MONITORING GRINDING PARAMETERS BY VIBRATION SIGNAL MEASUREMENT - A PRIMARY APPLICATION

Grinding plays an important role on energy consumption and subsequent separation stage in a mineral processing plant. To maintain higher gri nding efficiency, the operating parameters must be continuously monito red and adjusted close to the setup of the optimal operating condition s. It is difficult and expensive to trace the frequent variations of t he grinding parameters by traditional methods in commercial scale oper ation. Since mechanical grinding emits strong vibration signals, it ca n be picked up by commercially available instrument in the form of tim e-domain waveform. The variations of the vibration signals were govern ed by the changes of the grinding state. A primary application was stu died based on industrial scale measurements, where the mechanical vibr ation was picked up by an accelerometer and acoustic pressure changes by a microphone. The digitised time-domain source signals were process ed by digital signal processing technique. The variable grinding param eters were the power draw, the feed rate, the pulp density, and the pa rticle sizes of the mill feed and ground product. By principal compone nt analysis and parameter identification, the variations of the grindi ng parameters were related to the changes of the source vibration sign als. By vibration measurement, a new alternative could be developed fo r monitoring the operating parameters in grinding.