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Wen Yan Guiyuan Wu Sanbao Ma Stefan Schafföner Yajie Dai Zhe Chen Jiangtao Qi Nan Li 《Journal of the European Ceramic Society》2018,38(12):4276-4282
This study presents a new lightweight periclase-magnesium alumina spinel castable (LPSC) for the working lining of steel ladles using porous periclase-spinel aggregates to replace conventional dense magnesia aggregates. The porous periclase-spinel aggregates were produced by an in-situ decomposition technique resulting in an apparent porosity of 23.3% and a median pore size of 5.66?μm. Scanning electron microscopy revealed a better porous aggregate/matrix interface bonding in the LPSC, which significantly improved its strength and thermal shock resistance. Additionally, the higher amount of micropores of the porous aggregates in the LPSC absorbed more penetrated slag from the matrix, which enhanced the slag resistance. Thus, compared with conventional castables, the LPSC had a lower bulk density of 9.2–10.8% and a lower thermal conductivity of 18.8% (1000?°C) while at the same time a higher strength, thermal shock resistance and slag resistance was achieved. 相似文献
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Si3N4对镁质浇注料抗渣性能的影响 总被引:1,自引:0,他引:1
以95烧结镁砂为主要原料,以SiO2微粉为结合剂,在配料的细粉部分分别以0、3%、4%、5%的β-Si3N4细粉替代等量的镁砂细粉,搅拌均匀后浇注成氮化硅含量不同的镁质坩埚试样。选用宝钢中间包渣,采用静态坩埚法,在1550℃3h条件下对这些坩埚试样进行了抗渣试验。试验结果表明:加入Si3N4可以明显改善镁质浇注料的抗渣性能,并且随着Si3N4加入量的增加,试样的抗渣性能提高;在含氮化硅的镁质浇注料表面,由于Si3N4被氧化为SiO2而形成了致密烧结层,能阻止渣的进一步渗透;在加入Si3N4的镁质浇注料试样内部深处,由于氧分压非常低,Si3N4稳定存在;由于Si3N4在还原气氛下难以烧结,造成镁质浇注料内部结构疏松。 相似文献
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在以8~5mm(18%,质量分数,下同)、5~3mm(18%)、3~1mm(22%)的97高纯镁砂和≤1mm(12%)的97电熔镁砂为骨料,≤0.088mm(20%)的97电熔镁砂,SiO2微粉(2%),α-Al2O3微粉(5%),亚白刚玉粉(3%)为基质细粉,六偏磷酸钠等为复合分散剂的镁质浇注料基础配方中,分别用5%、8%、15%的铬矿砂(0.833~0.178mm和≤0.088mm的混合料)等量替代≤0.088mm的电熔镁砂制成不同铬矿含量的镁质浇注料试样。分别测试样经110℃24h、1100℃3h和1550℃3h处理后的线变化率、显气孔率和抗折强度,并利用SEM和EDX分析1550℃3h处理后试样的显微结构。结果表明:(1)镁质浇注料中加入适量的铬矿,有利于提高方镁石晶粒间的直接结合强度,使材料抗折强度提高,显气孔率下降;适量微裂纹的产生有利于浇注料抗热震性的提高。铬矿的适宜加入量为5%~8%。(2)SEM和EDX分析表明,试样经1550℃3h处理后,铬矿和镁砂呈相互扩散,并脱溶出二次尖晶石,增强了晶粒间的直接结合程度,从而有效地提高了镁质浇注料的力学性能。 相似文献
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将宝钢RH炉废镁铬砖和电熔镁砂均破碎成5~3mm、3~1mm、<1mm的粒度,添加3%的粒度<1μm的二氧化硅微粉,按照浇注料的生产工艺制备了镁铬浇注料,研究了废镁铬砖在镁质浇注料中的应用。结果表明:浇注料悬浮液的碱度可控制在pH值=7~9,用0.15%(质量分数,下同)的六偏磷酸钠为减水剂时,该悬浮液ζ电位的绝对值最大,悬浮液最稳定,分散性也最好。随着废镁铬砖加入量的降低,烘干、中温和高温处理后的耐压强度、抗折强度、体积密度均逐渐增大。废镁铬料添加量为36%的试样FM3的性能指标均达到了纯镁质浇注料M4的;试样FM3对渣的抗熔蚀性能要优于试样M4的。 相似文献
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This study investigated the reaction between CaO-SiO2-Al2O3-xFeO-MgO-MnO (CaO/SiO2?=?1.2, x?=?20–50?wt%) slag and magnesia refractory. Using SEM-EDS analysis, we confirmed the formation of a (Mg,Fe)Oss(solid_solution), called magesiowüstite (MW), intermediate layer at the slag-refractory interface. MgO dissolved from refractory and reacted with the bulk slag to form MW layer at the interface. Simultaneously, slag penetrated through micro-pores and reacted with the refractory to form MW layer. In other words, the MW layer built up in both directions from initial refractory-slag interface. The thickness of the MW layer increased as the FeO content in the slag increased, and using EDS line scanning, a Mg and Fe concentration gradient was confirmed within the MW layer. The slag, which penetrated into the refractory, had a chemical composition of the CaO-SiO2-Al2O3-MgO system without FeO, indicating that FeO was consumed by forming a MW layer at the refractory hot face. The slag-refractory interfacial reaction was simulated using thermochemical software, FactSage?7.0. The results predicted a MW monoxide composed of MgO and FeO. A spinel phase was formed when FeO was greater than 40?wt%. These thermochemical computations were comparable to our experimental findings. 相似文献
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以电熔镁砂、二氧化硅微粉、MA尖晶石粉、α-Al2O3微粉、氧化铁粉为原料制备MgO-Al2O3质浇注料,研究氧化铁粉加入量(0、2%、4%、6%)对MgO-Al2O3质浇注料常温物理性能、抗热震性和抗渣性的影响.按照国家相关标准进行各项物理性能检测,并用X射线衍射仪对1550℃3 h烧后试样进行物相分析,采用风冷法进行抗热震性试验,静态坩埚法进行抗渣试验.结果表明加入氧化铁粉对MgO-Al2O3质浇注料的抗渣渗透性能和常温力学性能有利.随着基质中氧化铁粉加入量的增加,试样抗渣侵蚀能力有所减弱,抗渣渗透能力明显增强,试样经1100℃3 h和1550℃3 h热处理后的常温力学性能得以提高,但抗热震性降低.氧化铁粉加入量≤2%时,试样的抗热震性较好. 相似文献
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基质组成对MgO-尖晶石浇注料抗渣性能的影响 总被引:2,自引:2,他引:0
采用静态坩埚法研究了添加不同组成尖晶石的MgO- 尖晶石浇注料基质组成与抗渣性能的关系。实验结果表明:随着基质中Al2O3 含量增加,浇注料抗渣侵蚀能力减弱,而抗渣渗透能力增强。在基质中SiO2 含量固定在10 % 的情况下,基质中Al2O3 含量在30 % ~50 % 时浇注料抗渣侵蚀性能较好;Al2O3 含量超过50 % 时,侵蚀速率急剧增加两倍以上。不同组成尖晶石对浇注料抗渣侵蚀性能没有明显影响,但含富铝尖晶石的浇注料具有较好的抗渣渗透性能。 相似文献
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主要研究了SiO2 微粉、MgCl2 ·6H2 O和ρ Al2 O3 3种结合剂对镁质浇注料的耐压强度、显气孔率和抗水化性能的影响。结果表明 :采用SiO2 微粉和MgCl2 ·6H2 O为结合剂时 ,镁质浇注料 110℃2 4h处理后的耐压强度和抗水化性能优于采用ρ Al2 O3 的 ;采用MgCl2 ·6H2 O和 ρ Al2 O3 为结合剂时 ,浇注料 110 0℃ 3h热处理后的耐压强度明显下降 ;经 16 0 0℃ 3h热处理后 ,浇注料的耐压强度随着SiO2 微粉含量的增加先增大后减小 ,而MgCl2 ·6H2 O的影响较小 ,随着 ρ Al2 O3 加入量的增大浇注料的耐压强度明显降低。 相似文献
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采用致密电熔刚玉、氧化铝粉、黑碳化硅为主要原料,固体磷酸铝为结合剂,研究分别加入8%、10%、12%、14%和16%富镁尖晶石对Al2O3-SiC浇注料性能的影响。结果表明富镁尖晶石是固体磷酸铝结合Al2O3-SiC质浇注料较好的促凝剂,但其加入量不宜太多,最佳加入量为12%。 相似文献
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Hongfeng Yin Kui Gao Qifa Wan Yalou Xin Yun Tang Hudie Yuan 《Ceramics International》2021,47(15):21310-21318
Lightweight corundum-spinel refractory with a density gradient structure from exterior to interior was fabricated. Slag resistance of lightweight and dense corundum-spinel refractory is investigated by X-ray diffraction, scanning electron microscopy, energy dispersive analysis, mercury intrusion porosimetry and Factsage. The results show that lightweight corundum-spinel refractory with high apparent porosity exhibits comparable slag resistance to dense corundum-spinel refractory, especially with superior slag penetration resistance. The dense exterior with small pore size in the lightweight corundum-spinel refractory can effectively hinder slag penetration. Corrosion product phases (C2S, CA2, CA6, and C2M2A14) with high melting point and inconsistent melting temperature, most of Fe and Mn elements in steel slag solubilizing in spinel, especially strip CA6 around corundum aggregate, prevent the refractory from further slag penetration and corrosion. 相似文献
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对钢包用后镁碳砖进行拣选、除杂、破碎、颗粒分离处理,制成回收料,研究回收料加入量和粒度对镁碳砖性能的影响.结果发现:(1)引入回收料均不同程度降低了镁碳砖的致密度、常温耐压强度、高温抗折强度和抗渣侵蚀性,以引入≤0.074 mm回收料对其各项性能降低程度影响最大.(2)引入5~3 mm回收料对镁碳砖致密度影响最小,平均引入1%质量分数的5~3 mm回收料,其体积密度降低0.003 9 g·cm-3,显气孔率增加0.108 7%.(3)引入3 ~1 mm 回收料对镁碳砖常温耐压强度和高温抗折强度影响最小,乎均引入1%质量分数的3 ~1 mm回收料,其常温耐压强度降低1.66 MPa,高温抗折强度降低0.11 MPa. 相似文献
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Role of Mg(OH)2 in pore evolution and properties of lightweight brine magnesia aggregates 总被引:1,自引:0,他引:1
《Journal of the European Ceramic Society》2023,43(8):3778-3787
Lightweight magnesia aggregates were fabricated using high-purity MgO agglomerates with the addition of Mg(OH)2 as a pore former. The pore evolution and its relationship to the resulting properties were investigated. Mg(OH)2 decomposition increased the number of inter-agglomerate pores, which subsequently affected the porosity and pore structure. When Mg(OH)2 was 0–20 wt%, the inter-agglomerate pores were converted to both open and closed small pores, which effectively reduced the thermal conductivity and improved the thermal shock resistance (TSR) by accommodating thermal stress and inducing crack deflection. Small pores also favored the formation of a dense (Mg, Fe)O corrosion layer, preventing further slag penetration. However, large open pores occurred with further increasing Mg(OH)2 content, which dramatically deteriorated the TSR and slag resistance. The specimen with 20 wt% Mg(OH)2 exhibited the best overall performance, with a thermal conductivity of 16.6 W/(m·K) at 500 °C, and a residual flexural strength ratio of 32.3%; its slag resistance was comparable with that of dense magnesia. 相似文献
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研究了锆英石微粉对镁质浇注料结构及性能的影响。结果表明:微粉粒径一定时,控制锆英石微粉加入量可以明显改善镁质浇注料显微结构和性能。由于MgO同ZrSiO4反应形成的ZrO2,能吸收渣中的CaO形成CaZrO3,堵塞材料中的气孔,同时提高熔海粘度,抑制了渣的渗透。 相似文献
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《Ceramics International》2023,49(5):8058-8070
This article aims to illustrate the influence of the composite micro-powder of α-Al2O3 and zirconium basic carbonate (ZBC) on the microstructure, mechanical and thermal properties, and slag resistance of corundum castable. The results show that the addition of the composite micro-powder to corundum castable sintered at 1550 °C optimized its pore structure, which presented an apparent porosity of 16.8% and a slump in pore size from 10.80-45.72 μm to 0.36–1.83 μm. The ZrO2 dissolving from ZBC combined with corundum matrix to form “intergranular” and “intragranular” submicron structures, which promoted the densification of matrix structure and improved the strength of castable by 25.8%–42.9%. In terms of slag resistance, castable with composite micro-powder saw an absorption of liquid slag in micropores and a Cr-rich complex spinel blocking layer with high melting point during slag erosion. Moreover, the in-situ ZrO2 could enter slag to boost its viscosity, thus inhibiting the penetration capacity. Consequently, the penetration and erosion ratios of castable reduced by 6.32% and 83.99%, respectively. 相似文献