F-Cubed at the Circular Materials Conference: Application prospect of paper mill sludge hydrochar as steel production auxiliary
The presentation by Ludvig Ånnhagen examined the potential for fossil free value chains for iron and steel making with a focus on two main areas:
The F-CUBED project scope:
- TORWASH® pilot plant for paper sludge upgrading;
- Investigation of utilising bio-sludge hydrochar in the steelmaking industry;
- Evaluation of NPK recovery potential.
Swerim´s role in the project:
- Metallurgical properties testing of hydrochar derived from paper sludge;
- Production and performance testing of hydrochar briquette;
- Analysing the feasibility of hydrochar for metallurgical plants.
The results from the testing and analysis of the hydrochar briquettes as a blast furnace injectant were promising, with a 30% blend of hydrochar with anthracite coal considered the optimal ratio when taking into account combustion and safety parameters. Different agglomeration technologies have been used to make hydrochar briquettes with and without iron-containing materials received from steel plants, and a high mechanical strength of cold bond briquettes (CBBs) was achieved with vibro press, which can be top charged into the blast furnace. Analysis and testing of nutrient recovery from the paper sludge hydrochar and effluent is currently being conducted by the University of Hohenheim.
The scientific publication relating to the research into paper sludge treatment is available on the F-CUBED community page in the Zenodo open access repository – Feasibility Study of Bio-Sludge Hydrochar as Blast Furnace Injectant | Zenodo