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Introduction
Published in M. Rashad Islam, Civil Engineering Materials, 2020
Metals are the most abundant materials in the earth, accounting for about two-thirds of all the elements and about 24% of the mass of the earth (Askeland et al. 2011). Metals have a crystalline structure and are bonded by a metallic bond with free electrons that are free to move easily from one atom to another. These free electrons make metallic materials good electrical conductors. Metals have very useful mechanical properties, such as strength, ductility, toughness, high melting points, and thermal and electrical conductivity. Metallic materials can be further classified into the following two categories, considering the presence of ferrous materials or not: Ferrous metals and alloys, such as irons, carbon steels, alloy steels, stainless steels, etc.Nonferrous metals and alloys, such as aluminum, copper, magnesium, nickel, titanium, etc.
® Molecular Recognition Technology (MRT) Approach
Published in Abhilash, Ata Akcil, Critical and Rare Earth Elements, 2019
Steven R. Izatt, Reed M. Izatt, Ronald L. Bruening, Krzysztof E. Krakowiak, Neil E. Izatt
Increasing global market demand for PGM, REE, and Co as well as other critical metals requires recycling in addition to mine output wherever possible (Ueda et al. 2016). Major benefits of recycling are that it alleviates depletion of valuable resources, decreases environmental effects of mining, and provides a reliable domestic source for the recycled metal. In the case of PGM, relatively low-ore grades of g/ton mean that >99% of mined ore becomes solid waste and must be dealt with as part of the mining operation. It has been estimated that, on average, production of one ounce of high-purity Pt requires processing of 7–12 tons of ore (Mooiman et al. 2016). Limited distribution of Pt in earth’s crust requires mining existing deposits at increasingly greater depth to meet demands, which exacerbates the problem (Gordon et al. 2006). Mooiman et al. (2016) discussed the current and emerging challenges confronting the mining industry in meeting the global demand for PGM. These challenges include metal price volatility; decreasing grades and increasingly complex mineralogy of global PGM deposits; increasing metal production costs; increased requirements to properly dispose of deleterious byproducts such as toxic metals; increasing need to deal with geopolitics, public perception, and environmental regulations in the mining region; maintenance of sustainable development in the mining region; and increased energy and water use as mining increases in complexity. Similar concerns exist for REE (Binnemans 2013) and Co (Roberts and Gunn 2014).
Sustainability of Minerals Processing and Metal Production for European Economies in Transition
Published in Sheila Devasahayam, Kim Dowling, Manoj K. Mahapatra, Sustainability in the Mineral and Energy Sectors, 2016
Vladimir Strezov, Natasa Markovska, Meri Karanfilovska
Mineral processing and metal production industries play an important role for the environmental and socio-economic development of nations. On one hand, these industries have positive impacts on economic development and employment, which is even more profound for countries with economies in transition. On the other hand, mineral processing and metal production industries have adverse impacts on the environment and on resource depletion. The NAEI for each country, which was developed in this work, shows no clear trend between the developed and the European countries with economies in transition on the level of environmental implication of mineral processing and metal production. This is specifically the case for ferrous metal production, as the European countries in transition, although lagging behind with environmental technology adoption, tend to follow the EU leadership in environmental standards and implementation of environmental technologies. The environmental performance of the EU ferrous production industries ranks well above the other developed countries considered here, such as United States and Australia. The study also shows the importance for a wider acceptance and integration of the national reporting inventories by the other countries with economies in transition, such as China and India, which would enable broader scientific discussions and developing industrial sustainability standards of the industrial activities across different economies.
Assessing the energy efficiency potential of a closed-loop supply chain for household durable metal products in China
Published in International Journal of Production Research, 2023
In addition to economic benefits, recycling metals can also save large amounts of energy consumption in the metal primary manufacturing process, which could bring tremendous environmental and economic benefits (Shankar, Bhattacharyya, and Choudhary 2018). Liu et al. (2020a) modelled a recycling flow of end-of-life vehicles and found that recycling one unit vehicle can reduce 3816 kgCO2eq compared with the equivalent metals’ primary production. Similarly, many papers have focused on metallic or nonmetallic material recycling from end-of-life products and the evaluation of the economic and environmental benefits compared with equivalent materials in primary manufacturing (Gorman, Dzombak, and Frischmann 2022). However, building a CLSC from the primary production to the recycling process is a complex task that requires a large amount of empirical data. Although some researchers have attempted to apply this framework, there is still a lack of comprehensive assessments for energy consumption, recycling, remanufacturing, environmental benefits, etc., from the entire CLSC perspective. Much previous research in the fields of energy efficiency and CLSC has focused on consumers’ perceptions of remanufactured products in CLSC (Abbey et al. 2015), pricing competition (Shen et al. 2022), eco-efficiency of products in CLSC (Quariguasi-Frota-Neto and Bloemhof 2012), green product strategies (Shen, Cao, and Xu 2020), etc.
Application of UV-synthesized anion exchange membranes to improve nickel removal through galvanic deposition process
Published in Journal of Dispersion Science and Technology, 2023
Masoud Delsouz Chahardeh, Ali Bozorg
Many technologies and processes such as chemical precipitation,[4] membrane technologies,[5] adsorption,[6,7] ion exchange resins,[8] and electrochemical technologies[9–11] have been introduced and used in practice to treat nickel contaminated water. Electrochemical methods such as electrocoagulation,[12] electrodialysis,[13] and electrodeposition[14] have drawn much attention in recent decades as tools for not only removal, but also recovery of the heavy metals. Since almost no additional chemicals would be involved in such processes, they are considered as sustainable and environmentally friendly methods that facilitate the recovery of heavy metals and thereby, their wide applications including water and wastewater treatment would be expected in the future.
Research on separation mechanism of waste palladium catalyst in a structure-optimized compound dry separator based on DEM-CFD
Published in Particulate Science and Technology, 2020
Jinpeng Qiao, Long Huang, Chenlong Duan, Haishen Jiang, Yuemin Zhao, Huannan Shao, Miao Pan
Solid catalysts are widely used to improve the efficiency of chemical reactions in the field of chemistry and chemical engineering, and more than 2000 kinds of industrial catalysts have been developed worldwide. (Silvy 2004; Barbaro and Liguori 2009; Singh 2009; Duan et al. 2015). These catalysts usually contain a certain amount of precious metals or nonferrous metals, and even some toxic components such as As2O3, Cr2O3, and As2O5 (Cole-Hamilton 2003; Jagadeesh et al. 2011; Koukabi et al. 2011; Wang et al. 2015; Duclos et al. 2016; Wang et al. 2017). The catalyst itself does not react with other components in chemical reactions in the industrial process. Therefore, some amounts of nonferrous metals (Cu, Ni, Co, Cr, etc.) and precious metals (Pt, Pd, and Ru) remain in the waste catalysts, and the grade of these metals is much higher than that of lean ore. The recycling of useful metals from waste catalysts can help reduce environmental pollution and improve the utilization efficiency of resources, which is of great significance for the sustainable development of society (Arcoya, Seoane, and Gomez-Sainero 2003; Lai et al. 2007; Yamaguchi et al. 2010; Asghari and Mousavi 2014). The waste palladium catalysts in petrochemical industry are mainly composed of rod-shaped materials, which are rich in noble metals and spherical materials without precious metals. If there is no treatment to remove the spherical materials in the process of recovering spent catalysts, the workload will be greatly increased and production facilities may go out of order at times, leading to extra expense for plants (Fernandes et al. 2016; Paiva et al. 2017; Thi, Wang, and Lee 2017). Therefore, it is extremely critical to effectively separate the rod-shaped materials and spherical materials in waste palladium catalysts by a pollution-free and low-energy consumption technology.