Seznam abstraktů 2026: SEKCE A - POKROKOVÉ TECHNOLOGIE VÝROBY ŽELEZA, OCELI A VE SLÉVARENSTVÍ

Argon is the currently used and relatively simple method for refining liquid steel. This is most often done in a ladle furnace. Contemporary porous plugs used for refining liquid steel are characterized by a high degree of design sophistication. Further increasing their efficiency is difficult and inefficient. In response to growing process requirements, an innovative solution was developed in the form of a slotted gas-permeable module. The proposed design is based on a modular structure, representing a new concept in the construction of porous plugs. This solution allows for a significant increase in the active surface area modulus compared to the active surface area of currently used porous plugs.
This article presents the results of numerical simulations and physical modeling of a new design solution for a slot-type gas-permeable module. Initial research - numerical simulations were conducted using a 1:1 scale ladle and a hot metal-argon system. The studies were comparative between the currently used technology (porous plug) and the proposed solution. To verify the numerical modeling results, tests were conducted on a physical water model of ladle in a 1:3.4 scale. Experimental results demonstrated high agreement with data obtained from CFD. The qualitative criteria for assessing the functionality of the tested solution included visualization results in the form of the gas column formation mechanism, the degree of gas dispersion in the model fluid, and gas bubble fragmentation. Quantitative criteria included the minimum time for complete mixing of the tracer in the model fluid volume and the proportion of slow-flow regions (dead zones) in the metal bath volume.

The European steel industry is facing transformational changes that will affect metallurgical quality, including steel cleanliness. In the face of this, digital simulation and virtual engineering methods are being increasingly employed in the steel industry to test and optimize process and equipment designs quickly and accurately. The present work deals with design optimization to improve the steel flow conditions in a 6-strand tundish of a billet caster for enhanced cleanliness through virtual prototyping using CFD simulations and subsequent plant trials of the most promising designs. A 3D Reynolds-Averaged Navier-Stokes (RANS) approach using the realizable k-ε model of turbulence together with a two-phase model of Steel-Argon flows was employed to simulate the tundish flow and to propose design modifications. Several virtual prototypes of additional flow modifiers were evaluated to predict performance and optimize the design configurations. A pair of appropriately sized extra flow diversion elements, placed at 100 mm from the weirs on either side of the tundish center, was found to give the best results. This configuration allows minimizing the steel short-circuiting from the in-gate region to the tundish trough while ensuring a stable, uniform flow with lesser turbulence towards the bath surface. Further effect was to achieve a slow plug-flow underneath the bath surface reaching up to the tundish ends, leading to low turbulence levels and increased steel residence times thereby providing enhanced conditions for the removal of non-metallic inclusions. The effectiveness of the approach is demonstrated by means of metallurgical results on inclusion characterization from plant trials.

This study aims to determine the composition of scrap (recycled material) used in Electric Arc Furnaces (EAF) or Basic Oxygen Furnaces (BOF) based on mass balance assumptions. Accurate knowledge of this composition can increase the usage of recycled material in steel production, reducing the need for raw ore extraction and minimizing environmental impact by conserving natural resources and lowering carbon emissions.

Two models are developed to describe element behavior in EAF and BOF processes. A linear state space model is used for elements transferring completely from scrap to steel, while a non-linear state space model is applied to elements distributing between steel and slag. The Kalman filter and unscented Kalman filter are employed to solve these models, respectively.

Importantly, the models leverage only data already collected during standard production, avoiding the need for additional costly measurements. This paper outlines both model formulations, the algorithms used, and discusses hyperparameter selection. Practical guidance is provided on choosing appropriate hyperparameters based on expert knowledge and historical data. The models are validated using real BOF data, with Cu and Cr serving as examples for the linear and non-linear cases, respectively. Results demonstrate that both models can reconstruct scrap composition for these elements, providing valuable insights for improving process control and ensuring product quality in steelmaking.

During the production of aluminium and steel cast parts for safety-critical applications, it is standard practice to reduce unwanted impurities by filtration of the liquid metal prior to casting using ceramic foam filters. The most critical stage of the filtration process is the infiltration of the ceramic foam during start-up, especially when the filter cannot be preheated, as heat loss to the filter may lead to freezing and casting failure. The present study aims to reduce this risk through a better understanding of its sensitivity with respect to the process parameters and geometric properties of the filter. Therefore, the infiltration process was numerically simulated using a 2D pore-scale model, enabling extensive parameter variations to investigate the influence of parameters such as porosity, pore density and melt superheat temperature. The results are qualitatively consistent with experimental observations of the process.

In integrated steel mills, the desulphurization of pig iron from the blast furnace is a crucial pretreatment step before the hot metal is converted into steel in the basic oxygen converter. During this process, significant dust emissions can occur, reaching up to 1 kg per tonne of liquid steel, with dust concentrations in the exhaust gas reported as high as 10 g/m³. The exhaust air from the desulphurization unit is typically cleaned using dry dedusting systems, most commonly electrostatic precipitators or bag filters. The separated dust is often recycled to the sinter plant, closing material loops within the steelworks. In contrast to other residues generated in steel plant off gas cleaning systems, comparatively little information is available on the physical properties and chemical composition of dust originating from pig iron desulphurization. To address this gap, dust samples from desulphurization units at two different steel mills were systematically investigated. Mechanical properties—including bulk density, particle size distribution, flowability, and wall friction angle—were determined alongside detailed chemical analyses. The results reveal substantial differences between the two dust samples, particularly in their carbon content, but also in the concentrations of sulphur, zinc, and alkali metals. Significant variations were likewise observed in key physical properties, including bulk density and particle size distribution. These parameters strongly influence both the handling behaviour of the material and its recycling. Taken together, the findings underscore the importance of plant specific characterization when assessing utilization strategies for desulphurization dust.

This study examines the efficacy of hydrogen in diminishing iron compounds found in dust emissions during the electric arc furnace (EAF) steelmaking processes at "Uzbeksteel" JSC. EAF dust is a fine secondary material that is made up of 30 to 60 percent iron oxides (Fe₂O₃, Fe₃O₄, FeO). The fact that approximately 60,000 tons of this dust has built up shows how important it is to find ways to recycle it that will last. The current investigation involved hydrogen reduction experiments performed at 1100 °C for 30 minutes, utilizing a continuous low-pressure hydrogen flow.
Thermodynamic research using Ellingham diagrams showed that iron oxides are selectively reduced between 650 and 750°C, where the standard free energy (ΔG) values are negative. But, the decrease of ZnO is only good at temperatures above 900°C. The reduction process is marked by the interactions between gas and solid, the passage of hydrogen through porous particles, and the gradual transition of Fe₂O₃ to Fe₃O₄ to FeO to Fe. The experimental results show that iron can be turned into metal, and that some zinc can shift into gas, which makes the process easier. Hydrogen, on the other hand, encourages processing without CO₂ and improves environmental performance. It has been shown that hydrogen can help with processing without making carbon dioxide, which makes it better for the environment than carbon-based reductants.

Electroslag melting is a promising approach to the recycling of fine scrap and high-alloy steel waste. Owing to the refining capacity of slag and the controlled thermal conditions of melting and solidification, the process makes it possible to produce high-quality ingots of secondary metal suitable for further use in high-tech industries. This paper presents the results of theoretical and experimental studies on the application of electroslag melting in a current-carrying mould for processing high-alloy steel waste. The features of heat and mass transfer during the melting of fine and very fine metal fragments in a molten slag bath were determined, and the main routes for improving process efficiency were identified. The process was experimentally studied in the recycling of used small medical items made of high-alloy stainless steels, including injection needles and surgical instruments. Experimental trials carried out on semi-industrial equipment confirmed adequate retention of alloying elements and the production of ingots with a high-quality surface suitable for subsequent forming without additional surface conditioning. These results demonstrate the potential of this process for the recycling of fine scrap and high-alloy steel waste.

Extrusion is a plastic deformation process in which a block of metal (ingot) is forced to flow by compression through the die opening of a smaller cross-sectional area than that of the new original profile (aircraft-asymmetric / billet). Extrusion is an indirect-compression process. Use of AI, automation / improvements to deployment technologies can move towards a community-driven, closed loop process. This includes advances at each step, for example, to extract, integrate, and reason with knowledge at scale to better respond to question, to the use of deep generative models to AI-automatically propose new hypotheses, to automating testing and experimentation using robotic labs. Important advances in the machine representation of knowledge also enable new results to lead to new questions and hypotheses. Different modules, advanced models able to assess the hot extrusion aircraft-asymmetric process are showed. The accuracy of numerical predictions was demonstrated in terms of extrusion load, cooling efficiency, and die stress analysis. The AI-experimental (numerical-comparisons) also showed the limits of industrial practices, sometimes based on experience and / or empirical approaches. This work aims presents and describe innovative 3D numerical models for the extrusion process implemented within (Mphy)-Multiphysics®) that combine different modules. Several industrial case studies [2, 4], were discussed to show and handle some challenges for the advanced optimization of the process through numerical simulation. Notably, to commercial software specifically dedicated to extrusion aircraft-asymmetric for the new airbus-2030, it is possible to implement customized and flexible models for analyzing the entire process from different points of view