Agglomeration Characteristics of River Sand and Wheat Stalk Ash Mixture at High Temperatures  

作　　者：Shang Linlin Li Shiyuan Lu Qinggang 

机构地区：[1]College of Mechanical and Transportation Engineering, China University of Petroleum(Beijing Campus) [2]Institute of Engineering Thermophysics, Chinese Academy of Sciences

出　　处：《Journal of Thermal Science》2013年第1期64-70,共7页热科学学报（英文版）

基　　金：supported by National Natural Science Foundation of China(Project Code:50706055)

摘　　要：The agglomeration characteristics of river sand and wheat stalk ash mixture at various temperatures are investi- gated using a muffle furnace. The surface structural changes, as well as the elemental makeup of the surface and cross-section of the agglomerates, are analyzed by polarized light microscopy, scanning electron microscopy （SEM）, and energy dispersive X-ray （EDX）. Multi-phase equilibrium calculation is performed with FactSage in identifying the melting behavior of the river sand-wheat stalk ash mixture at high temperatures. No indication of agglomeration is detected below 850~C. At a temperature of 900-1000~C, however, obvious agglomeration is observed and the agglomerates solidify further as temperature increases. The presence of potassium and calcium enrichment causes the formation of a sticky sand surface that induces agglomeration. The main component of the agglomerate surface is KEO-42aO-SiO2, which melts at low temperatures. The formation of molten silicates causes particle cohesion. The main ingredient of the binding phase in the cross-section is K20-SiO2-Na20- Al2Oa--CaO; the agglomeration is not the result of the melting behavior of wheat stalk ash itself but the compre- hensive results of chemical reaction and the melting behavior at high temperatures. The multi-phase equilibrium calculations agree well with the experimental results.

关 键 词：Wheat stalk ash River sand AGGLOMERATION Phase equilibria MICROSTRUCTURE 

分 类 号：TK16[动力工程及工程热物理—热能工程]