TY - JOUR

T1 - Valorisation of metallurgical residues via carbothermal reduction

T2 - A circular economy approach in the cement and iron and steel industry

AU - Krammer, Anna

AU - Doschek-Held, Klaus

AU - Steindl, Florian Roman

AU - Weisser, Katharina

AU - Gatschlhofer, Christoph

AU - Juhart, Joachim

AU - Wohlmuth, Dominik

AU - Sorger, Christoph

N1 - Publisher Copyright: © The Author(s) 2024.

PY - 2024/4/7

Y1 - 2024/4/7

N2 - The decarbonisation of the steel and cement industry is of utmost importance in tackling climate change. Hence, steel production in modern integrated steel mills will be shifted towards electric arc furnaces in the future, in turn causing dwindling supplies of blast furnace slag, which is used as a supplementary cementitious material inter alia to reduce the CO2 emissions of cement production. Achieving a sustainable circular steel and building material economy requires the valorisation of currently landfilled steel slags and investigating utilisation options for electric arc furnace slag, which is increasingly being generated. For this purpose, different metallurgical residues and by-products were treated by carbothermal reduction in an inductively heated graphite crucible and then rapidly cooled by wet granulation, yielding a slag fraction similar to granulated blast furnace slag and a metal fraction valuable as a secondary raw material. A spreadsheet-based model was developed to calculate residue combinations to accomplish target compositions of the slag and metal fractions to fulfil previously identified requirements of the targeted cementitious and ferrous products. The results demonstrate the high accuracy of the model in predicting the properties (e.g. main oxide composition) of the generated slag and metal fraction, which fulfil the needed requirements for their use as (i) a supplementary cementitious material and (ii) a secondary raw material in steel production.

AB - The decarbonisation of the steel and cement industry is of utmost importance in tackling climate change. Hence, steel production in modern integrated steel mills will be shifted towards electric arc furnaces in the future, in turn causing dwindling supplies of blast furnace slag, which is used as a supplementary cementitious material inter alia to reduce the CO2 emissions of cement production. Achieving a sustainable circular steel and building material economy requires the valorisation of currently landfilled steel slags and investigating utilisation options for electric arc furnace slag, which is increasingly being generated. For this purpose, different metallurgical residues and by-products were treated by carbothermal reduction in an inductively heated graphite crucible and then rapidly cooled by wet granulation, yielding a slag fraction similar to granulated blast furnace slag and a metal fraction valuable as a secondary raw material. A spreadsheet-based model was developed to calculate residue combinations to accomplish target compositions of the slag and metal fractions to fulfil previously identified requirements of the targeted cementitious and ferrous products. The results demonstrate the high accuracy of the model in predicting the properties (e.g. main oxide composition) of the generated slag and metal fraction, which fulfil the needed requirements for their use as (i) a supplementary cementitious material and (ii) a secondary raw material in steel production.

KW - carbothermal reduction

KW - circular economy

KW - CO-reduced cement

KW - industrial residue

KW - metal recovery

KW - metallurgical residues

KW - steel slags

KW - Supplementary cementitious material

UR - http://www.scopus.com/inward/record.url?scp=85190404450&partnerID=8YFLogxK

U2 - 10.1177/0734242X241240040

DO - 10.1177/0734242X241240040

M3 - Article

C2 - 38584402

AN - SCOPUS:85190404450

VL - 42.2024

SP - 1

EP - 9

JO - Waste management & research

JF - Waste management & research

SN - 0734-242X

IS - ??? Stand: 22. April 2024

ER -