To achieve future recycling targets and CO₂ and waste reduction, the transfer of plastic contained in mixed waste from thermal recovery to mechanical recycling is a promising option. This requires extensive knowledge of the necessary processing depth of mixed wastes to enrich plastics and their processability in polymer processing machines. Also, the selection of a suitable processing method and product application area requires appropriate material behaviour. This paper investigates these aspects for a commercial processed, mixed waste, and two different mixed polyolefin fractions. The wastes are processed at different depths (e.g., washed/not washed, sorted into polyethylene, polypropylene, polyethylene terephthalate, polystyrene/unsorted) and then either homogenised in the extruder in advance or processed heterogeneously in the compression moulding process into plates. The produced recyclates in plate form are then subjected to mechanical, thermal, and rheological characterisation. Most investigated materials could be processed with simple compression moulding. The results show that an upstream washing process improves the achievable material properties, but homogenisation does not necessarily lead to an improvement. It was also found that a higher treatment depth (recovery of plastic types) is not necessary. The investigations show that plastic waste recovery with simple treatment from mixed, contaminated wastes into at least downcycling products is possible.

In this study, possible leaching control mechanisms for Cr and V in electric arc furnace slags were investigated by using a multi-methodological approach. Aside from chemical and mineralogical bulk analyses, special emphasis was given to surface investigations of the slags prior to and after leaching. In addition, pH dependence leaching tests were performed and the obtained data were evaluated with hydrogeochemical models. Investigations revealed that Cr and V are mainly bound in spinel and wuestite as well as minor amounts of olivine. Spinel and wuestite do not dissolve during water leaching for 48 h, whereas, depending on the composition of olivine, this phase either dissolves and releases V and Cr congruently, or does not dissolve but may hydrate. Melilite may also hydrate, but neither V nor Cr were detected in this phase. It appears that leached V is subsequently adsorbed onto these newly hydrated phases. The combination of the applied methods further showed that the abundance of calcium silicates, spinel, and wuestite is influenced by the FeO/SiO₂ and CaO/SiO₂ ratio in the slag. Therefore, it is assumed that the leaching of V and Cr can be minimized by changing these ratios to favor the formation of Fe bearing calcium silicate and spinel instead of wuestite.

Increasing occurrences of waste fires that are caused by improperly discarded lithium-based portable batteries threaten the whole waste management sector in numerous countries. Studies showed that high quantities of these batteries have been found in several municipal solid waste streams in recent years in Austria. This article reveals the main influence factors on the risk of lithium-based batteries in their end-of-life and it focuses on the quantification of damages to portable batteries during waste treatment processes. Hazards are identified and analysed and potential risks in waste management systems are comprehensively assessed. In two scenarios, the results showed that the potential risks are too high to maintain a sustainable form of waste management. According to the assessment, a small fire in a collection vehicle is located in the risk graph’s yellow region (as low as reasonably practicable, ALARP), while a fully developed fire in a treatment plant has to be classified as an unacceptable risk (red region of risk graph). Finally, basic recommendations for action were made.

Mineral wool products are man-made vitreous fibres that are used as thermal and acoustic insulation materials and as substrates for horticulture. Mineral wool waste is generated from demolition activities by the building and construction industry. Unfavourable mechanical properties, such as low compressibility, elastic behaviour, high volume and low bulk density, cause problems in landfills when mineral wool waste is disposed of. Mineral wool waste with a certain content of carcinogenic fibres is classified as hazardous waste type 31437 g “Asbestos Waste, Asbestos Dust” in Austria, since some characteristics of such fibres are similar to those of asbestos fibres. An exception is those mineral wool materials that have been tested to be noncarcinogenic due to their characteristics of biological solubility or geometrical dimension. Such noncarcinogenic mineral wool waste is classified as non-hazardous waste type 31416 “Mineral fibres”. Generally, it can be assumed that most of the industrial producers of mineral wool in the EU have not been producing carcinogenic material since 1998; however, carcinogenic mineral wool material has not yet been banned in Austria. Therefore, a segregation between so-called “old” and “new” mineral wool material is not necessarily possible. The medical aspects of mineral wool products are still controversial. The International Agency for Research on Cancer (IARC) evaluated mineral wool (glass wool and rock wool) as “possibly carcinogenic” in 1988 but revised this evaluation to “inadequate evidence in humans for the carcinogenicity” in 2002. Fibrous dusts that reach the alveolar region of the lungs undergo a congruent or incongruent chemical dissolution process. Alveolar macrophages ingest the intruded fibres and fulfil anti-infection and clearance functions. Biosolubility is a key property of this process. The recycling of mineral wool waste has not yet been performed in Austria due to economic inefficiency, technical problems and suspected health issues. However, some recycling and processing options already exist; other options are investigated in the project RecyMin, which compares different concepts with respect to environmental and economic criteria.

According to Directive (EU) 2018/851 of the European Union, higher recycling rates for municipal waste have to be met in the near future. Besides improvements in the collection systems, the mechanical processing and sorting efficiencies need to be increased to reach the EU´s targets. Sensor-based sorting (SBS) plants constitute an integral part of today's sorting processes. Two main factors influence the sorting performance, namely the throughput rate and the input composition. To improve recycling efficiencies, especially SBS machines must be adjusted accordingly to guarantee the highest possible machine efficiency. Three evaluation criteria, yield/product quantity, product yield, and product purity, are used to describe the performance of these processes. Therefore in this study, 160 sorting trials with 1,000 red and white low-density polyethylene (LDPE) chips were conducted to investigate the influence of the throughput rate and input composition on the sorting processes. For each evaluation criteria, the testing results are plotted in graphs enabling the possibility for process optimization. With increasing throughput rates, the product quantity rises (despite an exponential decrease in yield) in the form of a saturation curve. A higher throughput rate also results in an exponential decrease of the product yield, while a change in the input composition has no effect on the product yield. The third evaluation criteria, the product purity, decreases linearly with an increasing occupation density. The slope of this function depends on the input composition.