Research on desulfurization of aphanitic graphite

This paper presents the research on desulfurization of aphanitic graphite ore (from Hunan), which contains 60% carbon and 1% sulfur minerals.Phase and chemical analyses revealed that the harmful impurity element sulfur existed mainly in pyrite and pyrrhotite.Microscopic identification results showed that graphite had coverage effects on sulfur minerals, leading to similar surface properties with graphite.These similarities caused non-selective flotation, and resulted in a difficult desulfurization.Based on these characteristics, different oxidant, dispersant and inhibitor were chosen to strengthen pulp flotation.Experimental tests suggested OL-IIC (served as inhibitor) contributed best in graphite coverage effects inhibition, with a good flotation index.The closed-circuit floatation process indicated that the graphite concentrate obtained carbon grade 80.25% and recovery 81.27%, with 0.23% sulfur contented.