Abstract: In order to recycle the low-grade iron resources in Bayan Obo surrounding rock dump，the pre-dry concentrate of iron-bearing surrounding rock in dump is taken as the object，a multi-process comparative test was carried out on the basis of total iron content of 20.00% and magnetic iron content of 14.20% by using the stage grinding process. The test results show that the iron concentrate with iron grade of 66.60%，magnetic iron grade of 65.60%，total iron recovery rate of 89.09% and magnetic iron recovery rate of 97.76% is obtained by using Isa mill as the two-stage grinding equipment，which lays a good foundation for the recovery and utilization of related iron resources.

Key words: iron surrounding rock, preseparation, Isa mill, magnetic separation