氯元素含量对准东煤中钠、钙迁移特性影响实验研究

摘要

借助电感耦合等离子体原子发射光谱仪、X 射线衍射仪及管式炉实验系统，通过钠、钙平衡实验研究氯元素对准东煤中钠、钙迁移规律影响。结果表明：氯元素的含量对准东煤中的钠元素迁移起促进作用，随着聚氯乙烯（PVC）添加量从0增加到0.6%（质量分数），钠的逃逸率从76.6%升高至92.9%，这是由于更多的钠元素与氯元素结合形成氯化钠进入气相中，且逃逸出来的钠元素会与SO2、SO3等形成硫酸盐并在管壁温度450～650℃的管壁上沾污，形成沾污初始层；氯元素的含量对准东煤中钙元素迁移规律的影响不大，因为钙盐稳定不易挥发，仅有5%左右的钙挥发进入气相，且最多仅有0.7%的钙被尾部水洗装置吸收，剩余的3%左右的钙会沉积在管壁上，形成结渣层。为解决或减轻准东煤结渣问题提供数据支撑及理论指导。%The influence of chlorine content on transfer of sodium and calcium during combustion of Zhundong coal is conducted by the equilibrium experiment with inductively coupled plasma and atomic emission spectrum(ICP-AES),X ray diffraction analysis and horizon tube furnace. Results show that the chlorine content in Zhundong coal can promote the volatilization of sodium. The escape rate of sodium rises from 76.6 % to 92.9% when PVC content increases from 0 to 0.6wt.%. More sodium chloride is produced and then transported into gas phase due to the higher concentration of sodium and chlorine,and the sulfate formed by votatile sodium and SO2/SO3 sticks on the tube wall between 450℃ and 650℃. Consequecely,the initial contamination layer is formed. Chlorine content in Zhundong coal has little effect on the migration of calcium because calcium salt is stable and difficult to volatilize. Only around 5% of the calcium volatilizes into gas phase and only 0.7% of calcium is absorbed by the water washing system. Around 3% of calcium sticks on the wall to form a slagging layer. This paper provides data support and theoretical guidance in solving or relieving slagging problems during combustion of Zhundong coal.