Abstract: Gushan hematite has high hardness and micro-fine dissemination size， and low ore dressing technology index（48% of iron lump concentrate grade and 57% of iron powder concentrate grade）.In order to explore the way to improve the process index of Gushan ultrafine hematite ore dressing， the stage grinding-High Intensity Magnetic Separation（HIMS）-anion reverse flotation test was carried out in the laboratory. The results show that: at first stage grinding fineness of 85% passing 0.074 mm， via first stage magnetic separation （one roughing one scavenging， magnetic field intensity of roughing and scavenging is 477 kA/m and 637 kA/m， respectively）， the magnetic concentrate reground to 87% passing 0.030 mm， via second stage magnetic separation （one roughing one scavenging， magnetic field intensity of roughing and scavenging is 477 kA/m and 716 kA/m， respectively）， one roughing one scavenging anionic reverse flotation（（NaOH as pH adjusting agent， starch as inhibitor， lime as activator， RA-915 as collector）， the iron grade of flotation concentrate is 63.96%， which shows that it is feasible to use the stage grinding-stage HIMS-anion reverse flotation process to increase the iron concentrate to larger than 63%. The experimental results can provide references for the determination of reasonable beneficiation process of ultrafine hematite in Gushan.

Key words: Micro-fine hematite ore, HIMS, Anionic reverse flotation