Abstract: In view of magnetic reduction roasting-fine grinding-magnetic separation process of high phosphorus oolitic hematite,many fine particles produced in the fine grinding process have an adverse effect in subsequent magnetic separation process.According to the principle of magnetic aggregation,the natural magnetic seeds was introduced into the experiment in order to selectively adsorb the fine particle iron minerals,and to investigate its effect on the recovery of iron in the process of improving the weak magnetic separation process.This experiment determined that the optimum magnetic particle size range was-0.0385mm⁺0.0308 mm,the magnetic field intensity was 67.2kA/m and the magnetic seed ratio was 3%.Under the optimal conditions,the actual grade of iron concentrate is 61.58%,and the recovery rate of iron is 59.68%.In ensuring that the total iron grade of the iron concentrate was increased at the same time,the recovery rate was increased by 12.56% compared with the same condition without magnetic seeds.