Abstract: The useful mineral in a low-grade refractory manganese ore is rhodochrosite， and the manganese grade is 14.50%. In order to provide technique basis for the beneficiation of the ore， the chemical composition， mineral composition and embedding characteristics of the ore were systematically studied by means of optical microscopy， chemical analysis and X-ray diffraction. The results show that the main manganese-bearing minerals in the ore are rhodochrosite， manganite and pyrolusite， of which the content of rhodochrosite is 19.17%； the gangue minerals are mainly quartz， dolomite and sericite， among which the quartz content is 32.05%. The structure characterize of the ore is mainly thin layer structure， flaky structure， massive structure， strip structure and disseminated structure； the structure of minerals in ore is mainly characterized by self-form and semi-self， crystal structure， and the interstitial structure carbonate mineral. The rhodochrosite is mainly occurrences in automorphic， semi-automorphic granular and granular aggregates. Rhodochrosite is produced by fine granular and granular aggregates， interwoven with quartz and muscovite. Quartz is mainly occurrences in the form of automorphic， semi-automorphic with granules in small grain size， intercalated with rhodochrosite， dolomite， chlorite and muscovite.. Dolomite is mainly occurrences in fine granule and granular aggregate， embedded with quartz and mica. The size of the inlaid grain of rhodochrosite is polarized and the distribution rate is higher in the fine fraction. The research results have guiding significance for the formulation of ore sorting process， which can provide reference for the development and utilization of such refractory manganese ore.

Key words: Rhodochrosite ore, Process mineralogy, Dissemination size