制服丝袜影音先锋-日韩av在线免费看-四级黄色片-av中文字-欧美性乱-免费午夜影院-美国免费高清电影在线观看-黄色免费国产-亚洲奶汁xxxx哺乳期-久久久久国产一区-a级黄色片在线观看

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.