resource of coal, the quality of Indian coal is not so good. A considerable amount of good quality coal deposits in India lies in the thickness range of 5-12 m. However, an appropriate mining method for such thick seams could not be developed so far.The coal's share of total electric power generation in India is 75.5% in 2001. Because it is a reliable, domestic, and low-cost source of fuel, coal has played and will continue to play a significant role in the development of the Indian economy. Production, processing, and consumption of coal, however, can have significant environmental impacts, if not properly managed.The paper describes the present situation of the Indian coal mining industry, discusses problems in thick seam mining methods, and proposes a new mining method for thick seams considering today's environmental issues in Indian coal mining.

著者

井上 聡大 羅 武輝 森山 紗好 平島 剛 島田 英樹 笹木 圭子

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.133, no.10, pp.235-240, 2017-10-01 (Released:2017-10-14)

参考文献数

28

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Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident produced much amount of radioactively contaminated water at the Great East Japan Earthquake. 137Cs and 90Sr have been focused to remove from the contaminated water using zeolite types of adsorbents. Other radionuclides have been treated and removed separately by Advanced Liquid Processing System (ALPS), where resin is used to immobilize anions. However, these kinds of spent-adsorbents are not suitable for long-terms burying because of its instability, and the representative anionic radionuclides (129I, 36Cl, 99mTc and 79Se) have quite long half-life (105-107 years). Montmorillonite (Mt) is an useful adsorbent because of its high chemical stability and large cationic exchange capacity. In the present work, surfactant modified Mt (OMt) has been developed using hexadecylpyridium chloride for adsorption of ClO4-, which is a surrogate of 99mTcO4-. For stabilization of spent-OMt, cement solidification was examined with varying the ratio of spent-OMt content. To evaluate its chemical and physical stability, soaking and compressive strength tests were conducted. As a result, it was revealed by FTIR and 29Si-NMR that with increase in OMt contents, the linkage of calcium silicate hydrate was more developed.

著者

古賀 誠 島田 英樹 松井 紀久男

出版者

The Mining and Materials Processing Institute of Japan

雑誌

資源と素材 : 資源・素材学会誌 : journal of the Mining and Materials Processing Institute of Japan (ISSN:09161740)

巻号頁・発行日

vol.118, no.1, pp.29-35, 2002-01-25

被引用文献数

4 7

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A bleeding examination and a flow characteristic examination of grout materials were performed to understand the fundamental characteristic of grout materials. Moreover, an injection experiment of grout materials which used a decomposed granite was conducted to understand the applicability of the analysis technique which introduced filtration theory. The results are as follows:<BR>1) When cement water ratio is large, a bleeding speed becomes slow, but the bleeding ratio becomes small.<BR>2) Plastic viscosity and yield stress become large with increase of cement water ratio. Particularly, plastic viscosity change greatly on <i>C</i> / <i>W</i> = 1 / 1.6. And as compared with yield stress, it is larger about influence on the discharge.<BR>3) Where a cement water ratio does not exceed <i>C</i> / <i>W</i> = 1 / 5, the clogging of the voids was done by a suspension custody. And where <i>C</i> / <i>W</i> = 1 / 3.5, that was done by a surface filter layer.<BR>4) The plastic viscosity measured using Brookfield viscometer is a result when some cement particles aggregate, and shows big value as compared with the theoretical relative viscosity.<BR>5) The result of injection analysis using the theoretical relative viscosity assumed that the cement particle is distributing completely is well as an experiment result in agreement. In the grout materials which flow the inside of the voids, it cleared that plastic viscosity follows the theoretical relative viscosity which the cement particles distributed.

著者

植田 武 松井 紀久男 島田 英樹

出版者

一般社団法人 資源・素材学会

雑誌

資源と素材 (ISSN:09161740)

巻号頁・発行日

vol.121, no.9, pp.438-445, 2005 (Released:2007-02-24)

参考文献数

9

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Increased opposition from environmental groups is severely restricting the operation and planning of large-scale surface mines in the world. Some projects of surface mining will have to be cancelled and downsized due to environmental issues. Under this social situation, the mining industry has started the campaign and the public relations for the importance of extracting and using coal resources in order to mitigate the protection. It has been recognized throughout the industry that planning is essential to minimize the effects of mining on the environment. Environmental management and rehabilitation are now integral parts of planning for mining.Mines have a finite life that ceases when the mineral has been fully extracted. During the life of mine, mining, especially surface mining, has the potential to have environmental effects that extend beyond the confines of the mine boundary. These include erosion with increases in sedimentation and turbidity in surrounding water courses and leaching of salts that also result in the reduction of water quality. These effects may range from minimal to quite severe and widespread, depending upon the physical and chemical properties of the overburden and reject materials, the climate and location of the mine, and its relationships with surrounding land uses. Rehabilitation of mines is aimed towards the projected future land-use of the area.This paper describes surface mining systems in Australia and then discusses the factors that should be considered in order to avoid potential environmental issues resulting from surface mining when developing a new surface mine.