文献类型：期刊文献

英文题名：Melting-dissolving kinetics and mechanism of high silica-alumina coal ash particles deposited to liquid slag wall in entrained flow gasification

作者：Zhang, Haigang[1,2];Shen, Zhongjie[1,2];Yu, Lihong[3];Liu, Junjie[1,2];Guo, Xiaolei[1,2];Liu, Haifeng[1,2,4]

机构：[1]East China Univ Sci & Technol, Natl Energy Coal Gasificat Technol Res & Dev Ctr, POB 272, Shanghai 200237, Peoples R China;[2]East China Univ Sci & Technol, Shanghai Engn Res Ctr Coal Gasificat, POB 272, Shanghai 200237, Peoples R China;[3]Natl Engn Res Ctr Coal Gasificat & Coal based Adv, Shandong Energy Grp Coal Gasificat & New Mat Techn, Beijing, Peoples R China;[4]Liaoning Petrochem Univ, Fushun 113001, Liaoning, Peoples R China

年份：2024

卷号：500

外文期刊名：CHEMICAL ENGINEERING JOURNAL

收录：;EI(收录号：20244517313579);WOS:【SCI-EXPANDED(收录号:WOS:001350744000001)】；

基金：This study is supported by the National Natural Science Foundation of China (22378130 and U23B20170) , the National Key R & D Program of China (2022YFC3902502-04) , the Key R & D Program of Xinjiang Uygur Autonomous Region (2022B03026-1) , the Fundamental Research Funds of the Central Universities (JKB01241715) .

语种：英文

外文关键词：High silica-alumina ash particle; Melting-dissolving; Molten slag surface; Dissolution kinetics

摘要：The depositing and subsequent physicochemical behaviors of coal ash particles to the liquid slag wall in an entrained flow gasifier are essential to the wall reaction, slag flow and discharge. In this study, the meltingdissolving behavior and kinetics of high silica-alumina ash on the typical molten slag surface were investigated at a particle scale through in-situ melting experiments. The multifactorial effect on the ash fusibility was further evaluated. Experimental results revealed that the presence of molten slag significantly reduced the melting temperatures of high silica-alumina ash particles, with an initial melting temperature of around 1270 degrees C. Dissolvability was linearly correlated with temperature, and the melting rate increased with increasing temperature or decreasing particle size. However, complete melting was difficult to achieve at 1400 degrees C. Consequently, the effect of adding flux (CaO) in the molten slag on the ash fusibility was further evaluated. The ash particles achieved complete melting at a 4 wt% CaO addition, and the flux addition increased the melting rate and solubility. Besides, the mechanism-level explanation of the melting-dissolving process showed that Ca ion migration led to the transformation of aluminum to higher coordination sites, which destabilized the silicaaluminium tetrahedra structure and manifested in the generation of Bytownite macroscopically. Comparative analysis showed the melting rate depended on the diffusion process, and the melting-dissolution kinetics was established to predict the dissolution rate, which could provide a reference for the slag discharge of coals with high ash fusion temperatures in the industry.