Stopping Scheme And Two Step Charmber Mining Method Based On Stope Stability Analysis Research

The underground mining was the main way to get the mineral resources in recent years.Filling was a very important method to deal with goaf. Filling body size would increase with time passing by. It leaded some ore-body would hard to mining. The engineering background was the east five stope of Anqing copper mine, because it was a typical two-step-hard mining ore body for surrendering by filling body in east No. 1 stope in Anqing copper mine.Instability mechanism analysis, field monitoring analysis and numerical simulation were used for mining effect analysis. At the same, mining method and tracking evaluation also were carried out. The main results were as following:Rock-mass properties classification was taken which base on the sample in the field and Hydro-geological data in the whole mine. Experiments on rock mechanics parameter were conducted after field sampling, and experimental data were handled by the comprehensive method of Hook and Brown and experience subtraction, and corresponding rock mechanics parameters were obtained. The stability of the rock in mining area was preliminary evaluated,providing reliable parameter basis for further research.In-break mechanism, rock-burst mechanism and rock-burst mechanism based on fuzzy matter-element, Combing with field situation and special stress distribution investigation in Anqing copper mine, were used for instability mechanism analysis. The reason leading rock-burst were various, including hanging wall rock-mass crushed, surrendering filling body concentrating, secondary stress concentration and the energy of VCR explosion was too large.These factors would lead rock-mass instability. The stress would concentrate on the hanging wall because of the mining actives last year. It came from secondary stress and monitoring data which record in monitoring system. The mining safety situation was not good because of fracture has happened in stope’s hanging wall. It’s recorded in geological radar. Luckily, It can reduced instability by controlling explosion size and expose area in generally speaking.A detailed demonstration of stope parameters used FLAC numerical simulation,, both safety and economic benefit of mining stope in two steps, one step mining width 20 m, the cementation filling, another step used The stope 63 m flushing plan.The characteristics of stress concentration Combined with the theory and the results of monitoring data analysis, in view of the east five surrounded by a pack of the stope and the plate, to point the optimization of mining method, safety handed in first, economy under thepremise of give attention to two or more thing into the deep hole been made between flat-back cut and fill, down to the deep hole filling and later on to fill in the three extraction methods, it is concluded that the best extraction Method for to fill stopping.This track mining practice used in the mining method of the evaluation, five east stope achieved safety mining, ore recovery rate reached 86%, loss rate of ores reached 17%, the dilution rate was 8%, and the surrounding filling body in a stable state, instability of events did not happen.At last,it achieved good economic benefit.