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矿渣阿利特—硫铝酸盐水泥性能的研究 总被引:5,自引:0,他引:5
探讨了高炉矿渣及石膏和石灰石参与下阿利特-硫铝酸盐水泥的性能。结果表明,在阿利特-硫铝酸盐水泥熟料中掺加较多量矿渣,强度的降低幅度较小,当前适量的石膏及石灰石存在时,水泥的7d,28d强度可赶上或超过不掺矿渣的试样。这一结果归结为所造成的AFt生长的良好条件及对矿渣的良发激发作用以及对硅酸盐矿物水化的促进作用;掺加矿渣,水泥的凝结时间有所延长。 相似文献
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阿利特—硫铝酸盐水泥与硅酸盐水泥复合性能的研究 总被引:10,自引:1,他引:10
研究了阿利特-硫铝酸盐水泥与硅酸盐水泥复合所制备的水泥的性能。结果表明,复合后水泥的强度性能优于单一品种水泥的性能;凝结时间则由复合体中占比例较多的一种水泥所控制。 相似文献
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MgO对阿利特—硫铝酸盐水泥熟料矿物形成及性能影响的研究 总被引:8,自引:0,他引:8
研究了MgO对阿利特-硫铝酸盐水泥熟料矿物形成及性能的影响。结果表明,含有适量的MgO可改善生料的易烧性,促进fCaO的吸收,促进C3S及C4A3S两种主要矿物的形成,有利于其在熟料中的共存;适量的MgO亦可提高水泥的强度;阿利特-硫铝酸盐水泥熟料中可允许有较高的MgO存在,使高镁原料的利用成为可能。 相似文献
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研究了石膏对阿利特─硫铝酸盐水泥强度、凝结时间、干缩性等性能的影响。结果表明,掺加5%左右的石膏,可显著提高水泥强度,当掺量达约8%时,水泥的早期强度降低,更多的石膏则造成水泥安定性不良;石膏可延长水泥的凝结时间;存在适量石膏,水泥的干缩值减小。 相似文献
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The texture of Fe2O3 support and Ru/Fe2O3 catalysts supported on iron oxides obtained from β-FeOOH (B) or δ-FeOOH (D) and their catalytic activity in WGSR were studied. Also their susceptibilities to reduction and reoxidation, were studied by TPR, using H2 or CO and TPO methods. In the case of TPRCO the composition of the reducing mixture containing traces of H2O enabled investigation of water gas shift reaction (WGSR).
The catalysts from series D were found more readily reducible and oxidised than those from series B. The supported ruthenium enhanced the redox effects and caused the appearance of additional effects related directly to its presence. Depending on the kind of support and on ruthenium presence considerable differences in temperatures of WGSR onset were found. It is suggested that the susceptibility of the catalysts to reduction and oxidation is responsible for their activity in the WGSR. 相似文献
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Bo-Ra Kim Hyo-Jin Oh Kang-Seop Yun Sang-Chul Jung Wooseung Kang Sun-Jae Kim 《Progress in Organic Coatings》2013
For an electrochemical water splitting system, titanate nanotubular particles with a thickness of ∼700 nm produced by a hydrothermal process were repetitively coated on fluorine-doped tin oxide (FTO) glass via layer-by-layer self-assembly method. The obtained titanate/FTO films were dipped in aqueous Fe solution, followed by heat treatment for crystallization at 500 °C for 10 min in air. The UV–vis absorbance of the Fe-oxide/titanate/FTO film showed a red-shifted spectrum compared with the TiO2/FTO coated film; this red shift was achieved by the formation of thin hematite-Fe2O3 and anatase-TiO2 phases verified using X-ray diffraction and Raman results. The cyclic voltammetry results of the Fe2O3/TiO2/FTO films showed distinct reversible cycle characteristics with large oxidation–reduction peaks with low onset voltage of I–V characteristics under UV–vis light illumination. The prepared Fe2O3/TiO2/FTO film showed much higher photocurrent densities for more efficient water splitting under UV–vis light illumination than did the Fe2O3/FTO film. Its maximum photocurrent was almost 3.5 times higher than that obtained with Fe2O3/FTO film because of the easy electron collection in the current collector. The large current collection was due to the existence of a TiO2 base layer beneath the Fe2O3 layer. 相似文献
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为改善碳材料比电容低的问题以及氧化铁(Fe2O3)导电性和循环稳定性差的问题,采用氧化铁修饰生物质衍生碳(ATC)表面制备氧化铁/生物质碳(Fe2O3/ATC)复合材料,通过氧化铁和生物质衍生碳的协同效应使复合材料获得更高的比电容和更好的稳定性。利用扫描电镜(SEM)、X射线光电子能谱(XPS)、拉曼(Raman)光谱等技术手段对样品进行了表征。结果表明,制备的复合材料存在一定的孔隙结构,氧化铁纳米粒子被锚定在碳表面。当氧化铁和生物质衍生碳的质量比为1:1时,制备的复合材料具有最优的电化学性能,在3.0 mol/L氢氧化钾溶液中显示出430.8 F/g(电流密度约为1.0 A/g)的高比电容,电流密度增大20倍时电容保持率大于60%。将其作为负极构建的不对称超级电容器具有较高的电压窗口(0~1.6 V),并且实现了39.1 W·h/kg的高能量密度;同时表现出优异的循环稳定性,在电流密度为10 A/g下循环5 000次后拥有111%的电容保持率。 相似文献
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酶诱发均匀沉淀法制备纳米Fe2O3 总被引:3,自引:0,他引:3
《精细化工》2004,21(5):331-333
以硝酸铁和尿素为原料,草酸为掩蔽剂,室温下采用脲酶催化分解尿素诱发均匀沉淀,制备了纳米氧化铁前驱物.经TG-DTA,FTIR,XRD等测试表明,前驱物经热处理(500
℃,2 h)后,可得到α-Fe 相似文献
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B. Fernández J.M. AlmanzaJ.L. Rodríguez D.A. CortesJ.C. Escobedo E.J. Gutiérrez 《Ceramics International》2011,37(8):2973-2979
The effects of V2O5, NiO, Fe2O3 and vanadium slag on the corrosion of Al2O3 and MgAl2O4 have been investigated. The specimens of Al2O3 and MgAl2O4 with the respective oxides above mentioned were heated at 10 °C/min from room temperature up to three different temperatures: 1400, 1450 and 1500 °C. The corrosion mechanisms of each system were followed by XRD and SEM analyses. The results obtained showed that Al2O3 was less affected by the studied oxides than MgAl2O4. Alumina was only attacked by NiO forming NiAl2O4 spinel, while the MgAl2O4 spinel was attacked by V2O5 forming MgV2O6. It was also observed that Fe2O3 and Mg, Ni, V and Fe present in the vanadium slag diffused into Al2O3. On the other hand, the Fe2O3 and Ca, S, Si, Na, Mg, V and Fe diffused into the MgAl2O4 structure. Finally, the results obtained were compared with those predicted by the FactSage software. 相似文献
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Effects of fluoride fluxes, especially CaSiF6·2H2O upon phase equilibria in the system CaOAl2O3Fe2O3 are described, presenting liquidus data, new phase field boundaries and invariant points and solid solution areas. The primary phase field for C12?xA7·CaF2 is increased substantially in size, and liquidus or invariant temperatures are depressed by amounts ranging from 20 to 80°C. 相似文献
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L. Holz J. Macias N. Vitorino A.J.S. Fernandes F.M. Costa M.M. Almeida 《Ceramics International》2018,44(15):17962-17971
Yttria-stabilized zirconia (Y-TZP) samples with different Fe concentrations were prepared aiming to study the effects of Fe2O3 doping on colour and mechanical properties. Since colour is an important optical property for jewellery and watchmaking, the investigation of colour in zirconia ceramics has a great scientific and technological interest. An investigation of the mechanical and optical properties, specifically the colour, was developed starting from commercial partially yttria-stabilized zirconia (Y-TZP) powders produced by Emulsion Detonation Synthesis (EDS). Within the strategies to get colours, the use of colouring oxides such as iron oxide (Fe2O3) was the chosen approach. The addition of specific ions into the ZrO2 matrix can be used to tune zirconia colour without compromising its outstanding mechanical properties. Doping with iron oxide has proved to be a suitable, reproducible and irreversible colouring mechanism, allowing the development of a chromatically beige stable material with respect to its use in different processing conditions such as different atmospheres and temperature ranges. XRD results suggested that iron ions dissolved into tetragonal zirconia phase are at interstitial positions since the unit-cell volume of the tetragonal zirconia increases with increasing iron content. The effect of dopant addition on the mechanical properties of Y-TZP ceramics was also assessed. Compared to the undoped samples, doped ones exhibit a similar Vickers hardness (>1200?MPa) and biaxial flexural strength (>1000?MPa). However, it was observed that Fe2O3 doping slightly decreased the fracture toughness of Y-TZP ceramics. 相似文献
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纳米A12O3改性聚四氟乙烯力学性能的研究 总被引:4,自引:0,他引:4
通过压制和烧结,制备了纳米Al2O3改性聚四氟乙烯(PTFE),并研究了改性PTFE的物理机械性能。结果表明:纳米Al2O3粒子对PTFE有显著的增强作用,提高了复合材料的拉伸强度和硬度;降低了摩擦系数,但也使复合材料的断裂伸长率降低。 相似文献