Seznam abstraktů 2026: SEKCE F - EKONOMIKA A ŘÍZENÍ VÝROBY V HUTNÍM, OCELÁŘSKÉM A NAVAZUJÍCÍM PRŮMYSLU

This review combines research on chemical processes involved in calcium carbide production using low-rank coal as a reductant to address gaps in understanding reaction mechanisms, process efficiency, and raw material utilization. The review aimed to evaluate reaction pathways, benchmark energy consumption, assess coal properties and preparation effects, identify additives enhancing yield and purity, and compare thermodynamic and kinetic models. Literature from experimental, modeling, and process optimization studies published up to mid-2024 was systematically analyzed using a framework integrating chemical, thermodynamic, kinetic, and reactor design perspectives. Key findings reveal that one-step direct reactions between calcium oxide and carbon dominate under industrial conditions, with coal rank and pelletizing methods critically influencing reaction kinetics and product quality. Energy efficiency improvements arise from waste heat recovery, oxy-thermal furnace designs, and alternative carbon sources such as biomass and waste plastics, though scalability remains limited. Additives including potassium and lithium compounds catalyze formation and lower reaction temperatures, while advanced thermodynamic and kinetic models provide predictive insights but require further validation under heterogeneous feedstock conditions. These findings collectively underscore the potential of low-rank coal and process innovations to enhance sustainable calcium carbide production. The review highlights the need for integrated experimental and modeling approaches to optimize industrial application and reduce environmental impact.

Energy analyses in the metallurgical sector traditionally focus on upstream processes such as steelmaking and refining. However, when energy consumption is evaluated at the level of individual products, downstream manufacturing stages can represent a significant share of the total energy demand. This study investigates the energy flow associated with the manufacturing of a large forged steam turbine shaft using industrial production data from a European forging facility.
The analysis covers the complete manufacturing route of the shaft, including electric arc furnace (EAF) steelmaking, casting, reheating, forging, multiple heat treatment stages, machining operations and final heat stability testing. The results show that downstream thermal operations dominate the energy profile of the finished shaft. Heat stability testing represents approximately 29% of the total energy demand per tonne of finished shaft, followed by reheating (21%) and preliminary heat treatment (20%). In contrast, upstream steelmaking operations account for a relatively small share of the energy demand when allocated to the final shaft.
These findings demonstrate that analysing energy flow at product level changes the identification of energy hotspots compared with plant-level assessments. The results highlight the importance of optimising downstream thermal operations, furnace utilisation and process scheduling to improve the energy efficiency of forged component manufacturing and support ongoing decarbonisation efforts in the steel industry.

Carbon emission has been at the center for searching alternative solutions to combat the carbon footprint in the last years. The pyrometallurgical industry is a major contributor, this has opened a way for carbothermic reduction innovation. Different biochars have been tested for different pyrometallurgic processes. The current project dealt with the carbothermic reduction of basic manganese ore using Palm Kernel Shell biochar (PKS) in presence of hydrogen. The head samples and products have been characterized using XRF, XRD, SEM-EDS. The weight loss was recorded during experiments against temperature and time. Results have shown that addition up to 30% biochar excess led to a considerable low reduction extent. The manganese reduction rate of MnO was affected not only by the reducing agents but also the biochar content and temperature as well while the sample reduced in absence of hydrogen and excess biochar content showed the slowest reduction rate while the reduction in hydrogen presence and biochar was the fastest. The addition of hydrogen in the reductions using biochar improved the rate of reduction and increasing the temperature also showed a positive impact. The SEM micrographs confirmed the formation a metallic phase for the reductions with biochar.

This study presents "WeldTrack: Intelligent Guidance System," developed to minimize operator-induced errors in manual laser welding operations and to protect device longevity against the risk of "back-reflection," a critical issue particularly in highly reflective metals such as aluminum. The system architecture consists of two main units communicating via Wi-Fi. The first unit is a reference apparatus equipped with a BNO055 9-axis absolute orientation sensor and an ESP32-S3 microcontroller, designed to measure the spatial orientation of the surfaces to be joined by touching each sequentially before welding. The sequential data obtained from both surfaces are utilized to calculate the three-dimensional model of the volume to be filled by the weld seam (joint geometry) and its absolute orientation relative to the gravity axis. The second unit is a tracking module integrated into the welding torch, also housing a BNO055 sensor and an ESP32-S3 processor pair. Based on the digital "zero point" data received from the reference apparatus, the torch unit calculates the ideal welding angle and provides real-time guidance to the operator through visual (RGB LED) and haptic (vibration) feedback to maintain the correct angular position along the weld line. Experimental studies demonstrate that this dual-sensor dynamic referencing method standardizes weld penetration, minimizes the risk of back-reflection, and provides Industry 4.0-based digital data tracking fully compliant with Welding Procedure Specifications (WPS), even in manual operations.

The increasing demand for critical metals required for modern technologies has led to recycling waste or any secondary sources containing valuable metals in the present case germanium. Copper slags are generally rich in iron and silicate phases in form of fayalite, which contains trace metals of germanium, gallium, zinc and other critical elements that can be liberated. Although traditional hydrometallurgical techniques offer quick extraction they are linked to significant high energy consumption, extensive chemical use and secondary pollutants which limits their environmental sustainability and sometimes selectivity might be required. According to the review of research for more than a decade bioleaching has shown more selectivity where viable microorganisms like Acidithiobacillus and Bacillus species. These Bacillus are prone to promote an improve dissolution of phases containing within the iron and silicon compounds, increasing the valuable trace metal amount of germanium release. Research has shown that factors like pH, slurry, concentration, aeration and microbial collaborations affected how well bioleaching will work. Additionally, the strain adaptability and mutagenesis increase extraction yields. Although bioleaching has clear benefits over chemical leaching such as selective solubilisation, reduce energy needs and environmental friendliness the slow kinetics leaching remains a challenge. Research conducted examined selective germanium bioleaching from fayalitic copper slag using Bacillus species. Slag characterization employed XRF, XRD, and SEM. Leaching with oxalic acid and hydrogen peroxide at pH 4-5 achieved optimal recovery at 1.5 M within 30 minutes, with leachates analysed using ICP. These findings highlight the potential of this method for efficient germanium recovery.