Experimental investigation on magnetic-gravity combined beneficiation of low-grade iron ore

Iron ore is an important raw material for manufacturing steel, while the grade of domestic iron ore is relatively low in China, thus it is difficult to concentrate. The low-grade iron ore with a total iron content of only 33.51% is innovatively upgraded by the magnetic-gravity combined beneficiation method. The effects of three key operating parameters of magnetic induction, grinding concentration, and centrifuge speed on magnetic-gravity combined beneficiation are investigated. These results show that the magnetic-gravity combined beneficiation method significantly improves the iron grade of the concentrates at high recovery. The feasibility is further confirmed through continuous expansion semi- industrial tests with the optimized parameters. The grade of the iron ore concentrate is increased from 33.51% to 63.58% with an iron recovery of 71.01% and a productivity of 37.43%. It is thus concluded that the magnetic-gravity combined beneficiation method has provided a technical reference for the recovery of iron resources from low-grade ores.