Abstract:With the gradual reduction of high-quality iron ore resources, high sulfur magnetite will become an important direction for the development and utilization of iron ore resources in the future. Based on the characteristics of a high sulfur magnetite ore from abroad, first conduct process mineralogy research to determine its chemical composition, mineral composition, and content. Then, flotation conditions were studied, including pH value, activator, collector, grinding fineness, etc. The types and dosage system of reagents using CuSO4 as activator and ethyl xanthate+butyl xanthate as mixed collector were determined. A one coarse, two fine, and one sweep flotation closed circuit process was adopted to obtain a flotation sulfur concentrate with a sulfur grade of 38.42% and a sulfur recovery rate of 90.41%. The flotation tailings were further desulfurized through magnetic separation, resulting in an iron concentrate with an iron grade of 70.56%, a sulfur content of 0.17%, and an iron recovery rate of 89.31%. Through infrared spectroscopy and XPS analysis, the reason why the collector needs to be mixed and used in large quantities was identified. After adding ethyl xanthate, and butyl xanthate, a series of oxidation-reduction reactions occurred on the surface of the ore, generating a large amount of hydrophobic sulfides such as S-, S0, Sn2-, which underwent chemical synergistic adsorption on the mineral surface. Adding a large amount of butyl xanthate significantly increases the copper content on the surface of pyrrhotite. Compared with ethyl xanthate, butyl xanthate can better promote the adsorption of Cu2+ on the surface of pyrrhotite. The presence of a large amount of ethyl xanthate and butyl xanthate in the slurry promotes the adsorption of Cu2+ on the surface of pyrrhotite, thereby promoting the adsorption of xanthate on the ore surface.