Modification of the sewage sludge ash P-mineralogy by thermo-chemical
treatment with LF slags© Lehrstuhl für Abfallverwertungstechnik und Abfallwirtschaft der Montanuniversität Leoben (11/2022)
As an essential nutrient Phosphorus (P) is an important constituent in fertilisers used in agriculture. However, almost the entire amount of P used in Europe must be imported from sources worldwide. High amounts of P are concentrated in sewage sludge from mostly municipal sewage. From 2029 P-recycling from sewage sludge is mandatory for wastewater treatment plants in Germany. In this study, a process which uses a thermo-chemical treatment of sewage sludge ash (SSA) with Ca-carriers, is developed. The method succeeds in producing materials which match the demands for plant available P and as proven by chemical extraction and pot trials as required by national and European regulations for fertilisers. This was achieved by treating the molten SSA with burnt lime and slags from Ca-rich ladle furnace (LF-slag) which results in the formation of better soluble P-minerals in comparison to the phases whitlockite and apatite mostly abundant in SSA.
Development of an approximation model for the evaluation of slag treatment strategies© Lehrstuhl für Abfallverwertungstechnik und Abfallwirtschaft der Montanuniversität Leoben (11/2022)
Sustainable management of resources and circular economy are key focal points of
research and development activities within the iron and steel industry. In the project Slagreus, a novel approach enhancing internal and external recycling of basic oxygen furnace (BOF) slag has been developed.
“Spray-Slag” – Processing of liquid blast furnace slag© Lehrstuhl für Abfallverwertungstechnik und Abfallwirtschaft der Montanuniversität Leoben (11/2022)
Blast furnace slags are a by-product of iron production. These slags typically are
used in powder form in the building industry, e.g. as an additive for cement production. Therefore, the liquid slags are wet granulated, dried and grinded, which is an energy, water and emission intensive process. To save natural resources, reduce the CO2-emissions and enhance the flowability of the particles, the liquid state of the slag and its heat energy could be utilized by atomizing
the melt directly at the blast furnace.
Improving the dry magnetic separation of BOF-slag by applying an
innovative pre-treatment process© Lehrstuhl für Abfallverwertungstechnik und Abfallwirtschaft der Montanuniversität Leoben (11/2022)
To approach circular economy by enhancing the internal recycling potential of BOFslag, an innovative pre-treatment process for the dry magnetic separation is investigated. It consists of slow-cooling to enlarge the slag crystals, followed by microwave irradiation to generate intergranular cracks to enhance the mineral liberation during comminution. It can be shown that the pre-treatment leads to an increase in the separation degree by at least four percent. This can be further enhanced by a factor of five by using solid-state oxidation.
Sustainability & Circular Economy at voestalpine High Performance
Metals Division© Lehrstuhl für Abfallverwertungstechnik und Abfallwirtschaft der Montanuniversität Leoben (11/2022)
Sustainability is a focus topic in the High Performance Metals (HPM) Division of the voestalpine group. Within inSPire, our sustainability framework, we are setting goals for sustainable production and reducing our carbon footprints. Circular economy is an important divisional strategic field for two years now and deals with 4 fields of action: Alternative raw material sources, Recycling of by-products, Material & scrap cycles and Zero waste. Two challenges concerning the recycling of by-products are presented in this article to show the difficulties we face when we want to recover alloy elements from our production wastes: EAF-dusts and scales. Valuable elements are lost by landfill or downcycling. Finding solutions for these challenges is part of our focus on Circular Economy in the High Performance Metals Division.
The Use of Textile Waste for Fibre-Reinforced Geopolymer Composite
Production© Lehrstuhl für Abfallverwertungstechnik und Abfallwirtschaft der Montanuniversität Leoben (11/2022)
The textile industry is among the top largest industries in the world, as the demand for new products proportionally increases with population growth. In 2014, 90.8 million tons of textile fibres have been produced which is expected to exceed 100 million tons by 2025. Many different types of fibres can be used for textile production, such as cotton, hemp, nylon, polyester, however, the application of synthetic fibres had become more common compared to natural fibres in the recent years (Pensupa et al. 2017).
FuLIBatteR – Future Lithium-Ion Battery Recycling for Recovery of
Critical Raw Materials© Lehrstuhl für Abfallverwertungstechnik und Abfallwirtschaft der Montanuniversität Leoben (11/2022)
Global crises, like the Sars-CoV-2 pandemic, and dependency on the economic situation on raw material markets, as well as unexpected issues in global supply chains, such as the Suez Canal obstruction by a large container ship, intensify the efforts of local production and consequently, of sufficient raw material supply as well as regional solutions for recycling. Unfortunately, the raw materials for producing our daily life goods and things for saving the living standard are not evenly distributed worldwide (European Commission, 2022; Olivetti, Gaustad, & Fu, 2017).
How will tramp elements affect future steel recycling in Europe?© Lehrstuhl für Abfallverwertungstechnik und Abfallwirtschaft der Montanuniversität Leoben (11/2022)
Global steel production has grown massively since the Second World War. In recent decades, however, the steel market has become saturated in affluent regions such as the US and the EU. This has resulted in stagnate steel production and increased quantities of old scrap. The increasing shares of post-consumer scrap offer the opportunity to increase the share of scrap in crude steel production.
Digitalisation of Refuse Sorting with Image Recognition and Time Series
Analysis© Lehrstuhl für Abfallverwertungstechnik und Abfallwirtschaft der Montanuniversität Leoben (11/2022)
The recycling of municipal solid refuse is a major challenge on the way towards a circular economy. Although solid refuse generation is increasing in the EU, the recycling rates are still below 50% on average (Neligan 2018). Hence, innovative technologies are required to increase recycling rates and cope with the predicted amount of municipal solid refuse. The KI-Waste project researches new technologies and optimisations to increase the sorting quality and yield of municipal solid refuse, thus providing solutions to increase the recycling rates. The vision of KI-Waste is to determine the compositions of the refuse streams in a sorting facility and combine this information with telemetry data from the sorting machines.
Paradigm Shift in the plastics industry: from linear to circular© Lehrstuhl für Abfallverwertungstechnik und Abfallwirtschaft der Montanuniversität Leoben (11/2022)
The reliable supply of high-quality recyclate is a prerequisite for a functioning circular economy. As Borealis, we cooperate with our partners along the value chain to enable our customers and partners to achieve their circularity goals and reduce their overall carbon footprint and, at the same time, underpins our Borealis journey towards more sustainable living.