Dynamic modeling of temperature in a wet ball mill based on integrated energy-mass-size balance approach

Abstract

This paper presents a dynamic model of mill temperature that could be used alongside mill conventional control systems to provide indications of changes in mill slurry solids concentration and by extension the slurry holdup and mill mixing behaviour based on in-mill temperature profile. The model combines information of energy and mass balance, material breakage mechanisms, fundamental material properties and the milling conditions in a simple and clear representation of the physics and thermodynamics of the wet milling process. Model tests at steady state conditions using industrial mill data show a closer match between measured and predicted temperatures. The test results depicting the dynamic response of the model show clear sensitivity of in-mill temperature to perturbations in the mill slurry solids concentration and solids feed rate. The trends in the milling data from the model simulations corroborate long held believe that mixing is better at lower slurry solids concentration. Overall, the results are indicative of the available potential to improve the accuracy of the conventional mill monitoring and control schemes based on information extracted from in-mill temperature profile.