Design And Research Of Ball Mill Lifting Bar's Surface Based On The Bionic Coupling Theory

As a core device of grinding operations,ball mills play an important role in the beneficiation industry and even the entire national economy.At present,China is undergoing an economic transformation and puts forward to new requirements for energy-saving and high efficiency equipment.How to improve the mill's production efficiency and reduce the maintenance time is an important issue in front of us.Therefore,choosing a suitable wear-resistant material and designing a reasonable wear-resistant structure for the liner are of great significance for improving the operation rate of the ball mill.Today,the research on the wear-resistant design of liners focuses on the overall structure and materials of the lifting bars.Bionic tribology provides a new method for the development of new wear resistant parts.The results have shown that the wear of liner focused on the lifting bars in the previous studies.In this paper,the bionic coupling theory and finite element discrete element(DEM-FEM)coupling theory were used.Through observing the wear resistance coupling characteristics of several typical organisms with the extension analytic hierarchy process(EAHP),the decisive coupling elements,secondary coupling elements and general coupling elements of the two biological wear-resistant coupling characteristics were determined,respectively.Four ball mill models with different bionic coupling structures were established,which were designed as smooth,horizontal stripes,vertical stripes,and convex hulls,respectively.Particle models with different geometrical were built.Coupled simulations of discrete elements and finite elements were performed.On this basis,the lifting bar with the characteristic of bionic coupling structures was designed and manufactured.The grinding experiment was carried out with the same conditions as the simulation.The stress distribution,cumulative force,cumulative energy,average wear depth,effective collision,mass loss,microscopic wear topography and final yield of-80 mesh materials for the four different surface characteristics lifting bars in the grinding process were investigated by simulation and grinding experiments.The results have shown that the lifting bar with a bionic coupling structure composed of the soft matrix-hard bearing units can effectively slow down the release of the equivalent stress of the lifting bar during grinding,protect the lifting bar substrate,reduce the wear of the lifting bar and be conducive to ore crushing.It founded that the horizontal stripe bionic coupling structure has the best wear resistance and grinding effect in the four different lifting bars.Under the same conditions,the quality loss reduced by 56%,and the ore yield of-80 mesh increased by 17.8% compared to the lifting bars with smooth surface.The results can bring better economic benefits for the company and has certain guiding significance for the design of the new liner lifting bars.