Desktop Study on the Handleability of Coal

Testing of 28 coal and coal-shale samples showed the coals to be more liable to spontaneous combustion than the shales, though reactive coal-shales still self-heat and pyrite in them speeds the process. Higher carbon, moisture, hydrogen, volatile matter and nitrogen with lower ash all raised proneness to self-heating, so proximate and ultimate analysis can serve as a screening tool.

Practical guidance for opencast operations covers early detection with low cost thermal cameras, prevention, and the treatment methods in current use: water sprays and cannons, sand cladding of highwalls and stockpiles, removal of burning coal by dragline, tipping into water ponds and the treatment of sinkhole areas. A three month full scale trial of sprayed fly ash as an antioxidant is reported.

A high internal phase water in oil emulsion binder upgraded weathered ultra fine coal discard. At 5 kg/ton on a feed of 29.34 per cent ash and 20.94 MJ/kg, flotation gave a clean coal of 11.76 per cent ash and 28.61 MJ/kg at 15.61 per cent mass yield. Calorific value rose with agitation speed and fell with binder dosage.