准东煤灰与液态排渣煤粉炉耐火材料的烧结特性

采用TGA-DSC分析确定了准东煤灰和其混合灰样(不同质量比的准东煤灰和耐火材料)燃烧过程中的特征温度,并分别采用XRD和FSEM-EDS对不同特征温度段灰样进行矿物识别和形貌、能谱分析,得到了原灰与混合灰的烧结温度、灰中主要矿物的转化和熔融过程,并对比了不同耐火材料含量的煤灰熔融温度;在此基础上提出了耐火材料构型的极...

Sintering Characteristics of Zhundong Coal Ash and Refractory Material of Slag Tap Pulverized Coal Boiler

The TGA-DSC analysis of Zhundong coal ash and mixed ash(different mass contents of Zhundong coal ash and refractory material)were carried out to determine their characteristic temperatures in the combustion process,and XRD and FSEM-EDS were used to conduct mineral identification and the analysis of the morphology and composition of ash samples in different characteristic temperature sections,then obtained the sintering temperatures of ash samples,as well as conversion and melting processes of the main minerals in the ash samples,we also compared the ash fusion temperatures of these different ash samples;the concept of ultimate thermal load of refractory configuration is proposed based on the above analysis,which is an index to evaluate thermal stability of refractories.Experimental results show that SiC refractory material reduced the deformation temperature of coal ash(from 1130℃to 1080℃),and promoted the sintering of coal ash and refractory material to form a dense protective layer.The sintering of coal ash reduced the ultimate thermal load of the refractory material by one third.After 1200℃,SiC in the refractory material was oxidized under the effect of coal ash.Therefore,the temperature at the interface between the slag and the refractory material must be strictly controlled during the operation of the boiler.Refractory materials increased both the viscosity of coal ash at high temperature and its flow temperature,which was more conducive to the formation of a solid and stable slag protective layer on the surface of refractory material.