| Due to the superior performance of ultra-fine powder raw materials,the application in high-tech industries is increasingly important,so the current countries are very concerned about the production and processing of ultra-fine powder raw materials.In the preparation of ultra-fine powder,the method is varied,the more common methods are liquid chemical precipitation method,gas phase reaction method and mechanical crushing method.In this paper,we use mechanical crushing method to prepare ultrafine powder.At present,when using the mechanical crushing method to prepare ultrafine powder,the types of equipment are various.The most representative ones are planetary ball mills,vertical agitator ball mills,roller ball mills,and horizontal agitator mills.In this experiment,we studied the horizontal high-energy stirring mill as the research object,and mainly studied the following aspects:(1)The effect of different milling process parameters on the particle size and crushing efficiency of the powder was studied.By studying the three ball milling parameters of ball milling speed,ball milling time,and ball milling media diameter,the powder D50 after ball milling was obtained when the stirring speed was 1000-1100 rpm,the grinding time was 90 minutes,and the ball grinding medium was a 3 mm steel ball.About 1.75 μm,crushing efficiency is about 76.03%.(2)The influence of the length and width of the blade on the particle size and crushing efficiency of the stirring shaft was studied.By studying the two structural parameters of blade length and blade width respectively,it is concluded that when the blade length is 115 mm and the width is 8mm,the powder D50 after ball milling is about 0.5μm and the crushing efficiency is about 85.51%.(3)The EDEM discrete element simulation software was used to study the relationship between the length and width of the blade and the number of collisions and the impact force of each unit in the grinding chamber.Through research,it was found that when the length of the blade increases from 110 mm to 125 mm,the number of effective collisions in the grinding chamber increases from 41599 times to 47872 times,and the effective collision frequency increases by approximately 13.1%;the tangential force between the materials increases by 0.405 N.As large as 0.943 N,the increase is approximately 133%;the normal force between the material and the grinding media increases from 1.31 N to 13.5 N,an increase of approximately 930%.When the blade width increases from 6mm to 8mm,the number of effective collisions in the grinding chamber increases from 45028 times to 50608 times,and the effective collision frequency increases by approximately 12.4%;the tangential force between materials increases from 0.405 N to 0.943 N.The increase was approximately 133%;the normal force between the material and the grinding media increased from 0.263 N to 0.536 N,an increase of approximately 104%.When the blade width increases from 6mm to 8mm,the number of effective collisions in the grinding chamber increases from 45028 times to 50608 times,and the effective collision frequency increases by approximately 12.39%;the tangential force between materials increases from 2.37 N to 4.56 N.The increase is approximately 92.41%;the normal force between the material and the grinding media increases from 0.538 N to 1.08 N,which is approximately 100%.In this dissertation,the milling process parameters and the blade size of the horizontal high-energy agitator mill were studied.According to the results of the study,the ball milling process was: speed 1000/1100 rpm,ball milling time 90 min,ball diameter 3mm,blade size For a length of 115 mm and a width of 8 mm,the average crushing efficiency of the entire ball milling process is about 94.18%,and the final particle size of the resulting powder is about 0.5 μm. |
