物理富集—熔盐电解法从二次铝灰回收金属铝

二次铝灰是铝工业生产过程中产生的固体废弃物，含有金属铝、氧化铝和氮化铝等。通过球磨—筛分富集铝灰中的金属铝，研究球磨过程铝灰的粒度分布和金属铝的分离规律。结果表明，球磨后铝灰中的金属铝粒径变大，而其他盐类组分变细。较优条件是球磨3 h并筛分，粒度范围97～150μm的铝灰中金属铝的质量分数为24.51%，金属铝的质量占原料中金属铝总质量的41.40%。在冰晶石熔盐中电解最优条件下球磨—筛分后的铝灰，XRF分析表明：电解产物中Al和Si的质量分数分别为97.3%和1.6%，铝回收率为45.89%，电流效率为46.06%。

Recovery of metallic aluminum from secondary aluminum dross by physical enrichment and molten salt electrolysis

Secondary aluminum dross is a kind of solid waste produced in the aluminum industrial production process, containing metallic aluminum, alumina, aluminum nitride and other substances. In this paper, we enriched metallic aluminum in aluminum dross by ball milling and screening, and study the particle size distribution of aluminum dross and the separation law of aluminum in the ball milling process. The results showed that ball milling made the metallic aluminum in aluminum dross larger in particle size, while other components became finer. The optimal conditions were ball milling for 3 h and screening. Material characterization studies have revealed that the metallic aluminum content in aluminum dross with a particle size range of 97~150 μm was 24.51%. In contrast, metallic aluminum's mass accounted for 41.40% of the aluminum's total mass in the as-received dross. The aluminum dross was electrolyzed under the optimal conditions of ball milling and screening in cryolite molten salt, and the mass fractions of Al and Si in the electrolysis products were 97.3% and 1.6% by XRF analysis, respectively. The metal yield of the aluminum alloy product obtained by the electrolysis was 45.89%, and the current efficiency was 46.06%.