Views:1 Author:Site Editor Publish Time: 2019-08-20 Origin:Site
Types and functions of grinding media
According to the shape of the grinding media, it can be divided into three types: ball, column (segment) and rod. Classified by material, it can be divided into carbon steel balls, stainless steel balls, high chromium cast iron balls, corundum balls (alumina balls), glass balls, agate balls, zirconia balls, natural sand, etc.
As to which shape of the grinding media is best for the ultrafine grinding process and effect, there is no satisfactory conclusion in theory at present, which is also a controversial issue. However, at present, spherical media that are relatively easy to manufacture, relatively low-cost, and whose shape remains relatively unchanged during the crushing process are still used, and a small number of processes use columnar media. In the micron or sub-micron or even nano-powder dispersion, due to the small size of the grinding media used, currently only spherical microspheres (or microbeads) can be used.
The material of the grinding medium is a very important issue in the superfine grinding process, which determines the cost and efficiency of the grinding process and the quality of the final product.
From the aspect of crushing efficiency, in the grinding process, the density of the medium determines the strength of the impact force. Generally speaking, the higher the density of the medium, the stronger the grinding ability and the higher the grinding efficiency. For example, the use of zirconia balls in the ultra-fine agitated mill has a difference of more than several digits in grinding ability compared with the use of alumina balls and glass balls.
Considering the cost of the processing process, the wear and crushing failure of the media will cause the loss of the media, which will increase the cost of the grinding and crushing process. In the chemical, fine ceramics and non-metallic mineral industries, materials such as corundum, zirconia, glass, etc. are mostly used. The selected medium should be comprehensively determined according to the value of the material to be ground and the price of the medium, and the purity of the crushed product should also be considered.
From the consideration of the quality of crushed products, the medium is constantly worn during the crushing process, and the worn fine powder is distributed in the product. Therefore, the choice of the material of the medium is in the fine ceramics, new material preparation, non-metallic minerals and chemical industries. It is very important. Ideally, it is hoped that no impurities will be added to the product. Therefore, in the crushing process of high-purity materials, zirconia balls are preferred.