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尖晶石对凝胶结合氧化铝空心球浇注料性能的影响 总被引:1,自引:0,他引:1
以5~3mm、3~2mm、2~1mm、1~0.2mm粒度氧化铝空心球为原料,引入二氧化硅微粉制成凝胶结合氧化铝空心球浇注料,研究了预合成镁铝尖晶石对凝胶结合氧化铝空心球浇注料性能的影响。用各种耐火制品检测设备和仪器对引入不同量尖晶石的试样性能进行了检测。结合氧化镁-氧化铝-二氧化硅相图进行理论分析,结果发现:尖晶石的引入促进了浇注料中刚玉相的烧结,提高了凝胶结合氧化铝空心球浇注料的常温耐压强度和显气孔率,降低了浇注料的体积密度。尖晶石对凝胶结合氧化铝空心球浇注料基质具有强化作用,有利于提高浇注料的热震稳定性 相似文献
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为了进一步减少钢包浇注料中低熔物组分的含量,提高浇注料的高温性能,以特级高铝矾土熟料为骨料,以97电熔镁砂粉、亚白刚玉细粉、铝镁尖晶石细粉和α-Al2O3微粉为基质料,研制了一种以铝凝胶为结合剂的新型无水泥钢包浇注料,并重点研究了铝凝胶加入量(3%、5%和7%,质量分数,下同)和电熔镁砂粉加入量(6%、8%、9%和10%)对浇注料性能的影响。研制结果表明,加入5%左右的凝胶细粉和6%~8%的电熔镁砂粉研制的钢包浇注料,其各项性能指标都达到了使用要求。现场试验发现,研制浇注料的一次使用寿命比普通的铝镁浇注料有一定的提高。但是从产品的性价比来看,试验效果不太理想,原因是此浇注料的抗渣侵蚀性能较差,并且在高温使用中的体积稳定性能也较差,导致其使用寿命不太稳定,有待进一步的研究。 相似文献
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以电熔刚玉、烧结刚玉、刚玉细粉、尖晶石微粉(<5μm)、氧化铝微粉(<2μm)、铝酸钙水泥(Secar 71)、电熔镁砂细粉为主要原料,制备了镁砂加入质量分数分别为1.5%、2.5%、3.5%的铝镁浇注料.测定1 500℃3 h处理后试样的体积密度、显气孔率、强度和加热永久线变化率,并在1 500℃3 h条件下进行抗高炉渣侵蚀试验.结果表明:随着镁砂加入量的增加,材料烧后的显气孔率增大,强度降低,抗高炉渣侵蚀性能下降.这主要是电熔镁砂在高温下与氧化铝反应生成尖晶石产生体积膨胀所至,因此,镁砂的加入质量分数以2.5%为宜. 相似文献
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铝镁浇注料具有优良的高温强度、抗蠕变性、抗热震性和较高的使用温度,其抗碱性渣的能力较强,不易与碱性渣发生反应,广泛应用于钢包包壁.作为起主要结合作用的氧化镁对铝镁浇注料性能影响较大,本文通过在铝镁浇注料中引入电熔镁砂细粉,分析了电熔镁砂细粉对铝镁浇注料性能的影响及影响机制.研究结果表明,在研究范围内,铝镁浇注料体密及强度随着电熔镁砂细粉含量基本呈现先增加后降低的变化规律,1773 K热处理试样弹性模量随着电熔镁砂细粉含量增大而增大,1373 K热处理加入11.5%电熔镁砂细粉试样线膨胀系数比9.5%电熔镁砂细粉的试样线膨胀系数大,1773 K热处理试样的线膨胀系数比1373 K热处理试样的大.综合铝镁浇注料在钢包的使用过程中各方面的性能,在现有颗粒级配工艺下,电熔镁砂细粉含量较为合适的配比值为9.5% ~ 10.5%. 相似文献
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针对镁质浇注料在使用过程中抗渣渗透能力差,易剥落等问题,本实验加入铝镁尖晶石对镁质浇注料进行改性研究.实验分为两部分:先将镁砂细粉、镁质添加剂和铝镁尖晶石细粉等机压成型,进行高温热处理,研究其物相组成和显微结构;然后以电熔镁砂为骨料,电熔镁砂细粉、氧化铝微粉、铝镁尖晶石细粉和镁质添加剂为基质,按骨料:细粉=75∶25进行配制,研究铝镁尖晶石加入量对镁质浇注料性能的影响.结果表明:在镁质材料中引入尖晶石,能促进结构致密化;加入9%的铝镁尖晶石的浇注料试样显气孔率低,线变化率小,体积密度大,强度大,抗渣性能最好,由于镁铝尖晶石生成时体积膨胀,使得材料结构致密化;同时能有效吸收渣中CaO及FeOx等成分,减少渣的渗透作用,从而提高了浇注料的抗渣性能. 相似文献
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水泥和水合氧化铝对铝镁浇注料性能的影响 总被引:1,自引:0,他引:1
固定电熔白刚玉、电熔镁砂粉、αAl2O3微粉、SiO2微粉等原料的含量不变,分别加入不同量的水合氧化铝和纯铝酸钙水泥作结合剂(ρAl2O3加入量为2%、3%和4%,水泥加入量为3%、5%和7%),对比研究了水泥结合和水合氧化铝结合铝镁浇注料的显气孔率、体积密度、耐压强度、抗折强度、抗热震性和抗渣性能。结果表明:与水泥结合铝镁浇注料相比较,水合氧化铝结合浇注料具有更好的抗热震性、抗渣侵蚀和渗透性能;水合氧化铝在浇注料中的合适加入量为3%;水泥结合铝镁浇注料具有较高的常温强度,但其抗渣侵蚀和渗透性能随着水泥含量的增加而逐渐降低。 相似文献
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Jean-Michel Auvray Christian Gault Marc Huger 《Journal of the European Ceramic Society》2008,28(10):1953-1960
This paper deals with the evolutions of thermo-mechanical properties of castable refractories versus temperature. The measured properties are mainly Young's modulus evaluated by a high temperature ultrasonic technique and thermal expansion followed by dilatometry. Materials are alumina-based low cement castables with a fraction of alumina eventually substituted by spinel or magnesia. The granularity of the different used raw materials is chosen by using a packing model, in order to reduce the final porosity in the hydrated state. The interpretation of results is carried out by considering the materials as composites, constituted of aggregates (size > 100 μm) into a matrix where most of chemical and phase transformations occur. By using two-phase analytical models, it is shown that the evolutions of thermo-elastic properties of castables can be qualitatively predicted from measurements performed in a matrix-equivalent simplified material. Moreover, considering the elastic properties after heat treatment, the castable with magnesia is comparable to the castable processed with synthetic spinel. 相似文献
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Satyam Kumar Ritwik Sarkar 《International Journal of Applied Ceramic Technology》2024,21(3):1527-1542
The role of alumina dispersant as a flow modifier, completely replacing fume silica, on the properties of preformed and in situ spinel-containing low cement high alumina castables was investigated with variations in spinel content and granulometry. Both 10 and 20 wt.% spinel-containing compositions were prepared using preformed spinel or magnesia in alumina castable compositions with vibratable and self-flowing consistency. The castables underwent conventional processing methods and accessed for various refractory-related parameters post-heat treatments. No glassy phase was observed in the castables upon firing. The presence of self-flowing consistency led to improved characteristics. Preformed spinel-containing compositions showed improved density, strength, hot strength, and thermal shock resistance properties, whereas slag corrosion and penetration resistances were found to be higher for in situ spinel-containing castable. 相似文献
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The addition of nanoscaled alumina and magnesia particles to the matrix of alumina–magnesia refractory castables drastically reduces the residual expansion related to the in situ spinel formation. Nonetheless, as their benefits on other relevant properties have not been reported so far, the effectiveness of such nanoengineering design for castables applied in steel ladles is still uncertain. In the present work, not only the expansion level, but also the corrosion resistance, the hot modulus of rupture and the creep deformation of different nanoparticle-containing castables were evaluated and compared with the results attained by refractory materials designed only by micrometric-scaled Al2O3 and MgO. Although the addition of a nanoalumina and nanomagnesia mixture ensured the best results regarding to the expansive behavior, thermo-mechanical and thermo-chemical properties, its performance was only slightly superior to the castable containing micrometric alumina and magnesia particles. Therefore, as the cost–benefit ratio is one of the main requirements for the end users, the nanotechnology use in the refractory production must be previously carefully analyzed. 相似文献