新疆高钠煤中钠的赋存形态及其对燃烧过程的影响

摘要

The existence form of sodium in Xinjiang coals was studied by extraction with distilled water,ammonium acetate and hydrochloric acid step by step.The extraction liquid and the residual coal samples were analyzed using an ion chromatography and an inductively coupled plasma atomic emission spectroscopy.The influences of different forms of sodium on the combustion characteristics of the high sodium coal were evaluated by the ignition temperature,the burnout temperature and the combustion characteristic index.The results indicate that the sodium existing in the coals is mainly in the form of water-soluble sodium,while the proportions of acidsoluble sodium and insoluble sodium are smaller.The particle size and inner pore structure of coal may have great influences on the water-soluble sodium content in coal samples,while the organic sodium contained in different particle size ranges of coal remains relatively constant.The water-soluble sodium and chlorine in different coals differ from each other.The water-soluble sodium would increase the ignition temperature and burnout temperature and decrease the combustion characteristic index,while the organic sodium would have catalysis on the combustion of coal.%采用不同萃取液对中国新疆高钠煤进行逐级萃取实验,利用离子色谱仪和电感耦合等离子体原子发射光谱仪对萃取制得的滤液和固体煤样进行相应的元素分析,并通过逐级萃取后煤样的着火温度、燃尽温度和综合燃烧特性指数来分析高钠煤中不同存在形式钠对其燃烧特性的影响.结果表明,中国新疆高钠煤中的钠主要以水溶钠为主,有机钠和不可溶钠含量较少.影响高钠煤中水溶钠含量的主要因素有煤颗粒内部孔隙结构和颗粒粒径,且高钠煤中有机钠在各个粒径范围都保持了相对稳定的含量.煤种不同会导致煤中水溶钠与水溶氯的存在形式不同.煤中水溶钠的存在不利于高钠煤的着火温度和燃尽温度的降低与燃烧特性的提高,相反煤中的有机钠却对其具有促进作用.