Abstract: To investigate the application performance of high-pressure grinding rolls (HPGR) technology in a low-grade
hematite ore from abroad,this study takes a representative hematite sample from the mine as the research object. The effects of
roll surface pressure and feed moisture content on the particle size distribution,specific energy consumption,and grindability of
HPGR products were systematically investigated,and the separation efficiency of the crushed products was verified through wet
pre-concentration tests. The results of closed-circuit tests with 3 mm screening show that under the conditions of roll surface
pressure of 5. 54 N/ mm2,feed moisture content of 3%,and stable operation,the -3 mm fraction in the final discharge increased
from 9. 10% to 49. 46%,an increase of 40. 36 percentage points,with an F50 / P50 ratio of 6. 21,indicating satisfactory
crushing performance. The circulating load was 115. 95%,specific energy consumption was 1. 75 kWh/ t,and specific throughput
was 280. 16 t·s/ (h·m3). Relative grindability tests indicate that the HPGR closed-circuit product (-3 mm) is more readily
grindable than the coarsely crushed ore,requiring less grinding time to achieve the same fineness. Wet pre-concentration
tests using two stages of high-intensity magnetic roughing separation at a background magnetic induction intensity of 1. 4 T yielded
a combined concentrate with an iron grade of 42. 20% and iron recovery of 96. 32%,while the tailings had an iron grade of
7. 60% with a yield of 17. 54%. The research findings provide technical support for optimizing HPGR process parameters and
implementing pre-concentration strategies for this low-grade hematite ore in abroad.