TY - CONF A1 - Schraut, Katharina T1 - Hydraulic reactivity of alite rich material from post-treated basic oxygen furnace slags N2 - Basic oxygen furnace slags (BOFS) are a by-product of steel production. In 2016, 10.4 Mt of BOFS were produced in the European Union (EU). The main part of BOFS is used in road construction, earthwork and hydraulic engineering. A smaller part is returned to the metallurgical circle, used as fertilizer or landfilled. However, it is also possible to produce higher value products from BOFS. For example, many researchers have investigated the possibility of producing Portland cement clinker and crude iron from BOFS by a carbothermal post-treatment. In this study, German BOFS was reduced in a small-scale electric arc furnace using petrol coke as reducing agent. The carbothermal treatment reduces the iron oxides in the BOFS to metallic iron, which accumulates at the bottom of the furnace by density separation. In addition to metallic iron, the process generates a mineral product rich in the tricalcium silicate solid solution alite. As the main constituent of Portland cement clinker, the hydraulic reactive mineral alite is of high economic importance. In previous studies, the hydraulic reactivity of the mineral product was investigated by testing the compressive strength of blends with 70 wt.% ordinary Portland cement (OPC). Recent investigations focused on the hydraulic properties of the pure mineral product from the reduced BOFS. The heat of hydration of the mineral product was measured by isothermal calorimetry and compared with the heat of hydration of a synthetic low-iron slag and OPC. In addition, the formation of hydration products was investigated with differential scanning calorimetry (DSC) and x-ray diffraction analysis (XRD) on freeze-dried samples after defined curing times. The results of the calorimetric measurements indicate that the mineral product produced less heat of hydration and its reaction was delayed compared to the synthetic low-iron slag and OPC. Hydration products such as portlandite and calcium silicate hydrates (C-S-H) formed later and in lower amounts. The production of a hydraulic material from BOFS by reductive treatment is of great interest to both the cement and steel industries. The substitution of cement clinker in OPC with a hydraulic material such as reduced BOFS leads to a reduction in greenhouse gas emissions from cement production. The steel industry benefits from an application for its by-products that avoids cost expensive landfilling and may even bring economic advantages. Furthermore, it may be possible to return the recovered crude iron to production. T2 - 3rd European Mineralogical Conference CY - Cracow, Poland DA - 30.08.2021 KW - BOFS KW - Calcium silicate KW - Hydraulic reactivity PY - 2021 AN - OPUS4-53473 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schraut, Katharina T1 - Formation and hydraulic reactivity of an alite rich material from post treated basic oxygen furnace slag N2 - Basic oxygen furnace slag (BOFS) is a by-product of steelmaking of which about 10.4 Mt are produced annually in the EU. BOFS is mostly used in road construction, earthwork and hydraulic engineering. However, in this use, the iron bound in BOFS is lost and the opportunity to produce higher value products from BOFS is forgone. In recent decades, many researchers have investigated a thermochemical process to reduce iron oxides to metallic iron in molten BOFS. The metallic iron formed separates from the reduced slag due to its higher density and can be recovered. An advantage of this process is that simultaneously the chemical composition of the reduced slag is adapted to that of the Portland cement clinker and the hydraulic reactive mineral alite is formed. In this study, BOFS was reduced in a small-scale electric arc furnace using petrol coke as reducing agent, and the hydraulic properties of the reduced, low-iron BOFS were investigated. Despite a chemical and mineralogical composition similar to that of Portland cement clinker, the reduced BOFS produced less heat of hydration, and its reaction was delayed compared to Portland cement. However, the addition of gypsum, as is also done in cement production from Portland cement clinker, has been found to accelerate the hydration rate of reduced BOFS. Further research to improve the hydraulic properties of the reduced slag is essential. If successful, the production of a hydraulic binder and crude iron from BOFS could have economic and ecological benefits for both the cement and steel industry. T2 - GeoMin Köln 2022 CY - Cologne, Germany DA - 11.09.2022 KW - BOFS KW - Portland Cement KW - Hydraulic reactivity PY - 2022 AN - OPUS4-56080 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schraut, Katharina T1 - Production of a hydraulic material from post-treated steelmaking slags N2 - Steelmaking slag is a by-product of steel production of which 4.5 Mt were produced in 2020 in Germany alone. It is mainly used in road construction, earthwork and hydraulic engineering. A smaller part is returned to the metallurgical circle, used as fertilizer or landfilled. With this use, iron oxides still contained in steelmaking slag are lost. In addition, the possibility of producing higher-grade products from steelmaking slag is foregone. In recent decades, many researchers have investigated the production of Portland cement clinker and crude iron from basic oxygen furnace slags (BOFS) via a reductive treatment. Carbothermal treatment of liquid BOFS causes a reduction of iron oxides to metallic iron, which separates from the mineral phase due to its higher density. Simultaneously, the chemical composition of the reduced slag is adapted to that of the Portland cement clinker. In this study, German BOFS was reduced in a small-scale electric arc furnace using petrol coke as a reducing agent. The resulting low-iron mineral product had a similar chemical composition to Portland cement clinker and was rich in the tricalcium silicate solid solution alite (Ca3SiO5). Based on its chemical and mineralogical composition, similar to that of Portland cement clinker, the reduced BOFS has the potential to react comparably. In our study, the reduced BOFS produced less heat of hydration compared to OPC and its hydraulic reaction was delayed. However, adding gypsum has been shown to accelerate the hydration rate of the reduced BOFS compared to that known from the calcium silicates of Portland cement clinker. Further research to improve the hydraulic properties of the reduced slag is essential. If successful, producing a hydraulic binder and crude iron from BOFS could have economic and ecological benefits for both the cement and steel industry. T2 - 16th International Congress on the Chemistry of Cement ICCC 2023 CY - Bangkok, Thailand DA - 18.09.2023 KW - Steelmaking slag KW - Alite hydraulic reactivity KW - Clinker substitute PY - 2023 AN - OPUS4-58522 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schoknecht, Ute A1 - Kalbe, Ute A1 - Happel, O. T1 - Combination of leaching tests with ecotoxicity and chemical analysis – Lessons learnt N2 - The presentation describes analytical methods to characterize eluates from leaching tests and identify organic substances in leachates. Chances to obtain complementary information from ecotoxtests and chemical analysis are discussed. T2 - Workshop: Ecotoxicological evaluation of construction products – test results, implementation in Guidance, Technical Standards and Ecolabelling CY - Online meeting DA - 21.03.2022 KW - Leaching KW - Ecotoxicity KW - Construction products PY - 2022 AN - OPUS4-55276 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schoknecht, Ute T1 - Leaching und Transformation von Bioziden aus Fassadenfarben N2 - Anhand von Beobachtungen aus Labor- und Freilandversuchen wird dargestellt, wie Wasserkontakt und Strahlung die Auslaugung und Transformation der Wirkstoffe Diuron und Terbutryn beeinflussen. Auf Optionen zur modellhaften Darstellung dieser Prozesse wird kurz eingegangen. T2 - OMiBiB - Optimierung und Minimierung des Biozideinsatzes in Baustoffen CY - Online meeting DA - 09.02.2022 KW - Leaching KW - Transformation KW - Biozide KW - Fassadenfarben PY - 2022 AN - OPUS4-54318 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schoknecht, Ute T1 - Leaching und Transformation von Bioziden aus Fassadenfarben N2 - Anhand von Beobachtungen aus Labor- und Freilandversuchen wurde dargestellt, wie Wasserkontakt und Strahlung die Auslaugung und Transformation der Wirkstoffe Diuron und Terbutryn beeinflussen. Auf Optionen zur modellhaften Darstellung dieser Prozesse wurde kurz eingegangen. T2 - Optimierung und Minimierung des Biozideinsatzes in Baustoffen CY - Online meeting DA - 09.02.2022 KW - Leaching KW - Transformation KW - Biozid KW - Fassadenfarbe PY - 2022 AN - OPUS4-55273 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schoknecht, Ute T1 - The Impact of Weather Conditions on Biocides in Paints N2 - Aim. The European biocidal products regulation requires environmental risk assessments for biocidal products under service conditions. This is only possible, if processes that lead to biocide emissions into the environment are understood and can be reasonably predicted. Actual emissions due to leaching result from different processes that are affected by material properties and environmental conditions. Transformation of biocides can affect emissions considerably. Leaching and possible transformation of the film preservatives carbendazim, diuron, OIT and terbutryn in paints was observed under laboratory and field conditons in order to investigate the influence of different factors, e.g. water contact and radiation on biocide emissions. The paints contained either white titanium dioxide or a red iron oxide pigment to check whether pigments affect leaching processes. Methods. Test specimens of a water-based styrene acrylic dispersion paint on glass were exposed to UVA-radiation in a UV weathering device and/or exposed to water contact by immersion events on the basis of the European standard EN 16105. Plywood panels were coated and exposed to natural weather conditions in a semi-field experiment. Concentrations of biocides and transformation products were analysed in leachates from laboratory tests, runoff samples and remaining coatings. Results. The impact of weathering conditions on transformation processes differs for the investigated active substances. Water contact, radiation as well as pigments in the paints determine the pattern and amount of transformation products on coatings, leachates and runoff water. Observations from laboratory and field experiments were compared. It proved that results from laboratory tests support understanding of data from field experiments. Detailed knowledge on the fate of active substances under environmental conditions supports manufacturers to develop safe applications of film preservatives and authorities to evaluate its environmental impact. T2 - European Technical Coatings Congress 2022 CY - Kraków, Poland DA - 12.07.2022 KW - Paints KW - Biocides KW - Transformation KW - Emission PY - 2022 AN - OPUS4-55274 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schneider, Joachim T1 - Usage of BOF slag and next generation EAF slag in the cement industry N2 - Increasing amounts of new types of EAFS from the DRP-EAF-route and still significant amounts of BOFS from the DRP-SAF-BOF-route will be produced while BFS will vanish. In two BMBF funded research projects, BAM and FEhS examine the application of slags from future steel production in the cement industry. The project “SlagCEM” investigated the recovery of iron from BOFS while producing a mineral product with good cementitious properties. The reduction of BOFS to recover metallic iron along with the generation of a clinker-like material for the cement industry increases the viscosity of the BOFS. This would require a process at unfeasibly high temperatures of >1.700 °C. Therefore, SlagCEM aimed to modify the BOFS to reduce the viscosity to suitable ranges at lower temperatures of ~1.600 °C. A demonstration trial (20 tons) was carried out and the potential for substitution of OPC was determined. DRI-EOS investigates the utilization of increasing amounts of DRI-based EAFS in the cement industry to compensate the reduced production of GBFS. This requires an adjustment of the slag’s chemical composition and a rapid quenching to create an amorphous structure with latent hydraulic characteristics. The project studies the behavior of the modified slag during the metallurgical process and during solidification, any possibly negative impact on the cementitious or environmental properties as well as the potential to recover metals such as Fe, Cr, Mo and V. The final results of the project “SlagCEM”, finished in 2024, as well as the current state and insights of the project “DRI-EOS”, started in July 2022, shall be presented in this talk. T2 - 9th International Slag Valorisation Symposium CY - Leuven, Belgium DA - 08.04.2025 KW - Steel slags KW - Basic oxygen furnace (BOF) KW - Electric arc furnace (EAF) KW - Cement KW - Slag valorisation PY - 2025 AN - OPUS4-64712 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schneider, Joachim T1 - Production of raw materials for the cement industry based on steel making slags from future hydrogen based steel production routes N2 - Increasing amounts of new types of EAFS from the DRP-EAF-route and still significant amounts of BOFS from the DRP-SAF-BOF-route will be produced while BFS will vanish. In two BMBF funded research projects, BAM and FEhS examine the application of slags from future steel production in the cement industry. The project “SlagCEM” investigated the recovery of iron from BOFS while producing a mineral product with good cementitious properties. The reduction of BOFS to recover metallic iron along with the generation of a clinker-like material for the cement industry increases the viscosity of the BOFS. This would require a process at unfeasibly high temperatures of >1.700 °C. Therefore, SlagCEM aimed to modify the BOFS to reduce the viscosity to suitable ranges at lower temperatures of ~1.600 °C. A demonstration trial (20 tons) was carried out and the potential for substitution of OPC was determined. DRI-EOS investigates the utilization of increasing amounts of DRI-based EAFS in the cement industry to compensate the reduced production of GBFS. This requires an adjustment of the slag’s chemical composition and a rapid quenching to create an amorphous structure with latent hydraulic characteristics. The project studies the behavior of the modified slag during the metallurgical process and during solidification, any possibly negative impact on the cementitious or environmental properties as well as the potential to recover metals such as Fe, Cr, Mo and V. The final results of the project “SlagCEM”, finished in 2024, as well as the current state and insights of the project “DRI-EOS”, started in July 2022, shall be presented in this talk. T2 - Euroslag 2024 CY - Bilbao, Spain DA - 23.10.2024 KW - Slag KW - Steel KW - Cement KW - Electric Arc Furnace (EAF) KW - Basic Oxygen Furnace (BOF) PY - 2024 AN - OPUS4-61839 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schmidt, Selina T1 - Antimicrobial resistance in soil microbes mediated by resistance evolution and horizontal gene transfer (HGT) N2 - Biocides are in contact with soils through direct application and passive leaching from protected materials. Consequently, soil microorganisms are exposed to biocides even though they are not their primary targets. Soil is a large reservoir of microbial diversity and has been hypothesized to be a crucial factor for the evolution and spread of antimicrobial resistance. Currently, there is little knowledge on how biocides used to protect materials affect the evolution and spread of resistance. Thus, our aim is to investigate the risk for the evolution of biocide resistance and cross-resistance to antibiotics. In addition, we aim to elucidate the affect of biocides on the spread of resistance via horizontal gene transfer (HGT). In adaptive laboratory evolution experiments we cultured selected model soil microorganism with representative biocides under selection regimes with increasing and stable biocide concentrations followed by antibiotic and biocide cross-resistance determination. Moreover, we investigate if the selected biocides affect the rates of de novo mutations and HGT of plasmids that carry resistance genes among soil microorganism. Our results show only small increases of biocide resistance during serial transfers under increasing biocide concentrations. One reason for this might be the narrow selective window for biocide resistance due to steep dose-response relationships. Furthermore, our results indicate that a stable low-level biocide regime did not select for high level cross-resistance to antibiotics and other biocides. Moreover, material preservatives affected the rates of HGT via conjugation and the mutation rates at sub-inhibitory concentrations. The results will enable future risk assessment regarding resistance evolution for biocides used as material preservatives. T2 - 4th Evo Eco PhD Meeting CY - Lutherstadt Wittenberg DA - 04.03.2020 KW - Microbiology KW - Biocides KW - Horizontal gene transfer HGT KW - Resistance evolution KW - Antimicrobial resistance PY - 2020 AN - OPUS4-51313 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -