Abstract Magnesia-chrome bricks are commonly used as the lining of smelters in copper and lead industry because of their resistance against the thermal, mechanical and chemical loads in the pyrometallurgical production process. In fact, the pyrometallurgical production process of lead-copper matte is generally a reducing process with plenty of coke and iron fillings as reducing agent, which implies that the magnesia-chrome bricks service in stronger reducing atmosphere. In this work, the microstructure, mechanical properties and slag resistance of such materials were investigated in reducing atmosphere to simulate the influence of the atmosphere on the properties of magnesia-chrome refractories. The results show that obvious increase in porosity and decrease in strength occurred to the magnesia-chrome samples after treating in reducing atmosphere. This is related to the structural damage of samples, in which Fe3+/Fe2+ within spinel (Mg, Fe)(Cr, Al, Fe)2O4 were partly reduced to metallic Fe under reducing atmosphere. Consequently, the slag penetrated much easily into the matrix of the samples. Moreover, the slag corrosion also aggravated due to the aggressive FeO in slag and the formation of magnesiowustite in the penetration layer. Nevertheless, the high melt phases of spinel and forsterite were formed when the slag corrosion test was conducted in air atmosphere, thereby preventing further slag corrosion and penetration.

中文翻译：

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气氛对镁铬砖力学性能和抗渣性的影响

摘要 镁铬砖由于在火法冶金生产过程中能抵抗热负荷、机械负荷和化学负荷，因此常被用作铜、铅工业冶炼厂的内衬。事实上，铅铜锍的火法冶金生产过程一般是一个还原过程，以大量的焦炭和铁填料为还原剂，这意味着镁铬砖在更强的还原气氛中工作。本工作在还原气氛中研究了此类材料的显微组织、力学性能和抗渣性，以模拟气氛对镁铬耐火材料性能的影响。结果表明，镁铬试样经还原气氛处理后，孔隙率明显增加，强度明显下降。这与样品的结构损伤有关，其中尖晶石 (Mg, Fe)(Cr, Al, Fe)2O4 中的 Fe3+/Fe2+ 在还原气氛下部分还原为金属 Fe。因此，炉渣很容易渗透到样品的基体中。此外，由于炉渣中的腐蚀性 FeO 和在渗透层中形成镁铁矿，炉渣腐蚀也加剧。然而，在空气气氛中进行渣腐蚀试验时，形成了尖晶石和镁橄榄石的高熔点相，从而防止了进一步的渣腐蚀和渗透。由于炉渣中具有腐蚀性的 FeO 和在渗透层中形成镁铁矿，炉渣腐蚀也加剧了。然而，在空气气氛中进行渣腐蚀试验时，形成了尖晶石和镁橄榄石的高熔点相，从而防止了进一步的渣腐蚀和渗透。由于炉渣中具有腐蚀性的 FeO 和在渗透层中形成镁铁矿，炉渣腐蚀也加剧了。然而，在空气气氛中进行渣腐蚀试验时，形成了尖晶石和镁橄榄石的高熔点相，从而防止了进一步的渣腐蚀和渗透。