Research Data Repository of Saxon Universities
OPARA is the Open Access Repository and Archive for Research Data of Saxon Universities.
Researchers of Saxon Universities can either publish their research data on OPARA, or archive it here to comply with requirements of funding acencies and good scientic practice, without public access.
You can find the documentation of this service at the OPARA manual websites. If you need suppourt using OPARA please contact the Servicedesk of TU Dresden.
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Recent Submissions
GRK 2802: Thermophysical Properties of the Desulphurization Slags With Various CaS and CaO/Al2O3 Ratio
(Technische Universität Bergakademie Freiberg, 2026-09-25) Salpagarov, Eldar; Bellé, Matheus Roberto; Yehorov, Anton; Richter, Julia; Volkova, Olena
Low sulphur content is essential for high-quality steels and can be achieved by using desulphurization slag. During the desulphurization process the chemical composition of the slag changes leading to alteration in its thermophysical properties, such as surface tension, viscosity, and density. However, the influence of CaS on these thermophysical properties is poorly investigated nowadays. In this study, the influence of various CaS content (0-10 wt%) and CaO/Al2O3 ratio (1.87-1.36) on the viscosity, surface tension, and density of desulphurization slags is investigated. Measurements of surface tension and density are carried out using the maximum bubble pressure method, while viscosity is determined using the rotating bob method. The obtained results show that a decrease in viscosity value is observed with an increase in CaS content only up to 6 wt%, however, further addition of CaS sharply increases viscosity. In case of surface tension and density measurements, an increase in CaS content up to 10 wt% results in a reduction of both property values. Additionally, to study microstructure differences of the investigated slags, they were quenched and examined using Scanning electron microscopy (SEM) and Energy-dispersive X-ray spectroscopy (EDX).
GRK 2802: Anodes based on MgO-C Recyclates and 316L Steel for Prospective Aluminium Fused-Salt Electrolysis Application
(Technische Universität Bergakademie Freiberg, 2026-09-25) Gehre, Patrick; Yaroshevskyi, Serhii; Kaiser, Patricia; Brachhold, Nora; Hubálková, Jana; Aneziris, Christos
Every year, approx. 28 million tons of used refractories accumulate worldwide. The majority of them are used as aggregates for road construction (downcycling) or are deposited in landfills. For ecological and economic reasons, an increased research potential was identified in recent years, dedicated to increasing the recycling rate and finding new markets and application fields with a higher value of the refractory recyclates. The study presents the
current findings of the development of inert electrodes for the aluminum fused-salt electrolysis composed of steel and MgO gained from MgO-C recyclates. To withstand the chemical attack of molten aluminum and cryolitic melts, the metal-ceramic composites were preoxidized (PO) at 800 °C, 900 °C, and 1000 °C. The microstructure after each PO thermal treatment was analyzed. After PO at 800 °C, a (Cr,Fe)3O4 spinel-like phase and Fe-O Mg-O solid solution form. After PO at 900 °C, a larger amount of the Fe-O Mg-O solid solution and a (Cr,Fe)2O3 solid solution around the steel grains was identified. Furthermore, the electrical conductivity of the metal-ceramic-composites preoxidized at 900 °C amounts to 1.49·102 S·cm-1 and hence is in the range of carbon, which exhibits a value of 1.54·102 S·cm-1. Additionally, the impact of different preoxidation treatments at 900 °C by applying furnaces equipped
with electrical heating, natural gas burner, and microwave plasma burner on the microstructure was investigated.
GRK 2802: MgO-C Ladle Bricks based on Recyclates and Lignin-Collagen-Fructose Binder System
(Technische Universität Bergakademie Freiberg, 2026-09-25) Gehre, Patrick; Gunasekar, Dinesh Kumar; Hubálková, Jana; Aneziris, Christos
Every year, approx. 28 million tons of used refractories accrue worldwide. After their break out, the majority of them are used in subordinate application fields such as aggregates for road construction (downcycling) or deposited in landfills. Their recycling in the field of refractory materials played an underpart so far. For ecological and economic reasons, an increased research potential was identified in the last years consecrated to increasing the recycling rate of refractories and finding new markets and application fields with higher value for them. The study presents current findings of a long-term research training group addressing (amongst others) the development of MgO-C ladle bricks containing MgO-C recyclates and being bonded with pitch- and resin-free environmentally friendly binders. So far, the favored batches contained an oxidic grain fraction composed of 40.5 wt.-% fused MgO raw material, 40.5 wt.-% MgO-C recyclates, 14 wt.-% sintered magnesia (DBM) raw material together with 5 wt.-% graphite and optional antioxidants (TiO2, Al, SiO2). A binder system composed of a mixture of lignin, collagen, and polyethylene glycol (PEG) was developed. The latter served as a pressing aid and was necessary due to the absence of liquid resin in the batch. Even after a considerable and auspicious optimization during previous studies, this basic batch containing recyclates and no pitch or resin does not meet the physical and mechanical properties of standard industrial bricks. Hence, in the present study, the binder system was enhanced by using varying amounts of lignin, collagen, and tannin together with polyethylene glycol, fructose, and citric acid addition. The new developed MgO-C mixtures were pressed uniaxially, dried, cured, and carbonized at 1000 °C. It has been found that polyethylene glycol, which impairs the material properties, can be omitted using sufficient amounts of fructose. The addition of citric acid leads to a further increase in CCS. Consequently, actual optimized environmentally friendly MgO-C batches show a CCS of 85 % of the value of industrial pitch- and resin-bonded bricks without recyclates.
Dataset for the Criterion Validation of Four Activity Sensors against Doubly Labelled Water for Assessing Habitual 24-Hour Energy Expenditure
(Universität Leipzig, 2026-09-24) Heydenreich, Juliane; Lutz, Helena; Manzke, Christopher; Oeschger, Regina; Gilgen-Ammann, Rahel
This dataset contains data from a study evaluating the criterion validity of four activity sensors for assessing habitual 24-hour energy expenditure (EE) against doubly labelled water (DLW), used as the reference method. The dataset includes measurements of habitual energy expenditure obtained using DLW and estimates derived from four activity sensors, together with relevant participant characteristics and study-related variables. The data were collected to enable the comparison of sensor-derived estimates with DLW-based measurements of habitual 24-hour energy expenditure and to support analyses of agreement, validity, and measurement error across the four devices.
Thermophysical Properties of Ladle Slag with Different SiO2 Content
(Technische Universität Bergakademie Freiberg, 2026-09-23) Yehorov, Anton; Volkova, Olena
The growing demand for electric vehicles, driven by global decarbonization policies, has led to an increase in the production of electric steel, which is characterized by a high silicon content. Producing this type of steel necessitates careful control of slag composition, particularly with high SiO2 content. This study investigates the thermophysical properties of cleanness slags with varying silicon oxide (SiO2) content, specifically examining viscosity, surface tension, and density. Silicon oxide, ranging from 1 to 20 wt%, was added to slags with a CaO/Al2O3 ratio of 1. The results show that increasing SiO2 content raises viscosity at temperatures above 1550 °C but reduces it at lower temperatures. Additionally, a linear decrease in density and surface tension was observed with increasing SiO2, which is attributed to the substitution of CaO with SiO2, thereby reducing the number of unsatisfied bonds in the slag network. Understanding these dynamics enhances control over slag-steel interactions in the steel ladle, ultimately improving process efficiency and steel quality.