Formation and hydraulic reactivity of an alite rich material from post treated basic oxygen furnace slag
- Basic oxygen furnace slag (BOFS) is a by-product of steelmaking of which about 10.4 Mt are produced annually in the EU. BOFS is mostly used in road construction, earthwork and hydraulic engineering. However, in this use, the iron bound in BOFS is lost and the opportunity to produce higher value products from BOFS is forgone.
In recent decades, many researchers have investigated a thermochemical process to reduce iron oxides to metallic iron in molten BOFS. The metallic iron formed separates from the reduced slag due to its higher density and can be recovered. An advantage of this process is that simultaneously the chemical composition of the reduced slag is adapted to that of the Portland cement clinker and the hydraulic reactive mineral alite is formed.
In this study, BOFS was reduced in a small-scale electric arc furnace using petrol coke as reducing agent, and the hydraulic properties of the reduced, low-iron BOFS were investigated. Despite a chemical and mineralogicalBasic oxygen furnace slag (BOFS) is a by-product of steelmaking of which about 10.4 Mt are produced annually in the EU. BOFS is mostly used in road construction, earthwork and hydraulic engineering. However, in this use, the iron bound in BOFS is lost and the opportunity to produce higher value products from BOFS is forgone.
In recent decades, many researchers have investigated a thermochemical process to reduce iron oxides to metallic iron in molten BOFS. The metallic iron formed separates from the reduced slag due to its higher density and can be recovered. An advantage of this process is that simultaneously the chemical composition of the reduced slag is adapted to that of the Portland cement clinker and the hydraulic reactive mineral alite is formed.
In this study, BOFS was reduced in a small-scale electric arc furnace using petrol coke as reducing agent, and the hydraulic properties of the reduced, low-iron BOFS were investigated. Despite a chemical and mineralogical composition similar to that of Portland cement clinker, the reduced BOFS produced less heat of hydration, and its reaction was delayed compared to Portland cement. However, the addition of gypsum, as is also done in cement production from Portland cement clinker, has been found to accelerate the hydration rate of reduced BOFS.
Further research to improve the hydraulic properties of the reduced slag is essential. If successful, the production of a hydraulic binder and crude iron from BOFS could have economic and ecological benefits for both the cement and steel industry.…
Autor*innen: | Katharina Schraut |
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Weitere Person: | Burkart Adamczyk, Sebastian SimonORCiD, Julia von WerderORCiD, Birgit MengORCiD, Dietmar Stephan, Christian AdamORCiD |
Dokumenttyp: | Vortrag |
Veröffentlichungsform: | Präsentation |
Sprache: | Englisch |
Jahr der Erstveröffentlichung: | 2022 |
Organisationseinheit der BAM: | 4 Material und Umwelt |
4 Material und Umwelt / 4.4 Thermochemische Reststoffbehandlung und Wertstoffrückgewinnung | |
7 Bauwerkssicherheit | |
7 Bauwerkssicherheit / 7.1 Baustoffe | |
7 Bauwerkssicherheit / 7.4 Baustofftechnologie | |
DDC-Klassifikation: | Technik, Medizin, angewandte Wissenschaften / Ingenieurwissenschaften / Sanitär- und Kommunaltechnik; Umwelttechnik |
Freie Schlagwörter: | BOFS; Hydraulic reactivity; Portland Cement |
Themenfelder/Aktivitätsfelder der BAM: | Umwelt |
Umwelt / Circular Economy | |
Veranstaltung: | GeoMin Köln 2022 |
Veranstaltungsort: | Cologne, Germany |
Beginndatum der Veranstaltung: | 11.09.2022 |
Enddatum der Veranstaltung: | 15.09.2022 |
Verfügbarkeit des Dokuments: | Datei im Netzwerk der BAM verfügbar ("Closed Access") |
Datum der Freischaltung: | 24.10.2022 |
Referierte Publikation: | Nein |
Eingeladener Vortrag: | Nein |