Experimental Study On Stability And Failure Mode Of High-pressure Roller Mill Tailings Accumulation

In recent years,my country's demand for iron ore has continued to increase,making some of the existing low-grade lean and ultra-lean iron ore resources in China also have a certain mining value,and the emergence of high-pressure roller milling technology The beneficiation of this type of ultra-lean magnetite provides a favorable guarantee.High-pressure roller mill tailings have the characteristics of loose structure and not easy to consolidate,so the safety problem of accumulation needs to be solved urgently.However,the high-pressure roller mill technology has not appeared for a long time,and there are not many studies on the characteristics of the high-pressure roller mill tailings and the problem of stacking of the high-pressure roller mill tailings.Based on this,the main work of this article is as follows:(1)Perform physical and mechanical tests on high-pressure roller mill tailings,including natural density,dry density,moisture content,specific gravity,gradation,shear strength,and permeability coefficient of tailings sand.The test results show that the water content of high-pressure roller mill tailings is relatively high.Low,relatively dry,and uneven gradation,very low cohesion,so it is not easy to consolidate during stacking,and it is easy to cause damage;(2)Indoor stacking tests were carried out on the high-pressure roller mill tailings,including the density,slope angle,and loading tests of different gradation ratios.The test results showed that the stability of the high-pressure roller mill tailings deposits increased with the increase in slope.Gradually decrease,and the bearing capacity of the slope in the compact state is greatly improved compared to the loose state;(3)Numerical simulation tests of particle flow software under natural accumulation conditions for high-pressure roller mill tailings sand accumulations,including different slope angles and different gradation ratios,to observe the destruction of high-pressure roller mill tailings sand accumulations under different conditions The model and stability can be obtained through numerical simulation experiments.Under the condition of the same slope angle,the stability of high-pressure roller mill tailings sand accumulation is the most stable when the number of mediumsized particles is the largest,followed by the largest number of coarse particles and the largest number of fine particles.The most unstable.It is consistent with the results of the heap load test.Through observation,it can be known that the slope is a circular-arc landslide,so the slope and the toe are the most unstable,and they are also the first and most damaged places.Therefore,for the high-pressure roller mill tailings to increase the compactness of the slope as much as possible during the stacking process,the particles of different gradations can be combined during the stacking process,and try to avoid stacking the fine-grained ore separately to ensure Stability of the heap load;finally,certain reinforcement measures should be taken for the slope,the slope surface and the slope toe,such as setting the slope toe protection wall,etc.,to prevent the slope from slipping from the slope surface and the slope toe.