TY - JOUR A1 - Vogel, Christian A1 - Hermann, P. A1 - Kästner, B. A1 - Adamczyk, Burkart A1 - Hoehl, A. A1 - Ulm, G. A1 - Adam, Christian T1 - Air and chlorine gas corrosion of different silicon carbides analyzed by nano-Fourier-transform infrared (nano-FTIR) spectroscopy N2 - The present study shows the potential of high-resolution imaging and nano-Fourier-transform infrared (nano-FTIR) spectroscopy for corrosion science. The protective oxidation layers of different chlorine-gas treated silicon carbides (SiCs) were characterized with these techniques. A nitrified SiC showed the highest resistant strength against chlorine corrosion at 1000 °C compared to the other SiCs. Nano-FTIR spectroscopy with a lateral resolution below 40 nm detected differences in the crystallinity of the bulk-SiC and in the transitional region to the protective layer. Furthermore, high-resolution imaging provides deep insight in the interfacial layer between bulk-SiC and the protective oxidation layer on sub-micrometer scale. KW - Nano-Fourier-transform infrared spectroscopy KW - Scattering-type scanning near-field optical microscopy (s-SNOM) KW - Synchrotron radiation KW - Corrosion KW - Silicon carbide KW - Chlorine PY - 2018 U6 - https://doi.org/10.1016/j.corsci.2017.12.002 SN - 0010-938X VL - 131 SP - 324 EP - 329 PB - Elsevier AN - OPUS4-43648 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schraut, Katharina A1 - Adamczyk, Burkart A1 - Adam, Christian A1 - Stephan, Dietmar A1 - Meng, Birgit A1 - Simon, Sebastian A1 - von Werder, Julia A1 - Hirsch, Tamino A1 - Manninger, Tanja T1 - Effect of gypsum on the hydration of fused cement clinker from basic oxygen furnace slag N2 - Fused cement clinker can be produced from molten basic oxygen furnace slag (BOFS) by way of a reductive thermochemical treatment. During the thermochemical treatment, oxidic iron is reduced to metallic iron and separated. The resulting low-iron slag has a chemical and mineralogical composition similar to ordinary Portland cement (OPC) clinker. In this study, the hydraulic reactivity of the fused clinker from BOFS with and without gypsum was investigated using isothermal calorimetry, differential scanning calorimetry, in situ X-ray diffraction and powder X-ray diffraction. Furthermore, a synthetic fused clinker without foreign ions and fused clinker produced by a mixture of both materials was studied. The hydraulic reaction of the fused clinker from BOFS was considerably slower than that of OPC. However, the reaction can be accelerated by adding gypsum as a sulfate carrier. Furthermore, the results showed an increased reaction rate with decreasing content of foreign ions such as Fe, P or Mn. KW - General Materials Science KW - Building and Construction PY - 2024 U6 - https://doi.org/10.1680/jadcr.23.00070 SN - 0951-7197 SP - 1 EP - 19 PB - Telford AN - OPUS4-59391 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schraut, Katharina A1 - Adamczyk, Burkart A1 - Adam, Christian A1 - Stephan, D. A1 - Meng, Birgit A1 - Simon, Sebastian A1 - von Werder, Julia T1 - Synthesis and characterisation of alites from reduced basic oxygen furnace slags N2 - Basic oxygen furnace slags (BOFS) are by-products of the steelmaking process. Several researchers have studied the production of Portland cement clinker and metallic iron from BOFS via a reductive treatment. In this study, we applied a carbothermal reduction of BOFS in a technical-scale electric arc furnace and characterised the clinker-like products. Those clinker-like non-metallic products (NMPs) had a chemical and mineralogical composition comparable to clinker for ordinary Portland cement (OPC) and contained large elongated alite crystals as major component. The pure NMPs reacted more slowly and achieved a lower degree of hydration compared with commercial OPC. If the reactivity of the products can be further increased by employing specific adaptations, it can be used as a full clinker substitute for OPC. Nevertheless, it is also an option to use the material without further modifications as a cement component or concrete addition, which contributes to the strength development in both cases. KW - BOFS KW - Hydration products KW - Thermal analysis KW - X-ray diffraction PY - 2021 U6 - https://doi.org/10.1016/j.cemconres.2021.106518 SN - 0008-8846 VL - 147 SP - 6518 PB - Elsevier Ltd. AN - OPUS4-52939 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Neuhold, S. A1 - Algermissen, D. A1 - Drissen, P. A1 - Adamczyk, Burkart A1 - Presoly, P. A1 - Sedlazeck, K. P. A1 - Schenk, J. A1 - Raith, J. G. A1 - Pomberger, R. A1 - Vollprecht, D. T1 - Tailoring the FeO/SiO2 Ratio in Electric Arc Furnace Slags to Minimize the Leaching of Vanadium and Chromium N2 - Based on recently published research on leaching control mechanisms in electric arc furnace (EAF) slags, it is assumed that a FeO/SiO2 ratio of around one leads to low leached V and Cr concentrations. This ratio influences the mineral phase composition of the slag toward higher amounts of spinel and a lower solubility of calcium silicate phases by suppressing the formation of magnesiowuestite and highly soluble calcium silicate phases. To evaluate this hypothesis, laboratory and scaled up tests in an EAF pilot plant were performed on slag samples characterized by elevated V and Cr leaching and a high FeO/SiO2 ratio. Prior to the melting experiments, the optimum FeO/SiO2 ratio was calculated via FactSageTM. In the melting experiments, the ratio was adjusted by adding quartz sand, which also decreased the basicity (CaO/SiO2) of the slag. As a reference, remelting experiments without quartz sand addition were conducted and additionally, the influence of the cooling rate of the slag was examined. The remelted (without quartz sand) and the remelted modified slags (with quartz sand) were analyzed chemically and mineralogically and the leaching behavior was investigated. The modification of the slags yielded a minimized release of V and Cr, supporting the hypothesis that the FeO/SiO2 ratio influences the mineralogy and the leaching behavior. KW - Electric arc furnace (EAF) slags KW - FactSageTM calculations KW - Leaching control mechanisms KW - Melting experiments PY - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-571517 VL - 10 IS - 7 SP - 1 EP - 18 PB - MDPI AN - OPUS4-57151 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Adamczyk, Burkart A1 - Neuhold, S. A1 - Drissen, P. A1 - Algermissen, D. A1 - Presoly, P. A1 - Sedlazeck, K. P. A1 - Schenk, J. A1 - Raith, J. G. A1 - Pomberger, R. A1 - Vollprecht, D. T1 - Tailoring the FeO/SiO2 ratio in electric arc furnace slags to minimize the leaching of Vanadium and Chromium N2 - Based on recently published research on leaching control mechanisms in electric arc furnace (EAF) slags, it is assumed that a FeO/SiO2 ratio of around one leads to low leached V and Cr concentrations. This ratio influences the mineral phase composition of the slag toward higher amounts of spinel and a lower solubility of calcium silicate phases by suppressing the formation of magnesiowuestite and highly soluble calcium silicate phases. To evaluate this hypothesis, laboratory and scaled up tests in an EAF pilot plant were performed on slag samples characterized by elevated V and Cr leaching and a high FeO/SiO2 ratio. Prior to the melting experiments, the optimum FeO/SiO2 ratio was calculated via FactSageTM. In the melting experiments, the ratio was adjusted by adding quartz sand, which also decreased the basicity (CaO/SiO2) of the slag. As a reference, remelting experiments without quartz sand addition were conducted and additionally, the influence of the cooling rate of the slag was examined. The remelted (without quartz sand) and the remelted modified slags (with quartz sand) were analyzed chemically and mineralogically and the leaching behavior was investigated. The modification of the slags yielded a minimized release of V and Cr, supporting the hypothesis that the FeO/SiO2 ratio influences the mineralogy and the leaching behavior. KW - Electric arc furnace slags KW - FactSage calculations KW - EAF slags KW - Leaching control mechanisms KW - Melting experiments PY - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-507748 VL - 10 IS - 7 SP - 2549 EP - 2565 AN - OPUS4-50774 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -