Unintentional flow of alloying elements in steel during recycling of end-of-life vehicles

Hajime Ohno*, Kazuyo Matsubae, Kenichi Nakajima, Shinichiro Nakamura, Tetsuya Nagasaka

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

78 Citations (Scopus)


Alloying elements in steel add a wide range of valuable properties to steel materials that are indispensable for the global economy. However, they are likely to be effectively irretrievably blended into the steel when recycled because of (among other issues) the lack of information about the composition of the scrap. This results in the alloying elements dissipating in slag during steelmaking and/or becoming contaminants in secondary steel. We used the waste input-output material flow analysis model to quantify the unintentional flows of alloying elements (i.e., chromium, nickel, and molybdenum) that occur in steel materials and that result from mixing during end-of-life (EOL) processes. The model can be used to predict in detail the flows of ferrous materials in various phases, including the recycling phase by extending steel, alloying element source, and iron and steel scrap sectors. Application of the model to Japanese data indicates the critical importance of the recycling of EOL vehicles (ELVs) in Japan because passenger cars are the final destination of the largest share of these alloying elements. However, the contents of alloying elements are rarely considered in current ELV recycling. Consequently, the present study demonstrates that considerable amounts of alloying elements, which correspond to 7% to 8% of the annual consumption in electric arc furnace (EAF) steelmaking, are unintentionally introduced into EAFs. This result suggests the importance of quality-based scrap recycling for efficient management of alloying elements.

Original languageEnglish
Pages (from-to)242-253
Number of pages12
JournalJournal of Industrial Ecology
Issue number2
Publication statusPublished - 2014 Apr
Externally publishedYes


  • End-of-life vehicles (ELVs)
  • Flow analysis (WIO-MFA)
  • Industrial ecology
  • Iron and steel scrap
  • Material flow analysis (MFA)
  • Metal recycling
  • Waste input output material

ASJC Scopus subject areas

  • General Environmental Science
  • General Social Sciences


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