Optimization of Particle Shape and Gradation of Machine-Made Sand
In order to optimize the particle shape and gradation of machine-made sand,a vertical bar stirring mill was adopted for shaping tests.The effects of medium type,medium ratio,mill rotation speed and material/ball ratio on the particle shape of machine-made sand were investigated.The gradation and shape characteristics of unshaped and shaped sands were comparatively analyzed by using optical microscopy and image processing software.The results show that the shaping effect of zirconia medium is better than that of steel or alumina medium.With the zirconia balls with diameter of 6 mm and 8 mm in a mass ratio of 1∶1,rotation speed of 300 r/min,feed/ball mass ratio of 1∶3 and pulp volume fraction of 62.5％,the milling process results in the shaped sand with fineness of+0.15 mm 84.98％and flake granule accounting for 4.5％.The shaped machine-made sand has better compactness and angular characteristics,and it is qualified as the type Ⅰ sand according to the standard GB/T 14684-2022,with better gradation and particle shape compared to the unshaped sand.The contour shape and angular characteristics of coarse granules can be greatly optimized than those of fine particles.It is concluded that under suitable conditions,a vertical bar stirring mill can obviously improve the shape of machine-made sand and optimize coarser grain composition.
machine-made sandparticle shapegradationvertical bar stirring millshaping
万方数据
维普
