Evaluation of beneficiation options for recovery of ultrafine thermal coal

Recent requirements to reduce thermal coal plant emissions, and ultrafine coal’s tendency to produce these emissions due to its typically high ash and moisture contents have limited the use of ultrafine coal. Ultrafine coal in beneficiation plants are usually either disposed of in tailing ponds at a loss in combustible material or disposed of by blending with coarser higher-grade products, resulting in a reduction in marketed product quality. A study of the options for processing ultrafine coal, consisting of < 200 μm hydrocyclone overflow, with 38.8 percent ash content is presented here. Ultrafine coal was processed based on 200-μm sieve bend and 10-μm hydrocyclone classifications, enhanced gravity separation (EGS) and froth flotation concentration as well as combinations of these. Yield, combustible material recovery (CMR) and product humidity were evaluated as test results.