Pellet feed grinding by HPGR

Apart from tertiary and quaternary crushing applications in a wide variety of ore types, High Pressure Grinding Roll (“HPGR”) technology is also applied in regrinding of iron ore pellet feed concentrate. A relatively large number of units have been or are being installed in iron ore pellet feed over the last few years throughout the world, in various circuits of single pass or closed circuit in combination with ball milling or stand-alone arrangement, and a number in a set-up involving a closed circuit of partial product recycle. s the HPGR function in comminution operations obviously is the size reduction, the main purpose in pellet feed applications is a combination of fines generation with a main emphasis of creating a high specific surface area increase. ublication discusses three aspects of the features and experiences for pellet feed applications; an approach on the effect of discharge recycle ratio on the product quality and HPGR operation, a description of the effects of material moisture, and a discussion on the use HPGR for final grinding in iron ore pellet feed preparation by use of air classification.