Study On Energy Consumption Characteristics Of Magnetite Crushing Under One-dimensional Dynamic And Static Combined Loading

For the low energy utilization rate,serious energy consumption,high mining and dressing costs in iron mines in all links of the processes,based on Hopkinson pressure bar test device and numerical simulation methods,under different working conditions The magnetite ore specimens were subjected to impact crushing test.Through studying deformation,strength characteristics,failure modes,and so on,the characteristics of energy consumption of ore were systematically explored.The main results are as follows:1)At the same impact speed,the elastic modulus and dynamic load strength of the ore under the axial compression ratio of 25% are the largest,while the maximum strain is the opposite.After the axial compression ratio is increased to 50%,the before will decrease,even lower than the non-axial compression Conditions,the maximum strain gradually increases,when the axial compression ratio reaches 75%,its value suddenly drops,and the maximum strain increase is higher;under the same compression,as the impact speed increases,they both increase accordingly,showing a good rate effect;2)Analyze the failure mode load by GDEM simulation.When the axial pressure is 0,the ore mainly undergoes tensile shear failure,and after the axial pressure is applied,the ore mainly undergoes compression shear failure;3)The axial pressure ratio has a great effect on the energy transfer.With the axial pressure ratio increasing,the ore will undergo three stages of "absorbing energy-releasing energy-absorbing energy",the specimen is slightly broken with energy released,and the ore fragmentation is large.With axial compression ratio increased to more than 50%,the energy density of ore is obviously reduced,ore fragmentation moving from the coarse end to fine end.Choosing the appropriate axial compression ratio for the fragmentation;4)Based on test,it can be seen that when the axial pressure ratio is less than 50%,it is not conducive to rock breaking.Only when the axial pressure ratio reaches 50% or more,the better crushing effect can be obtained under the same incident energy condition.Figure 42;Table 10;Reference 84...