The Materials Science behind Sustainable Metals and Alloys

Abstract

Production of metals stands for 40% of all industrial greenhouse gas emissions, 10% of the global energy consumption, 3.2 billion tonnes of minerals mined, and several billion tonnes of by-products every year. Therefore, metals must become more sustainable. A circular economy model does not work, because market demand exceeds the available scrap currently by about two-thirds. Even under optimal conditions, at least one-third of the metals will also in the future come from primary production, creating huge emissions. Although the influence of metals on global warming has been discussed with respect to mitigation strategies and socio-economic factors, the fundamental materials science to make the metallurgical sector more sustainable has been less addressed. This may be attributed to the fact that the field of sustainable metals describes a global challenge, but not yet a homogeneous research field. However, the sheer magnitude of this challenge and its huge environmental effects, caused by more than 2 billion tonnes of metals produced every year, make its sustainability an essential research topic not only from a technological point of view but also from a basic materials research perspective. Therefore, this paper aims to identify and discuss the most pressing scientific bottleneck questions and key mechanisms, considering metal synthesis from primary (minerals), secondary (scrap), and tertiary (re-mined) sources as well as the energy-intensive downstream processing. Focus is placed on materials science aspects, particularly on those that help reduce CO2 emissions, and less on process engineering or economy. The paper does not describe the devastating influence of metal-related greenhouse gas emissions on climate, but scientific approaches how to solve this problem, through research that can render metallurgy fossil-free. The content is considering only direct measures to metallurgical sustainability (production) and not indirect measures that materials leverage through their properties (strength, weight, longevity, functionality).

Function and Direction of Cyanide in Coking Wastewater: From Water Treatment to Environmental Migration

“…In the actual water environment, there are a variety of coordination ions, such as OH – , Cl – , NH 3 , and anionic DOM . Meanwhile, the global greenhouse effects and climate changes bring about the leaching of heavy metals into the aquatic environment. , Therefore, the binding pattern of heavy metals and ligands should be rightly examined. In Figure , based on the contents of Cl – , NH 3 , and DOM in the effluent of the biological system, the changes in various metal binding forms of cyanide were analyzed at several concentrations (0.2–20 mg/L) and pH values (6–8).…”

Phosphine Oxide‐Functionalized Terthiophene Redox Systems

“…Redox systems based on main group elements are emerging as next‐generation building blocks for organic batteries, electrochromic materials, magnets, photovoltaics, and sensors [1, 2] . Although they are attractive from economic and sustainability perspectives, [3] main group elements typically feature a lower density of redox states compared to transition metals and consequently yield difficult‐to‐control, highly reactive radical species upon electron transfer [4] . The discovery of new main group systems capable of undergoing controlled redox processes therefore continues to be of both fundamental and applied interest, and research on persistent main group radicals continues apace [5] …”

“On-water” synthesis of thioxoimidazolidinone-isatin/ninhydrin conjugates, followed by temperature-induced dehydration by a ZnMnO3@Ni(OH)2 nano-catalyst

“…The utilization of water serves as a common solvent in our reaction, and zero waste materials were generated during the process and it not only accelerates the reaction rate, but also contributes to the overall environmental sustainability, as documented. 22…”