Summary
Concerns about the future availability and continuity of metal supplies have triggered research efforts to define and assess metal criticality. In this study, we apply a comprehensive ...methodology to the elements of the geological zinc, tin, and lead family: zinc (Zn); germanium (Ge); cadmium (Cd); indium (In); tin (Sn); and lead (Pb). Zn, Sn, and Pb have played important roles in various technological sectors for centuries, whereas Ge, Cd, and In are by‐product metals that are increasingly utilized in emerging and strategic technologies. Criticality assessments are made on national (i.e., the United States) and global levels for 2008. The results are presented with uncertainty estimates in three‐dimensional “criticality space,” comprised of supply risk (SR), environmental implications, and vulnerability to supply restriction (VSR) axes. SR is the highest for In for both the medium (i.e., five to ten years) and long term (i.e., a few decades). Pb and Zn have the lowest SR for the medium term and Pb the lowest SR for the long term. In and Ge production have the highest environmental burdens, mainly as a result of emissions from Zn smelting and subsequent metals purification and recovery from Zn leaching residues. VSR is highest for Pb at the global and national levels.
Fast electroflotation extraction of heavy metals from wastewater is described. The results of experimental investigations of the extraction of iron, aluminium and chromium hydroxides from aqueous ...solutions in the presence of surfactants of various natures and ions of calcium by electroflotation are presented. It was found that the presence of Ca
2+
in the solution at a concentration of 0.5 g/L reduced the degree of electroflotation extraction of Al(OH)
3
, Fe(OH)
3
, Cr(OH)
3
regardless of the nature of the electrolyte. The addition of surfactants in the system in the presence of Ca
2+
increased the amount of extraction of the dispersed phase. The greatest effect is achieved with the help of anionic surfactant sodium dodecyl sulphate, while the degree of extraction reached 98%. The high efficiency of the process of electroflotation extraction of the dispersed phase was due to the hydrophobization of the particle surface owing to the adsorption of surfactants on the surface of hydroxides. The recent method is useful to treat wastewater contaminated with aluminium, iron and chromium metal ions. The reason is that this method is very fast working within 20 min; Moreover, pH 7.0 working made this method ideal for utilisation in natural water treatment economically.
À l’heure des discours sur les besoins en métaux de la transition énergétique, les entreprises minières prétendent être d’incontournables alliées de la lutte contre le changement climatique. Elles se ...présentent comme des entreprises soucieuses de la préservation des écosystèmes, de la prévention des risques professionnels et du développement économique des territoires d’implantation. La mine andalouse de Rio Tinto, qui a recommencé à produire du cuivre en 2015, est emblématique de ce tournant. Au-delà des discours de façade sur la « mine durable », l’ethnographie de la mine de Rio Tinto donne à voir les transformations à l’œuvre, notamment concernant la fragmentation et l’individualisation des conditions de travail, parallèlement à l’affaiblissement des structures syndicales. Dans ce contexte, l’article analyse comment l’encadrement des formes d’engagement au travail qui accompagne les promesses de « mine durable » alimente des logiques de (dé)mobilisation oscillant entre l’allégeance et la résistance.
In order to reuse the waste fabric and develop a novel textile-based adsorbent for heavy metal removal, the waste silk fabric was modified by tannic acid (TA) and the prepared adsorbents were ...characterized using Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS) analysis. The removal of Cd(II), Cu(II), and Ni(II) ions from aqueous solutions was investigated using the modified silk fabric (TA-SF) under various conditions and the adsorption behavior of heavy metal ions was compared with the original silk fabric. The results showed that the maximum metal adsorption amounts reached 100% in 10 min. The adsorption isotherm models were demonstrated using Langmuir, Freundlich, and Temkin isotherm models, and the adsorption of TA-SF to Cd(II), Cu(II), and Ni(II) were well fitted with Langmuir isotherm than Freundlich and Temkin isotherm model. Moreover, the adsorption kinetics was well fitted with to the pseudo-first-order and pseudo-second-order kinetic models, and adsorption kinetics indicated that the former model was better suited than the latter. For 60 mg/L initial concentrations of Cd(II), Cu(II), and Ni(II) at pH 9.0, the adsorbents' maximum adsorption capacity was 8.03 mg g−1, 7.42 mg g−1, and 7.47 mg g−1, respectively. Within 5 min, the absorbed metal ions on TA-SF could mostly be desorbed. Moreover, TA-SF can adsorb heavy metal ions from dyeing aqueous solution, showing its capability of simultaneous removal of heavy metal and waste dyes. The results suggest that the lower-cost TA-SF could be an effective adsorbent for removing heavy metals from industrial wastewater.
This study estimates the potential and costs for mitigating CO2 emission in Brazil´s steelmaking industry. Two main scenarios were developed: (1) a reference scenario considering the actual trends of ...the steel industry; and (2) a scenario where the use of charcoal from planted forests is stimulated for the additional steelmaking capacity. In addition, the effects of 13 Best Available Technologies (BAT) and one disruptive technology (TGRBF) on the industrial sector were calculated for both scenarios. Findings show that the increase in charcoal usage in pig iron production from 23.0% to 32.5% can reduce the total CO2 emissions in 11.3% in 2050, while the adoption of the BAT and TGRBF in new steel plants can reduce the CO2 emission levels in 15.6%. If both effects are considered, the CO2 reduction potential would reach 23.2% in 2050. As the TGRBF technology was developed to a coke based-route, a simply structural change towards charcoal (without using BATs) can be less effective in reducing cumulative CO2 emissions than applying BATs in a scenario without structural change. However, in terms of costs, the switch towards an increasing use of charcoal is less expensive. Correct incentives are needed in the industry to achieve such reduction levels.
•Brazilian steelmaking can abate GHG emissions through a high or a low-cost strategy.•BATs, CCS and charcoal based-routes can reduce GHG emissions in 23%.•Switch towards more use of charcoal is less expensive than applying disruptive BATs.•In Brazil structural changes have higher cost-benefit for CO2 emissions reduction.
The metal industry (MI) is the largest energy consumer and producer of environmental pollution within the industrial sector in China. This paper investigated the sustainability of China's metal ...industry since the 21th century through an overview and an analysis of green total-factor productivity (GTFP) of this sector. The results showed the following: (1) since the beginning of the 21th century, the scale of China's MI expanded rapidly. However, the rapid development of this sector relies on an extensive mode that has triggered off a series of resources and environmental problems. The promotion of green development in this sector becomes urgently. (2) The GTFP of China's MI increased from 2000 to 2015, and technological progress (or technological innovation) was the key driver. The GTFP growth of the mining and processing of ferrous metal ores occurred due to technological progress and efficiency improvements. In other industries, the GTFP growth mainly resulted from technological progress/innovation. (3) The industries involved in the mining and processing of ferrous and nonferrous metal ores were on the state of increasing returns to scale, the returns to scale of the smelting and pressing of nonferrous metals and the manufacture of metal products transformed from increasing to constant, and the returns to scale of the smelting and pressing of ferrous metals experienced three states: increasing, decreasing, and constant.
•An overview is provided for deepening the understanding of China's metal industry.•GTFP of sub-sectors of China's metal industry since the 21th century was analyzed.•GTFP of China's metal industry has been greatly improved from 2000 to 2015.•Technological progress (or technological innovation) is the key driver.•Returns to scale of sub-sectors of China's metal industry are quite different.
Summary
There are abundant sources of metal‐oxide‐based wastes from industries such as electronics and metal production, which generally have a detrimental effect on the environment when not ...recycled. In this concise review, we aim to provide a brief overview of the state‐of‐the‐art research on how these metal‐oxide wastes are being used by the scientific community in the applications of energy storage, catalysis, and sensing. We focus on three important waste streams: E‐waste, waste from the production of metals, such as red mud and slag, and waste from metal recovery, for example, rusted wires and discarded capacitors. We review some promising routes for obtaining high‐quality metal‐oxide nanoparticles and nanowires and critically review potential pitfalls that hinder the wide‐scale application of these waste‐streams.
► Pyrolysis of plastic waste. ► Comparison of different samples: real waste, simulated and real waste+catalyst. ► Study of the effects of inorganic components in the pyrolysis products.
Pyrolysis may ...be an alternative for the reclamation of rejected streams of waste from sorting plants where packing and packaging plastic waste is separated and classified. These rejected streams consist of many different materials (e.g., polyethylene (PE), polypropylene (PP), polystyrene (PS), polyvinyl chloride (PVC), polyethylene terephthalate (PET), acrylonitrile butadiene styrene (ABS), aluminum, tetra-brik, and film) for which an attempt at complete separation is not technically possible or economically viable, and they are typically sent to landfills or incinerators. For this study, a simulated plastic mixture and a real waste sample from a sorting plant were pyrolyzed using a non-stirred semi-batch reactor. Red mud, a byproduct of the aluminum industry, was used as a catalyst. Despite the fact that the samples had a similar volume of material, there were noteworthy differences in the pyrolysis yields. The real waste sample resulted, after pyrolysis, in higher gas and solid yields and consequently produced less liquid. There were also significant differences noted in the compositions of the compared pyrolysis products.
Four Moroccan local industrial wastes were identified as potential high temperature (up to 1000 °C) thermal energy storage (TES) materials for application in solar tower power plants. These wastes ...are namely induction furnace slag (IFS) from the metallurgical industry, and three solid wastes from the coal-fired power plant industry (i.e. coal fly ashes (CFA), coal bottom ashes (CBA), and coal bottom clinker (CBC)). In the present paper, these wastes would be used as raw materials to develop/synthesize novel low-cost high-temperature TES materials for the same application. The main motive of this work is to manufacture enhanced versions of the selected wastes in order to eliminate their main points of weakness, i.e.: (1) their glassy form which restricts their structural strengths, (2) transform the wastes in the form of powder into solid crystalline materials with improved TES properties, and in the desired regular shapes. To fulfill this aim, a summary of the results of the different conducted characterizations on the four raw materials is presented. Then, the used synthesis method is described from the preparation of the raw materials formulations to the obtained final products. Finally, a laboratory experimental investigation was conducted on these obtained materials in order to assess their potential for TES application up to 1000 °C. Thus, their structural and thermophysical properties were evaluated, as well as their thermal stability up to 1000 °C. The obtained results suggest that most of the synthesized materials are good candidate materials for high-temperature thermal energy storage application (up to 1000 °C).
•Potential wastes are identified for high-temperature TES application (up to 1000 °C).•Novel low-cost glass-ceramic TES materials are developed from wastes.•Sintering process is a promising and cost-effective route for wastes valorization into TES materials.•The developed glass-ceramics are stable up to 1000 °C and they have good TES properties.
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