Effect of Grinding Media Shape on Dry Rod Mill Power Draw

Abstract

One of the inseparable components of the grinding process in tumbling mills is the grinding media used in them. Despite the simplicity of grinding media shapes in a tumbling mill, their effect on breakage performance as well as on the mill power draw has remained a complex problem. A large share of energy consumption in mineral processing plants is related to grinding operations, so the study of power consumption in this sector is very important. This study compares the effects of conventional rods (simple rods) and grooved rods on the mill power draw in a dry rod mill at various mill speeds and grinding media filling. The results of the study showed that with an increase in grinding media weight and mill speed, power consumption was increased for both types of grinding media studied. The specific power rate decreased with increasing the speed and media filling. By increasing mill speed, the sensitivity of the specific power draw to the grinding media filling was increased. The specific power draw of grooved rods at low and medium speeds was shown to be more than that of simple rods, but at speeds above 60% of the critical speed, the specific power draw of the grooved rods was lower than that of the simple rods. Using an empirical model, the experimental and model values were compared. The results showed that the prediction of the mill power draw using the presented empirical model, in the range of low and medium speeds is more reliable. Therefore, using this model at low speeds is perfectly valid. However, as speed increases, its credibility decreases.

Keywords

• rod mill
• power draw
• grinding media shape