Edge effect is the widely observed condition of impaired comminution performance at the edges of High Pressure Grinding Roll (HPGR) tires. This effect is caused by a reduction in the local crushing pressure at the edges of the tires resulting from the interaction between the static cheek plates and HPGR feed material. In open circuit operations, this effect results in coarser particles reporting to downstream equipment. In closed circuit applications, edge effect results in an increased circulating load and diminished HPGR circuit capacity. Results will be presented to demonstrate how edge effect was significantly reduced through innovations in the Metso HRC™ HPGR design, which incorporates an Arch-frame and a flanged tire design. Through a series of pilot plant tests comparing a 750 mm x 400 mm HPGR with flanges versus the same HPGR with traditional cheek plates, the enhanced performance when operating with a flanged tire design are demonstrated. A detailed description of the pilot testing protocols, results and analysis are presented. In addition, insights into the implications for circuit design, energy efficiency and overall plant performance are also presented.
B. Knorr1 , V. Herman1 and D. Whalen2 ;
1 Metso, York, PA
2 Freeport-McMoRan Inc., Phoenix, AZ