为了研究可水合氧化铝在硅溶胶中的水化行为和流变性，将可水合氧化铝分别在水和硅溶胶中配制成固含量约60％（w）的料浆，在25℃恒温水浴中分别水化1～120 h 后，再烘干并检测其质量变化率，观察水化后的物相组成和显微结构，并研究可水合氧化铝分别在水和硅溶胶中的 Zeta 电位随 pH 的变化及料浆黏度随时间和切变速率的变化。结果表明：1）可水合氧化铝在水中的水化速率比在硅溶胶中的快，尤其在反应前期；可水合氧化铝在硅溶胶中料浆的流变特性近似牛顿流体，而在水中料浆表现出剪切变稀的特征；可水合氧化铝在硅溶胶中料浆的黏度和颗粒表面的等电点 pH 均比在水中的小。产生这些差异的主要原因是可水合氧化铝颗粒表面被硅溶胶中的 SiO2粒子包覆。2）可水合氧化铝在水中水化后的主要物相为三羟铝石和少量勃姆石，而在硅溶胶中水化后的主要物相为勃姆石。
s:To study the hydration behavior and rheological properties of hydratable alumina in silica sol,the hydratable alumina was added into silica sol and water,respectively,to prepare two kinds of slurries with 60 mass% solid content.After thermostatic waterbath at 25 ℃ for 1 -120 h and drying,the mass changing rates of hydratable alumina in the water and silica sol were characterized;the phase composition and mi-crostructure of the hydration products were analyzed;the relationships between Zeta potential and pH val-ue of hydratable alumina in water and silica sol were investigated;and their slurry viscosity as a function of the testing time or the shear rate was studied.The results indicate that:(1)the hydration of hydratable alu-mina in the water is faster than that in the silica sol,especially at the prior stage of the reaction;as for the rheological behavior,hydratable alumina in the silica sol behaves as an approximate Newtonian fluid,while the hydratable alumina in the water shows a shear thinning behavior;compared with the slurry of hydratable alumina in the water,the slurry with silica sol has lower viscosity and pH value of isoelectric point on the particle surface;the main reason for such differences is the hydratable alumina particles are covered with SiO2 in the silica sol;(2)the main phases of hydration products in the water were bayerite and a small amount of boehmite,while that in the silica sol was boehmite.
参考文献
| [1] | S. Mukhopadhyay;P. K. Das Poddar.Effect of preformed and in situ spinels on microstructure and properties of a low cement refractory castable[J].Ceramics International,20043(3):369-380. |
| [2] | R. Salomao;V.C. Pandolfelli.The role of hydraulic binders on magnesia containing refractory castables: Calcium aluminate cement and hydratable alumina[J].CERAMICS INTERNATIONAL,20098(8):3117-3124. |
| [3] | 富强;张晖;牛益民;寇志奇;华远才.不同结合系统刚玉-方镁石-尖晶石浇注料的性能[J].耐火材料,2002(2):104-106. |
| [4] | 彭从华;梁永和;雷中兴;洪学勤;田学光.水泥和水合氧化铝对铝镁浇注料性能的影响[J].耐火材料,2006(2):123-125. |
| [5] | 王青峰;叶国田;穆元冬;朱玲玲;宋秀娟;张传银.SiO2微粉对水合氧化铝结合刚玉质浇注料中温烧结性能的影响[J].耐火材料,2014(2):103-105,110. |
| [6] | 王玺堂;张保国;王周福;曾伟.溶胶结合刚玉质耐火浇注料的研究[J].稀有金属材料与工程,2009(z2):182-185. |
| [7] | 徐勇;韩兵强;邹国荣;薛海涛;夏昌勇.硅溶胶结合不定形耐火材料的研究及应用现状[J].耐火材料,2014(5):391-396. |
| [8] | 孔德玉;杨辉;王家邦;韦苏;程本军.氧化铝粉体在硅溶胶中的分散机理研究[J].稀有金属材料与工程,2004(z1):83-87. |
- 下载量()
- 访问量()
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%