Abstract: The main chemical composition analysis and Mn-phase analysis on a low-grade manganese carbonate ore were made. With oleic acid as collector，SDBS as synergist， sodium silicate as depressor of quartz and silicate minerals，and sodium carbonate as the regulator of Pulp pH value，the conditioning tests for flotation process are carried out. The results indicate that under the grinding fineness of the content of -0.074 mm is 90%，final manganese concentrate with Mn grade of 17.10% and Mn recovery of 87.65% was achieved by the closed-circuit process of one roughing-two cleanings-one scavenging and middles back to the flow-sheet in turn.

Key words: Manganese carbonate, Rhodochrosite, Oleic acid+SDBS, Flotation