The Rule And Its Prediction Model Of Ore-Rock Migration In The Storage Section Of The Orepass

In the process of underground deposit mining,the orepass is responsible for the transportation and storage of the ore and is an important project to realize the low-cost transportation.The blockage of the orepass and the deformation and the damage of the orepass wall are the common problems in the use of the orepass project,which have an important influence on the normal operation of mine production,and also bring greater safety hazards.Studying the law of ore-rock migration in the orepass is helpful to analyze,study and solve the problems of the orepass blockage and the shaft wall damage.Taking the ore storage section of the orepass as the object,using physical experiments and numerical simulations method,The research takes the ore storage section of the orepass as the object,uses physical experiments and numerical simulation as the means,the related theories and analysis methods,such as particle flow dynamics and fluid mechanics,are used to analyze the mesoscopic and macroscopic movement laws of the ore-rock,and the influence of factors such as the diameter of the storage section and the size of the ore discharge port on the law of ore and rock migration.The prediction model of ore-rock migration speed,displacement and trajectory in the storage section is established.The research has achieved the following main results:(1)Based on the loose medium stress limit theory,combined with the analysis of the force of the ore-rock particles,the force characteristics of the ore-rock particle system under the action of the shaft wall boundary are analyzed by studying the limit equilibrium conditions of the ore-rock and the distribution of the sliding micro-faces in the storage section.It is found that the friction between the ore-rock and the shaft wall is an important reason for the velocity difference between adjacent ore-rock blocks in the same plane,which affects the velocity distribution characteristics of the ore-rock.(2)Using the method of combining theoretical analysis,physical simulation and numerical simulation experiment,the influence of the factors such as the diameter of the storage section,the size of the ore discharge port and the friction coefficient of the shaft wall on the ore-rock migration law is analyzed systematically.The characteristics of the influence of the parameters such as the diameter of the ore storage section and the size of the ore discharge port on the law of the ore-rock migration under the condition of and without friction between the ore-rock and the orepass wall.(3)Using numerical simulation experiments,combined with time-average analysis,quantitatively analyzed the movement law of individual pulsating changes of ore particles during the ore drawing process of the storage section from a meso-level perspective,and obtained the migration trajectory and displacement characteristics of ore particles with time.The ore rock mainly moves vertically downward in the silo part,first with an accelerated movement with reduced acceleration,and then with a constant time-average velocity;after reaching the ore drawing funnel,the ore moves toward the ore drawing port with an increased acceleration;the speed of ore and rock fluctuates during movement.(3)Combined with the time-averaged analysis,the numerical simulation experiment was used to analyze the movement law of the individual ore-rock particles pulsating changes during the ore drawing process of the storage section from a meso-level perspective.The migration trajectory and displacement of the ore-rock particles were obtained.The ore-rock moves vertically downward in the silo,showing the movement characteristics of constant time-average speed from the initial acceleration movement to the later period.After the ore-rock reaches the ore-drawing funnel,the speed of its movement to the ore-drawing port keeps increasing.During the entire movement of the ore-rock,its speed presents pulsating characteristics.(4)Using physical simulation experiments and numerical simulation experiments,the ore-rock movement process,velocity field change characteristics and ore-rock migration characteristics are analyzed qualitatively from a macro perspective.The ore-rock velocity under a certain plane of the storage section is symmetrically distributed along the centerline of the pass,showing an approximate "convex function" distribution.In the process of ore-rock drawing,the closer to the shaft wall,the more the ore-rock is affected by the friction effect,the slower the ore-rock movement,and the greater the speed difference between the adjacent ore-rocks.(5)Based on the theory of particle flow dynamics and related theories of fluid mechanics,using the flow network,the mass flow theorem,the isolation method analysis and the other methods,The migration law of the ore-rock in the circular section orepass structure is studied under the condition of that the centerline of the ore-drawing funnel coincides with the centerline of the orepass.A prediction model of ore-rock migration trajectory,displacement and velocity is established.The reliability of the model is verified through numerical simulation experiments and physical experiments,the results show the established model can basically meet the prediction of ore-rock migration characteristics demand.