Abstract: The ore mineralogy of a banded iron-formation gold deposit in Tanzania is characterized by the altered ores on the broken zone with pyrite mineralization and silicifications.The ore’s mineralogical characteristics,including ore composition,mineral species,particle size distribution,and occurrence of gold,were studied in detail through methods such as microscopic identification,scanning electron microscopy analysis,X-ray diffraction analysis,and chemical phase analysis.The results showed that the gold minerals in the ore were native gold,with a fine particle size mainly distributed below 50 μm,and the portion below 10 μm accounted for 27.54 %.The main gold-carrier minerals in the ore were quartz,pyrite,and arsenopyrite.The gold occurrence was mainly in intergranular form,accounting for 52.72 %,followed by inclusion form,accounting for 37.23 %.The presence of abundant inclusion of gold and fine-grained magnetite in the ore was the main factor affecting the beneficiation indicators.The research results provide a basis for the design of the beneficiation process for this deposit.