吃奶揉捏奶头高潮视频丨黑人巨大亚洲一区二区久丨人善交video另类hd国产片丨亚洲 欧美变态 另类 综合丨一本到高清丨在线播放亚洲第一字幕丨久久婷婷五月综合97色丨久久亚洲网站丨亚洲精品无码一区二区三区久久久丨久久久久久久亚洲国产精品87丨成人性生交大片免费看中文视频丨女人十八毛片嫩草av丨新版天堂资源中文8在线丨日韩手机看片丨国产爆操视频丨超碰影院在线观看丨亚洲色图40p丨好看的黄色网址丨av日韩在线播放丨亚洲天堂一二三丨欧美大色丨都市激情自拍丨在线播放成人丨在线激情小视频丨特级无码毛片免费视频

Jinshandian Iron Ore Mine, located in Jinshandian Town, Daye City, Hubei Province, is under Wuhan Iron & Steel Group Minerals Co., Ltd. and is among the four ferrous metallurgical mines that are difficult in mining. It consists of two mining area: Zhangfushan and Yuhuasi.

Pillarless sublevel caving method is adopted. The two mining areas of Zhangfushan and Yuhuasi are integrated and the primary production capacity of mine 1.5 million t/a is extended to 3 million t/a.

Main shaft and auxiliary shaft development is adopted for the mine. The depth of the main shaft is 924 m, and it was the deepest shaft at ferrous metallurgical mines. The application of one-time construction and equipping by stages reduced the effect on mine production in the transition from one stage to another. It is the first time to use double skip hoisting at ferrous metallurgical mines and the hoisting capacity is 3.5 million t/a. The modification and expansion project was put into production in 2007 with good operation.