准东高碱煤气化过程中碱金属赋存形态迁移转化

利用循环流化床煤气化试验、三步萃取分析和X射线衍射（XRD）分析，对新疆准东煤田的天池木垒煤（TC）中碱金属钠和钾的赋存形态进行了研究，初步获得了天池木垒煤中不同赋存形态钠和钾的转化规律。研究结果表明：钠在天池木垒煤中主要以水溶形式存在，钾主要以不溶形式存在；在煤气化过程中，以有机形式和水溶形式存在的钠易挥发到煤气中，不溶钠总含量增加，且主要存在底渣中，飞灰中钠和钾主要以水溶形式存在；煤气化温度升高，更多水溶钠和酸溶钠挥发至煤气中，同时有更多不溶钠生成；尾部煤气温度降低，煤气中钠会以水溶钠和酸溶钠的形式凝结；通过XRD可以确定天池木垒煤中主要有，NaCl，Na2SO4和K3Na(SO4)2等水溶钠，不溶钠则以硅铝酸盐矿物形式存在且经过煤气化后，有更多硅铝酸盐生成，而会挥发进入煤气，在固态样品中无法检测到。

Transformation and migration of alkali metal with different occurrences of Zhundong high-alkali coal during gasification

Circulating fluidized bed (CFB) gasification,three-step extraction and X-ray diffraction (XRD) were conducted on Tianchi Mulei coal (TC) from Zhundong coal mine to study the migration and transformation of alkali metals,referring to Na and K,in different occurrences.The results indicate that most of sodium in TC is water-soluble,which mainly exists in the form of,and determined by XRD,and potassium mainly exists in insoluble form.Alkali metal in the ammonium-acetate-soluble and water-soluble form is released easily to gas during gasification.Though lots of NaCl in TC is found,there is little NaCl in slag and fly ash through the analysis of fly ashes phase,indicating that this component has volatilized.The content of insoluble Na mostly residing in slag in the form of aluminosilicate,increases after the process,and the water-soluble Na in fly ash is dominant.Higher gasification temperature leads more Na in the water-soluble and acid-soluble form to volatilize and more insoluble Na to generate.Water-soluble and acid-soluble Na in gas condenses to fly ash with the temperatures of back pass gas decrease,which may cause the contamination of tail heating surface.