The Evaluation of the Fine Grindability of Solid Materials based on the Work Index

The demand for fine particles is increasing in many industries, thus, it is important to evaluate the fine grindability of solid materials. The Work Index proposed by Bond is an important factor in designing a grinding process and has been widely used. In this paper, the authors proposed a corresponding Work Index Wi, c. which is proportional to the Work Index. Wi, c could be estimated by the examination of the zero-order increasing rate constant of the mass fraction less than a sieving size. Ball mill grinding was carried out on silica glass to measure the rate constant. The mill used was made of alumina with a diameter of 144mm and an inner length of 130mm. Its volume was about 2.1 liters. The grinding balls were also alumina with a diameter of 20mm. The relationship between Wi, c and the sieving size was studied. As the results, it was presumed that the Work Index could be approximately constant to a sieving size of 20μm and increased in the range of a size less than 20μm.