Study On Grinding Mechanism Of Disperse Milling Medium Dynamical For Vibration Mill

The vibration mill is a complex vibrating system which is made up of a collection of elastomer, discrete body, non-linear bearing and infinite degree-of-freedom. The movement law of grinding medium group is a key problem of the studies of vibration mill work mechanism, as well as the grinding dynamics characteristic research of the vibration mill under different operating conditions. Based on the elementary material broken theory, taking the vibration mill disperse milling medium group dynamics model as a foundation, this article analyzed the discrete grinding medium group flow pattern, the math relationship of revolution (rotation) movement and stratified movement of the disperse milling medium group. Then established the stress distribution function and the discrete grinding medium moore stress circle. Last in-depth discussed the laws of the borders distribution of the shear zone, the impact areas, the lack of energy region. Through the grinding experiment of two different materials(quartz and calcite). The article mainly focused on the studies of the product particle granularity characteristics, fracture type, as well as fracture morphology characteristics and so on, which are under different working mechanisms of vibration mill, providing a new approach for further research of the vibration mill grinding mechanism.Research showed that:â‘ Grinding medium group's flow pattern in cylinder included both mass central flow and gyration radius change. The differences between the overall revolution and the individual rotation of the medium group formed the centrifugal stress field which corresponded with a cluster of rays. In this stress field, through grinding medium group moore stress circle, the mutual coupling relations between shearing stress and impact stress could basically be determined under different operating mode conditions.â‘¡In the tube, various regions (the shear zone, the impact area, the lack of energy region) had the relatively stable boundary condition, and along with the grinding machine different operating mode parameters, various regions were in dynamic change. Increases of the operating frequency could enlarge the shear regions and diminish the lack of energy region which were good for the attrition; Otherwise, The relatively increase of the impact area and the lack of energy region would be good for breaking.â‘¢When vibration mill was under operating condition of great amplitude and small frequency, grinding medium manifested the impact characteristic to the material, the impact of broken grinding was the main form of broken. Such a job status was more appropriate to the broken grinding materials which have the characteristics of high hardness, wear resistance, and lower granularities demand, such as quartz, etc. When vibration mill was under conditions of small amplitude and great frequency, grinding medium manifested cutting attrition characteristic to the material, the cutting grinding was the main form of broken. Such a job status was more appropriate to the materials which have the characteristics of relatively lower hardness, the higher granularity demand, such as calcite, etc.â‘£Better matching relations of mill operating frequency and amplitude is of great importance to grinding materials. Reasonable matching parameters of excitation are favor of effective impact or grinding for grinding medium group. It is manifested macroscopically as the grinding speed and particle distribution.