【摘要】 研究了脉石成分对铁矿球团还原膨胀性能的影响。以纯铁矿物为原料采用压块-焙烧-还原方法进行的研究表明:纯赤铁矿团块的还原膨胀率明显大于纯磁铁矿团块;CaO、SiO2、MgO、Al2O3可显著降低赤铁矿团块的还原膨胀率;SiO2、MgO可在一定程度上降低磁铁矿团块还原膨胀率,CaO、Al2O3则使磁铁矿团块的还原膨胀率增大。在此基础上研究了赤铁精矿为主配加磁铁精矿制备的氧化球团矿的还原膨胀性能,确定了抑制球团矿还原膨胀的适宜添加物及其用量。对CaO导致球团异常膨胀的机理进行了探讨:在浮氏体还原成金属铁的过程中,固溶于铁氧化物晶格中的Ca2+会促进“铁晶须”的生成与发展,导致球团产生异常膨胀。更多还原

【Abstract】 The effect of gangue composition on reduction swelling of iron ore pellets was investigated.The briquettes were prepared by briquetting-baking-reducing process.The results show,that reduction swelling index(RSI) of pure hematite briquettes is markedly greater than that of pure magnetite ones.With adding gangue components such as CaO,SiO2,MgO,Al2O3,the RSI of hematite briquettes is reduced obviously.However,SiO2 and MgO can decrease but CaO and Al2O3 increase RSI of magnetite briquettes to a certain extent.RSI of oxidizing pellets prepared from hematite concentrate added with magnetite concentrate and gangue components were also studied and the reasonable content of gangue components were detemined.The mechanism of abnormal swelling caused by CaO is that Ca2+ in crystal lattice of iron oxide accelerates the formation and growth of metallic iron whisker during the reducing procedure from wüstite to metallic iron giving abnormal swelling.更多还原