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

Abstract

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 × 500 mm). To this end, a copper ore (−1000 µm) 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.

Building a model of the impact grinding mechanism in a tumbling mill based on data visualization

“…The applied relative parameters (2) to ( 15) are dynamic criteria for the similarity of loading movement and grinding process in a tumbling mill by impact action. The values of the dynamic parameters according to the expressions (3), ( 5), ( 9), (13), and (15) make it possible to numerically evaluate the changes in the technological effect of the shock action of loading depending on the initial characteristics of the grinding process.…”

“…The high energy intensity of grinding is caused by energy dissipation due to the shear circulation of internal mill loading [2,[8][9][10]. The estimate of the consumed power can be considered as an indirect indicator of the mill's productivity [11][12][13]. Therefore, the problem of reducing the energy intensity of work processes of tumbling mills remains relevant [14].…”

Establishing the effect of decreased power intensity of self-oscillatory grinding in a tumbling mill when the crushed material content in the intra-chamber fill is reduced

“…It was shown that with an increase in slurry content, the impact action of the fill decreases because of damping the interaction of grinding bodies. The influence of material content on the power of the mill drive during wet grinding of copper ore was studied in [24]. Slurry concentration was 40, 50, 60, 70, and 80 %.…”

Establishing the effect of a decrease in power intensity of self-oscillating grinding in a tumbling mill with a reduction in an intrachamber fill

“…It was found that a significant decrease in κ increases magnitude and frequency of impacts and productivity of the grinding process. Effect of values of the chamber filling degree κ = 0.12, 0.18, 0.24, 0.3 and 0.36 on the tumbling mill drive power during wet grinding of copper ore was experimentally studied in [28]. A significant increase in power was observed with an increase in κ.…”