煤气化是实现煤炭从燃料向原料转变,推进煤炭清洁高效利用的重要途径之一。气流床气化技术是目前的主流气化技术,气化炉的稳定运行要求液态熔渣应具有良好的流动性。排渣过程中的熔渣结晶行为会导致熔渣流动性变差,是造成气化炉非正常停车的主要原因。总结了影响熔渣流动性的主要结晶特征及研究结晶行为的关键———结晶动力学的研究现状。论述根据结晶行为判断结晶机制并选择合适的结晶动力学模型的方法。为获得更准确的结晶行为数据,总结多种结晶检测手段的原理和特点并分析了根据研究重点、仪器特性与熔渣特性选择合适结晶行为的检测手段。最后,论述了化学组成与操作条件对结晶行为的影响。研究发现不同晶体之间结晶机理差异明显,同一化学组成对不同晶体结晶行为的影响不同。当限定熔渣化学组成所处相区时,化学组成与操作条件对第一相结晶矿物质结晶行为的影响更具规律性,可为调控结晶行为提供更准确指导。研究结果与相图结合或建立简单易得的预测模型能更好指导熔渣结晶行为调控。目前,结晶行为研究主要依赖试验手段,后续研究可结合相场模拟与分子动力学模拟等方法,深入挖掘结晶机理,并考察气化炉内温度场、流场等因素对结晶特性的影响。

Gasification is one of the important technologies to realize the transformation of coal from fuel to raw material and to promotethe clean and efficient utilization of coal. Entrained-flow gasification is currently the predominate gasification technology, and the stableoperation of gasifiers requires that the liquid slag must have good fluidity. The crystallization behavior of the slag can lead to decreasedflowability, resulting in abnormal shutdown of the gasifier, which is a major cause of abnormal shutdowns of gasifiers. The main crystallization characteristics were summarized and discussed that affected the fluidity of slag and the key to studying crystallization behavior: crystallization kinetics. Firstly, the methods of judging the crystallization mechanism based on crystallization behavior and selecting appropriate crystallization kinetics models were summarized. The principles and characteristics of different crystallization detection methodswere compared to obtain more accurate crystallization behavior data by selecting the appropriate crystallization behavior detection methodaccording to the research focus, facility characteristics and slag properties. Finally, the effects of chemical composition and operating conditions on crystallization behavior were summarized. Significant differences in the crystallization mechanisms between different crystals cause that the same chemical composition has different effects on the crystallization behavior of different crystals. When the chemical composition of the designated slag is within a specific phase region, the influence of chemical composition and operating conditionson crystallization behavior of the primary phase mineral becomes more regular, and the conclusions obtained can provide more accurate guidance for the regulation of crystallization behavior. Combining research results with phase diagrams or establishing simple and accessible predictive models can better guide the control of slag crystallization behavior. Currently, the study of crystallization behavior mainly relies on experimental methods. Future research could integrate phase-field simulation and molecular dynamics simulation, among other methods, to further explore the mechanisms of crystallization and examine the effects of factors such as temperature fields and flow fieldswithin gasifiers on crystallization characteristics.

0 引言

1 影响熔渣流动性的主要结晶特征

   1.1 晶体的尺寸和形状

   1.2 晶体的化学组成

   1.3 结晶的动力学（结晶速率与结晶机理）

2 常见的熔渣结晶表征方法

   2.1 非原位表征

   2.2 高温原位热分析

   2.3 光学观测方法

   2.4 高温电子扫描显微镜

   2.5 FactSage热力学模拟在煤气化熔渣结晶研究中的应用

   2.6 其他可应用于熔渣结晶行为的研究手段

3 化学组成及操作条件对熔渣结晶行为的影响

   3.1 化学组成对结晶的影响

   3.2 操作条件对结晶的影响

   3.3 熔渣中不同结晶机制的晶体结晶特点

4 结语及展望