Effects of operating parameters on vibration signal under laboratory scale ball grinding conditions

Abstract Experiments were performed under batchwise wet grinding conditions with dolomite. The vibration signal was received by an accelerometer and transmitted to a vibrometer. The vibration signal was first stored on a Digital-Audio-Tape recorder in voltage format during the grinding tests. The original signal was then resampled and converted into data format for an IBM or compatible personal computer by a digital oscilloscope. The Root-Mean-Square and the power spectrum were estimated on the time-domain vibration signal. A partial correlation analysis was applied to the frequency-domain spectrums to detect the non-zero correlation between the frequency bands and the operating parameters in grinding. A stepwise regression analysis was used to locate the key frequency bands for describing the changes of a particular operating parameter. After vibration analysis, the operating parameters in grinding, e.g., the mill speed, the powder filling, the pulp density, the pulp temperature and the batchwise grinding time were found to be strongly correlated with a few frequency bands. It is therefore possible to develop an efficient method for monitoring the operating parameters in grinding based on the vibration signal.