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Cheng-hang Zheng Li Wang Yong-xin Zhang Wei-guo Weng Hai-tao Zhao Jin-song Zhou Xiang Gao 《浙江大学学报(A卷英文版)》2018,19(1):68-79
The co-benefit of hazardous trace elements such as mercury (Hg), arsenic (As), and selenium (Se) capture in dust removal devices of ultra-low emission coal-fired power plants was investigated. Feed fuel and ash samples collected from 15 different coal-fired power units equipped with ultra-low emission systems were characterized to determine the concentrations and distribution characteristics of trace elements. It was found that the low-low temperature electrostatic precipitator (LLT-ESP) and the electrostatic fabric filter (EFF) had greater abatement capacity for Hg than normal cold-side ESP (CS-ESP). Only 0.8%–36.1% of Hg escaped from LLT-ESP and EFF, whereas 42.1%–90.6% of Hg escaped from CS-ESP. With the employment of EFF and ESP (inlet temperature<125 °C), 72.3%–99.1% of As and 70.7%–100% of Se could be captured before the wet flue gas desulfurization (WFGD) system. The significance level of the effects on the abatement capacity for Hg, As, and Se in ESP were analyzed by the Pearson correlation analysis and grey relational analysis. The results indicated that the low inlet temperature of LLT-ESP had significant promotional effect on the simultaneous removal of Hg, As, and Se. The smaller particle size of fly ash can be conducive to the adsorption of hazardous trace elements. The inhibitory effect of sulfur content in coal was significant for the enrichment of Hg and Se in fly ash. 相似文献
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许利惟 《福建工程学院学报》2011,9(4)
采用盐酸选择溶解法测定粉煤灰的水化程度,再结合水化热法计算复合浆体中水泥的水化程度。试样结果表明,在水化早期粉煤灰仅作为惰性材料填充于复合浆体的孔隙中。随着粉煤灰掺量的增大,水泥的水化程度越高,单位体积中水化产物的总体数量仍为减少。 相似文献
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The properties of two types of fly ash geopolymers made from class F fly ashes produced in wet bottom and dry bottom boilers were investigated in the present study. The source material used in the geopolymer concrete was activated with sodium hydroxide and sodium silicate solution. The results revealed that the geopolymer produced with wet bottom boiler fly ash(CZ-FA)hardened quickly, and had higher early-age strength and lower shrinkage than the geopolymer produced with dry bottom boiler fly ash(SX-FA). The compressive strength of the two geopolymers made from CZ-FA and SX-FA was 45 MPa and 15 MPa respectively when cured at 60 ℃ and delayed for 14 d. However, after 90 days' delay, the compressive strength of both the samples is almost the same, up to 80 MPa. Nearly 20% volume shrinkage of the samples made from SX-FA was much higher than that made from CZ-FA, which was almost zero. XRD, SEM/EDS and FT-IR were used to analyze the main reason of the differences. 相似文献
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研究表明,花椒利用的历史可以上溯到先秦时期,中国古代主要将花椒应用于烹饪调味、酿酒制茶等食品饮料加工及食疗保健之中。花椒的利用推动了川菜的发展,麻味这种源于中国的特有风味,已成为食品的一种基本味,是中国对世界饮食文化的一大贡献。 相似文献
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利用石家庄附近炼铝厂废弃的铝灰及工厂回收的盐酸,生产液体聚合氯化铝.基本工艺为：酸溶后沉降聚合,废渣洗涤、中和后混合入粉煤灰作为建筑添加剂使用.通过实验制备了聚合氯化铝,进行了中试和工业试验,完成了综合利用铝灰的整体设计. 相似文献
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To study the influence of slenderness on the axial compressive performance of autoclaved fly ash solid brick masonry columns, compression experiments were conducted on 12 samples of autoclaved fly ash solid brick masonry column and 4 samples of fired clay brick masonry column. The damage patterns and compressive performance were compared and analyzed. The experimental results indicate that the compressive bearing capacity decreases as slenderness increases from 3 to 18, and the compressive bearing capacity of the autoclaved fly ash solid brick masonry columns is lower than that of the fired clay brick masonry columns. The formulae for the axial compressive bearing capacity of autoclaved fly ash solid brick masonry columns were derived based on the experiments. The nonlinear FEA program ANSYS was adopted to simulate the behaviors of masonry columns. By comparing the simulation results and experimental results, it is shown that the simulation results agree well with the experimental ones. The rationality and applicability of the simulation results were verified. 相似文献
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利用灰色关联分析方法研究粉煤灰的粒度分布对水泥性能的影响．结果表明：O～5μm、5～10μm粉煤灰颗粒分别是水泥3d、28d抗压强度的最强影响因子;水泥3d、28d强度随小于33μm的粉煤灰颗粒含量增大而提高,随大于33pm的粉煤灰颗粒含量增大而降低;可以通过优化粉煤灰的粒度分布来改善水泥性能． 相似文献
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张乃明 《石家庄铁路工程职业技术学院学报》2014,(1):26-31
矿物掺合料如粉煤灰、矿渣等,能显著改善结构混凝土的耐久性,而得到普遍应用。从微观角度出发,采用压汞法（MIP）和X-CT断层扫描技术分析粉煤灰分别为10%、30%和50%对水泥基材料微结构的影响,进一步从氯离子传输角度分析掺合料对微结构改变的本质。压汞法的结果表明,粉煤灰掺量从10%到50%,水泥基材料的毛细孔和凝胶孔的体积率分别减少和增加,但总孔隙率在50%时出现增加;X-CT三维重构的结果显示,水泥基材料的微缺陷随着掺合料的增加而减少;氯离子传输的实验显示,含50%掺合料的试样,具有较大的传输系数,表明不适量的掺合料会降低水泥基材料的抗渗透性能。 相似文献
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按照河南省西南部的水系分布,依据JGJ52－2006,对河砂资源丰富地区的混凝土用砂进行采样,采用快速碱活性试验和砂浆长度法相结合的检验方法对样品砂进行碱活性测试．指出了该地区不同区域河砂的碱活性状况：大部分河砂碱活性测试合格,少数地区存在一定程度的潜在碱活性．采用掺加粉煤灰的方法对对存在潜在碱活性的砂进行集料的活性抑制试验．指出了粉煤灰不同掺量对砂的碱活性抑制作用,并提出了工程应用建议． 相似文献
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干法脱硫灰用作水泥混合材的试验研究 总被引：1，自引：0，他引：1
为探索干法脱硫灰的利用途径,系统研究了LIFAC干法脱硫灰用作水泥混合材对水泥标准稠度需水量、凝结时间、安定性及强度等性能的影响规律.结果表明,LIFAC干法脱硫灰用作水泥混合材是可行的.掺加脱硫灰的水泥性能良好,各项指标符合国标规定.实际生产时建议采用脱硫灰与粉煤灰双掺工艺,脱硫灰适宜掺量为5%～12%. 相似文献
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陈三姗陈峰 《福建工程学院学报》2021,(1):61-67
从粉煤灰-水泥相互作用、粉煤灰-淤泥质土相互作用两个方面开展一系列试验,研究粉煤灰对水泥和淤泥质粘土的强度及固化过程的影响,然后通过扫描电镜(SEM)试验,观察粉煤灰水泥土的微结构变化以探究其机理。粉煤灰水泥石强度试验表明粉煤灰能使水泥石28d及以上龄期的强度提高,粉煤灰淤泥质土的含水率试验和固结不排水试验表明,粉煤灰使淤泥土的硬度变大,X射线衍射(XRD)试验表明粉煤灰能细化水泥中Ca(OH)2晶粒,SEM试验结果表明粉煤灰可以使水泥土的微结构更加密实。 相似文献
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In this study, an artificial neural network （ANN） model for studying the strength properties of steel fiber reinforced concrete （SFRC） containing fly ash was devised. The mixtures were prepared with 0 wt%, 15 wt%, and 30 wt% of fly ash, at 0 vol.%, 0.5 vol.%, 1.0 vol.% and 1.5 vol.% of fiber, respectively. After being cured under the standard conditions for 7, 28, 90 and 365 d, the specimens of each mixture were tested to determine the corresponding compressive and flexural strengths. The pa- rameters such as the amounts of cement, fly ash replacement, sand, gravel, steel fiber, and the age of samples were selected as input variables, while the compressive and flexural strengths of the concrete were chosen as the output variables. The back propagation learning algorithm with three different variants, namely the Levenberg-Marquardt （LM）, scaled conjugate gradient （SCG） and Fletcher-Powell conjugate gradient （CGF） algorithms were used in the network so that the best approach can be found. The results obtained from the model and the experiments were compared, and it was found that the suitable algorithm is the LM algorithm. Furthermore, the analysis of variance （ANOVA） method was used to determine how importantly the experimental parameters affect the strength of these mixtures. 相似文献
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才敏智 《河北能源职业技术学院学报》2014,(2):67-69
目前,在建筑工程中,水泥粉煤灰碎石桩是地基处理的一种常用技术。根据所监理的工程结合自身实际经验,从监理的角度对水泥粉煤灰碎石桩的施工质量控制进行了分析探讨。 相似文献
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采用高温和酸分别对粉煤灰进行改性,对比了改性后的粉煤灰对焦化废水深度处理的效果,确定了最佳工艺条件。结果表明,焦化废水COD135~170mg/L,NH3-N 96~135mg/L,体积150mL,pH值5,改性粉煤灰投加量25g,粒径100~160目,吸附时间60min,石灰量0.25g,高温改性粉煤灰对焦化废水COD和氨氮的去除率分别达到了85.2%和89.6%,而酸改性粉煤灰对焦化废水COD和氨氮的去除效果劣于高温改性粉煤灰,去除率分别为78.3%和82.7%。 相似文献
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骆慧芳 《江西教育学院学报》2004,25(5):5-8
反倾销已不再是横亘在中国企业面前无法逾越的天堑。随着中国加入世贸组织后对世贸规则的有效运用和经济的不断增强,西方发达国家纷纷利用非关税壁垒,设置技术性贸易壁垒,以阻止发展中国家的产品进入本国市场。文章就技术壁垒对中国的损害和损害产生的原因以及如何破解壁垒等问题进行了探讨。 相似文献
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陈遥 《华侨大学学报(哲学社会科学版)》2010,(2):82-88
中国在东南亚的软实力日益提高。海外华侨华人与中国的互动也日趋频繁,他们成为中国与东盟国家经贸合作和文明对话的桥梁,成为提升中国在东南亚的软实力的重要途径。华侨华人在经贸、文化教育和政治等方面,促进了中国在东南亚软实力的提高。中国应开展软实力与华侨华人学相结合的研究,加强侨务和外交的合作,追求中国与华侨华人及其所在国多赢的局面,为中国崛起服务。 相似文献