Abstract: The process mineralogical properties of a sulfur-containing complex refractory magnetite ore were systematically studied by chemical analysis，microscope and MLA. The results show that the con⁃ tent of main valuable element iron in the ore is 32.55%，and iron is mainly present in magnetite，with dis⁃ tribution rate of 80.88%. The main harmful element S content is 3.01%，and S is mainly present in pyrite， with distribution rate of 98.02%. The content of magnetite in the ore is 36.67%，which is mainly associated with gangue minerals. In addition，the content of pyrite is 5.44%，which also has certain recovery value. Pyrite is mainly associated with magnetite and gangue minerals. The gangue minerals in the ore are mainly potassium feldspar，chlorite，albite and quartz. The particle size of magnetite and gangue is different. It is advisable to adopt the process of step grinding and step selection and coarse grain discarding. The ore is dominated by massive structure and disseminated structure. The ore structure mainly includes granular structure，vein structure，metasomatic structure and disseminated structure. When the ore is finely ground to 95% of -0.074 mm，the magnetite monomer is well dissociated. The research results of process mineralo⁃ gy provide a reference for the determination of the subsequent beneficiation test process of the ore.

Key words: sulfur-containing magnetite ore, process mineralogy, embedding features, pyrite