Light Metals 2017 pp 1457-1464

Part of the The Minerals, Metals & Materials Series book series (MMMS) | Cite as

Understanding of Interactions Between Pyrolysis Gases and Liquid Aluminum and Their Impact on Dross Formation

  • R. Dittrich
  • B. Friedrich
  • G. Rombach
  • J. Steglich
  • A. Pichat


Organic contaminated aluminum scraps have to be recycled in an economical, effective and ecological way. It is state of the art to remove organic coatings by thermal pre-treatment under reduced oxygen atmosphere, which can be achieved in multi chamber furnaces. If the organic coating is not removed completely during pre-treatment, gasification can continue while the scrap is submerged into the melt. Subsequently, undesirable gas-melt reactions cause an increase of dross formation and a decrease of metal recovery. This work aims to improve the understanding of interactions between pyrolysis gases and liquid aluminum as a scientific basis to reduce oxidation losses. Experiments were performed in a lab-scale furnace with injection of synthetic pyrolysis gases (CO2, CO, CxHy) into molten aluminum. Thermochemical calculations, off-gas and dross structure analysis were performed to support the evaluation of the experimental findings. The paper presents qualitative and quantitative results about the impact of reactive gases on oxidation of aluminum melts and finally derives a mechanism model.


Pyrolysis gases Gas injection Dross formation 


  1. 1.
    J. Steglich et al., Pre-treatment of beverage can scrap to increase recycling efficiency. Eur. Aluminium Congr. 2015, Düsseldorf (2015)Google Scholar
  2. 2.
    B. Jaroni, Einfluss von organischen Komponenten auf das Aluminiumrecycling. Ph.D. thesis, RWTH University, ISBN: 3844026339 (2014)Google Scholar
  3. 3.
    A. Kvithyls et al., Gases evolved during de-coating of aluminium scrap in inert and oxidizing atmospheres. Light Met. 1091–1095 (2003)Google Scholar
  4. 4.
    S. Levchik, E. Weil, Thermal decomposition, combustion and flame—retardancy of epoxy resins—a review of the recent literature. Polym. Int. 53, 1901–1929 (2004)CrossRefGoogle Scholar
  5. 5.
    M. Wang et al., Study on de-coating used beverage cans with thick sulfuric acid for recycle. Energy Convers. Manag. 48(3), 819–825 (2007)CrossRefGoogle Scholar
  6. 6.
    K. Brenzinsky, M. Pecullan, I. Glassmann, Pyrolysis and oxidation of phenol. J. Phys. Chem. A 102, 8614–8619 (1998)CrossRefGoogle Scholar
  7. 7.
    W. Thiele, Die oxydation von aluminium- und aluminium legierungs-schmelzen. Aluminium 38(12), 707–715 (1962)Google Scholar
  8. 8.
    E. Bergsmark, C. Simensen, P. Kofstad, The oxidation of molten aluminium. Mater. Sci. Eng. A 120, 91–95 (1989)CrossRefGoogle Scholar
  9. 9.
    S. Bonner, Oxidation of commercial purity aluminum melts: an experimental study. Light Met. 993–997 (2013)Google Scholar
  10. 10.
    G. Wigthman, D. Fray, The dynamic oxidation of aluminum and its alloy. Metall. Trans. 14b, 625–631 (1983)Google Scholar
  11. 11.
    FactSage 6.4 2013, ThermfactGoogle Scholar
  12. 12.
    C. Thomas et al., Catalytic effect of metals on paraffin hydrocarbons. Ind. Eng. Chem. 31(9), 1090–1098 (1939)CrossRefGoogle Scholar
  13. 13.
    M. Serban et al., Hydrogen production by direct contact pyrolysis of natural gas. Energy Fuels 17(3), 705–713 (2003)CrossRefGoogle Scholar

Copyright information

© The Minerals, Metals & Materials Society 2017

Authors and Affiliations

  • R. Dittrich
    • 1
  • B. Friedrich
    • 1
  • G. Rombach
    • 2
  • J. Steglich
    • 3
  • A. Pichat
    • 4
  1. 1.IME Institute of Process Metallurgy and Metal Recycling, RWTH Aachen UniversityAachenGermany
  2. 2.Hydro Aluminium Rolled Products GmbHBonnGermany
  3. 3.TRIMET Aluminium SEEssenGermany
  4. 4.Constellium Technology Center, Parc Economique Centr’alpVoreppe cedexFrance

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