Flotation Characteristics and Particle Size Distribution of Micro-fine Low Rank Coal

In this work, attempts to float the micro-fine low rank coal and its particle size distribution in the flotation were made. Then, standard screening, FT-IR, XRD and SEM were adopted to characterize the size distribution and flotation of micro-fine Shendong low rank coal. The results indicated that the size fraction of -0.045 mm was the dominant size fraction in raw coal with a yield of 91.65% and ash content of 46.25%. Flotation of Shendong low rank coal required a larger dosage of collector, 50 kg/t of diesel oil, to achieve a higher combustible matter recovery (63.25%) and flotation efficiency index (40.70%) accompanied with a significant decrease in ash content (22.44 percentage points) due to the hydrophilicity of coal surface. Under this condition, concentrate contained 83.38% of -0.045 mm size fraction (38.04% of total particles in feed) with ash content of 24.98%. In comparison, tailing was almost consisted of -0.045 mm fraction (93.63%) with a higher ash content of 60.82%. It seems that the higher ash particles in feed were largely migrated in tailing at a proper collector dosage. The analysis of FT-IR, XRD and SEM would contribute to the understanding of the flotation and size distribution.