TY - JOUR A1 - Jovičević-Klug, Matic A1 - Souza Filho, Isnaldi R. A1 - Springer, Hauke A1 - Adam, Christian A1 - Raabe, Dierk T1 - Green steel from red mud through climate-neutral hydrogen plasma reduction N2 - AbstractRed mud is the waste of bauxite refinement into alumina, the feedstock for aluminium production1. With about 180 million tonnes produced per year1, red mud has amassed to one of the largest environmentally hazardous waste products, with the staggering amount of 4 billion tonnes accumulated on a global scale1. Here we present how this red mud can be turned into valuable and sustainable feedstock for ironmaking using fossil-free hydrogen-plasma-based reduction, thus mitigating a part of the steel-related carbon dioxide emissions by making it available for the production of several hundred million tonnes of green steel. The process proceeds through rapid liquid-state reduction, chemical partitioning, as well as density-driven and viscosity-driven separation between metal and oxides. We show the underlying chemical reactions, pH-neutralization processes and phase transformations during this surprisingly simple and fast reduction method. The approach establishes a sustainable toxic-waste treatment from aluminium production through using red mud as feedstock to mitigate greenhouse gas emissions from steelmaking. KW - Multidisciplinary PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-594424 DO - https://doi.org/10.1038/s41586-023-06901-z SN - 0028-0836 VL - 625 IS - 7996 SP - 703 EP - 709 PB - Springer Science and Business Media LLC AN - OPUS4-59442 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Machado Ferreira de Araujo, F. A1 - Duarte-Ruiz, D. A1 - Saßnick, H.-D. A1 - Gentzmann, Marie C. A1 - Huthwelker, T. A1 - Cocchi, C. T1 - Electronic Structure and Core Spectroscopy of Scandium Fluoride Polymorphs N2 - Microscopic knowledge of the structural, energetic, and electronic properties of scandium fluoride is still incomplete despite the relevance of this material as an intermediate for the manufacturing of Al−Sc alloys. In a work based on first-principles calculations and X-ray spectroscopy, we assess the stability and electronic structure of six computationally predicted ScF3 polymorphs, two of which correspond to experimentally resolved single-crystal phases. In the theoretical analysis based on density functional theory (DFT), we identify similarities among the polymorphs based on their formation energies, chargedensity distribution, and electronic properties (band gaps and density of states). We find striking analogies between the results obtained for the ow- and high-temperature phases of the material, indirectly confirming that the transition occurring between them mainly consists of a rigid rotation of the lattice. With this knowledge, we examine the X-ray absorption spectra from the Sc and F K-edge contrasting firstprinciples results obtained from the solution of the Bethe−Salpeter equation on top of all-electron DFT with high-energy-resolution fluorescence detection measurements. Analysis of the computational results sheds light on the electronic origin of the absorption maxima and provides information on the prominent excitonic effects that characterize all spectra. A comparison with measurements confirms that the sample is mainly composed of the high- and low-temperature polymorphs of ScF3. However, some fine details in the experimental results suggest that the probed powder sample may contain defects and/or residual traces of metastable polymorphs. KW - Scandium KW - X-ray spectroscopy PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-570727 DO - https://doi.org/10.1021/acs.inorgchem.2c04357 SN - 0020-1669 VL - 62 IS - 10 SP - 4238 EP - 4247 PB - ACS Publications CY - Washington DC AN - OPUS4-57072 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Dombinov, V. A1 - Herzel, Hannes A1 - Meiller, M. A1 - Müller, F. A1 - Willbold, S. A1 - Zang, J. W. A1 - da Fonseca-Zang, W. A. A1 - Adam, Christian A1 - Klose, H. A1 - Poorter, H. A1 - Jablonowski, N. D. A1 - Schrey, S. D. T1 - Sugarcane bagasse ash as fertilizer for soybeans: Effects of added residues on ash composition, mineralogy, phosphorus extractability and plant availability N2 - Sugarcane bagasse is commonly combusted to generate energy. Unfortunately, recycling strategies rarely consider the resulting ash as a potential fertilizer. To evaluate this recycling strategy for a sustainable circular economy, we characterized bagasse ash as a fertilizer and measured the effects of co-gasification and co-combustion of bagasse with either chicken manure or sewage sludge: on the phosphorus (P) mass fraction, P-extractability, and mineral P phases. Furthermore, we investigated the ashes as fertilizer for soybeans under greenhouse conditions. All methods in combination are reliable indicators helping to assess and predict P availability from ashes to soybeans. The fertilizer efficiency of pure bagasse ash increased with the ash amount supplied to the substrate. Nevertheless, it was not as effective as fertilization with triple-superphosphate and K2SO4, which we attributed to lower P availability. Co-gasification and co-combustion increased the P mass fraction in all bagasse-based ashes, but its extractability and availability to soybeans increased only when co-processed with chicken manure, because it enabled the formation of readily available Ca-alkali phosphates. Therefore, we recommend co-combusting biomass with alkali-rich residues to increase the availability of P from the ash to plants. KW - Combustion and gasification KW - Phosphate extractability and availability KW - X-ray diffraction (XRD) PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-567632 DO - https://doi.org/10.3389/fpls.2022.1041924 SN - 1664-462X VL - 13 SP - 1 EP - 13 PB - Frontiers Media CY - Lausanne AN - OPUS4-56763 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -