Study On The Optimization Of Deep Stope Support Parameters And Mining Sequence Of Xingcheng Gold Mine

With the increasing demand for mineral resources and the development of mechanized mining technology, mining intensity in Xincheng Gold Deposit is gaining, the scale becomes much larger and the mineral deposit in shallow has been removed in succession while mining is gradually transfering to the deep. Compared with mining in shallow, geo-stress becomes higher and geological conditions are more complex because geo-stress characteristics and rock mechanical properties have been fundamental changed in deep, which easily leading to stope roof falling and slabbing. All that has brought great difficulties to stope maintaining and seriously affects the safe and efficient production.An effective measure to reduce the roof falling, rib spalling and other safety incidents is to introduce a scientific and reasonable support pattern. However, supporting parameters used in Xincheng Gold Deposit are determined by engineering experience, lacking of interrelated theoretical foundation. Combining the comprehensive understanding of the geological and mining technical conditions of the Xincheng Gold Deposit with the cave-in mechanism of stope roof in deep, the influencing factors of roof collapsing in deep stope are fully analysed, so summarized the principles and methods of supporting. To integrate with the engineering experience of Xincheng Gold Deposit, the mechanical characteristics and the mechanism Action of Mortar Bolt are analysed at the same time. On the basis, three supporting parameters design theories of the anchor cable are introduced to design new supporting parameters of the stope so as to give the theoretical foundation of follow-up support parameter selections.Another important study of this paper is the optimization of mining sequence in deep stope. A traditional mining sequence that a layer of ore has been removed and then separated by a layer near the layer of ore mining is dynamically simulated by the FLAC3D, a kind of geotechnical engineering software. Choosing three mining periods, the stress and displacement of the surrounding rock and backfill in each mining period are analysed to determine the variation of its intrinsic. Based on fully understanding of the stress and displacement variation of surrounding rock and backfill, three mining schemes are proposed and two mining periods are selected, then, the stress and displacement in the same mining period of each scheme were comparatively analysed to determine the optimal mining scheme. Through the study, the parameters of anchor support and the optimal mining scheme are determined, providing an important theoretical basis for mining operations in Xincheng Gold Deposit-630m middle segment and deeper segment, which also has high reference value for similar mines.