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俄罗斯公布2003年的钻石开采量
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作者 岳萍 《中亚信息》 2005年第1期44-44,共1页
俄罗斯财政部新闻司透露,俄罗斯2003年共开采了3302万克拉钻石,价值约16.76亿美元。这是国家首次公开未加工钻石的开采及进出口数据。
关键词 俄罗斯 2003年 钻石开采量 钻石出口
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Study on control of rock fragmentation at limestone quarry 被引量:2
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作者 SASAOKA Takashi SHIMADA Hideki +2 位作者 SASAKI Takayuki ICHINOSE Masatomo MATSUI Kikuo 《Journal of Coal Science & Engineering(China)》 2008年第3期365-368,共4页
The size distribution of a muck pile depends not on only the blasting standard but also on the mechanical properties,joint system,and crack density of the rock mass. As,the cracks in the rock masses are especially hea... The size distribution of a muck pile depends not on only the blasting standard but also on the mechanical properties,joint system,and crack density of the rock mass. As,the cracks in the rock masses are especially heavily developed at the limestone quar- ries in Japan,they,along with the joints,have a large impact on the effects of blasting, such as the size of the muck pile.Therefore,if the joint system and/or crack density in a rock mass can be determined and quantitatively evaluated,the blasting operation can be conducted more effectively,efficiently and safely.However,guidelines for designing ap- propriate blasting standards based on the rock mass conditions have not yet been scien- tifically developed.Therefore,blasting tests were conducted on different mines and faces, under different geological conditions and blasting standards,in order to determine the im- pacts of each factor on the effects of blasting.Summarized the results of a series of blast- ing tests and described the impacts of geological conditions on the size of the muck pile produced by blast. 展开更多
关键词 FRAGMENTATION blasting standard BLASTING borehole scoping
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