Coal quality characteristics and washability of coal in Lihua coal mine of Dafang,Guizhou

To effectively use the coal resources, coal quality characteristics and washability of the coal in Lihua coal mine of Dafang were investigated. The results showed that the M₄, M₆ coal seams were rich-high sulfur coal, but the M₁₂, M₁₆ coal seams were extremely low-low sulfur coal. The sulfurs in the M₄, M₆ coal seams were dominated by pyrite. Compared with M₄, M₆ coal seams, the proportions of the pyritic sulfur in the M₁₂, M₁₆ coal seams decreased significantly, while the proportion of organic sulfur increased obviously. Based on sulfur, ash compositions, the M₁₂ coal seam in the Lihua coal mine was accumulated in the peat swamp influenced minimally by sea water, totally different from M₄ coal seam. Compared with M₄ coal seam, the M₆,M₁₆ coal seams were less affected by sea water.The floating and sinking test results indicated that the washability of raw coal in the Lihua coal mine was in the extremely difficult degree, because the mineral compositions were dominated by small clay minerals, followed by fine granular and fine-grained disseminated pyrites.