Recovery of Silicon and Iron Oxides from Alumina-Containing Sweepings of Aluminum Production

Abstract

The method of recovery of contaminating components from sweepings of the aluminum production for their further return into the electrolyzer is proposed. To concentrate the material, the following processing flowsheet is proposed: milling-classification-reverse flotation-thickening. For the most complete removal of silicon and iron oxides during the flotation of sweepings, the Flotigam 7266 flotation reagent produced by Clariant (Germany), which is a mixture of primary fatty alkyl amines, is used. To remove carbon particles, the combination of pine oil in a mixture with kerosene is used. Flotation is performed using a FML 0.3 flotation machine. The initial material, chamber product, and tails are analyzed for the content of carbon and aluminum, iron, and silicon oxides using X-ray spectral (XSA), X-ray phase (XPA), and chemical analyses. It is established that processing the total material mass does not make it possible to acquire a product with an acceptable content of silicon and iron oxides. Based on the XPA of various fractions of the initial material, it is proposed to process the material fractions containing the minimal amount of contaminating substances (carbon and silicon and iron oxides). Two fractions are selected for processing using the flotation method by the XRS results of various material fractions: -0.071 mm and +5.0 mm. When processing the first of them, the chamber product of the acceptable quality is acquired. A product with a high content of alumina and fluorinated components at low carbon and iron oxide concentrations but a considerable amount of silicon oxide is acquired from a coarse electrolyte-containing fraction (+5.0 mm). The further use of this product is possible to fabricate aluminum-silicon alloys.

The Study of Carbon Recovery from Electrolysis Aluminum Carbon Dust by Froth Flotation

“…Regarding the problem of aluminum electrolysis solid waste recycling, Vasyunina et al [31] adopted a grinding-classification-reverse flotation-concentration process using flotation agents such as kerosene to remove silicon, iron oxide, and carbon particles, finally recovering aluminum electrolysis production sweep materials. Tropenauer et al [32] introduced flotation and chemical treatment technology to solve the problem of industrial waste generated in the aluminum electrolysis process.…”

Time-Series Prediction of Iron and Silicon Content in Aluminium Electrolysis Based on Machine Learning

“…Sun [4] applied colorimetric method to determine the content of Fe in the anode for the electrolytic cell, which provides theoretical support to remove impurities. Vasyunina [5] used flotation reagent produced by Clariant(Germany) to filter out Fe and Si elements of waste aluminium products, which is convenient for recycling of aluminium. However, most of the research is on physical and chemical properties, and there is still no efficient method for removing Fe and Si of aluminium production [6], which leads to slow progress in energy saving and emission reduction for aluminium electrolysis technology [7].…”