A large amount of carbon dust is generated in the process of aluminum smelting by molten salt electrolysis. The carbon dust is solid hazardous waste but contains a large quantity of recyclable components such as carbon and fluoride. How to recycle carbon dust more effectively is a challenge in the aluminum electrolysis field. In this study, X-ray diffraction, scanning electron microscope, and other methods were used to analyze the phase composition of electrolytic aluminum carbon dust. The effects of particle size distribution of carbon dust, impeller speed, reagent addition, mixing time, and flotation time on the flotation recovery of carbon dust were studied. The optimal flotation conditions were obtained and the flotation products were analyzed. The results show that the optimal particle size distribution is 70% of particles below 200 mesh, corresponding to a grinding time of 11 min. The optimum speed of the flotation machine was to be between 1600 and 1800 r/min with the best slurry concentration of 20–30% and 5 min mixing time, and the collector kerosene was suitable for adding in batches. Under the above conditions, the recovered carbon powder with a carbon content of 75.6% was obtained, and the carbon recovery rate was 86.9%.

中文翻译：

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泡沫浮选法从电解铝粉尘中回收碳的研究

在铝通过熔融盐电解进行熔炼的过程中会产生大量的碳粉尘。碳尘是固体危险废物，但包含大量可回收成分，例如碳和氟化物。如何更有效地回收碳粉尘是铝电解领域的一个挑战。在这项研究中，使用X射线衍射，扫描电子显微镜和其他方法来分析电解铝碳尘的相组成。研究了碳粉粒度分布，叶轮转速，试剂添加量，混合时间和浮选时间对碳粉浮选回收率的影响。确定了最佳浮选条件，并对浮选产物进行了分析。结果表明，最佳粒度分布是200目以下的颗粒的70％，对应于11分钟的研磨时间。浮选机的最佳速度为1600至1800 r / min，最佳浆料浓度为20％至30％，混合时间为5分钟，并且收集器煤油适合分批添加。在上述条件下，获得了碳含量为75.6％的回收碳粉，碳回收率为86.9％。