n(Al_(2)O_(3))∶n(SiO_(2))对气化飞灰制备的莫来石陶瓷结构及性能的影响  

Effects of n(Al2O3)∶n(SiO_(2)) on Structures and Properties of Mullite Ceramics Prepared from Gasification Fly Ash

作　　者：黄俊 李寒旭[1,3] 滕艳华 赵帅[1] 夏宝亮 HUANG Jun;LI Hanxu;TENG Yanhua;ZHAO Shuai;XIA Baoliang(School of Chemical Engineering,Anhui University of Science and Technology,232001 Huainan,China;School of Materials Science and Engineering,Anhui University of Science and Technology,232001 Huainan,China;Hefei Comprehensive National Science Center Energy Research Institute,230031 Hefei,China)

机构地区：[1]安徽理工大学化学工程学院,安徽淮南232001 [2]安徽理工大学材料科学与工程学院,安徽淮南232001 [3]合肥综合性国家科学中心能源研究院,合肥230031

出　　处：《煤炭转化》2021年第5期64-72,共9页Coal Conversion

基　　金：国家重点研发计划资助项目(2019YFC1904304).

摘　　要：为了综合利用气化飞灰,以煅烧除杂后的气化飞灰为硅源、氧化铝粉为铝源、氮化硅粉为发泡剂,通过反应烧结掺有不同量氧化铝的气化飞灰试样制备了莫来石陶瓷,研究了n(Al_(2)O_(3))∶n(SiO_(2))对陶瓷样品的相组成、显微结构、宏观形貌和物理性能的影响。结果表明,n(Al_(2)O_(3))∶n(SiO_(2))对陶瓷样品的相组成、显微结构、宏观形貌和物理性能具有很大影响。XRD分析表明,莫来石在所有样品中均为主导晶相;样品中主要出现了三种微观结构——玻璃区域、棒状莫来石结构和块状莫来石结构。随着原料中n(Al_(2)O_(3))∶n(SiO_(2))的升高,玻璃区域和棒状莫来石结构逐渐减少而块状莫来石结构逐渐增加;由于非晶态玻璃相的减少、莫来石相的增加及赤铁矿的出现,样品的颜色随着n(Al_(2)O_(3))∶n(SiO_(2))的增加逐渐由浅棕色变化为淡粉色。同时,样品由于反应产物的种类与含量的不同发生了不同程度的膨胀与收缩;随着n(Al_(2)O_(3))∶n(SiO_(2))由0.6增加到1.8,样品的显气孔率(最大值为68.81%)和吸水率(最小值为19.08%)不断降低并在n(Al_(2)O_(3))∶n(SiO_(2))为1.5时趋于平缓,样品体积密度的变化趋势(最小值为0.96 g/cm 3)则与显气孔率和吸水率的变化趋势相反,而抗折强度呈现随n(Al_(2)O_(3))∶n(SiO_(2))的增加先增大后减小的趋势,并在n(Al_(2)O_(3))∶n(SiO_(2))为1.5时达到最大值(89.21 MPa)。In order to facilitate a comprehensive use of gasification fly ash,mullite cera-mics were prepared from the gasification fly ash specimens doped with different amounts of alumina by sintering.Among the raw materials,calcined and delaminated gasification fly ash were involved as a silicon source,alumina powder as an aluminum source and silicon nitride powder as a foaming agent.The effects of the mole ratio of the aluminum to the silicon(n(Al_(2)O_(3))∶n(SiO_(2)))on the phase composition,microstructure,macroscopic morphology and physical properties of the ceramic samples were investigated.The results show that the n(Al_(2)O_(3))∶n(SiO_(2))has great influences on the phase composition,microstructure,macroscopic morphology and physical properties of the samples.Based on the XRD analysis results,the mullite is the dominant crystalline phase in all the samples.There are mainly three kinds of microstructures in the samples,namely glass region,rod-shaped mullite structure and block-shaped mullite structure.With the increasing n(Al_(2)O_(3))∶n(SiO_(2))in the raw material,the glass region and rod-shaped mullite structure gradually decrease while the block-shaped mullite structure gradually increases;the color of the samples gradually changes from light brown to light pink with the increase in the n(Al_(2)O_(3))∶n(SiO_(2))due to the decrease in the amorphous glassy phase,the increase in the mullite phase and the appearance of the hematite.At the same time,the samples also undergo different degrees of expansion and contraction according to the type and content of the reaction products.As the n(Al_(2)O_(3))∶n(SiO_(2))increases from 0.6 to 1.8,the apparent porosity(maximum value corresponding to 68.81%)and water absorption(minimum value corresponding to 19.08%)of the samples decrease and level off at n(Al_(2)O_(3))∶n(SiO_(2))=1.5,while the bulk density(minimum value corresponding to 0.96 g/cm 3)of the samples is exactly opposite to the changes in the apparent porosity and water absorption,while the flexural strengt

关 键 词：气化飞灰 莫来石 陶瓷 N (Al 2O 3)∶ N (SiO 2) Riley相图 

分 类 号：TQ536.4[化学工程—煤化学工程] TQ174