Björn Glaser

This study investigates the use of sustainable hydrochar‐mill‐scale briquettes for promoting slag foaming in the electric arc furnace (EAF) process. Two types of biochar are tested, namely, a pristine green waste hydrochar (GWH) and its pyrolyzed char (PGWH) produced at 873 K. Each briquette weighs ≈20 g and has C _fix /O _FeOx molar ratios ranging from 0.07 up to 0.90. Briquettes are charged into a molten EAF slag (600 g) at 1923 K. Successful foaming is achieved for all seven briquette recipes developed. The maximum slag foaming height is 1.6–2.5 times of the initial slag height, and the slag foaming duration is in the range of 1.5–3.4 min. GWH briquettes promote rapid slag foaming through the abrupt release of volatile matter, while PGWH briquettes promote a more gradual and long‐lasting foaming process through gas production (CO and CO ₂ ) from carbothermic reduction. It is estimated that 1 kg of anthracite applied for slag foaming should be replaced by 2.4 kg of GWH or 1.9 kg of PGWH added in composite briquette form. At the given briquette addition rate tested in this study (30 g per kg of slag), no appreciable impurity (sulfur, phosphorous) transfer from hydrochar to the slag is observed.

Magnesia–carbon refractories are widely used as ladle lining materials in steelmaking due to their excellent thermal and chemical stability. Carbon retention is critical for extending refractory lifespan, as carbon loss significantly accelerates wear. Preheating‐induced decarburization typically occurs in oxygen‐rich atmospheres and in the presence of combustion byproducts from hydrocarbon fuels. This study investigates plasma heating as an alternative preheating method to mitigate initial decarburization. Full‐scale industrial trials are conducted using 0.7 and 1.5 MW plasma torches with nitrogen as primary gas. For comparison, a ladle is also preheated using a conventional natural gas burner. Although all samples experience some decarburization, the plasma‐heated samples demonstrate the lowest rate, at 0.14 mm h ⁻¹ , compared to 0.20 mm h ⁻¹ for the gas‐heated sample. The unexpectedly elevated decarburization in the plasma‐treated bricks is attributed to residual oxygen within the ladle during the trials. Additionally, the plasma‐heated bricks exhibit reduced surface disintegration and superior structural integrity, attributed to partial sintering at temperatures exceeding 1400 °C and enhanced retention of calcium silicates in intergranular regions. These findings indicate that plasma heating provides improved structural preservation of MgO–C linings, even under partially oxidizing conditions, compared to traditional preheating methods.

In the central area of a blast furnace, called “cohesive zone,” the high temperature up to 2000°C allows us to melt most of the materials in input. The performance of a blast furnace depends on the shape and density of the cohesive zone, and, therefore, its characteristics (i.e., location and extension) are important. Muography, being a passive and non-invasive technique, represents a valid alternative to the most common techniques in the steel industry for the blast furnace monitoring that involve the use of special probes capable of reaching very high temperatures, but which, however, are unable to reach this area before melting or functioning for a long time. The cohesive zone could be passively and continuously observed for a long time with muography and could be visible as a high-density anomaly inside the blast furnace. In this work, the BLEMAB (BLast furnace stack density Estimation through on-line Muon ABsorption measurements) European project (2020–2024) is described. The detectors, the two measurements performed and the first results on the density distribution showing the potential of the technique in the steel industry, will be presented. These results have then been compared with measurements performed in parallel with other techniques such as eMPVP (enhanced MultiPoint Vertical Probes) finding some compatibilities.

The operational efficiency of continuous casting in steel production is often hindered by the clogging of submerged entry nozzles (SEN), caused due to the agglomeration of nonmetallic inclusions (NMIs). SEN clogging is challenging to monitor and requires probabilistic models for accurate real‐time prediction. In this context, data‐driven models emerged as a promising tool to be used in the existing industrial settings. Despite frequent occurrence of SEN clogging, collecting large datasets under varied operational conditions remains challenging. The scarcity of data hampers the ability to develop and train traditional data‐driven models effectively. To overcome these challenges, physics‐informed data‐driven models are proposed in this work. The integration of outputs generated from theoretical calculations is sufficient to compensate for the lack of available datasets. To further enhance accuracy, an advanced methodology involving use of ab initio repository is developed. This repository contains material‐specific data including high‐temperature nonretarded Hamaker constants of NMIs in specific particle size range of 1–10 μm. A novel parameter, “Clogging Factor” is proposed to monitor and integrated into the modeling architecture to track the reduction in the available volume inside SEN due to the accumulation of NMIs. The proposed model has yet to be validated online but has shown potential in reducing SEN clogging.

In this paper, we extend a recent asymptotic axisymmetric model for isothermal gas–solid flow in a countercurrent moving-bed reactor to a non-isothermal model for the heat transfer in an ironmaking blast furnace. The appended heat transfer model accounts for conduction, convection, thermal non-equilibrium between the gas and solid phases and the dominant endothermic chemical reaction in the bulk of the furnace, the Boudouard reaction. Asymptotic analysis is used to determine the leading-order heat balances and to interpret numerically obtained solutions for the phase temperatures. Although the model is considerably simpler than the many numerical models that already exist for blast-furnace operation, its future extension would form the basis of a computationally efficient approach for modelling the transient state of a blast furnace.