Abstract: The process mineralogy and flotation tests of a large scale crystalline graphite ore in Tanzania were carried out. The results show that the useful mineral in the ore is flake graphite with a fixed carbon content of 5.67%. At the conditions of grinding fineness of -0.15 mm, content of 47%, kerosene dosage of 90 g/t, 2^# oil dosage of 60 g/t and roughing time of 2.5 min, the roughing concentrate was obtained by the flotation process of "one roughing, one cleaning and one scavenging" was processed by six times of strip grinding, seven times of cleaning, and middling returned in batches. The fixed carbon content was 95.06% and the recovery was 90.16%, +0.15 mm products accounting for 72.47% of the concentrate. This process can effectively protect large flake graphite.