Influences of operating parameters on dry ball mill performance

The paper is aimed to investigate the influence of operating parameters on dry fine grinding of calcite in a laboratory scale conventional ball mill. Within the context, the influence of operating parameters such as mill speed, ball filling ratio, ball size distribution, powder filling ratio, grinding aid dosage and grinding time were studied. The results of grinding tests were evaluated based on the product particle size (d50, d80) and surface area (m2/kg). As a result of this study, optimum grinding test conditions determined to be 70% of Nc, J=0.35 for ball filling ratio, 40 mm (10%), 32 mm (10%), 20 mm (40%), 12 mm (40%) for ball size distribution, fc=0.125 for powder filling ratio, 2000 g/Mg for grinding aid dosage and 60 min for grinding time. After determining optimum grinding conditions, the influence of grinding aid dosage on powder fluidity was determined. The use of 2000 g/Mg grinding aid dosage had a greater fluidizing effect compared to the other dosages and no aid condition (0 g/Mg). The influence of grinding aid on dry fine grinding of calcite was also examined by Fourier Transform Infrared Spectroscopy (FTIR). FTIR measurements indicated that grinding aid was adsorbed on the ground calcite particles surface.