Wet grindability of an industrial ore and its breakage parameters estimation using population balances

Abstract

The grindability of a diasporic ore was studied by wet grinding in a laboratory ball mill and its breakage parameters were determined based on the population balance model (PBM). Four different feeds with unnatural size distributions were designed to save grinding and sieving work. It was found that three size-intervals fitted the first-order breakage, but the coarsest interval did not. The non-first order breakage was most probably caused by the heterogeneity of the material. The heterogeneity was then confirmed by experiments. The breakage rate and the breakage distribution parameters were back calculated by treating the non-first order breakage as two linear segments according to the grinding time. The back-calculated breakage rates were in good agreement with the values calculated directly from the experimental data, and non-normalizable breakage distribution was observed. The model with the obtained parameters simulated the experimental product size distributions with good accuracy. These findings are valuable to the simulation and optimization of the industrial grinding processes of diasporic ores.