Abstract: In order to solve the problems of concentrate of low iron grade and high SiO₂content in Qijiaojing Iron Mine,the optimization of beneficiation process was studied.The results show that: introduction of HPGR technology in crushing stage,and adding wet preconcentration technology before grinding,there are a yield of 11.62% of the coarse tailings can be thrown,the feeding grade of grinding can be increased by 2.89 percentage points,the grinding granularity can be effectively reduced,the grinding amount can be reduced,and the purpose of energy saving and consumption reduction can be achieved;the three-stage grinding is carried out with a tower mill for fine grinding,and then the washing magnetic separator is used for concentration,under the condition of grinding fineness of -0.038 mm accounting for 95%,the iron concentrate with TFe grade of 65.37%,TFe recovery of 72.34% and SiO₂content of 4.97% can be obtained.

Key words: HPGR, Tower mill, Elutriation machine, Quality improvement and impurity reduction