Abstract: In order to find out the production status of the grinding and separation system in the con⁃ centrator and understand the rationality of the existing process flow and the production capacity of the key links，the process flow investigation and research are carried out.Through chemical analysis，particle size analysis，X-ray diffraction analysis（XRD）and other means，the properties of raw ore，the types and con⁃ tents of minerals in each process are analyzed，the operation status of each process is comprehensively di⁃ agnosed，and the production capacity of key links is verified.The results show that the pre-concentration effect before grinding is ideal，and the existing grinding process is reasonable. However，the load of the first stage mill is high，and the load of the second stage mill is low. The grinding fineness of the first stage mill can be appropriately reduced，and the concentration magnetic separator of the second stage mill be⁃ fore grinding needs to be replaced by a larger size.There is power redundancy in three-stage grinding，and ball mill or tower mill with smaller processing capacity can be replaced to reduce energy consumption and improve grinding effect.

Key words: iron ore, pre-concentration before grinding, grinding and separation system, process in?vestigation, production capacity