碳酸钠和氯化钠助剂对粉煤灰碱熔的影响（重）.pdf

42 5 () Vol.42 No.5 2011 5 Journal of Central South University (Science and Technology) May 2011 ( 310058) TG−DTAXRD SEM TQ170.4 A 1672−7207(2011)05−1220−06 Effects of sodium carbonate and sodium chloride additives on alkaline fusion of coal fly ash YAO Zhi-tong, XIA Mei-sheng, YE Ying (Department of Ocean Science and Engineering, Zhejiang University, Hangzhou 310058, China) Abstract: The chemical reaction activities of mullite and quartz in coal fly ash were low, which had negative effects on zeolitization and extracting of silica and aluminium elements. Alkaline fusion was an efficient approach for coal fly ash activation. The ash sample was subjected to alkaline fusion treatment using sodium carbonate and sodium chloride as additives. Effects of various amounts of additives, alkaline fusion temperatures and time on products were investigated. The fused samples were also characterized by TG−DTA, XRD and SEM. The results show that the phase transformation temperature decreases after adding sodium carbonate and sodium chloride into coal fly ash. The mass loss becomes greater in fusion process as well. The addition of sodium carbonate favors transformation of fly ash into metastable nepheline, while the addition of sodium chloride favors nepheline to sodalite. The effect of fusion temperatures on products is significant compared with that of fusion time. The fused product aluminum sodium silic