Industrial-scale performance evaluation of highpressure grinding rolls in an iron ore beneficiation plant

Abstract

High-Pressure Grinding Rolls (HPGR) are widely recognized for their superior energy efficiency and throughput compared to conventional grinding technologies; however, industrial-scale performance data remain limited. This study evaluates the influence of key operating parameters, including operating pressure (145-185 bar), roll speed (0.6-1 m/s), feed rate (1000, 1400 t/h), feed fines content (30%, 42%), feed moisture (1.8-4%), and roll wear (new rolls, worn rolls), on the performance of an industrial HPGR operating in the primary grinding circuit of an iron ore beneficiation plant. The results demonstrate that operating pressure and roll speed are the dominant factors governing product size reduction, energy consumption, and throughput, while feed characteristics and moisture content exert secondary but measurable effects. Increased pressure and roll wear improve size reduction but reduce throughput and increase energy demand, whereas higher roll speeds enhance throughput with moderate energy penalties. Progressive stud wear significantly degrades grinding efficiency and necessitates higher operating pressures to maintain product quality. Overall, the findings provide practical insights into the operational trade-offs affecting HPGR performance and offer guidance for improving energy efficiency, throughput, and equipment utilization in industrial iron ore grinding circuits.