Separation of fluorine and aluminum from secondary aluminum dross by calcium-cured alkali roasting−water leaching

• Published in: Transactions of Nonferrous Metals Society of China Vol. 34; no. 6; pp. 2007 - 2019
• Main Authors: DONG, Liang-min, JIAO, Fen, LIU, Wei, HUANG, Ya-lin, WEI, Xin, QIN, Wen-qing
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.06.2024
• Subjects: aluminum; calcium-cured alkali roasting; clean production; fluorine; secondary aluminum dross; separation; sodium aluminate; separation; secondary aluminum dross; calcium-cured alkali roasting; clean production; sodium aluminate; aluminum; fluorine
• ISSN: 1003-6326
• DOI: 10.1016/S1003-6326(24)66522-2

A combined strategy of calcium-cured alkali roasting and water leaching was devised to treat secondary aluminum dross. The effects of calcium oxide dosage, sodium hydroxide dosage, roasting temperature, and time on aluminum extraction behavior and fluorine curing behavior were studied. Under optimal experimental conditions: roasting temperature of 1000 °C, Al꞉NaOH mole ratio of 1꞉0.6, F꞉CaO mole ratio of 1꞉2.5, and roasting time of 2.0 h, fluorine and aluminum were separated, with 99.98% of the fluoride solidified and 52.97% of the aluminum extracted. The sodium aluminate products obtained by evaporation and crystallization from leaching solution met the industrial standards of China. The aqueous residue can be used as a raw material for quick-setting cement. Overall, this study provides an effective and environmentally friendly strategy for the treatment of secondary aluminum dross.