铁尾矿在蒸压养护过程中的物相变化(英文)  

Phase Transformation of Iron Ore Tailings During Autoclaved Curing

作　　者：李德忠[1] 倪文[1] 张静文[1] 吴辉[1] 张玉燕[1] 

机构地区：[1]北京科技大学,金属矿山高效开采与安全教育部重点实验室,北京100083

出　　处：《硅酸盐学报》2011年第4期708-713,共6页Journal of The Chinese Ceramic Society

基　　金：国家“十一五”科技支撑计划(2006BAC21B03)资助项目

摘　　要：以铁矿尾矿替代河砂或者粉煤灰作为主要原料,铝粉作为发气剂,研究制备出了蒸压加气混凝土砌块。在铁矿尾矿、石灰、水泥和脱硫石膏的配合比(质量比)为60:25:10:5时,加气混凝土砌块的强度最优,约为4.43MPa,此时体积密度为513kg/m^3,比强度为8.34MPa。由X射线衍射测试分析可知,成品中主要的矿物成分为托贝莫来石,此外还有石膏和尾矿中残留的石英等。扫描电镜结果显示,成品中形成了一种呈扭曲状态的针状或板状的结晶相。^(29)Si和^(27)Al的核磁共振分析表明,在前期养护温度为70℃时,尾矿中部分石英和富钙的长石颗粒分解,其它大多数的含铁相矿物在180℃的蒸压合成反应下才得以分解。新形成的针状或板状的物相,包括托贝莫来石,都是具有呈扭曲状态的富铁的水化铝硅酸盐类矿物。An autoclaved aerated concrete（AAC） was prepared by mixing iron ore tailings of 60%（in mass,the same below）,lime of 25%,cement of 10%and gypsum of 5%in flue gass desulfurization waste（FGDW）.A small amount of aluminum powder was used as a foaming agent.The compressive strength and the calculated specific strength of the finished AAC samples with the bulk density of 513kg/m^3 were 4.43 MPa and 8.34 MPa,respectively.The major mineral phases in the AAC product were tobermorite with residue quartz and anhydrite.The most of the iron-containing minerals in the iron ore tailings were decomposed during the autoclaving hydrothermal reaction.The examination by scanning electron microscope depicted a waving curved morphology of newly formed crystalline phases.The ^（29）Si and ^（27）Al nuclear magnetic resonance analysis indicated that part of quartz and calcium-rich plagioclase particles were consumed during the hydrothermal curing at 70℃,and most of the raw particles in the iron ore tailings were consumed during the autoclaving hydrothermal reaction at 180℃.The newly formed and platy phases such as tobermorite were the iron-rich alumina silicate hydrates with the waving-curved morphologies.

关 键 词：加气混凝土 铁尾矿 水热合成反应 托贝莫来石 

分 类 号：TU522[建筑科学—建筑技术科学]