Valuable aluminum alloys obtained from secondary metallized raw materials

In this work, we aim to obtain a high-alloy product of the Al-Fe-Si-Mn system from scrap and metallized waste, as well as to determine the optimal technological mode of melting for increasing the yield of finished products during complex processing of the melt. The study involved the following methods: X-ray fluorescence (XRF), spectral, X-ray structural, and differential–thermal analysis. Chromatographic and mass-spectrometric analysis of gases released during the remelting of aluminum waste was carried out to determine irrecoverable losses. Analysis data indicate that volatile compounds account for 13–15% of the total mass of aluminum lost during heating and melting of the charge. As a result of the test melts carried out with various aluminum wastes, the obtained castings were shown to correspond to some grades of high-alloy aluminum alloys (for example, 3xxx and 8xxx) mainly belonging to the Al-Fe-Si-Mn system. The metal losses during loading of the charge into the melt at various layer heights in the furnace were determined. Its rational value was established based on the best results, representing 30–40% of the mass of the loaded charge. The implementation of a comprehensive technology for refining and step-by-step processing of the melt produced samples with a yield of 86 to 88%. According to the conducted analysis of the chemical composition, the castings contain a minimal quantity of non-metallic inclusions (SiO₂, CaO, Al₂O₃, TiO₂) with an acceptable hydrogen content (0.08–1.0 cm³/100 g). A study of the structural features characterized all samples as having a complex dendritic structure with the presence of intermetallic phases of the AlFe(Si)Mn type, which have a characteristic appearance known as "Chinese script" and reach sizes from 70 to 120 µm. The structure of the castings, which is generally characterized by its homogeneity and the uniform distribution of agglomerates of nanosized intermetallic compounds in the aluminum matrix, is suitable for obtaining cast blanks and rolled products for a wide range of purposes.

1. Litvinenko V.S. Digital economy as a factor in the technological development of the mineral sector. Natural Resources Research. 2020;29(3):1521-1541. https://doi.org/10.1007/s11053-019-09568-4. EDN: WGABFS.

2. Guseva E.N. Using secondary mineral resources of non-ferrous metallurgy is an important reserve for resource conservation. Journal of Mining Institute. 2003;155:194-197. (In Russ.).

3. Larichkin F.D. Mineral resources in the Russian economy. Journal of Mining Institute. 2008;179:9-13. (In Russ.). EDN: LHPXML.

4. Gorlanov E.S., Leont'ev L.I. Directions in the technological development of aluminium pots. Journal of Mining Institute. 2024;266:246-259. (In Russ.). EDN: PYSEVM.

5. Ünlü N., Drouet M.G. Comparison of salt-free aluminum dross treatment processes. Resources, Conservation and Recycling. 2002;36(1):61-72. https://doi.org/10.1016/S0921-3449(02)00010-1.

6. Raabe D. The materials science behind sustainable metals and alloys. Chemical reviews. 2023;123(5):2436- 2608. https://doi.org/10.1021/acs.chemrev.2c00799.

7. LavoieS., DubeG. Asalt-freetreatmentofaluminiumdrossusingplasmaheating. JOM.1991;54-55. https://doi.org/10.1007/BF03220144.

8. Makarov G.S. Global trends in secondary aluminum recycling and use. Light alloy technology. 2004;1:25-30. (In Russ.).

9. Meshram A., Singh K.K. Recovery of valuable products from hazardous aluminum dross: а review // Resources, Conservation and Recycling. 2018. Vol. 130. P. 95–108. https://doi.org/10.1016/j.resconrec.2017.11.026.

10. Gaustad G., Olivetti E., Kirchain R. Improving aluminum recycling: а survey of sorting and impurity removal technologies // Resources, Conservation and Recycling. 2012. Vol. 58. P. 79–87. https://doi.org/10.1016/j.resconrec.2011.10.010.

11. Domagala J., Haag P., Niehoff T., Schmitz C. Handbook of aluminium recycling: mechanical preparation, metallurgical processing, heat treatment. Essen: Vulkan-Verlag; 2014, 536 р.

12. Capuzzi S., Timelli G. Preparation and melting of scrap in aluminum recycling: а review. Metals. 2018;8(4):249. https://doi.org/10.3390/met8040249.

13. Trusov V.A. Reverberatory furnace for aluminium scrap remelting. Patent RF, no. 2529348; 2014. (In Russ.).

14. Rovin S.L., Kalinichenko A.S., Rovinc L.E. Recycling of dispersed metal wastes in rotary furnaces. Journal of Casting & Materials Engineering. 2019;3(2):43-49. http://doi.org/10.7494/jcme.2019.3.2.43.

15. Rovin S.L. Outlooks for application of rotary furnaces. Metal waste recycling. In: Litejnoe proizvodstvo i metallurgiya: sbornik trudov XXV Mezhdunarodnoj nauchno-tekhnicheskoj konferencii = Foundry Production and Metallurgy: Collected Proceedings of the 25th International Scientific and Technical Conference. 18–19 October, Minsk. Minsk: Belorusskij nacional’nyj tekhnicheskij universitet; 2017, р. 65-71. (In Russ.).

16. Drouet M.G., Meunier J., Laflamme C.B., Handfield M.D., Biscaro A., Lemire C. A rotary arc furnace for aluminium dross processing. In: Third International Symposium on Recycling of Metals and Engineered Mate-rials. 12–15 November 1995, Alabama. Alabama: The Mineral, Metals and Materials Society; 1995, p. 803-812.

17. Kos B. Direct dross treatment by centrifuging of hot dross. Aluminium. 2000;76:35-36.

18. Wibner S., Antrekowitsch H., Meisel T.C. Studies on the formation and processing of aluminium dross with particular focus on special metals. Metals. 2021;11(7):1108. https://doi.org/10.3390/met11071108.

19. Wallace G. 4 - Production of secondary aluminium. Fundamentals of Aluminium Metallurgy. 2011;70-82. https://doi.org/10.1533/9780857090256.1.70.

20. Raabe D., Ponge D., Uggowitzer P.J., Roscher M., Paolantonio M., Liu Chuanlai, et al. Making sustainable aluminum by recycling scrap: the science of “dirty” alloys. Progress in Materials Science. 2022;128:100947. https://doi.org/10.1016/j.pmatsci.2022.100947.

21. DrouetM.G., LeroyR.L., TsantrizosP.G. Drosrite salt-free processing ofhot aluminiumdross. In: TMSFallExtraction and Process, Metallurgy Meeting. 22–25 October 2000, Pittsburgh, Pennsylvania. Pittsburgh, Pennsylvania: The Minerals, Metals and Materials Society; 2000, р. 1135-1145.

22. Kolbeinsen L. The beginning and the end of the aluminium value chain. Matériaux & Techniques. 2020;108(5- 6):506. https://doi.org/10.1051/mattech/2021008.

23. Novichkov S.B. Regularities of aluminum slag smelting in a rotary tilting furnace. Tsvetnye metally. 2004;1:67- 70. (In Russ.).

24. Ibragimov V.E., Garcia M.L., Bazhin V.Y. Melting of thin walled paint scrap coatings for aluminum alloy production. International Research Journal. 2016;2:14-17. (In Russ.). https://doi.org/10.18454/IRJ.2016.44.068.

25. Shinzato M.C., Hypolito R. Solid waste from aluminum recycling process: characterization and reuse of its economically valuable constituents. Waste management. 2005;25(1):37-46. https://doi.org/10.1016/j.wasman.2004.08.005.

26. Wong David S., Lavoie P. Aluminum: recycling and environmental footprint. JOM. 2019;71(9):2926-2927. https://doi.org/10.1007/s11837-019-03656-9.

27. Zholnin A.G., Novichkov S.B. Mechanism of aluminum transition from slag to melt during smelting of aluminum waste in rotary furnaces. Nonferrous metallurgy. 2003;1:22-27. (In Russ.).

28. Nemchinova N.V., Belskii S.S., Vlasov A.A. Studying aluminum alloy defects. Solid State Phenomena. 2021;316:353-358. https://doi.org/10.4028/www.scientific.net/SSP.316.353.

29. Nemchinova N.V., Tyutrin A.A. Metallographic investigation of aluminum rondol samples. Fundamental research. 2015;3:124-128. (In Russ.). EDN: TNIQRV.

30. Fomin B.A., Moskvitin V.I., Mahov S.V. Metallurgy of secondary aluminum. Moscow: EKOMET; 2004, 238 р. (In Russ.). EDN: QMZMIB.