Roman lead silver smelting at Rio Tinto: the case study of Corta Lago

The Rio Tinto area is famous for the presence there of a rich concentration of several metals, in particular copper, silver and manganese, which were exploited from the Bronze Age up to few decades ago. The modern mining industry has been responsible for both bringing to light and destroying signs of past exploitation of the mines and metal production there. The Corta Lago site owes its discovery to the open cast exploitation that reduced the whole mount of Cerro Colorado to an artificial canyon. This exploitation left behind sections of antique metallurgical debris as well as revealing the old underground workings. The Corta Lago site dates from the Bronze Age up to the 2nd century AD, consisting mainly of silver and copper production slag, but also including litharge cakes, tuyéres and pottery. The project focused on the study of silver production slag from different periods using petrograhical and chemical techniques, such as Optical Microscopy, X-Ray Diffraction, X-Ray Fluorescence, Scanning Electron Microscopy associated to Energy Dispersive Spectrometry and Multi-Collector Inductively Coupled Plasma Mass Spectrometry. The aim of the project was to reconstruct the metallurgical processes of the different periods, detecting any differences and similarities. The mineral exploited was jarosite, XFe3+3(OH)6(SO4)2, where X can be K, Na, Pb, Ag and NH4, and the results show that the system of production was much more similar to iron production than silver. In the slag, the main mineral is fayalite, and the concentration of lead is around 1%. These results and study of the jarosite suggest the possibility of different sources of lead for the collection of silver in the system, and this is the reason for the utilization of the MC-ICP MS for the analysis of the lead isotopes. The results for the isotopes indicate the addition of a second source of lead used as lead metal in the system to increase the amount of lead and improve the collection of silver. The differences in the processes used at different periods are the amount of lead coming from another site that was added, and the level of standardization of the system. While the first difference is evident in a comparison between the pre-Roman process and one of the Republican phases, the second is mainly visible between the pre-Roman and Roman processes. At this stage the aim of the project was to attempt to correlate the differences in the processes, metallurgical skills and geological knowledge

An early medieval lead-smelting bole from Banc Tynddol, Cwmystwyth, Ceredigion

Excavations in 2002 at Cwmystwyth, in Central Wales, found an ancient lead smelting site. There are remains of the medieval and the Roman periods. This paper describes in brief the excavation of the medieval lead bole (Timberlake 2002a) but also provides an archaeological reconstruction of this and details of an experimental lead smelt carried out at the site in 2003 (by ST). The analytical study (by LA) is of the medieval metallurgical debris excavated in 2002, mostly slag, but also ore and lead. The aim was to understand the raw material, the metal produced and the smelting process. The ore smelted was predominantly galena but with no detectable silver, showing it was probably exploited to produce lead. The extremely high sulphur content of the slag indicates that the ore was not roasted before smelting. It is argued that the medieval activity was small-scale, smelting a very rich ore. The furnaces apparently did not require much capital investment, enabling a short-lived and/or exploratory smelting operation

Evidence of Circular Economy in Roman Northern Italy: Bronze Casting Technology

In several recent excavations carried out in Northern Italy, archaeologists have encountered the remains of metalworkers’ workshops where, in the Roman imperial period, large bronze objects were cast. The significance of these finds is considerable as, although the high levels of craftsmanship achieved by Roman bronze workers in the region are undisputed, little is still known regarding the layout of the workshops and the technologies used. The present research, still in its early stage, deals with the metalworking evidence from two bronze working sites located in Vimercate (Milan) and Verona, where remarkably well-preserved evidence was found, for instance, large casting pits, moulds and metalworking debris. A thorough review of the archaeological stratigraphy was carried out, in order to trace back the working processes and, where possible, the structure of the workshops. Moreover, archaeometric analyses were performed on both refractories and metal residues, aiming at reconstructing technological aspects. Analyses of slags, in particular, are meaningful because they help to retrace technical choices and pattern

Metallurgical evidence from a late antique context in the Forum of Grumentum

This paper is a preliminary report on metallurgical activity detected in the Forum of the ancient city of Grumentum (Basilicata, Italy). In an area next to one of the most important temples of the square a set of hearths belonging to a metallurgical plant was brought to light and investigated, together with a great quantity of metallurgical remains, a tuyère and a fragment of what might be identified as an iron crucible: according to stratigraphic evidence and the preliminary data from the study of pottery sherds, this intense metallurgical activity seems to be dating to the Late antique period. It is not clear yet if it has some relationship with the abandonment of the Forum itself

A Pilot Study into the Use of Qualitative Methods to Improve the Awareness of Barriers to Sustainable Medical Waste Segregation within the United Kingdom’s National Health Service

Data Availability Statement: The data presented in this study are available on request from the corresponding author.Within the United Kingdom, most medical waste is incorrectly classified as hazardous and disposed of via incineration or alternative treatment. Currently, no research has been conducted on why such a large quantity of medical waste is erroneously segregated. This pilot study explores the barriers to correct segregation with the aim to decrease the volume of incinerated waste by investigating why medical waste is wrongly identified as hazardous. No previous data are available to compare results, and so this study demonstrates the significance of using qualitative methods (questionnaires and focus groups) to bring awareness to issues faced within medical facilities when segregating waste. The low availability of different bins as well as lack of space and the healthcare workers’ busy schedules were identified as main reasons for poor segregation. Bins were sparsely placed, and staff lacked time to find the appropriate one leading to incorrect segregation of non-hazardous waste. Lack of information around whether a material was recyclable or not led to less recycled waste. When ways to engage with this issue were discussed, most medical staff favoured quick forms of information provision, such as posters, whereas a participant proclaimed longer hands-on style sessions as more effective. The findings of this study provide evidence that governmental strategies focused on sustainable medical waste management should direct their attention to the placement and availability of bins, whilst including ‘on-the-ground’ personnel in their decision making. This pilot study showed the value in using qualitative methods when current data are lacking and can be repeated by other healthcare facilities to collectively grow a greater awareness of the sustainability issues faced by the UK healthcare waste management system.This research was undertaken whilst receiving a studentship by a UK medical device manufacturer

Microstructural architecture and mechanical properties of empowered cellulose-based aerogel composites via TEMPO-free oxidation

Data availability: The data that has been used is confidential.Copyright © 2022 The Authors. This paper describes the development of cellulose-based aerogel composites enhanced via a new refinement process. The behaviour and microstructure of treated cellulose aerogel composites are examined including, how the constituents interact and contribute to the overall aerogel composite mechanism. The various forms of cellulose such as treated microcrystalline cellulose (MCT), nanofibrillated cellulose (NFC) and nanocrystalline cellulose (NCC) are also compared. Treated cellulose/Polyvinyl alcohol (PVA) aerogel composites show reinforced microstructural systems that enhance the mechanical property of the aerogels. The specific modulus of treated cellulose aerogels could be increased five-fold compared to the stiffness of untreated cellulose aerogels, reaching specific moduli of 21 kNm/kg. The specific strength of treated cellulose aerogels was also increased by four folds at 1.7 kNm/kg. These results provide insight into the understanding of the morphology and structure of treated cellulose-based aerogel composites

Circular waste management of electric vehicle batteries: legal and technical perspectives from the EU and the UK post Brexit

Copyright © 2021 The Authors. In light of the climate change, interdisciplinary solutions are needed to deal with end-of-life lithium-ion batteries (LIBs) that are used in Electric vehicles (EVs) in order to avoid a waste problem in the future. Building on both legal and technical perspectives, this paper criticises the current EU and UK frameworks and policies on batteries waste management which fail to address technological innovation, especially, in terms of the creation of a market for ‘second life’ of EV batteries which are subject to the electrochemical performance and durability and safety parameters, as well as LIB recycling in support of a circular economy. Most importantly, it also addresses recent developments in the EU in terms of a proposal for the EU new Batteries Regulation and the impact of Brexit in the UK for its future policy shape

Near-surface mounted-FRP flexural retrofitting of concrete members using nanomaterial-modified epoxy adhesives

Data availability: Data will be made available on request.Copyright © 2024 The Authors. This study investigates the effectiveness of nanomaterial-modified epoxy adhesives (NMEAs) for NSM-FRP flexural retrofitting of concrete. A total of 48 specimens (i.e. prisms) were retrofitted using three different types of FRP reinforcement bars (CFRP, GFRP, and BFRP) inserted in grooves with sizes of 8 × 8, 10 × 10 or 12 × 12 mm and bonded to the concrete substrate using either neat epoxy (NE) or NMEAs. NMEAs were developed by incorporating either carbon-based (i.e. CNF, cellulose, and graphite) or silicon-based (i.e. silica and MMT clay) nanoparticles into epoxy at 0.1 wt.% while the graphite NMEAs were prepared with more wt.% (i.e. 0.2 and 0.3). SEM and XRD techniques were used to assess the dispersion quality of nanoparticles within the matrix, along with the % porosity and % crystallinity of the NMEAs. Results showed that using silica, clay, and graphite NMEAs rather than NE enhanced the retrofitted concrete capacities, whereas a strength decrease was observed when using CNF- and cellulose-modified epoxies. Moreover, it was found that the specimens bonded with silicon-based NMEAs had, on average, higher capacities than those bonded using carbon-based NMEAs, which, on the other hand, showed more ductile behaviour. The results also suggested that the capacities of the specimens decreased with increasing the wt. % concentration of the nanoparticles (i.e. graphite). Increasing the groove size from 8 × 8 mm to 10 × 10 mm decreased the capacities but enhanced the ductility, whereas increases in both the capacities and ductility were achieved when moving from 8 × 8 mm to 12 × 12 mm

Effect of incorporating carbon- and silicon-based nanomaterials on the physico-chemical properties of a structural epoxy adhesive

Data availability: Data will be made available on request.Various carbon-based (i.e. carbon nanofibres (CNF), cellulose nanocrystals and graphite nanopowder) and silicon-based nanomaterials (i.e. silica nanopowder and MMT nanoclay) were incorporated into neat structural epoxy (NE) adhesive (Sikadur®-30) at 0.5, 1.0 and 1.5% by weight and mixed using a simple and cost-effective approach to produce the nanomaterial-modified epoxy adhesives (NMEAs). The impact of incorporating these nanomaterials into the NE on its chemical composition was investigated using Fourier transform infrared (FTIR) spectroscopy and Raman spectroscopy. X-ray diffraction (XRD) measurements were also used to identify the changes in the physical structure (i.e. the degree of crystallinity) that may occur in the NE with the addition of nanomaterials. Furthermore, the microstructure of the NE and NMEAs (in terms of the degree of dispersibility of the nanoparticles through the matrix) was investigated through scanning electron microscopy (SEM) analysis. A porosity analysis was also conducted across all samples. The results obtained from various tests were correlated to investigate the changes that occurred in the different properties of the matrix and the corresponding nanocomposites effectively and more critically. The SEM images showed some particle agglomeration, which increased with increasing wt%. An increase in the % porosity ratio of all nanocomposites over that of the NE was also observed, accompanied by a decrease in crystallinity compared to the NE. As per the FTIR spectroscopy, the chemical bonds in the NE and carbon-based NMEAs were observed to have different intensities, which were changed in the NMEAs, with the type and wt. % of the nanomaterials. No new bonds were formed by incorporating any of the nanomaterials (i.e. carbon- and silicon-based), except when adding 1.0 wt% CNF, where a bond at 1710 cm−1 was observed indicating a new Cdouble bondO stretching bond. As shown by Raman spectroscopy, all CNF and graphite NMEAs exhibited higher ID/IG values than those of the corresponding pristine materials