Abstract: In order to further improve the comprehensive benefits of the mine，in view of the prob⁃ lems of low grinding grade and large grinding particle size in Jinshandian Iron Mine of Wuhan Iron and Steel Co.，Ltd.，the pre-concentration treatment test of raw materials was carried out by high pressure roll⁃ er mill process. The effects of pressure，rotational speed and material moisture on the open-circuit process of high pressure roll mill and the effects of dry magnetic separation on the closed-circuit process and wet magnetic separation on the closed-circuit process were studied. The results show that the high pressure roll⁃ er mill process can effectively reduce the particle size of the raw ore. The material under the sieve is dis⁃ carded by wet magnetic separation，and the discarding rate can reach 46.43%. The iron grade and recovery of the concentrate are 42.26% and 89.98%，respectively. The material on the sieve was discarded by dry magnetic separation，the effect was poor，and the comprehensive discarding rate was only 9.61%.

Key words: high-pressure roller mill, magnetic separation, pretreatment, tails throwing, sieving