煤中氟分布与燃烧排放特性

采用高温水解 -离子选择电极法对我国典型煤种的氟含量进行测定 ,得到了煤中氟分布规律 ,分析了煤中氟含量与灰分的关系及氟化物的赋存形态 .首次通过燃烧实验探索了燃煤过程中氟化物生成规律 ,确定了燃煤氟排放的影响因素 ,得到了燃煤氟排放与煤种、燃烧温度、停留时间、燃烧气氛等因素的影响规律 ,提出了燃煤过程中氟化物的生成机理 .研究结果对煤中氟的燃烧转化和污染治理有指导意义

FLUORINE DISTRIBUTION CHARACTERISTICS IN COAL AND BEHAVIOR OF FLUORINE DURING COAL COMBUSTION

In this paper the Concentrations of fluorine in typical Chinese coals are determined by the pyrohydrolysis/FISE method.The distribution characteristics of fluorine in coal are obtained.The correlation between fluorine and ash,the probable mode of occurrence of fluorine in coal are discussed.Fluorine concentration ranges between 17-3145μg·g ^-1 and the mean value is close to 200μg·g ^-1 .Good correlation between fluorine and ash content suggested that fluorine is present in these coals in inorganic mineral species.Fluorine emission characteristics during coal combustion are studied systemically in tube furnaces for the first time.The influence factors on fluorine emission and the relationship of fluorine emission with coal type,combustion temperature,retention period and combustion atmosphere are obtained and the production mechanism of gaseous fluorine during coal combustion are proposed.Experimental results indicate that fluorine emission appears to begin at 573-673K and emission rates reaches about 96% at above 1473K.Gaseous fluorine is probably originated from fluorine occurring as organic forms or adsorbed inorganic form in coals at low temperatures,and appears to come mainly from fluorine occurring as inorganic salt forms in coal at high temperatures.