Modification Of UHMWPE And The Application In Mineral Processing

The object of the task was to study on properties of UHMWPE modified,so as to improve wear-resistance property of mineral processing equipment,based on the analysis of wear mechanisms of mineral processing equipment.From the forming processes of UHMWPE, compression molding process was chosen as the proper one for this task.The tensile strength,impact strength and hardness of UHMWPE composites filled with different kinds of filler,such as glass bead,nano-Al₂O₃,French chalk,PTFE,and the difference of mechanical properties was compared and discussed.SEM photographs of freeze fractured surface under liquid nitrogen of UHMWPE composites were examined.The results showed that nano- Al₂O₃ filled UHMWPE composite had good mechanical properties,when the content of nano- Al₂O₃ was 10 percent by mass,tensile strength,impact strength and hardness have been increased by 13.3%,18.4%,32.6%.The friction coefficient and wear mechanisms of UHMWPE composites were presented both in sliding wear against steel 45 under dry sliding and water lubrication.The effects of load and content,type of UHMWPE composites on their friction coefficient and wear rate were investigated.When filler keep a relatively lower content,friction coefficient of composites(except French chalk) declined under dry sliding.Friction coefficient declining with increasing of load,but wear rate increasing. UHMWPE composites register lower friction coefficients and wear rates under water lubrication than under dry sliding,owing to the boundary lubricating and cooling effect of distilled water.Slurry erosion tests were carried out with the manufactured test apparatus in order to study the erosion properties of the UHMWPE composites.High chromium cast iron was taken as a contrast in the test,relative wear resistance of composites were examined.The UHMWPE composite containing 10 percent Al₂O₃ nanoparticles showed that best wear resistance behavior,was increased 2.48 times than the high chromium cast iron.The erosion mechanism of UHMWPE composites was discussed through the worn surfaces analysis.The results of experiment proved that nano- Al₂O₃ filled UHMWPE composite had good mechanical properties and wear resistance properties,when the content of nano-Al₂O₃ was 10% by mass.The comparison of this composite with wear-resistance materials in tubing on wear tate and cost performance rate was studied,the conclusion showed that relative wear-resistance of composite was increased 1.6 times than ceramic material.