Abstract: The output of high purity iron concentrate with high added value in Aba Mining concentra⁃ tor was only about 25%. In order to increase the proportion of high purity iron concentrate，the optimization of beneficiation process was studied. The results showed that aming at the on-site iron concentrate (TFe grade is 66.50% and main impurity components is SiO₂ and Al₂O₃ and so on) for processing high-purity iron concentrate，content of -200 mesh in grinding productions increased from 36.8% to 41.9% by optimizing the grading of steel balls and using high chromium steel balls. By increasing the grinding concentration， content of -200 mesh in grinding products has been greatly increased to 92.6%. By increasing the screen⁃ ing area and replacing the screen，the screening efficiency (measured by - 200 mesh) increased from 81.71% to 91.63%. On the basis of the above process optimization，the open circuit regrinding of ordinary iron concentrate is further changed to closed circuit regrinding，and the proportion of output of high-purity iron concentrate increased from about 25% to more than 70%，which indicates obvious economic benefits.

Key words: grinding, screening efficiency, steel ball grading, sieving area, grinding concentration