A Review of Circular Economy Prospects for Stainless Steelmaking Slags

Lauri Holappa*, Marko Kekkonen, Ari Jokilaakso, Juha Koskinen

*Corresponding author for this work

Research output: Contribution to journalReview Articlepeer-review

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Abstract

The world of stainless steel production was 52 Mt in 2019, and the annual amount of slags including electric furnace, AOD converter, ladle, and casting tundish, was estimated at 15-17 Mt. Nowadays, only a minor fraction of slags from stainless steel production is utilized and a major part goes to landfilling. These slags contain high-value elements (Cr, Ni, Mo, Ti, V...) as oxides or in metallic form, some of them being environmentally problematic if dumped. Thus, any approach toward circular economy solutions for stainless steel slags would have great economic and environmental impacts. This contribution examines the slags from different process stages, and the available and new potential means to increase internal recycling and to modify slags composition and structure by optimizing their properties for reclaiming in high-value applications. Eventual methods are, e.g., fast controlled cooling and modifying additives. Means to recover valuable metals are discussed as well as potential product applications to utilize various slags with different chemical, physical, and mechanical properties. By integrating the treatments and steering of slags' properties to the total process optimization system, the principles of circular economy could be achieved.

Original languageEnglish
Pages (from-to)806-817
Number of pages12
JournalJournal of Sustainable Metallurgy
Volume7
Issue number3
Early online date28 Jun 2021
DOIs
Publication statusPublished - Sep 2021
MoE publication typeA2 Review article in a scientific journal
EventInternational Conference on Molten Slags, Fluxes and Salts - Virtual, Online, Korea, Republic of
Duration: 21 Feb 202125 Feb 2021
Conference number: 11

Keywords

  • Slags utilization
  • Metals recovery
  • Recycling
  • Slags properties
  • Productization
  • Environmental issues
  • ELECTRIC FURNACE DUSTS
  • WASTE TREATMENT-PLANT
  • STEEL SLAG
  • CHROMIUM RECOVERY
  • ENERGY RECOVERY
  • HEAT-RECOVERY
  • FILTER CAKE
  • CARBONATION
  • MECHANISMS
  • MINERALOGY

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