The effect of processing parameters on energy consumption of ball mill refiner for chocolate

Abstract

A laboratory ball mill consisting of a vertical cylinder, equipped with a rotating shaft with arms, and filled with steel balls as a grinding medium has been used in the experiments. The aim of the study was to examine the effect of agitator shaft speed and amount of grinding media (steel balls) on power requirements and energy consumption of a ball mill. With constant mass of the steel balls (20, 30 and 40 kg), the agitator shaft speed was increased from 10 to 100% of the maximum speed, which corresponds to a speed of 50 rpm. The power consumption (W) was recorded upon which milling energy consumption (J/kg) has been calculated. The results were statistically analyzed using ANOVA. The increase of the agitator shaft speed, in steps of 10% to the maximum speed of 50 rpm, led to a statistically significant increase in milling energy consumption. At low agitator shaft speed (10%), increase in the mass of the steel balls had no influence on the power requirements. Power requirements for the grinding runs using 30 and 40 kg are similar and higher compared to power requirement in trial with 20 kg, as agitator shaft speed increases from 20 to 70%. At high agitator shaft speeds (≥80%), increase in steel balls mass led to a significant increase in power requirements of the ball mill.