Abstract: A domestic molybdenum tailing is associated in low-grade magnetite，and the grade of iron concentrate is low in the recovery process. In order to improve the grade and recovery rate of iron concen⁃ trate，a detailed process mineralogy study is carried out on the molybdenum tailings.The results show that the iron grade in the sample is 6.93%，the content of harmful elements sulfur and phosphorus is low，and the impurity elements are mainly silicon and aluminum. Iron mainly exists in the form of magnetic iron，with a distribution rate of 44.96%，followed by iron silicate and hematite.The main useful iron mineral magnetite content is 4.34%，and the main gangue minerals feldspar and quartz content are 40.54% and 19.10% respec⁃ tively.The magnetite is mainly fine-grained and micro-fine-grained disseminated in the gangue base com⁃ posed of feldspar and quartz. The distribution rate of -0.04 mm particle size is 89.87%，and the distribution rate of -0.01 mm particle size is 38.42%. It is difficult for some micro-fine-grained magnetite to completely dissociate from gangue.When the grinding fineness is -0.03 mm 99%，the monomer dissociation degree of magnetite is 81.60%，in order to improve the monomer dissociation degree of magnetite，further fine grind⁃ ing should be carried out. According to the results of process mineralogy research，it is recommended that the tailings should adopt pre-throwing and stage grinding stage separation process.

Key words: magnetite, process mineralogy, dissemination characteristics, monomer dissociation degree