TY - JOUR
A1 - Taube, Mareike Carolin
A1 - Adamczyk, Burkart
A1 - Adam, Christian
A1 - Feldmann, Ines
A1 - Ostermann, Markus
A1 - Reuter, M.
A1 - Stelter, M.
T1 - Tantalrecycling aus pyrometallurgischen Rückständen
JF - World of Metallurgy – ERZMETALL
N2 - Gegenstand dieser Arbeit ist die Untersuchung eines bestehenden pyrometallurgischen Prozesses zur Rückgewinnung von Tantal und Niob aus metallurgischen Reststoffen mit vorwiegend niedriger Wertstoffkonzentration.
Zur näheren Erforschung der im vorliegenden Stoffsystem ablaufenden Reduktionsprozesse wurden in einem Elektrolichtbogenofen Schmelzversuche im Pilotmaßstab durchgeführt. Als Reduktionsmittel diente Koks, welcher mithilfe einer Argon-gespülten Eisenlanze in die flüssige mineralische Schmelze eingebracht wurde. Während der Reduktionsbehandlung werden Refraktärmetalle wie Tantal und Niob in ihre Carbide überführt und anschließend in der erschmolzenen eisenbasierten Metallphase am Boden des Reaktors angereichert. Neben Tantal und Niob gelangt auch ein Teil des im Einsatzmaterial enthaltenen Titans als unerwünschtes Begleitelement in die Metallphase.
Sein Großteil verbleibt jedoch als Oxid in der Schlacke und wird dort hauptsächlich im Mineral Perowskit (CaTiO3) gebunden. Die erstarrten Schlackeproben wurden mit verschiedenen Methoden wie Röntgenfluoreszensanalyse, Röntgenbeugung und Rasterelektronenmikroskopie mit gekoppelter energiedispersiver Röntgenanalyse untersucht, um die Bildung tantalhaltiger Mineralphasen zu verschiedenen Stadien des Reduktionsprozesses zu verfolgen.
Die hier gewonnenen Erkenntnisse zeigen, dass weniger die durch das Einblasen von Koks verursachte Reduktionsreaktion, sondern das Absinken der tantalreichen Eisentröpfchen in der flüssigen mineralischen Schmelze, gefolgt von ihrer Anreicherung in die Metallphase, für die Kinetik ausschlaggebend ist.
N2 - An existing pyrometallurgical process for tantalum and niobium recovery, mainly from low grade pyrometallurgical residues, was investigated. Melting experiments were carried out in a pilot-scale electric arc furnace to study the material system during the reduction process caused by blowing coke into the liquid mineral melt. During the pyrometallurgical treatment refractory metals such as tantalum and niobium are converted into their carbides and enriched in the molten iron-based metal phase. Titanium is also enriched in the metal phase as an unwanted accompanying element, but most of it remains in oxidic form in the slag and is mainly bound in the mineral perovskite. Cooled down slag samples were analysed using XRF, XRD, SEM and EDX to investigate the formation of mineral phases rich in tantalum during various stages of the reduction process.
The results show that the settling of the tantalum-rich iron droplets in the molten slag into the metal phase May play a greater role for the kinetics than the actual reduction reaction caused by blowing in coke.
KW - Tantal
KW - Recycling
KW - Reduktionsprozess
KW - Perowskit
KW - Elektrolichtbogenofen
PY - 2020
SN - 1613-2394
VL - 73
IS - 4
SP - 196
EP - 205
PB - GDMB Verlag GmbH
CY - Clausthal-Zellerfeld
AN - OPUS4-51064
LA - deu
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
JF - Applied Science
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
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-571517
DO - https://doi.org/10.3390/app10072549
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
JF - Applied Sciences
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
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-507748
DO - https://doi.org/10.3390/app10072549
VL - 10
IS - 7
SP - 2549
EP - 2565
AN - OPUS4-50774
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
JF - Cement and Concrete Research
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
DO - 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 - 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
JF - Frontiers in Plant Science
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 -
TY - JOUR
A1 - Herzel, Hannes
A1 - Dombinov, V.
A1 - Vogel, Christian
A1 - Willbold, S.
A1 - Levandowski, G. V.
A1 - Meiller, M.
A1 - Müller, F.
A1 - Zang, J. W.
A1 - da Fonseca-Zang, W. A.
A1 - Jablonowski, N. D.
A1 - Schrey, S. D.
A1 - Adam, Christian
T1 - Soybean Fertilized by P-Phases from Bagasse-Based Materials: P-Extraction Procedures, Diffusive Gradients in Thin Films (DGT), and X-ray Diffraction Analysis (XRD)
JF - agronomy
N2 - The Brazilian sugarcane industry produced around 173 million tons (Mt) of bagasse in 2018. Bagasse is a by-product of juice extraction for ethanol and sugar production and is combusted in order to generate power, producing up to 10 Mt of ash per year. This ash contains various concentrations of plant nutrients, which allow the ash to be used as a crop fertilizer. However, the concentration and extractability of phosphorus (P), an essential plant nutrient, are low in bagasse ash. To increase the P content, we co-gasified and co-combusted bagasse with P-rich chicken manure. The resulting ash was thermochemically post-treated with alkali additives (Na2SO4 and K2SO4) to increase the availability of P to plants. We aimed to: (i) investigate the effect of thermochemical post-treatment of co-gasification residue and co-combustion ash on P availability to soybeans, (ii) explore the potential of chemical extraction methods (citric acid, neutral ammonium citrate, formic acid, and Mehlich-I) and diffusive gradients in thin films (DGT) to predict the availability of P to soybeans, and (iii) identify the responsible P-phases using X-ray diffraction . We evaluated P availability to soybeans growing in Brazilian Oxisol soil in two independent greenhouse pot experiments. The positive effect of thermochemical treatment on P availability from gasification residue was confirmed through the observation of increased P uptake and biomass in soybean plants. These findings were confirmed by chemical extraction methods and DGT. The gasification residue contained whitlockite as its main P-bearing phase. Thermochemical post-treatment converted whitlockite into highly soluble CaNaPO4. In contrast, co-combustion ash already contained highly soluble Ca(Na,K)PO4 as its main P-bearing phase, making thermochemical post-treatment unnecessary for increasing P availability. In conclusion, increased extractability and availability of P for soybeans were closely connected to the formation of calcium alkali phosphate. Our findings indicate that this combined methodology allows for the prediction of P-fertilization effects of ash.
KW - Sugar cane bagasse
KW - Chicken manure ash
KW - Thermochemical treatment
KW - Nutrient
KW - Plant availability
PY - 2020
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-509735
DO - https://doi.org/10.3390/agronomy10060895
VL - 10
SP - 895
EP - 6
PB - MDPI
AN - OPUS4-50973
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Stawski, Tomasz
A1 - Karafiludis, Stephanos
A1 - Pimentel, Carlos
A1 - Montes-Hernández, German
A1 - Kochovski, Zdravko
A1 - Bienert, Ralf
A1 - Weimann, Karin
A1 - Emmerling, Franziska
A1 - Scoppola, Ernesto
A1 - Van Driessche, Alexander E.S.
T1 - Solution-driven processing of calcium sulfate: The mechanism of the reversible transformation of gypsum to bassanite in brines
JF - Journal of Cleaner Production
N2 - Here, we show that calcium sulfate dihydrate (gypsum) can be directly, rapidly and reversibly converted to calcium sulfate hemihydrate (bassanite) in high salinity solutions (brines). The optimum conditions for the efficient production of bassanite in a short time (<5 min) involve the use of brines with c(NaCl) > 4 M and maintaining a temperature, T > 80 °C. When the solution containing bassanite crystals is cooled down to around room temperature, eventually gypsum is formed. When the temperature is raised again to T > 80 °C, bassanite is rapidly re-precipitated. This contrasts with the better-known behaviour of the bassanite phase in low-salt environments. In low-salinity aqueous solutions, bassanite is considered to be metastable with respect to gypsum and anhydrite, and therefore gypsum-to-bassanite conversion does not occur in pure water. Interestingly, the high-salinity transformation of gypsum-to-bassanite has been reported by many authors and used in practice for several decades, although its very occurrence actually contradicts numerical thermodynamic predictions regarding solubility of calcium sulfate phases. By following the evolution of crystalline phases with in situ and time-resolved X-ray diffraction/scattering and Raman spectroscopy, we demonstrated that the phase stability in brines at elevated temperatures was inaccurately represented in the thermodynamic databases. Most notably for c(NaCl) > 4 M, and T > 80 °C gypsum becomes readily more soluble than bassanite, which induces the direct precipitation of the latter from gypsum. The fact that these transformations are controlled by the solution provides extensive opportunities for precise manipulation of crystal formation. Our experiments confirmed that bassanite remained the sole crystalline phase for many hours before reverting into gypsum. This property is extremely advantageous for practical processing and efficient crystal extraction in industrial scenarios.
KW - Industrial and Manufacturing Engineering
KW - Strategy and Management
KW - General Environmental Science
KW - Renewable Energy, Sustainability and the Environment
KW - Building and Construction
KW - Calcium sulfate
KW - Gypsum
KW - Bassanite
KW - Scattering
KW - Raman
KW - In situ
KW - Synchrotron
KW - BESSY
KW - MySpot
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-594698
UR - https://www.sciencedirect.com/science/article/pii/S0959652624004591#appsec1
DO - https://doi.org/10.1016/j.jclepro.2024.141012
SN - 0959-6526
VL - 440
SP - 1
EP - 12
PB - Elsevier B.V.
AN - OPUS4-59469
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Hamann, Christopher
A1 - Piehl, Patrick
A1 - Weingart, Eric
A1 - Stolle, Dirk
A1 - Al-Sabbagh, Dominik
A1 - Ostermann, Markus
A1 - Auer, Gerhard
A1 - Adam, Christian
T1 - Selective removal of zinc and lead from electric arc furnace dust by chlorination–evaporation reactions
JF - Journal of Hazardous Materials
N2 - Re-melting of scrap in an electric arc furnace (EAF) results in the accumulation of filter dust from off-gas treatment that predominantly consists of iron and zinc oxides. Filter dust is classified as hazardous waste due to its high contents of potentially toxic or ecotoxic elements such as Pb, Cr, Cd, and As. A promising processing route for this waste is selective chlorination, in which the non-ferrous metal oxides are chlorinated and selectively evaporated in form of their respective chlorides from the remaining solids via the process gas flow. Here, we investigate stepwise thermochemical treatment of EAF dust with either waste iron(II) chloride solution or hydrochloric acid at 650, 800, and 1100 ◦C. The Zn and Pb contents of the thermochemically processed EAF dust could be lowered from 29.9% and 1.63% to 0.09% and 0.004%, respectively. Stepwise heating allowed high separation between zinc chloride at the 650 ◦C step and sodium-, potassium-, and lead-containing chlorides at higher temperatures. Furthermore, the lab-scale results were transferred to the use of an experimental rotary kiln highlighting the possibilities of upscaling the presented process. Selective chlorination of EAF dust with liquid chlorine donors is, therefore, suggested as a potential recycling method for Zn-enriched steelworks dusts.
KW - Electric arc furnace dust
KW - Zinc
KW - Selective Chlorination
KW - Hazardous waste
KW - Resource Recovery
PY - 2024
DO - https://doi.org/10.1016/j.jhazmat.2023.133421
SN - 0304-3894
VL - 465
SP - 1
EP - 13
PB - Elsevier
AN - OPUS4-59345
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Rieger, J.
A1 - Colla, V.
A1 - Matino, I.
A1 - Branca, T. A.
A1 - Stubbe, G.
A1 - Panizza, A.
A1 - Brondi, C.
A1 - Falsafi, M.
A1 - Hage, J.
A1 - Wang, X.
A1 - Voraberger, B.
A1 - Fenzl, T.
A1 - Masaguer, V.
A1 - Faraci, E. L.
A1 - di Sante, L.
A1 - Cirilli, F.
A1 - Loose, Florian
A1 - Thaler, C.
A1 - Soto, A.
A1 - Frittella, P.
A1 - Foglio, G.
A1 - di Cecca, C.
A1 - Tellaroli, M.
A1 - Corbella, M.
A1 - Guzzon, M.
A1 - Malfa, E.
A1 - Morillon, A.
A1 - Algermissen, D.
A1 - Peters, K.
A1 - Snaet, D.
T1 - Residue Valorization in the Iron and Steel Industries: Sustainable Solutions for a Cleaner and More Competitive Future Europe
JF - Metals
N2 - The steel industry is an important engine for sustainable growth, added value, and high-quality employment within the European Union. It is committed to reducing its CO2 emissions due to production by up to 50% by 2030 compared to 1990′s level by developing and upscaling the technologies required to contribute to European initiatives, such as the Circular Economy Action Plan (CEAP) and the European Green Deal (EGD). The Clean Steel Partnership (CSP, a public–private partnership), which is led by the European Steel Association (EUROFER) and the European Steel Technology Platform (ESTEP), defined technological CO2 mitigation pathways comprising carbon direct avoidance (CDA), smart carbon usage SCU), and a circular economy (CE). CE ap-proaches ensure competitiveness through increased resource efficiency and sustainability and consist of different issues, such as the valorization of steelmaking residues (dusts, slags, sludge) for internal recycling in the steelmaking process, enhanced steel recycling (scrap use), the use of secondary carbon carriers from non-steel sectors as a reducing agent and energy source in the steelmaking process chain, and CE business models (supply chain analyses). The current paper gives an overview of different technological CE approaches as obtained in a dedicated workshop called “Resi4Future—Residue valorization in iron and steel industry: sustainable solutions for a cleaner and more competitive future Europe” that was organized by ESTEP to focus on future challenges toward the final goal of industrial deployment.
KW - Circular economy
KW - Steelmaking residues
KW - Clean steel
PY - 2021
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-530350
DO - https://doi.org/10.3390/met11081202
VL - 11
IS - 8
SP - 1202
PB - MDPI
AN - OPUS4-53035
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Singh, Amit Kumar
A1 - Mishra, Biswajit
A1 - Sinha, Om Prakash
T1 - Reduction Kinetics of Fluxed Iron Ore Pellets Made of Coarse Iron Ore Particles
JF - Steel research international
N2 - The present work demonstrates a sustainable approach of using relatively coarser iron ore particles for ironmaking. The motivation is to reduce the energy consumption in the milling of the iron ore by utilizing coarser iron ore particles (+0.05 mm) and to select a suitable binder for improving pellet properties. Iron ore fines in the range of 0.05–0.25 mm was selected and classified into three size ranges. Fluxed iron ore pellets were prepared using lime as a binder for the basicity of 0, 1, and 2. Reduction of these pellets with a packed bed of coal fines was performed in the temperature range of 900–1200 °C for a duration of 30–120 min. The direct reduction kinetics of the iron ore pellets were studied by employing diffusion and chemical reaction control models to the experimental data. The results show that pellets made with coarser iron ore particles have improved reduction behavior and kinetics. The reduction reaction is found to be a mixed control. The activation energy for the reduction reaction varies from 44.3 to 74.76 kJ mol−1 as iron ore particle size decreases from 0.25 to 0.05 mm and basicity increases from 0 to 2.
KW - Materials Chemistry
KW - Metals and Alloys
KW - Process Metallurgy
KW - Iron making
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-598326
DO - https://doi.org/10.1002/srin.202300669
SN - 1611-3683
IS - 2300669
SP - 1
EP - 9
PB - Wiley VHC-Verlag
AN - OPUS4-59832
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -