Abstract: In response to the characteristics of high ore hardness and low raw ore grade of a foreign iron ore，experimental studies were conducted on the combined process of high-pressure grinding roller （HPGR）- pre-concentration tailings rejection. Through systematic open-circuit and closed-circuit tests， the effects of HPGR working pressure，rotation speed，and feed moisture content on crushing performance and energy consumption were investigated. Comparative tests on wet and dry pre-concentration tailings re⁃ jection were carried out for the -3 mm product from closed-circuit screening. The results showed that un⁃ der the conditions of a working pressure of 9.0 MPa，a rotation speed of 20 r/min，and a feed moisture con⁃ tent below 8%，the HPGR operated stably with a suitable product size. The circulating load of the closed�circuit screening operation was 73.70%，and the content of -0.075 mm material in the screen undersize reached 17.79%. For the -3 mm product from closed-circuit screening，by wet magnetic separation pre�concentrationat with a magnetic induction intensity of 0.2 T and a linear speed of 0.78 m/s a concentrate TFe grade of 46.01% and a recovery rate of 80.85%，demonstrating better tailings rejection performance compared to dry magnetic separation. The study results provide a theoretical basis and technical reference for similar mines adopting the combined HPGR-pre-concentration process，contributing to improved min⁃ eral processing efficiency and economic benefits.

Key words: high-pressure grinding roller（HPGR）, screening, wet pre-concentration, tailings rejec? tion