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Publikation Life cycle assessment of a novel production route for scandium recovery from bauxite residues(Elsevier, 2024) Hengevoss, Dirk; Misev, Victor; Feigl, Viktória; Fekete-Kertész, Ildikó; Molnár, Mónika; Balomenos, Efthymios; Davris, Panagiotis; Hugi, Christoph; Lenz, MarkusScandium (Sc) has various technological applications, but the concentrations of Sc in ores are low. Both, the mining of low concentrated Sc and the production of industrial-grade Sc are a heavy burden on the environment. Bauxite residue (BR) from alumina production represents one of the major sources of Sc in Europe (Ochsenkühn-Petropulu et al., 1994). The goal of this study is to assess the environmental impacts from cradle to gate of a novel production route developed in the Scandium Aluminium Europe project (SCALE) to extract Sc at concentrations <100 ppm from BR, to concentrate and upgrade it to pure ScF3 and Sc2O3 and ultimately to refine it to an aluminium scandium master alloy with 2 % Sc mass fraction (AlSc2 %). Results show that the global warming potential (GWP), measured in CO2-eq per kg Sc2O3, generated with the novel route is about half the GWP of the state-of-the-art Sc2O3 production from rare earth tailings when applying equal allocation principles. The initial process step to dissolve BR and extract Sc consumes elevated amounts of acid and energy and is responsible for at least 80 % of the route’s total environmental impact. The amount of the generated filter cake (FC) is equal to the amount of the BR input and is a potential resource for cement clinker production. The ecotoxicological study indicates that both FC and BR are slightly ecotoxic.01A - Beitrag in wissenschaftlicher ZeitschriftPublikation Developing material recovery projects: Lessons learned from processing municipal solid waste incineration residues(Elsevier, 15.02.2020) Müller, Sandra Regina; Kral, Ulrich; Wäger, Patrick A.This research explores the material recovery from bottom-ash, which is a residue from municipal solid waste incineration. The investigations aimed to characterize, evaluate, categorize and classify the development status of the recovery projects in the Canton of Zürich, including two technology pathways, i.e. dry and wet bottom-ash recovery. The temporal scale commenced with the exploration phase in 2003 and concluded with two technological pathways, both operating commercial projects in 2017. A retrospective view allowed the identification of enablers and barriers that affected the development status of the recovery projects. Further the recovery perspective allowed the results to be communicated to the United Nations Framework Classification for Resources (UNFC). The investigation showed two main trends. Firstly, the development status of the recovery projects from exploration to commercial project phase was mainly driven by the knowledge increase regarding sampling and metal characterization in bottom-ash, the readiness and effectiveness of the recovery technologies and the changes of the legal and financial environment. Secondly, the amount of recovered material (dry matter content) increased from about 6900 tons in 2003 to 16,500 tons in 2017, which is congruent with an increase in the recovery rate from 5 to 14 percent per weight. In particular, the amount of elements recoverable with an economic and environmental benefit, such as copper, gold and silver, increased. Correspondingly, the residual particular metal content in the disposable bottom-ash (fraction 2–16 mm) decreased to < 1 percent per weight dry matter and therefore reduced the risk for environmental at the sanitary landfills. The findings provide ‘lessons learned’ for companies, authorities and investors who intend to develop material recovery projects. Even though the recovery potentials depend on site-specific conditions, the UNFC allows comparing individual recovery projects under different boundary conditions.01A - Beitrag in wissenschaftlicher Zeitschrift