Study On Dam Stability Of High Pressure Roller Mill Material Dump

Taking the crushing process simplification,the production capacity improvement of the system,the grinding effect or separation index improvement as the construction goal in China's mining enterprises,high-pressure roller mill,an efficient grinding equipment,has been continuously recognized and promoted by many concentrators to make full use of ore resources.However,while making full use of the ore resources,a large number of finegrained tailings are produced.At present,due to the wide application of high-pressure roller mill technology in China,the tailings storage problem is lack of corresponding laws,regulations and technical standards.The storage of high-pressure roller mill tailings can only be designed and discharged by referring to the dumping site or tailings pond.It is urgent to carry out relevant research on the storage of high-pressure roller mill tailings in order to guide the safety production of mining enterprises and provide theoretical support for the design department and government supervision department of high-pressure roller mill tailings storage.Based on the example of high-pressure roller mill tailings in Chengde District,Hebei Province,this paper systematically studies the mechanical properties,stability and the optimization of the main stacking parameters of this kind of materials by means of indoor test,numerical simulation,theoretical analysis and engineering design.The main research work and achievements are as follows:(1)Starting from the physical and mechanical properties of the material,the physical parameters such as particle size distribution,density,as well as mechanical parameters such as internal friction angle,cohesion,compression modulus and so on were obtained through the gradation test,compression test and shear test of the high-pressure grinding samples from Chengde Iron Mine;(2)Using FLAC3D simulation software,the safety factor of slope is calculated quantitatively by strength reduction method for the storage yard under different layer height and layer slope ratio.According to the simulation results,the influence of layer height and layer slope ratio on the overall stability is discussed.The results show that the height of the layer and the ratio of the layer have obvious influence on the stability of the storage site,and the safety factor decreases with the increase of the height of the layer and the angle of the layer to the slope.An optimization model is established on the basis of stability analysis,and taking the target storage capacity and slope safety as constraints,the optimal layer height corresponding to the lowest transportation cost is 10?20m,and the layer slope ratio is1:1.75(29°)?1:1.5(33°);(3)The limit equilibrium method is used to check the stability of the high-pressure roller mill tailings storage yard in the design scheme,and the results are compared with those of FLAC3 D.It is found that the stability analysis results are consistent,and the stability of the designed storage yard is in good condition.In view of the possible landslides and other disasters in the storage yard,the paper puts forward that anchor piles can be arranged to increase the anti sliding ability of materials,and puts forward corresponding suggestions for the safety management of the storage yard,which can be used for reference for similar highpressure roller mill tailings storage.