Abstract: The process mineralogy of a complex polymetallic lead-zinc-iron ore was studied to obtain a better beneficiation index. The results indicated that the iron and zinc grade is 59.94% and 2.93% respectively. The main mineral in the ore is magnetite， and a small amount of other iron minerals hematite and lignite (including goethite) are secondary oxides in the later stage of mineralization. Main metallic sulfide is sphalerite， pyrite， pyrrhotite， low amount of chalcopyrite and galena； Gangue minerals are mainly common amphibole， a small amount of diorite， in addition， a small amount of epidotite， chlorite， mica minerals and so on. The iron in the ore mainly exists in the form of magnetite， accounting for 87.82% of the total iron. The oxidation degree of zinc and lead is relatively high， zinc sulfide and zinc oxide account for 55.29% and 42.32% of the total zinc， lead sulfide and lead oxide account for 39.39% and 43.94% of the total lead， respectively. The ore structure is black dense block structure， and the ore is mostly autologous and semi-autologous granular intergranular crystal structure. Various minerals form metasomatic structure， metasomatic residual structure and so on. The dissemination particle sizes of the useful minerals magnetite and sphalerite are similar to the main gangue minerals amphibole. The dissemination relationship among magnetite， sphalerite and their minerals is complex and the minerals are difficult to be liberated. In order to ensure the sulfur content of iron concentrate does not exceed the standard， flotation should be used to remove sulfide minerals as much as possible before recovery magnetite by low intensity magnetic separation.

Key words: Lead-zinc iron ore, Process mineralogy, Polymetallic ore, Dissemination characteristics, Magnetite, Sphalerite