EXPLORING THE ULTRASONIC COMMINUTION OF COPPER ORES

This paper presents grinding results obtained with a Chilean porphyry copper ore in the ultrasonic nip roll grinder of the US Comminution Ce nter. Comparison with ball milling is performed by scaling-down indust rial ball mill behavior to the ultrasonic grinding conditions. For sma ll gap setting in the ultrasonic device, size distribution and specifi c energy consumption are in the same order of magnitude for both alter natives, but for larger openings in this ultrasonic prototype, the bal l mill is much more efficient. Current design of the ultrasonic device is analysed and reasons why oversize and undersize particles are not well fractured are discussed. In spite of the current limitations, it is concluded that there is great potential to improve its performance.