Grinding kinetics of quartz and chlorite in wet ball milling

Abstract

Under an invariant and self-similar mill environment, batch wet grinding studies were carried out by grinding mono-sized fractions of quartz, chlorite and their binary mixture at different blending ratios. The results obtained indicate that the breakage behavior of both minerals as well as their mixture followed a first-order model. The maximum breakage rate, Smax, for quartz and chlorite, obtained in the feed size fraction of −0.5+0.25mm, were 0.19min−1 and 0.33min−1, respectively. It was also found that the breakage rate Si of quartz or chlorite had a linear relationship with its mass ratio in the binary mix. The cumulative breakage distribution value, Bij of quartz was independent of the absence or presence of chlorite in the quartz-chlorite binary mix. However, the presence of quartz led to a reduced cumulative breakage distribution value for chlorite. In the mixture, the calculated energy split factors for the quartz and chlorite components were found to be greater than one and less than one, respectively. These results seem to suggest that the quartz particles required more energy in order to break and were the rate determining component in the breakage process of a mixture. In addition, the simulated product size distribution data obtained, using the discrete-size, continuous-time Population Balance Model (PBM), were consistent with experimental data for quartz-chlorite binary mineral system.