| Exploitation of shallow resources in the mine gradually depleted,the mining of underground ore bodies is gradually transferred to deep mining,while the mining of deep ore bodies faces many security problems.In this paper,a mine 800 m mid-section test stope for the study,the mine uses filling mining in the deep and tail sand as filling material.In order to ensure the safe mining of ore body and the stability of top and bottom of stope,the main research contents and related achievements of this paper are as follows:1?The mine tailings filling materials for laboratory tests,analysis of the basic physical parameters of the tailings materials,chemical composition were analyzed and determined to determine the mine tailings chemical composition of the normal,the strength of the filling strength greater S content Not high,only 0.55%.At the same time,it is concluded that the content of tailings fine particles is high,the settling performance of tailings and the clarification of filling slurry will have a greater impact,and the sedimentation characteristics and slump and expansion of tailings of mines are further tested.It is concluded that the tailing sand settling performance can reach the best condition when using the special flocculant of BASF tailings when the dosage is40 g / t.At the same time mine filling the best filling slurry concentration range of70%-72%.2?In the laboratory,different proportion of tailings cemented filling body was tested by mechanics,and the result showed that the filling body compressive strength and the change of tensile strength were mainly influenced by the sand-sand ratio,the concentration and the curing age.At the same time,using the method of orthogonal test and range analysis,it is found that the curing age has the most significant impact on the strength of the tailings cemented filling body and the cubic polynomial mathematics model.And according to the orthogonal optimization analysis,the strength of the filling body changes with the change of the slurry concentration,the intensity of the largest increase in the concentration of 70%-72%,in accordance with the previously recommended slurry concentration range,it is concluded that it is most suitable for mine to use 72% slurry concentration for filling operation.3?The mechanics mechanism of filling body and surrounding rock is studied and analyzed,and the main mechanism of filling body filling stope is expounded.On this basis,the principle of damage mechanics is used to study the filling body withdifferent ratio of sand to sand,and the damage mechanics model of the filling body with different mixing ratio is established,and the damage rules of the filling body with different mixing ratio are obtained.At the same time,the cusp catastrophe theory is used to analyze the reasonable matching between the filling body and the rock mass in the goaf.According to the analysis results,the lowest strength of the filling body design is 0.78 MPa when the mine is filled and mined.4?Based on the theoretical calculation of the critical strength of the filling body and the actual mining conditions,three kinds of filling and mining schemes are designed.By establishing a deep excavation calculation model,the stability of the stope under three different mining scenarios was simulated.According to the results of simulation analysis,using the filling scheme 1 and the filling scheme 2 as the mining scheme,in the two-step recovery process,tensile stress damage will lead to failure of the filling body,and a large range of plastic zones will occur and the phenomenon of penetration will occur.Loss of stability occurs during recovery.In Scheme 3,only the plastic zone appears on the top and bottom plates,and it is relieved after the two-step filling.There is no plastic zone inside the filling body.Therefore,after analysis,the selected filling scheme 3 is a more reasonable mining scheme. |
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