The experimental and theoretical analysis about toxic fluoride removal during coal combustion are reported in this paper.It has been identified that CaO can restrain the emission of fluoride and fluoride retention ratios are between 12.2% and 61.0%

with mean value 39.5% by blending CaO with coal during coal combustion in tubular furnace at 900 ℃. Influence factors on fluoride retention by blending CaO with coal are studied such as type of coals

combustion temperature

retention time and Ca/S molar ratio.The optimum conditions for fluoride retention by blending CaO with coal are that combustion temperature in the range 800 to 1000 ℃

retention time between 5—10 min and Ca/S ratio in the range 2.5 to 3.0. In chain-grate furnace combustion of coal

fluoride retention ratios are about 54.0%—64.8% with mean value 59.3% by blending calcium-based sorbents with coal and are about 72.5%—80.5% with mean value 75.5% by blending calcium-based sorbents with coal accompanied by injection of calcium-based sorbents.