Abstract: Aiming at the problems of low separation efficiency and severe metal loss in treating refractory iron ore at a beneficiation
plant in Liaoning,a new process of "one-stage grinding,one-stage low-intensity magnetic separation,one-stage medium-
intensity magnetic separation,and one-stage high-intensity magnetic separation,two-stage grinding and reverse flotation"
was proposed. The application of one-stage medium-intensity and one-stage high-intensity magnetic separation effectively reduced
the grade of tailings,and the addition of two-stage grinding before flotation precisely controlled the feed particle size for
flotation,significantly improving the system separation efficiency. Test results showed that for run-of-mine ore with a total iron
grade of 29. 33%,a magnetic separation concentrate with a total iron grade of 37. 51% was obtained through magnetic preconcentration,
the grade of tailings was reduced to 4. 88%,and the recovery rate in the magnetic separation stage reached
95. 83%. Through the optimization of flotation conditions and open-circuit and closed-circuit tests on this magnetic separation
concentrate,a final concentrate with a total iron grade of 65. 12% and an overall process total recovery of 72. 57% was ultimately
obtained. Compared with the original process,the new flow sheet reduced the grade of tailings from magnetic separation
by 8. 04 percentage points and increased the overall recovery by 11. 66 percentage points,effectively reducing iron resource
loss,which has practical significance for improving the economic efficiency and resource utilization rate of the beneficiation
plant.