Hengevoss, Dirk
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Life cycle assessment of a novel production route for scandium recovery from bauxite residues
Scandium (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.
Industrial Data-Based Life Cycle Assessment of Architecturally Integrated Glass-Glass Photovoltaics
Circularity and environmental sustainability of organic and printed electronics
In this chapter, the possible role and impact of organic and printed electronics (OPE) in a transition toward a circular economy and more sustainable society will be discussed. The learning targets are twofold: first, understanding main environmental issues associated with the emerging field of OPE, and second, identifying, through a systemic perspective, the enabling potential of these technologies.
Guidelines on pre- and co-processing of waste in cement production. Use of waste as alternative fuel and raw material
The main objective of these Guidelines is to improve waste management by offering updated and objective information about pre- and co-processing of waste in the cement industry. They contain knowhow and practical experiences gained in implementing pre- and co-processing since the first edition that served as a reference document in international agreements (e.g. Basel Convention for Hazardous Waste Treatment) and adaptation of various national guidelines. The Guidelines follow common understanding that avoiding and reducing waste is the best way of dealing with current waste problems all over the world. The extension of waste collection to 100% of the population and of waste fractions is notably a prerequisite to manage waste effectively in many countries. However, the Guidelines promote an approach that aims to reduce existing waste problems and at the same time to encourage the use of waste as an alternative source for primary energy and virgin raw materials in cement production. Wherever possible, the concepts of resource efficiency, circular economy, recycling and reuse must be given first priority. Improving waste management will take time. Reaching the status of an effective waste management solution in Europe has taken place over a period of 20-30 years. It has been supported by stringent legislation to monitor quality and emissions. Developing pre- and co-processing as a suitable waste management option requires also time and investments. Rigorous permitting and quality assurance procedures need to be applied. Pre- and coprocessing respects the waste hierarchy and does not contradict it, when these Guidelines are followed. In this context, it can be classified as a technology for energy recovery and mineral recycling. The key for implementation of these Guidelines and to achieve the maximum benefit from pre- and co-processing of waste in cement production continues to be close collaboration and co-operation between the public and the private sectors. Innovative techniques and technical knowhow are available and will be further developed by the private ector, whereas the public sector should ensure that environmental standards are maintained and health and safety regulations are applied and enforced. In addition ethical business conduct, good governance and social responsibility remain prerequisites for successfully implementing the Guidelines.