Oil Agglomeration Towards Quality Enhancement of High-Ash Coals: The Indian Scenario

Beneficiation of high-ash coals has been a topic of great concern around the world. There has been considerable research aimed at development of highly effective yet economically viable ways to perform coal beneficiation. At present, coal cleaning is primarily accomplished through physical separation of mineral matter from coal particles. However, the known processes like jig, density separation and froth flotation typically demineralizes coarse coal particles. The only two techniques which can handle coal fines are froth floatation and oil agglomeration; nevertheless froth flotation fails for ultra-fine coals (<6 μm). Oil agglomeration is an excellent and versatile technique to beneficiate ultra-fine coals which utilizes the difference in surface hydrophobicity of coal particles and mineral matter. The growth of agglomerates is essentially determined by acceleration and particle velocity of water and oil molecules. Our chapter will be discussing the several physical parameters on which the process of oil agglomeration largely depends on. In particular, focus will be given on the present scenario in India with respect to the research and development of oil agglomeration.