Industrial experiment research on magnetic levitation combined classification flowsheet about low-grade ferruginous rock in BayanObo, Inner Mongolia

BayanObo has huge iron ore reserves, which has made important contribution to relieve the country’s external dependence on iron ore and promoted the production development of Baotou Steel Group. However, a large amount of low-grade ferruginous rock with TFe grade less than 20% are produced in the mining process. For this kind of ore, the traditional continuous grinding and magnetic separation process is adopted, and the iron concentrate grade can reach up to 60.8% under the condition of fine grinding to −0.074 mm particle size content 95%, which cannot meet the quality requirements of qualified iron concentrate. If flotation process is used, the economic performance of beneficiation is not good. Therefore, this part of ore has always been stacked and has not been used. In this paper, through the analysis of raw ore, a new magnetic levitation separator as a magnetic selected separation equipment is used, and three whole magnetic separation flowsheets of industrial experiment are designed, all of which can obtain qualified iron concentrate with TFe grade above 64.5%, while the content of impurity elements K, Na, Si in iron concentrate is much lower than the flotation flowsheet. Among them, the self-developed stage grinding and magnetic levitation combined classification flowsheet, under the condition of fine grinding to −0.074 mm particle size content 95%, the final iron concentrate can get the excellent technical indicators of TFe grade 64.5%, magnetic iron recovery 95.07%, which has the advantages of high sorting efficiency and good sorting effect. After application, the economic and green utilization of BayanObo low-grade iron ore can be realized with remarkable economic benefits, and the supply period of BayanObo iron resources can be greatly extended, which has far-reaching significance for the continuation of the national iron ore production capacity, the sustainable development of the mine and the green utilization of resources.