Green approach to ironmaking: Briquetting and hydrogen reduction of mill scale using novel binders

• Published in: International journal of hydrogen energy 2024-04, Vol.62, p.732-738
• Main Authors: Elsadek, Mohamed, Mousa, Elsayed, Ahmed, Hesham
• Format: Article
• Language: English
• Subjects: Briquetting; Circular economy; Green transition; Hydrogen reduction; Ironmaking; Mill scale; Organic binders; Process Metallurgy; Processmetallurgi
• ISSN: 0360-3199; 1879-3487; 1879-3487
• DOI: 10.1016/j.ijhydene.2024.03.152

The transition to sustainable and low-carbon ironmaking processes has necessitated innovative solutions. The most prominent solutions are the establishment of a circular economy by recirculating the iron-rich residues from steelworks and the adoption of hydrogen as a clean reducing agent to mitigate fossil CO2 emission. One such residue is mill scale, which is generated during steelmaking, casting, and rolling processes. However, the fine particles and easy reoxidation of the mill scale make it difficult to be used directly in iron and steel production without proper compaction. This paper aims to demonstrate the feasibility of mill scale briquetting using organic binders to meet the requirements of hydrogen-based direct reduction. The study will investigate the influence of binder type, binder dosage, moisture content, and compaction pressure on the briquetting process and the briquettes quality. Moreover, the reducibility of optimized briquettes will be examined by hydrogen at 900 °C using a thermogravimetric analyzer coupled with a quadrupole mass spectroscopy (TGA-QMS). The optimal combination for achieving the best mechanical strength and reducibility was a briquette produced with 1% Alcotac® CB6, 1% KemPel, and 2.5% moisture content, compressed at a pressure of 125 kN. •Circular economy is a prominent solution for sustainable ironmaking.•Hydrogen is the way forward to decarbonize the steel industry.•Briquetting of mill scale is a way for its successful recirculation.•Organic binders can successfully be implemented in ironmaking.•Briquette compaction and moisture significantly influences its strength.