Original Article Experimental investigation of the power draw of tumbling mills in wet grinding

In comminution, mill power plays a major role from the economics standpoint and is a critical design criterion. It is influenced by a range of parameters such as media charge level (ball filling), slurry filling, slurry concentration and mill speed. In this work, the effects of these operating parameters were investigated using a pilot mill (1000 500mm). To this end, a copper ore (1000 mm) was used to prepare the slurry. The tests covered a range of slurry filling (U) from 0 to 1.7 with media charge between 12 % and 36 % of the mill volume and six different speeds between 60 % and 85 % of critical speed. A power analyser was utilized to measure mill power. Increase in mill speed and ball filling leads to a remarkable increase in the amount of the power. Preliminary results show that there is a definite trend between the power and the slurry filling U. Mill power draw is maximum at slurry concentration 60–70 % and slurry filling 0.84. An empirical equation was given that fits the data reasonably well