共查询到18条相似文献,搜索用时 62 毫秒
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0 引言 粉煤灰在水泥生产中主要用于生料配料和作活性混合材。当粉煤灰作活性混合材时,有直接用与预处理后用两种形式。目前预处理粉煤灰增加粉煤灰活性的工艺方法也较多,如粉煤灰磨细、粉煤灰增钙、粉煤灰石灰系统蒸养以及粉煤灰机械化学活化 相似文献
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粉煤灰表面活化处理新技术 总被引:8,自引:0,他引:8
采用化工原料配制成一种液体活化剂,将这种活化剂均匀喷洒在粉煤灰上即可达到活化粉煤灰的目的。经活化的粉煤灰用作水泥混合材可提高水泥标号或水泥中粉煤灰的掺量。 相似文献
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本文采用单独机械磨细和机械磨细与化学激发剂(NaOH、Na2SO4)相复合的方法来提高低等级粉煤灰的活性.研究时,用活化后的粉煤灰以超量取代部分水泥并掺加高效减水剂的方法配制C30~C50混凝土.研究结果表明:掺入一定量的粉煤灰配制的混凝土,其抗压强度与基准混凝土相比,早期抗压强度普遍有所降低,后期抗压强度可以接近基准混凝土;在取代率为15%~25%时,粉煤灰混凝土抗压强度可以超过基准混凝土的抗压强度;与原状粉煤灰相比,单独机械磨细和使用机械磨细与化学激化剂复合激发均能够提高粉煤灰混凝土的早期强度和后期强度,其中单独机械磨细的激发效果最明显,使用机械磨细与Na2SO4共同激发亦有较好的效果. 相似文献
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用活化粉煤灰配制砌筑水泥的研究 总被引:2,自引:0,他引:2
一种简单的活化粉煤灰新工艺,可大幅度提高粉煤灰活性。活化灰掺量≥70%条件下,可配制225#砌筑水泥。同等条件下,未活化的粉煤灰只能配制125#砌筑水泥。 相似文献
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机械活化粉煤灰性能的研究 总被引:1,自引:0,他引:1
研究了机械活化时间对粉煤灰的视密度、比表面积、粒度分布及活性的影响。将不同时间机械活化的粉煤灰按 3 0 %比例掺入硅酸盐水泥中 ,测定其净浆强度。结果表明 ,球磨时间以 2 0min~ 3 0min为宜 相似文献
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结构因素对粉煤灰活性激发的影响 总被引:14,自引:3,他引:14
从粉煤灰玻璃体结构入手,分析其活性特征;通过对机械细磨、水热合成、碱性激发等激活机理的分析,阐明结构对粉煤灰火山灰活性的决定性影响 相似文献
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谈提高粉煤灰火山灰活性的若干方法 总被引:1,自引:1,他引:1
在试验研究基础上,对磨细粉煤灰采用碱性激发剂及外掺可溶性硅铝材料等提高粉煤灰活性的方法进行系统分析评价,以期提高粉煤灰资源的有效利用并扩大其应用范围。 相似文献
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采用稻壳灰制备水玻璃,研究了碱浓度、固液比、溶煮时间对稻壳灰中二氧化硅溶出率和所得水玻璃模数的影响,试验表明稻壳灰制备水玻璃的最佳工艺为:NaOH浓度8 mol/L、固液比1∶2.5(1 g∶2.5mL)、溶煮时间3h;应用稻壳灰制备的水玻璃激发粉煤灰的活性,研究了水玻璃掺量、模数、固含量对粉煤灰胶砂强度的影响,试验发现当水玻璃模数为1.1、固含量为34%、水玻璃掺量为33%时,粉煤灰胶砂强度最大. 相似文献
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Man Park Dong Hoon Lee Choong Lyeal Choi Woo Taik Lim Suk Kee Lee Nam Ho Heo Sridhar Komarneni Jyung Choi 《Journal of Porous Materials》2002,9(4):291-298
Swelling mica exhibits unique characteristics for purification of drinking water contaminated by heavy metals and for selective removal of Sr2+ and Ba2+ ions from nuclear waste solution. As a new approach to recycle fly ash, conversion of fly ash to swelling mica has been attempted and ion-exchange properties of fly ash-derived swelling mica (referred to hereinafter as FA-swelling mica) were examined in this study. Thermal treatment of fly ash with MgO in the presence of excess NaF led to the formation of swelling mica along with trace quantities of impurities. A swelling mica of good quality was obtained from the reactant ratio of fly ash 1 g : MgO 0.75 g : NaF 1.75 g. Unlike gel or kaolinite-derived synthetic Na-4-micas, FA-swelling mica exhibited heterogeneity in its framework. Its uptake capacity for Sr2+ ions was estimated to be 17.4 meq/100 g from 0.1 mM SrCl2 aqueous solution and 5.0 meq/100 g from 0.5 N NaCl solution containing the same Sr2+ concentration. These capacities are less than that of metakaolin-derived Na-4-mica. However, its ion exchange capacity for divalent transitional metal ions was estimated to be 284 meq/100 g from their inaqueous solutions and 206 meq/100 g from the 0.5 N NaCl solution containing the mixed metal ions of Cd2+, Co2+, Mn2+, Ni2+ and Zn2+ each at 1 mN concentration. These capacities are comparable to that of metakaolin-derived Na-4-mica. Its selectivity for transition metal ions is as follows: Zn2+ > Ni2+ Co2+ Cd2+ > Mn2+ and this is consistent with the G° values from Gibbs-Duhem equation. These results clearly showed that fly ash could be converted to swelling mica with high uptake capacity for divalent transitional metal ions. Therefore, conversion of fly ash to highly pure swelling mica will lead to a resource from waste. 相似文献