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为取代RH炉用镁铬材料,以电熔镁砂为主原料,分别加入单斜锆、脱硅锆、单斜锆与脱硅锆的混合粉、锆英石制备了ZrO2质量分数分别为15%和20%的镁锆砖,并利用静态坩埚法对比研究了镁锆砖和镁铬砖的抗RH炉渣侵蚀性。结果表明:对于Al2O3含量高且碱度(CaO/SiO2比)大的RH炉渣,镁锆砖抗侵蚀性能优于镁铬砖的;镁锆砖的侵蚀机理是砖中的ZrO2与渣中的CaO迅速反应,形成高熔点物相CaZrO3,能堵塞砖中的孔隙而形成致密保护层,从而阻止钢渣对镁锆砖的进一步侵蚀;而镁铬砖的侵蚀机理是渣中的Al2O3、Fe2O3等R3 和镁铬尖晶石中Cr3 交换,渣与砖反应生成的镁铝尖晶石和镁铁尖晶石使得材料变性,同时由于体积效应使镁铬材料鼓胀开裂,从而导致镁铬砖的严重侵蚀。 相似文献
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以高铝矾土熟料、90碳化硅、棕刚玉为主要原料,添加红柱石粉、广西白泥等外加剂,通过合理的颗粒级配,采用高压成型、高温烧成等方法,制备出水泥窑用特种硅莫砖,并研究了烧成后试样的体积密度、气孔率、强度、微观结构和耐磨性.结果表明:添加6%红柱石粉在1420℃制备的硅莫砖的性能最优,其体积密度为2.74 g/cm3,抗热震性30次,磨损量为1.06 cm3,热导率为1.65 W/(m·K),耐压强度高达159 MPa,在5000 t/d水泥回转窑过渡带上使用该产品,寿命可达一年以上,这是由于窑简体外表面温度比使用镁尖晶石砖平均降低80℃以上,极为有效地延长了该砖衬的使用寿命. 相似文献
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The composition and microstructure of a periclase–composite spinel brick used in the burning zone of a cement rotary kiln were investigated and compared to the original brick. The results indicate that cement clinker and alkali salts are two important agents that cause corrosion especially of the bonding phase of refractories in cement rotary kilns. When the molar ratio of alkalis to anions ((Na+K)/(Cl+2S)) is more than one, alkali salts accumulated in the pores, cracks and grain boundaries of the refractory but the severe corrosion of the bonding phase of the refractory did not occur in zones with lower temperatures. The interaction between the cement clinker and the refractory formed a liquid, which, together with alkali salts, improved sintering. The reaction between the cement clinker and the refractory formed a dense reaction layer. Cracks formed in the dense layer and extended through the boundary between the reaction and non-reaction (penetrated) layers by mechanical and thermal stress, which caused the spalling of the reaction and coating layer from the refractory. The recurrence of this process during service leads to degradation of the refractory. 相似文献
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《Ceramics International》2016,42(13):14765-14773
Al2O3-SiC-SiO2-C refractories are widely used as blast furnace hearth lining but have low oxidation resistance in the presence of CO2. Carbon composite brick is a newly developed Al2O3-SiC-SiO2-C refractory that may function better in the blast furnace hearth due to improved erosion-resistance and high thermal conductivity. In this study, the oxidation behavior and kinetics of carbon composite brick, carbon brick, and corundum brick were investigated in CO2 atmosphere. The results show the oxidation resistance of carbon composite brick was better than that of carbon brick but worse than that of corundum brick. SiC functions as an antioxidant to play an important role in the oxidation process. For carbon composite brick, the oxidation activation energy was 141.72 kJ/mol at the step controlled by the interface reaction and 161.24 kJ/mol at the step controlled by gas diffusion. Carbon composite brick exhibits improved thermal conductivity and oxidation resistance relative to carbon brick and corundum brick that should allow improved performance in blast furnace hearth lining. 相似文献
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高炉炉身采用高导热高强度石墨砖技术 总被引:1,自引:0,他引:1
为了提高高炉的使用寿命和产能,宝钢4号高炉的炉身采用了密集式冷却板加高导热、高强度石墨砖的内衬结构。为减缓炉衬使用过程中受热应力的影响,在研究石墨砖及配套胶泥的技术指标到具体的结构设计等过程中,都采取了特殊方法。 相似文献
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The state-of-art of magnesia-chrome refractories from direct-bonded magnesia chroma brick to fused-grain rebounded magnesia chrome brick for P-S converter is discribed.The Cr2O3 conternt of the brick is continually increased with the reduction of the impurity content of brick ,the pre-synthetic raw material is applied and the operating condition of conerter is optimized so that the service life of converter is largely enhanced. 相似文献
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根据显微结构特征分析研究了水泥回转窑用无铬碱性耐火材料的性能和发展。这些氧化镁基或白云石基材料,引入低膨胀性且抗侵蚀的加入物改善其显微结构。镁铝尖晶石砖是从直接加入粒状氧化铝、烧成过程中生成原生尖晶石,到直接加入预合成的尖晶石,发展至细粒晶型尖晶石再增强的含电熔尖晶石镁质砖;白云石砖以其良好的对水泥熟料的粘着性而被广泛用于水泥回转窑烧结带,加入氧化镁粉和氧化锆改善其基质增强了抗侵蚀性及抗热震稳定性;新发展的氧化镁-铁铝尖晶石和氧化镁-锰铝尖晶石耐火材料以其优越的柔性而被用于轮箍部位。 相似文献
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水泥窑用镁铬砖的残砖中铬含量较高,对环境危害大。为降低铬盐对环境的危害,牡丹江新材料科技股份有限公司在水泥窑上进行了使用低铬砖和无铬砖的试验。试验表明,加锆改性尖晶石砖的使用情况较直接结合镁铬砖差,而加铬方镁石复合尖晶石砖(LYC砖)的使用效果好于直接结合镁铬砖。LYC砖不仅铬含量低,对环境的危害小,且其使用寿命是普通镁铬砖的5倍,是直接结合镁铬砖的1.72倍。使用LYC砖对提高窑运转率,降低生产成本有利。 相似文献
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LI Jiwei ZHOU Ningsheng BAI Hongyu High Temperature Materials Institute Henan University of Science Technology Luoyang China Yanshi Zhongyue Refractories Co. Ltd. Yanshi China 《中国耐火材料》2008,17(4)
MgO-ZrO2 unfired bricks with ZrO2 content up to 8% at the interval of 2% were prepared,using fused magnesia(MgO:97%)and fused MgO-ZrO2 clinker(ZrO2:14.33%)as starting materials and phenolic resin as binder.The effects of ZrO2 content on thermal shock resistance(TSR)and other properties such as cold and hot modulus of rupture have been investigated.Residual cold modulus of rupture ratio after heating at 1 000 ℃ and quenching by air blowing was adopted to characterize TSR.Addition of the MgO-ZrO2 clinker impr... 相似文献
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介绍了RH插入管的使用条件、损毁机理,并从浇注料、镁烙砖、金属壳体等几方面入手,对现用插入管进行了技术改进。改造后的产品在大钢二炼钢RH炉上使用,最高寿命达到了108次,基本上满足了生产需要。 相似文献