Deep Mining Recovery Into The Road Layout Of The Jinchuan Mining Sequence Optimization

In China, Jinchuan Group is one of three bases of many-sided utilizing minerals, and it is the largest provider of nickel and cobalt. Its ore deposit is buried in the poor strata with high horizontal ground pressure (tectonic stresses), and its mining situation extremely bad. Thus, how to effectively keep the relative structures of underhand cut-and-fill drift stoping stable is one of crucial technical problems to be solved in the mines. According to the investigation contents of a project from No.2 mine of Jinchuan Group, the stress distribution in filled mining drift was studied by theoretical analysis, and the effect of layout of mining drifts in the upper slice and under slice and mining sequence on the stability of drift stope and its surroundings was studied by numerical modeling (FLAC^3D). The main conclusions of this thesis are as followings:(1) Based on the structural parameters of underhand mining drift in the mine, two mechanical models, that is beam model and thin-slab model, were given, and the stability of bearing layer (partial artificial roof) of mining drift was studied by the models. Further, the stress distribution in filled drift was obtained according to the models.(2) Under the same situation of strata, the same structural parameters of drift stope, and the same mechanical properties of filling media as well, the effect of the different layout of drifts in the upper slice and in the under slice on the stability of stope and its surroundings was numerically modeled by FLAC^3D. The results showed that, in comparison with the parallel layout of drifts, in which the drifts in the upper slice are parallel to those in the under slice, the perpendicular layout of drifts, in which the drifts in the upper slice are perpendicular to those in the under slice, worked better. Under the perpendicular layout, the magnitude of stress and displacement of monitored points in the surroundings of stope was less than those under the parallel layout, respectively.(3) By the numerical modeling, it was found that change in mining sequence in a slice resulted in corresponding change in the range of plastic zone and magnitude of displacement in the surroundings. Compared with the mining sequence from two ends of orebody to its center, to some extend, the stability of stope and its surroundings was improved under the sequence from the center of orebody to its two ends.Aboved-mentioned conclusions are good for NO.2 mine to achieve its safe and efficient production objectives.