Slagreus – Reuse of slags from integrated steelmaking

Initial situation

  • In Europe about 10 Mio.t/year of BOF slag are produced at the steelmaking. A main part is reused for example in road construction. Nevertheless in 2016 about 23% are landfilled or stored temporarily.
  • Current discussions on environmental aspects are likely to impair the high percentage of utilisation in the traditional fields of application for steelmaking slags.

Working topics

  • An innovative process chain consisting of a primary liquid and a secondary solid enrichment will be investigated to gain an iron (Fe) enriched fraction with reduced phosphor content and a calcium (Ca) and phosphor (P)-enriched fraction.
  • The primary Fe enrichment is gained by liquid BOF slag treatment and by cooling of the slag to a slag temperature, which leads to a segregation of the solidified P-enriched slag fraction in the remaining Fe-enriched liquid slag.
  • The secondary Fe enrichment will be achieved by microwave supported comminution of the primary Fe-enriched slag, selective grinding and a magnetic separation.
  • An off-line prediction tool will be developed on the basis of the gained knowledge for the pre-treatment processes.

Results

  • A process chain will be developed to gain a Fe-enriched BOF slag fractions which can be used for internal recycling as substitute for primary raw materials.
  • A external utilisation of the Ca- and P-enriched slag fraction will be evaluated as cement additive as well as lime fertilizer.

This project is funded by the European Union. Views and opinions expressed are however those of the author(s) only and do not necessarily reflect those of the European Union. Neither the European Union nor the granting authority can be held responsible for them.

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