Despite the numerous advantages of using and recycling aluminum, inevitable by-products in the form of non-metallic residues (NMR) of aluminum white dross (AWD) can be environmentally harmful. The aim of this study was to find a solution regarding aluminum treatment via pyrometallurgical methods and, ultimately, to obtain calcium aluminate (CA) flux for the iron and steel industries. The optimum parameters, such as temperature, duration, and particle size of the limestone, for CA production from the NMR of AWD were investigated. Calcination experiments were divided into two categories. The aim of the first set of experiments was to increase alumina (Al₂O₃) purity and remove nitrogen (N) in the rotary furnace. N content was reduced to 0.25 wt% at 1150 °C and 2 h duration, while Al₂O₃ purity reached 94.67 wt% as the optimum results for the calcination experiments. The obtained results were also compatible with thermodynamic simulations. In the second set of experiments, NMR of AWD was synthesized via the addition of limestone to obtain CA. It was observed that the crushed limestone favors the forming of CA phases. Last, in order to determine the optimum fusing condition, the fusion process was applied 1350, 1450, and 1550 °C to mixture of limestone and NMR. It was observed that the material completely melted at 1550 °C and phases containing CA were formed. The produced samples were characterized by X-ray diffraction (XRD), atomic absorption spectroscopy (AAS), and N analyzer.

Graphical Abstract

中文翻译：

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铝白渣渣生产电熔铝酸钙

尽管使用和回收铝有许多优点，但铝白渣 (AWD) 的非金属残留物 (NMR) 形式的不可避免的副产品可能对环境有害。本研究的目的是找到一种通过火法冶金方法处理铝的解决方案，并最终获得用于钢铁行业的铝酸钙 (CA) 熔剂。研究了从 AWD 的 NMR 生产 CA 的最佳参数，例如温度、持续时间和石灰石的粒度。煅烧实验分为两类。第一组实验的目的是提高氧化铝 (Al ₂ O ₃ ) 的纯度并去除回转炉中的氮 (N)。在 1150 °C 和 2 小时的持续时间下，N 含量降低到 0.25 wt%，而 Al₂ O ₃纯度达到94.67 wt%作为煅烧实验的最佳结果。获得的结果也与热力学模拟兼容。在第二组实验中，通过添加石灰石合成 AWD 的 NMR 以获得 CA。据观察，粉碎的石灰石有利于 CA 相的形成。最后，为了确定最佳熔合条件，熔合工艺分别在 1350、1450 和 1550°C 下应用于石灰石和 NMR 的混合物。观察到该材料在 1550 °C 时完全熔化并形成了含有 CA 的相。所生产的样品通过 X 射线衍射 (XRD)、原子吸收光谱 (AAS) 和 N 分析仪进行表征。

图形概要