Upgrading Coal Washery Rejects Through Caustic-acid Leaching

ABSTRACT

Physical beneficiation of West Bokaro run-of-mine coal gives 15% ash clean coal with 38% yield. Further lowering the ash content in clean coal may cause significant yield loss as well as generation of enormous quantities of middling and reject coals, which are low value material. West Bokaro coal washery of Tata Steel Ltd produces 0.7 million tons of reject coal annually. This work deals with the effect of caustic-acid leaching route for producing 19.7% ash clean coal with more than 40% yield from the rejects with 60% ash. The clean coal obtained in this process can be utilized in thermal power stations and cement industries.

KEYWORDS:

• Ash
• coal
• leaching
• washery rejects
• caustic
• acid

Acknowledgements

We are thankful to Dr. Sanjay Chandra, Chief R&D and Scientific Services, R&D, Tata Steel Ltd. for allowing us to publish this paper.