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An estimated 30 % (∼11 million metric tons/year) of copper slag is still landfilled globally. Fayalitic copper slags are well-characterized, and they can be recycled into multiple safe end-products. Conversely, the major type of copper slag produced in Europe is lead-rich and warrants a deep understanding of phases present in it, properties, adverse environmental implications, and potential recycling strategies. The objective of this study is to thoroughly investigate such industrial slags by XRF, XRD, Mössbauer spectroscopy, SEM-EDS, novel automated image analysis using Aphelion, hot stage microscopy (HSM) and assess prospects for their valorization. These industrial slags were found to contain 26.1–50.5 wt% PbO, 3.4–5.4 % As 2 O 5 (both hazardous solid wastes), 5.7–42 % CuO (present partly as Cu 2 O, an irritant), 3.2–18.2 % Fe 2 O 3 , 14–15.9 % SiO 2 and oxides of chromium, cobalt (both carcinogenic), zinc and nickel (both toxic to aquatic life). The limitation of Rietveld XRD for glass quantification was overcome by newly-developed automated SEM-image processing which revealed that all three slags consisted of a lead silicate glass (36.3–65.8 vol%). Strikingly, rarely published arsenic- and lead-based compounds like (Ca,Pb) 4 As 2 O 9-x , (Ca,Cu) 2 PbO 4-x and Pb 3 Ca 2 Si 3 O 11 were found when slag's PbO/CuO was 0.6, and Ca 3 As 2 O 8 -Pb 2 SiO 4 formed when PbO/CuO equaled 9. The challenge of toxicity and landfilling can be overcome as these slags have high potential to be used for recovery of copper, cobalt, and lead. Radioactive waste immobilization glasses, gamma-ray shielding concrete and glass-ceramic consumer products may also be prepared from them. HSM revealed that a higher PbO/CuO ratio results in lower melting point and smaller melt contact angle indicating such slag can be useful for manufacturing recycled ceramics but corrosive towards refractories in copper converter. [ABSTRACT FROM AUTHOR]

Paper-based materials, due to their availability, environmental benefits and high thermal properties, have already been implemented in several building envelope designs. However, most of them either did not optimise the use of the material or did not provide sufficient thermal insulation for use in permanent buildings. The presented research analyses six original paper-based building envelope core proposals, suitable for use in permanent buildings in temperate climate of Europe, in terms of thermal and environmental efficiency. Proposals include cores with embedded paper tubes structural elements, timber-cardboard studs and sandwich designs. The heat transfer coefficient of the envelopes was obtained for repeatable modules via 2D computer simulations (ThermCAD software), and the environmental impact was assessed for a representative square metre of the envelope via LCA analysis, based in ecoinvent 3.8 database. All analysed designs showed high thermal insulation properties and met the requirements for U max = 0.20 W/m2K, did not cause the risk of surface condensation, nor have excessive thermal bridges. The analysed building envelope designs based on embedded frame wall structure showed environmental superiority over conventional envelopes (timber frame and SIP panels). The research may serve as a proof of concept, for using paper-based building envelopes in sustainable architecture. [ABSTRACT FROM AUTHOR]