流化床气相沉积法改性粉煤灰及其水化特征
作者:
基金项目:

“十二五”国家科技支撑计划项目(2014BAL03B02);国家自然科学基金资助项目(51678442,51478348);国家高铁联合基金资助项目(U1534207);上海市科委重点项目(14DZ1202302,15DZ1205003)


Modification of Fly Ash Using Fluidized Bed Reactor Vapor Deposition and Its Effect on Hydration of Cement Paste and Mortar
Author:
  • 摘要
  • | |
  • 访问统计
  • |
  • 参考文献 [37]
  • |
  • 相似文献 [20]
  • | | |
  • 文章评论
    摘要:

    采用流化床气相沉积法,将NaOH,Na2SO4等改性材料进行雾化,沉积于粉煤灰颗粒表面.采用扫描电子显微镜(SEM)及傅里叶变换红外光谱仪(FTIR)分析了改性材料结晶特征及其对粉煤灰的溶蚀机理,测试并分析了改性粉煤灰水泥净浆、改性粉煤灰水泥砂浆的强度发展,同时通过SEM,X射线衍射(XRD)研究了改性粉煤灰水泥净浆水化进程.结果表明:NaOH可以与粉煤灰发生溶蚀反应,使其中的Si—O键断裂,粉煤灰的水化活性得以提高;Na2SO4在粉煤灰表面晶粒尺寸更小、分布更均匀,并能在水化过程中存留于粉煤灰表面,促进了粉煤灰及其附近水泥熟料的水化;采用流化床气相沉积法,上述两种改性材料均可提高粉煤灰颗粒与水泥基体的锚固力,促进水泥石强度发展;当NaOH和Na2SO4掺量(质量分数)分别为0.23%,1.17%时,水泥净浆和砂浆强度显著提高,并高于同等掺量下用传统化学激发法制备的水泥净浆和砂浆强度.

    Abstract:

    Fluidized bed reactor vapor deposition(FBR VD) was utilized to modify fly ash, in which NaOH or Na2SO4 was deposited onto the surface of the fly ash beads. The crystallization and leaching processes were investigated by scanning electron microscopy(SEM) and Fourier transform infrared spectrometer(FTIR). The strength developments of cement paste and mortar with modified fly ash were analyzed. The hydration process of cement paste was investigated based on SEM and X ray diffractometer(XRD). Results figure out that leaching happens between fly ash and NaOH, breaking the Si—O bond and improving the hydration activity of fly ash. The crystals of Na2SO4 are smaller in size and better distributed and it remains undissolved in the cement paste, which enhances the hydration of the fly ash as well as the cement clinker nearby. These two effects may strengthen the anchor between the cement matrix and the fly ash and benefit the strength development. When the contents (by mass) of NaOH and Na2SO4 are 0.23% and 1.17% respectively, higher strengths of the cement paste and cement mortar are achieved, as compared to those with traditional chemical activation.

    参考文献
    [1]AHMARUZZAMAN M.A review on the utilization of fly ash[J].Progress in Energy and Combustion Science,2010,36(3):327 363.
    [2]MUKHERJEE A B,ZEVENHOVEN R,BHATTACHARYA P,et al.Mercury flow via coal and coal utilization by products:A global perspective[J].Resources,Conservation and Recycling,2008,52(4):571 591.
    [3]FERNNDEZ JIMNEZ A,PALOMO A.Composition and microstructure of alkali activated fly ash binder:Effect of the activator[J].Cement and Concrete Research,2005,35(10):1984 1992.
    [4]曹书勤,夏新奎,肖伟,等.改性粉煤灰对亚甲蓝的吸附及再生性能研究[J].非金属矿,2010,33(1):64 69.
    CAO Shuqin,XIA Xinkui,XIAO Wei,et al.Study on absorption and regeneration of modified fly ash to methylene blue[J].Non Metallic Mines,2010,33(1):64 69.(in Chinese)
    [5]梁郁,钱觉时,王智.磷酸激发粉煤灰的试验研究[J].粉煤灰综合利用,2004(3):44 45.
    LIANG Yu,QIAN Jueshi,WANG Zhi.Testing research on fly ash activated by phosphoric acid[J].Fly Ash Comprehensive Utilization,2004(3):44 45.(in Chinese)
    [6]QIAN J,SHI C,WANG Z.Activation of blended cements containing fly ash[J].Cement and Concrete Research,2001,31(8):1121 1127.
    [7]LEE C Y,LEE H K,LEE K M.Strength and microstructural characteristics of chemically activated fly ash cement systems[J].Cement and Concrete Research,2003,33(3):425 431.
    [8]ABDULLAH A,JAAFAR M S,TAUFIQ YAP Y H,et al.The effect of various chemical activators on pozzolanic reactivity:A review[J].Scientific Research and Essays,2012,7(7):719 729.
    [9]罗忠涛,马保国,李相国,等.水热碱性环境下粉煤灰水化进程研究[J].中国矿业大学学报,2010,39(2):275 278.
    LUO Zhongtao,MA Baoguo,LI Xiangguo,et al.Study of fy ash hydrated course in hydrothermal and alkaline environment[J].Journal of China University of Mining & Technology,2010,39(2):275 278.(in Chinese)
    [10]罗忠涛,马保国,杨久俊,等.高温对粉煤灰表面解聚作用研究[J].中国矿业大学学报,2011,40(5):793 798.
    LUO Zhongtao,MA Baoguo,YANG Jiujun,et al.Study of effect of high temperature on depolymerization of fly ashs exterior structure[J].Journal of China University of Mining &Technology,2011,40(5):793 798.(in Chinese)
    [11]张平平.粉煤灰表面预处理及其应用于制备复合水泥的研究[D].广州:华南理工大学,2011.
    ZHANG Pingping.Research on surface modification of fly ash and its application on prepartion of blended cement[D].Guangzhou:South China University of Technology,2011.(in Chinese)
    [12]郝成伟,邓敏,莫立武,等.粉煤灰表面改性及其对水泥浆体强度和自收缩的影响[J].硅酸盐学报,2011,39(4):697 702.
    HAO Chengwei,DENG Min,MO Liwu,et al.Surface modification of fly ashes and its effect on strength and autogenous shrinkage of cement paste[J].Journal of the Chinese Ceramic Society,2011,39(4):697 702.(in Chinese)
    [13]LIU S,XIAO W.CFD PBM coupled simulation of silicon CVD growth in a fluidized bed reactor:Effect of silane pyrolysis kinetic models[J].Chemical Engineering Science,2015,127:84 94.
    [14]VAHLAS C,CAUSSAT B,SERP P,et al.Principles and applications of CVD powder technology[J].Materials Science and Engineering:Reports,2006,53(1/2):1 72.
    [15]RATTANASAK U,CHINDAPRASIRT P.Influence of NaOH solution on the synthesis of fly ash geopolymer[J].Minerals Engineering,2009,22(12):1073 1078.
    [16]KIM K,MERSMANN A.Estimation of metastable zone width in different nucleation processes[J].Chemical Engineering Science,2001,56(7):2315 2324.
    [17]MASON R E A,STRICKLAND CONSTABLE R F.Breeding of crystal nuclei[J].Transactions of the Faraday Society,1966,62:455 461.
    [18]QI Y,KLAUSNER J F,MEI R.Role of surface structure in heterogeneous nucleation[J].International Journal of Heat and Mass Transfer,2004,47(14/15/16):3097 3107.
    [19]CRIADO M,FERNNDEZ JIMNEZ A,PALOMO A.Alkali activation of fly ash:Effect of the SiO2/Na2O ratio:Part I:FTIR study[J].Microporous and Mesoporous Materials,2007,106(1/2/3):180 191.
    [20]FERNNDEZ JIMNEZ A,PALOMO A.Mid infrared spectroscopic studies of alkali activated fly ash structure[J].Microporous and Mesoporous Materials,2005,86(1/2/3):207 214.
    [21]KVRA F,JLEK T,KOPECKY' L.Geopolymer materials based on fly ash[J].Ceramics Silikáty,2005,49(3):195 204.
    [22]张云升,孙伟,沙建芳,等.粉煤灰地聚合物混凝土的制备、特性及机理[J].建筑材料学报,2003,6(3):237 242.
    ZHANG Yunsheng,SUN Wei,SHA Jianfang,et al.Preparation,properties and mechanism of fly ash based geopolymer concrete[J].Journal of Building Materials,2003,6(3):237 242.(in Chinese)
    [23]PUERTAS F,FERNNDEZ JIMNEZ A.Mineralogical and microstructural characterisation of alkali activated fly ashslag pastes[J].Cement and Concrete Composites,2003,35(3):287 292.
    [24]PUERTAS F,MART′NEZ RAM′REZ S,ALONSO S,et al.Alkali activated fly ash/slag cement:Strength behaviour and hydration products[J].Cement and Concrete Research,2000,30(10):1625 1632.
    [25]MYNENI S C B,TRAINA S J,WAYCHUNAS G A,et al.Vibrational spectroscopy of functional group chemistry and arsenate coordination in ettringite[J].Geochimica et Cosmochimica Acta,1998,62(21/22):3499 3514.
    [26]PETERSON V K,NEUMANN D A,LIVINGSTON R A.Effect of NaOH on the kinetics of tricalcium silicate hydration:A quasielastic neutron scattering study[J].Chemical Physics Letters,2006,419(1 3):16 20.
    [27]PACEWSKA B,WILIN'SKA I,BLONKOWSKI G.Investigation of cement early hydration in the presence of chemically activated fly ash[J].Journal of Thermal Analysis and Calorimetry,2008,93(3):769 776.
    [28]SAJEDI F,RAZAK H A.Comparison of different methods for activation of ordinary Portland cement slag mortars[J].Construction and Building Materials,2011,25(1):30 38.
    [29]施惠生,孙振平,邓恺.混凝土外加剂实用技术大全[M].北京:中国建材工业出版社,2008:97 103.
    SHI Huisheng,SUN Zhenping,DENG Kai.Practical technique collections of concrete admixtures[M].Beijing:Chinese Building Materials Industry Press,2008:97 103.(in Chinese)
    引证文献
    网友评论
    网友评论
    分享到微博
    发 布
引用本文

李晨,朱洪波,吴梦雪,蒋正武.流化床气相沉积法改性粉煤灰及其水化特征[J].建筑材料学报,2016,19(6):1004-1012

复制
分享
文章指标
  • 点击次数:765
  • 下载次数: 0
  • HTML阅读次数: 0
  • 引用次数: 0
历史
  • 收稿日期:2016-05-26
  • 最后修改日期:2016-07-13
  • 在线发布日期: 2016-12-29
文章二维码