准东高钠煤气化过程中Na的迁移转化规律

针对新疆准东煤由于碱金属Na含量高而无法直接利用问题，基于0.25 t/d高碱煤热化学转化试验台，利用电感耦合等离子体-原子发射光谱（ICP-AES）、X射线衍射（XRD）以及扫描电镜-能谱（SEM-EDX）等先进检测手段，分析了准东高钠煤在循环流化床不同煤气化温度下碱金属Na的迁移转化特性，同时借助FactSage6.1化学热力学平衡计算软件，理论分析了碱金属Na的析出形式。研究结果表明：随着煤气化温度的升高，底渣中碱金属Na的含量降低，而飞灰中碱金属Na的含量增加；煤气化底渣中的Na主要以钠的硅铝酸盐形式存在，飞灰中的钠主要以NaCl形式存在，并含有少量硅铝酸钠；准东高钠煤在循环流化床煤气化试验时未发生失流现象，底渣和飞灰未发现熔融态；煤中Cl在煤气化过程中对金属壁面有腐蚀作用。

Sodium transformation law of Zhundong coal during gasification

Zhundongcoalcannot bedirectlyused due to its high sodium content.A 0.25 t/d test systemof high alkali coal thermochemical conversion was applied to investigate the alkali metal transformation of high-sodium Zhundong coal during gasificationat different temperatures.The transformation of sodium was investigated with inductive coupled plasma equipped with atomic emission spectrometer (ICP-AES),X-ray diffraction (XRD) and scanning electron microscopy with an energy dispersive X-ray spectrometer(SEM-EDX).Meanwhile,the transformation of sodium during gasification was simulated by FactSage6.1.The results show that Na in bottom ash decreases while Na in fly ash increases as the gasification temperature increases.Na in the bottom ash exists mainly as sodium aluminum silicate while Na in the fly ash exists mainly as sodium chloride.No slag is found in the bottom ashand fly ash,and no defluidization occurs during gasification.Corrosionis found due to the high Cl content.