The effect of CaO fluxing on slag morphology was investigated during the reduction of FeO in electric arc furnace slag by aluminum black dross (ABD). Macro- and microscopic observations, by evaluating entrapped gas bubbles and reduced iron droplets related to gas evolution, apparent slag morphologies, and vertical section of slag at different initial CaO contents and reaction times, confirmed that both aluminothermic (dominant reaction) and carbothermic (minor) reduction occurred. Thus, the production of CO(+CO 2 ) gas caused swelling-shrinking phenomena with repeated expansion and collapse of the slag pellet. In addition, macroscopic observation of slag morphologies as a function of the initial CaO content is well associated with quantitative consideration of the apparent viscosity as well as spinel ([Mg,Fe]Al 2 O 4 ) activity. Consequently, appropriate CaO fluxing is necessary to control the composition of highly fluid slag by changing the slag from a high-alumina system to calcium–aluminosilicate melts when utilizing ABD as a reducing agent.

中文翻译：

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铝黑渣对电弧炉渣中 FeO 还原的观察：CaO 熔剂对渣形态的影响

在用铝黑渣 (ABD) 还原电弧炉渣中的 FeO 过程中，研究了 CaO 熔剂对渣形态的影响。宏观和微观观察，通过评估与气体逸出、表观渣形态和不同初始 CaO 含量和反应时间下渣的垂直截面相关的夹带气泡和还原铁滴，证实了铝热（主要反应）和碳热（次要反应） ) 减少。因此，CO(+CO 2 ) 气体的产生引起溶胀收缩现象，伴随着矿渣球团的反复膨胀和坍塌。此外，作为初始 CaO 含量函数的炉渣形态的宏观观察与表观粘度以及尖晶石 ([Mg,Fe]Al 2 O 4 ) 活性的定量考虑密切相关。最后，