TY - CONF A1 - Adamczyk, Burkart A1 - Schraut, Katharina A1 - Adam, Christian ED - Thiel, S. ED - Thomé-Kozmiensky, E. ED - Friedrich, B. ED - Pretz, T. ED - Quicker, P. ED - Senk, D. G. ED - Wortruba, H. T1 - Nachbehandlung von Stahlwerksschlacken und deren Verwertung als Klinkermaterial T1 - Post-treatment of steelmaking slags and their utilisation as cement clinker N2 - Steelmaking slags produced using the Linz-Donawitz method (LD slags) are widely used as building and construction materials in road, earth and water works. Because the legal conditions become more and more re-strictive , this application is uncertain in the future. LD slags contain high amounts of mineral bound iron (in form of Fe2O3), which must be considered as a waste of resources. Except for the Iron the chemical composition is quite similar to that of Portland cement clinker. However, due to the high content of Fe2O3 the mineralogical composition differs significantly, resulting in a low hydraulic reactivity. A post-treatment of the liquid LD slag in an electric arc furnace under reducing conditions enables the reduction of the iron compounds to metallic iron, which separates from the mineral phase due to its higher density. The remaining solidified mineral fraction mainly contains typical crystalline phases of cement clinker in similar ratios: Alite (Ca3SiO5; > 60%) as main phase, Belite (Ca2SiO4, 10%), Tricalciumaluminate (Ca3Al2O6; 5%) and Brownmillerite (Ca2(Al,Fe)2O5, 1%) as secondary phases. Alite, which usually decomposes to Belite and free lime under slow cooling conditions, is stabilized in the Fe-reduced slag probably by integration of foreign ions into the lattice and is stable even if the slag is cooled down very slowly. Furthermore, the particularly large Alite crystals do not exhibit the typical decomposition edge of Belite and lime, found in Alite from ordinary ce-ment clinker. Technological tests for building materials show a high hydraulic reactivity and a compressive strength after 28 days comparable or even slightly higher to reference cement. Nevertheless, because of the increasing viscosity with decreasing Fe2O3 content, the treatment requires a temperature higher than the slag decanted from the LD converter. Furthermore, during the reduction of the bound Iron huge amounts of carbon monoxide are released, resulting in foaming of the slag. Both aspects make it difficult to manage the process. In addition, for economic reasons the treatment has to be carried out immediately after casting the slag from the LD converter to avoid the solidification, which is a logistical challenge for most steel plants. Otherwise the separation of the mineral bound iron as metallic phase and the utilisation of the mineral fraction as cement clinker will both save resources and lower the global CO2-output. For these reasons further initiatives should be considered in the medium term. N2 - LD-Schlacken weisen eine große chemische Ähnlichkeit zu Protlandzementklinker auf. Sie enthalten jedoch noch bis zu 30% Eisen, das mineralisch in oxidischer Form gebunden vorliegt. Dadurch kann sich bei der Erstarrung die wichtigste Klinkerphase "Alit" nicht ausbilden. Durch eine reduzierende Schmelzbehandlung der Schlacke kann des mineralisch gebundene Eisen als Metall separiert werden. Dadurch wird auch die Mineralogie der Schlacke so verändert, dass auch sie nun praktisch einem Portlandzementklinker entspricht. Entsprechende Versuche wurden am kleintechnischen Lichtbogenofen der BAM durchgeführt. Es werden Ergebnisse vorgestellt und auf Grenzen und Möglichkeiten eines derartigen Prozesses im Hinblick auf eine industrielle Umsetzung eingegangen. T2 - Berliner Konferenz Mineralische Nebenprodukte und Abfälle CY - Berlin, Germany DA - 11.06.2018 KW - Zementklinker KW - Stahlwerksschlacke KW - LD-Schlacke KW - Lichtbogenofen KW - Alit PY - 2018 SN - 978-3-944310-41-1 VL - 5 SP - 282 EP - 296 PB - Thomé-Kozmiensky Verlag GmbH CY - Neuruppin AN - OPUS4-45199 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Adam, Christian T1 - Phosphorus recovery from wastewater - Developments and perspective in Germany N2 - A new sewage sludge ordinance was set in force in Germany in 2017 that makes phosphorus recovery from sewage sludge mandatory. The technological possibilities for P-recovery from waste water, sewage sludge and sewage sludge ash were presented. T2 - International Workshop Nutrient Stewardship & Next-Generation Fertilisers CY - Heron Island, Australia DA - 15.12.2018 KW - Phosphorus recovery PY - 2018 AN - OPUS4-47110 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Adam, Christian T1 - Chemische Charakterisierung von P-Recyclaten N2 - Zukünftig werden vermehrt P-Recyclate auf den Düngemittelmarkt kommen. Diese müssen ausreichend charakterisiert werden, um Sicherheit und Wirksamkeit beurteilen zu können. Mit dem Vortrag wurde der wissenschaftliche Beirat für Düngungsfragen des Bundesministeriums für Ernährung und Landwirtschaft beraten. T2 - Fachgespräch Recycling-Phosphate als Düngemittel für die Landwirtschaft CY - Bonn, Germany DA - 14.02.2018 KW - P-Recyclate KW - Sekundärrohstoffe PY - 2018 AN - OPUS4-44178 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Steckenmesser, D. A1 - Vogel, Christian A1 - Adam, Christian A1 - Steffens, D. T1 - Effect of various types of thermochemical processing of sewage sludges on phosphorus speciation, solubility, and fertilization performance N2 - Sewage sludge has one of the highest phosphorus (P) recovery potentials of all waste materials. Therefore, P-recycling from sewage sludge could contribute to closing the P-cycle. Recently, various thermal processes for P-recovery have been developed, but there is still a demand for information on the effect of different process parameters (e.g. additives and temperature) on P-speciation and especially on the fertilization performance. In the present study, two common methods (low-temperature conversion at 400–500° C and thermochemical treatment at 950° C) were investigated and combined to produce highly bioavailable P-fertilizers from two different types of sewage sludge based on chemical phosphorus precipitation (Chem-P) and enhanced biological phosphorus removal (Bio-P). The results of P-fractionation, X-ray diffraction analysis, and pot experiments with maize showed that Bio-P sludges attain high P-plant-availability after treatment at low temperatures (400° C). In contrast, Chem-P sludges can adequately be treated at higher temperatures under reductive conditions with sodium additives to form highly bioavailable calcium-sodium-phosphate. Additionally, also highly heavy-metal contaminated sludges can be thermochemically treated at high temperatures to achieve the legal requirements for fertilizers. KW - P-recovery KW - Low-temperature-conversion KW - Thermochemical treatment KW - P-fractionation KW - P-plant-availability KW - Sewage sludge PY - 2017 DO - https://doi.org/10.1016/j.wasman.2017.02.019 SN - 0956-053X VL - 62 SP - 194 EP - 203 PB - Elsevier CY - Amsterdam AN - OPUS4-41646 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Adam, Christian T1 - Modifiziertes Rhenania Phosphat aus der Klärschlammverbrennung mit thermochemischem Aufschluss N2 - Es wurde der Stand des BMFTR-Projekts R-Rhenania vorgestellt. Mit einem thermochemischen Aufschluss werden Phosphatphasen in Klärschlämmen bei der Verbrennung zu bioverfügbaren Phosphaten mit guter Düngewirkung umgewandelt. Gleichzeitig werden im Prozess Schwermetalle über die Gasphase entfernt. Die Düngewirkung ist vergleichbar mit konventionellen P-Düngern wie TSP und wurde in Gefäß- und Feldversuchen im ökologischen Landbau nachgewiesen. Der Prozess wird großtechnisch in der Monoverbrennungsanlage Altenstadt, Oberbayern, umgesetzt. T2 - KlärschlammTage Würzburg CY - Würzburg, Germany DA - 03.06.2025 KW - Klärschlamm KW - Phosphorrecycling KW - Recyclingdünger KW - Rhenaniaphosphat PY - 2025 AN - OPUS4-63325 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Sichler, Theresa A1 - Adam, Christian A1 - Montag, D. A1 - Ehm, J. A1 - Barjenbruch, M. A1 - Pinnekamp, J. ED - Holm, O. ED - Thomé-Kozmiensky, E. ED - Quicker, P. ED - Kopp-Assenmacher, S. T1 - Auswirkungen der novellierten AbfKlärV auf die Kreislaufführung von Pflanzennährstoffen N2 - Because of the longstanding oversupply of nutrients in Germany, waste and fertilization legislation has been amended in 2017. As the new laws do still not meet the European nitrate ordinance, fertilization laws must be tightened again. In consequence, there is a rising competition for land between sewage sludge and organic fertilizers. Furthermore, the new sewage sludge ordinance (AbfKlärV) contains stricter thresholds and a ban on agricultural sewage sludge utilization for WWTPs > 50,000 p.e. from 2029. WWTPs which do not use their sludge for agriculture have to recover phosphorus from then on. However, sludges with less than 2% P content are not affected by that obligation. Every federal state of Germany must report amounts and quality of agricultural utilized sewage sludge yearly. An evaluation of raw data from 10 federal states shows that nearly 40% of both WWTPs and sewage sludge volume fall below the recovery limit of 2%. On the other hand, this means less than 30% of the P potential. In addition, there is no information whether the sludges fall reliably below the limit as required by the ordinance. This project aims to investigate this reliability by regarding the variations in the P content of sewage sludge. For this reason, samples will be taken monthly at 10 representative WWTPs over a year. Whereas phosphorus will still mostly be subject of recovery other nutrients are not affected by this. As a result, large amounts of N, K, Mg and Ca will be increasingly removed from the cycle. In 2017, WWTPs > 50,000 p.e. accounted for 30-60% of the nutrient potentials. These potentials will probably get lost to a large extent due to the fertilization ban. Many small WWTPs are also currently changing their utilization strategy from agriculture to incineration to ensure a safe disposal in future. Therefore, we can expect that even larger amounts of nutrients apart from phosphorus will be discharged from the circular economy. In comparison to the domestic sales volume of mineral fertilizers these other nutrients do only account for a very small fraction. A recovery could nevertheless replace parts of the mineral fertilizers, thus reducing environmental impacts. Energy consumption for technical nitrogen fixation is high and nutrient cycles are strongly anthropogenic influenced with diverse consequences such as eutrophication, acidification and endangered groundwater resources. Sewage sludge contains several micronutrients next to the macronutrients P, N, K, Mg, Ca and S. Because of lacking information on the actual German need for micronutrients contents and freights cannot evaluated. Moreover, former sewage sludge fertilization was probably not needs-based. It is therefore not possible to estimate a true loss in micronutrients due to the amended sewage sludge ordinance. N2 - Die landwirtschaftliche Klärschlammverwertung ist in der Bundesrepublik Deutschland seit Jahren rückläufig, hatte im Jahr 2017 jedoch noch einen Anteil von rund 18 % [20]. Diese Art der Verwertung wird kontrovers diskutiert, da der Klärschlamm im Rahmen der Abwasserreinigung eine Schadstoffsenke darstellt. In vergangenen Jahrzehnten wurden insbesondere die hohen Gehalte an Schwermetallen im Klärschlamm als kritisch für eine landwirtschaftliche Verwertung eingestuft. Diese Belastung konnte allerdings durch Absenkung der Einträge von Schmermetallen in das Abwasser signifikant gesenkt werden. Neben Schwermetallen kamen jedoch auch organische Schadstoffe wie Pharmazeutika, Kosmetika und Haushaltschemikalien in den Fokus der Diskussion über den Einsatz von Klärschlamm auf Agrarflächen. Heute geraten zunehmend weitere Inhaltsstoffe in den Fokus, deren Auswirkungen noch nicht abschließend geklärt sind, weshalb eine einheitliche Bewertung über Grenzwerte nicht darstellbar ist. Beispiele für diese neuen Stoffgruppen sind Mikroplastik, Nanopartikel, Antibiotikaresistenzen und persistente organische Spurenstoffe. Neben den angesprochenen Risiken gibt es in Deutschland Regionen mit einem stark erhöhten Nährstoffüberschuss. In der Kritik steht vor allem eine nicht ordnungsgemäße Düngung mit Stickstoff, welche mit Nitratauswaschungen in das Grundwasser einhergeht. Um diese Grundwasserbelastung zu verhindern wurde u.a. das Düngerecht erneut verschärft, was die Flächenkonkurrenz zwischen Klärschlamm und Wirtschaftsdünger weiter vergrößern wird. Auf Druck der EU-Kommission stehen zudem weitere Anpassungen im Düngerecht bevor, da die beschlossenen Änderungen aus Kommissionssicht nicht ausreichen, um die Nitratrichtlinie einzuhalten. Vor dem Hintergrund der angeführten Probleme wurde im Koalitionsvertrag der 18. Legislaturperiode (2013) festgeschrieben, „die Klärschlammausbringung zu Düngezwecken [zu] beenden und Phosphor und andere Nährstoffe zurück[zu]gewinnen“ [5]. Die novellierte AbfKlärV beinhaltet allerdings kein grundsätzliches Aufbringungsverbot und eine Rückgewinnungspflicht besteht lediglich für den Nährstoff Phosphor. Es ist davon auszugehen, dass sich die neuen Regelungen im Düngerecht und der Klärschlammverordnung massiv auf die landwirtschaftliche Verwertung von Klärschlamm und damit auf die Kreislaufwirtschaft verschiedener Nährstoffe auswirken werden. Zur Ermittlung dieser Auswirkungen wird seit Oktober 2018 im Auftrag des Umweltbundesamtes das REFOPLAN-Projekt „extraWERT“ (FKZ 3718 26 330 0) von der Bundesanstalt für Materialforschung und -prüfung (BAM) in Kooperation mit dem Institut für Siedlungswasserwirtschaft (ISA) der RWTH Aachen durchgeführt. In diesem Beitrag werden erste Ergebnisse dieses Projekts vorgestellt. T2 - Klärschlammkonferenz CY - Berlin, Germany DA - 04.11.2019 KW - Klärschlammdüngung KW - Landwirtschaft KW - Makronährstoffe PY - 2019 SN - 978-3-944310-49-7 VL - 2 SP - 362 EP - 374 PB - Thomé-Kozmiensky Verlag CY - Neuruppin AN - OPUS4-49603 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weimann, Karin A1 - Adam, Christian ED - Martins, I. M. ED - Ulsen, C. ED - Villagran, Y. T1 - Advantages of recycling gypsum plasterboards N2 - Advantages of recycling gypsum plaster boards During the last decades the material composition of buildings has become increasingly diverse. However, largely sorted material flows are needed for generating high quality secondary building materials. The use of secondary building materials can meet the requirements of sustainability in several ways: the extended time availability of primary raw materials and, thereby, the preservation of natural resources as well as the conservation of landfill sites. Recycling of gypsum (calcium sulfate) can be a good example for the environmental benefits of closed-loop recycling. The content of sulfates in other secondary building materials, in particular in recycled concrete aggregates, should be minimized for quality reasons. In contrast, separated gypsum can also be used in gypsum production if the high quality requirements for the recycled gypsum are met. Since almost all processing steps in the recycling process are associated with environmental impacts, an environmental evaluation of the use of recycled gypsum as a substitute in gypsum production has to be carefully conducted. This paper focusses on the techniques for generating recycled gypsum from gypsum plasterboards, the related quality requirements and a comprehensive environmental evaluation of the complete process. T2 - IV International Conference Progress of Recycling in the Built Environment CY - Lisbon, Portugal DA - 11.10.2018 KW - Environmental evaluation KW - Gypsum KW - CDW processing PY - 2018 SN - 978-2-35158-208-4 VL - PRO 124 SP - 243 EP - 250 PB - Rilem publications S.A.R.L. CY - Paris AN - OPUS4-48078 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Adam, Christian T1 - What is in your opinion the fertiliser of the future? N2 - Conventional fertilisers have their disadvantages as nutrient release is not synchronised with the demand of plants. Several approaches of "next generation fertilisers" are aiming at controlled nutrient release. Recycling fertilisers are often not soluble in water but fully plant available. They are suitable raw materials for the production of new types of controlled release fertilisers. T2 - CLOOP-Workshop "What is in your opinion the fertiliser of the future?" CY - Berlin, Germany DA - 22.10.2019 KW - Controlled release fertilisers KW - Recycling fertilisers PY - 2019 AN - OPUS4-49554 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Adam, Christian T1 - Verwertung carbonfaserhaltiger Reststoffe in der Pyrometallurgie N2 - Carbonfasern sind äußerst stabil und werden auch in Anlagen zur Verbrennung von Sondermüll kaum zerstört. Beim Handling carbonfaserhaltiger Abfälle können Gesundheitsrisken auftreten (Abgabe von WHO-Fasern). Es werden Methoden der Verwertung carbonfaserhaltiger Reststoffe in der Pyrometallurgie diskutiert. T2 - UBA Fachaustausch: Aufbereitung und Verwertung carbonfaserhaltiger Abfälle CY - Dessau, Germany DA - 19.09.2019 KW - Carbonfasern KW - Pyrometallurgie PY - 2019 AN - OPUS4-49555 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schraut, Katharina A1 - Adamczyk, Burkart A1 - Simon, Sebastian A1 - von Werder, Julia A1 - Meng, Birgit A1 - Stephan, D. A1 - Kargl, F. A1 - Adam, Christian T1 - Formation and chemical stabilisation of tricalcium-silicate during solidification from the melt of post-treated metallurgical slags N2 - Tricalcium-silicate (C3S) or Alite is the most important mineral in Portland cement. Since pure tricalcium-silicate is only stable above temperatures of 1250 °C, its decomposition has to be prevented technically by fast cooling after the sintering process. At room temperature, the decomposition velocity is very slow so that metastable tricalcium-silicate is obtained. Although the mechanisms of clinker phase formation during burning process of Portland cement in a rotary kiln were solved and improved over the years, in view of possible economic and ecological benefits current projects aim to produce clinker phases from metallurgical slags. Recent studies discovered that the mineral phase which remained after a reducing treatment and separation of formed metallic iron from molten Linz-Donawitz (LD-) slags contained about 60 wt.% Alite despite it was cooled slowly. Because the results could be verified using slags from different origins and varying cooling velocities a chemical stabilisation of the Alite can be assumed. First tests in mortars indicate that workability, hardening and solid state properties are comparable with an ordinary Portland cement. An application of the observed phenomenon in cement production requires enhanced knowledge about formation and stabilisation conditions of Alite during crystallisation from melts in contrast to the sintering reactions in conventional Portland cement production. Therefore, this study focuses on the stabilisation mechanisms of Alite in consolidating melts. Samples from different melting experiments are analysed to determine stabilising factors. T2 - 15th International Congress on the Chemistry of Cement CY - Prag, Czech Republic DA - 16.09.2019 KW - Tricalcium-silicate KW - Portland Cement KW - Alite KW - Steelmaking slag PY - 2019 SP - Paper 492, 1 EP - 10 AN - OPUS4-49050 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -