摘要
选取龙岩(LY)和上京(SJ)两种福建低灰熔点煤,利用灰熔点测定仪研究氧化铝、氧化钙及铝钙复合物对两种煤灰熔融温度的影响规律.研究结果表明:加入Al2O3(4%~18%,质量分数,下同)可以一直提高灰熔点,加入CaO(2%~8%)使灰熔点降低.但LY灰、SJ灰中添加较多Al2O3后再加少量CaO可使灰熔点比对应只加Al2O3的高,表现出铝钙协同作用.通过XRD和SEM-EDX分析煤灰在高温下的矿物转化行为、表面微观形貌及化学组成,研究铝钙协同作用对低灰熔点煤的影响规律及其机理.结果发现:加入氧化铝后,煤灰在高温下生成的耐熔矿物莫来石是提高灰熔点的主要因素;加入较高含量的氧化铝和少量的氧化钙后,灰中先生成莫来石矿物,其中的氧化钙则会生成钙长石;在有莫来石存在时,钙长石与莫来石一起导致其熔融温度升高,从而提高灰熔点.
Two kinds of Fujian coals with low ash fusion temperature(AFT),Longyan(LY)and Shangjing(SJ),were selected to study the influences of alumina,calcium oxide and aluminum-calcium composite on AFTs by using ash fusion temperature analyzer.The results showed that the AFTs could be raised continuously by adding Al2O3(4%to 18%,mass fraction,same below),the AFTs would be decreased continuously by adding CaO(2%to 8%).However,adding more Al2O3 and less CaO to LY ash and SJ ash could make the ash melting point higher than that of adding Al2O3 only,which showed the synergistic effect of aluminum and calcium.Therefore,aluminum-calcium synergistic effect occurred when high content of alumina and a small amount of calcium oxide were added to LY and SJ coals.The mineral conversion behavior,surface morphology and chemical composition of coal ash at high temperature were analyzed by XRD and SEM-EDX,through that the effects of aluminum-calcium synergistic effects on AFTs and its synergistic mechanism were studied.The results showed that mullite produced at high temperature was the main factor to increase the AFTs when Al2O3 was added in coal ash.After adding high content of alumina and a small amount of calcium oxide,the mullite minerals would be produced firstly,and the calcium oxide would form anorthite.In the presence of mullite,both anorthite and mullite would increase the AFTs,thus the AFTs were increased.
作者
林荣英
林晨昊
周家华
张柏茂
LIN Rongying;LIN Chenhao;ZHOU Jiahua;ZHANG Baimao(College of Chemical Engineering,Fuzhou University,Fuzhou,Fujian 350108,China)
出处
《福州大学学报（自然科学版）》
CAS
北大核心
2020年第1期116-121,共6页
Journal of Fuzhou University(Natural Science Edition)
基金
福建省自然科学基金资助项目(2016J01059)
福州大学贵重仪器设备开放测试基金资助项目(2018T028)
关键词
煤灰
灰熔融温度
协同作用
铝钙复合物
coal ash
ash fusion temperature
synergistic effect
aluminum-calcium composite
