The aim of this work is to produce α-alumina particles from aluminum (Al) dross via leaching–precipitation–calcination processes. In the leaching test, the effects of parameters such as the temperature, NaOH concentration, and time were investigated based on the Taguchi approach. In addition, the effect of the particle size on the Al extraction rate was determined. The Al extraction rate ranged from 78.64% to 93.11% and from 78.35% to 91.99% for ground dross and as-received dross, respectively. In the precipitation test, the pH of the leachate solution was decreased using HCl to remove Al ions as Al hydroxide precipitate. The precipitate was calcined at 1000°C to 1200°C for 270 min. The morphological and polymorphic properties of the products were characterized by scanning electron microscopy, atomic force microscopy, and x-ray diffraction analysis. The experimental findings indicated that the calcination temperature and stabilization time were critical for producing α-alumina particles rather than other polymorphs.

中文翻译：

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用 NaOH 浸取和煅烧从黑色铝渣中生产 α-氧化铝

这项工作的目的是通过浸出-沉淀-煅烧过程从铝 (Al) 浮渣生产 α-氧化铝颗粒。在浸出试验中，基于田口方法研究了温度、NaOH 浓度和时间等参数的影响。此外，还确定了粒径对 Al 提取率的影响。对于磨碎的浮渣和原样的浮渣，Al 提取率的范围分别为 78.64% 至 93.11% 和 78.35% 至 91.99%。在沉淀试验中，使用 HCl 降低浸出液的 pH 值以去除铝离子作为氢氧化物沉淀。将沉淀物在 1000°C 至 1200°C 下煅烧 270 分钟。通过扫描电镜、原子力显微镜、和 X 射线衍射分析。实验结果表明，煅烧温度和稳定时间对于生产 α-氧化铝颗粒而不是其他多晶型物至关重要。