Abstract: In order to improve the efficient development of complex magnetite resources and the level of energy saving and consumption reduction in beneficiation，a low-phosphorus and low-sulfur magnetite in Cameroon was taken as the object，and the beneficiation effects of conventional jaw crushing process and high pressure roller mill process were compared according to the ore characteristics of uniform distribution and hard discarding tailings. Through particle size analysis，dry preconcentration and discarding tailings test，Bond ball mill work index determination and grinding-magnetic separation test，it is found that after the high pressure roller mill is crushed to -3 mm，the proportion of fine particles is significantly increased， the dry discarding tailings yield rate is 25.85%，and the concentrate TFe grade is increased to 44.31%. At the same time，the Bond ball mill work index is reduced to 8.80（kW·h）/t，and the grinding energy con⁃ sumption is reduced by 20%. Finally，the TFe grade of concentrate reached 65.32% and the iron recovery rate was 95.07% after one magnetic separation，which was significantly better than that of jaw crushing pro⁃ cess. The research shows that the high pressure roller mill technology can effectively improve the beneficia⁃ tion efficiency of magnetite and reduce energy consumption through the strategy of 'more crushing and less grinding，early separation and early throwing'，which can provide theoretical support and technical route for the efficient development of complex magnetite resources.

Key words: magnetite, high pressure roller mill, pre-concentration and tailings discarding, Bond ball mill work index, magnetic separation efficiency, energy saving and consumption reduction