Coat-water slurries were prepd. by milling coal with water in a disc mill for 12 or 18 h. The slurries (coal content 50 or 60%) were burned in rotary kiln. The off-gases were analyzed for CO, CO2, NOx. and SOx. The emissions of SO2 and NOx were lower at the combustions of coal-water slurries than at combustion of dry coal.