From Bauxite as a Critical Material to the Required Properties of Cast Aluminum Alloys for Use in Electro Automotive Parts

There is a long process to transform bauxite, a critical raw material, into a substance with the required properties of cast aluminum alloys for use in electro automotive parts. Thanks to its unique properties, aluminum has become the material of choice for clean technology manufacturers in applications such as use in the automotive industry, renewable energy, batteries, electrical systems, resource-saving packaging, energy efficient buildings and clean mobility. Restructuring of the economy, the oil crisis, air pollution and global warming are some of the factors that have moved the automotive industry towards electrification since the beginning of the 21st century. This paper aims to highlight the required properties of cast aluminum alloys applied to the production of electro automotive parts, such as their mechanical and thermophysical properties, dimensional stability, corrosion resistance, electromagnetic compatibility and crashworthiness. Furthermore, this paper discusses which of the cast aluminum–silicon alloys, as well as the heat treatments and casting processes, are most suitable

The 6th European metallurgical conference EMC 2011: Proceedings review

The GDMB Society for Mining, Metallurgy, Resource and Environmental Technology organized the 6th European Metallurgical Conference (2011) in Duesseldorf from June 26 to 29, 2011. The same venue hosted the most important international metallurgical trade fairs for metallurgy of iron and steel, new casting and thermochemical processes METEC, GIFA, THERMOPROCESS and NEWCAST. The previous European metallurgical conferences were organized by GDMB in Friedrichshafen (2001), Hanover (2003), Leipzig (2005), Duesseldorf (2007), Innsbruck (2009). The GDMB is a non-profit organization situated in Clausthal in Germany, which is related to combining science with the practical experience in metallurgy, mining, materials engineering, mineral processing, recycling and refining of metals, and manufacturing of semi- and finishing products. The European Metallurgical conference EMC is one of the most known conferences worldwide in the field of non-ferrous metallurgy and is attended regularly by the decision makers from the industry and universities. The scientific program contained 6 plenary lectures and more than 160 presentations from 40 countries in 5 parallel series. An extensive poster exhibition was held, during which the authors had an opportunity to introduce their posters to the entire plenum as a part of a brief presentation. The best poster from the Montan-University in Leoben, Austria, was awarded the € 500 'Poster Award EMC 2011'. Not only were the most important European countries represented here, more than one third of the lecturers were from the non-European countries (Canada, Japan, China, USA, South Africa, Australia). The origin of the participants reflects the aim of the organizers: to make this conference a worldwide platform for the scientific exchange of experience and information. More than 400 participants from all over the world participated at this conference. The scientific presentations of the conference are presented in five Proceedings: Vol. 1: Copper, General Pyrometallurgy, Vessel Integrity, Process Gas Treatment; Vol. 2: Lead and Zinc, Process Control, Process Modeling, Vol. 3: Light metals, General Hydrometallurgy, Precious Metals; Vol. 4: Process Metallurgy, Recycling, Waste Treatment and Prevention, Vol 5: Sustainable technologies, Sustainable of non-ferrous metals production, waste effluents Treatment and Biohydrometallurgical application. The plenary lectures will be published in the scientific journal 'World of Metallurgy - ERZMETALL', which is published by the GDMB

Formation and application of hydrogen in non-ferrous metallurgy

Introduction/purpose: Hydrogen is the most abundant element in the universe (75 % by mass) and the lightest element (with a density of 0.00082 g/cm3) which consists of only one proton and one electron. Because of its presence in many different forms such as gaseous hydrogen, its plasma species, water, acid, alkalline, ammmonia and hydrocarbons, it has various applications in different industrial disciplines. Methods: Different hydrometallurgical and pyrometallurgical methods are considered in order to point out many different processes such as formation of hydrogen, reduction of metallic oxides and chlorides, and electrochemical reactions such as hydrogen overvoltage and the spillover effect. Ultrasonic spray pyrolysis enables the formation of very fine aerosols which can be used for the production of metallic powders. Results: Hydrogen formation was observed during the dissolution of metallic allloys with hydrochloric acid. The reduction of metallic oxides and metallic chlorides by hydrogen leads to the formation of metallic powders. Metallic powders were collected by a new developed electrostatic precipitator. Conclusion: Hydrogen can be applied in different reduction processes for the production of metallic powders. Recycling processes can be used for the formation of hydrogen. A new research strategy for powder production is proposed combining recycling of the black mass of used Li-Ion batteries, ultrasonic spray pyrolysis, and hydrogen reduction

Review of the past, present, and future of the hydrometallurgical production of nickel and cobalt from lateritic ores

Laterite ores are becoming the most important global source of nickel and cobalt. Pyrometallurgical processing of the laterites is still a dominant technology, but the share of nickel and cobalt produced by the application of various hydrometallurgical technologies is increasing. Hydrometallurgy is a less energy-demanding process, resulting in lower operational costs and environmental impacts. This review covers past technologies for hydrometallurgical processing of nickel and cobalt (Caron), current technologies (high-pressure acid leaching, atmospheric leaching, heap leaching), developing technologies (Direct nickel, Neomet) as well as prospective biotechnologies (Ferredox process)

Electrochemical Deposition of Al-Ti Alloys from Equimolar AlCl3 + NaCl Containing Electrochemically Dissolved Titanium

Al-Ti alloys were electrodeposited from equimolar chloroaluminate molten salts containing up to 0.1 M of titanium ions, which were added to the electrolyte by potentiostatic dissolution of metallic Ti. Titanium dissolution and titanium and aluminium deposition were investigated by linear sweep voltammetry and chronoamperometry at 200 and 300 °C. Working electrodes used were titanium and glassy carbon. The voltammograms on Ti obtained in the electrolyte without added Ti ions indicated titanium deposition and dissolution proceeding in three reversible steps: Ti4+ ⇄ Ti3+, Ti3+ ⇄ Ti2+ and Ti2+ ⇄ Ti. The voltammograms recorded with glassy carbon in the electrolyte containing added titanium ions did not always clearly register all of the three processes. However, peak currents, which were characteristics of Al, Ti and Al-Ti alloy deposition and dissolution, were evident in voltammograms on both working electrodes used. A constant potential electrodeposition regime was used to obtain deposits on the glassy carbon working electrode. The obtained deposits were characterized by SEM, energy-dispersive spectrometry and XRD. In the deposits on the glassy carbon electrode, the analysis identified an Al and AlTi3 alloy formed at 200 °C and an Al2Ti and Al3Ti alloy obtained at 300 °C

Rare-Earth/Manganese Oxide-Based Composites Materials for Electrochemical Oxygen Reduction Reaction

The main objective of this research was a systematic development of advanced micro/nanostructured materials based on the most used metal-oxides for ORR and metal-oxides with an extremely low-loading of Pt for comparison. Hybrid composites compared were: MnO2, La2O3, mixed lanthanum manganese oxides (LMO), and mixed lanthanum manganese oxides with reduced platinum load (LMO-Pt). The influence of the reduced amount of noble metal, as well as single oxide activity toward ORR, was analyzed. The complete electrochemical performance of the hybrid materials has been performed by means of CV, LSV, and EIS. It was shown that all synthesized catalytic materials were ORR-active with noticeable reduction currents in O2 saturated 0.1 M KOH. The ORR behavior indicated that the La2O3 electrode has a different mechanism than the other tested electrode materials (MnO2, LMO, and LMO-Pt). The EIS results have revealed that the ORR reaction is of a mixed character, being electrochemically and diffusion controlled. Even more, diffusion is of mixed character due to transport of O2 molecules and the chemical reaction of oxygen reduction. O2 diffusion was shown to be the dominant process for MnO2, LMO, and LMO-Pt electrolytic materials, while chemical reaction is the dominant process for La2O3 electrolytic materials

Sol-gel processing of ordered MnO2 structures toward enhanced O2 reduction catalysis for air batteries

Sol-gel processing of ordered MnO2 structures toward enhanced O2 reduction catalysis for air batteriesPoster presented at Meeting Point of the Science and Practice in the Fields of Corrosion, Materials and Environmental Protection - XX YuCorr International Conference (May 21-24, 2018, Tara Mountain, Serbia

Prevention of Silica Gel Formation for Eudialyte Study Using New Digestion Reactor

This work includes a combined hydrometallurgical treatment of a eudialyte ore sample with a subsequent preparation of leaching residue using mechanical separation methods. Hydrometallurgical treatment contains dry digestion with sulphuric acid at room temperature and filtration of the obtained product. The objectives of adopting these procedures are to test a new digestion reactor in order to prevent silica gel formation from the eudialyte ore. The obtained results revealed that silica gel formation is prevented during dissolution with sulphuric acid. A high leaching efficiency of light rare earth elements (La, Ce, Nd, Y) was reached using the dry digestion process with sulphuric acid, where the starting molarity was 12 mol/L. After the filtration process, magnetic separation is studied as the main method to recover weakly magnetic minerals like amphiboles and pyroxenes from the leaching residue in the magnetic fraction and feldspars in the nonmagnetic fraction. A new combined research strategy was developed for the production of different concentrates such as the one bearing Zr, Hf, and Nb

Synthesis and electrochemical performance of multicomponent oxide materials toward oxygen reduction reaction

Low cost and highly active electrocatalysts for the oxygen reduction reaction (ORR) are necessary for the development of fuel cells and metal air batteries. Currently, Pt based electrodes have the best catalytic performance but due to is high cost its employment on a significant scale is limmited. Perovskite materials would be a good alternative because of is abundant supply, envronmental benignity, electronic structure, ionic conductivity and redox behavior. Therefore, the aim of this work is synthesis and characterzation of Lanthanum cobalt oxide (LaCoO3) powders doped with Manganese (Mn) - LMCO or Strontium (Sr) - LSCO, as promissing candidates for energy storage and conversion devices. Ultrasonic spray pyrolisis (USP) was used to successfully synthsize spherical sub-microm-m-szed of Lai0.6Sr0.4CoO3 and La0.6Mn0.4CoO3 perovskite type materials. Detailed microscopic analysis (SEM-EDX, TEM, XRD) as well as electrochemical characterization by CV, LSV and EIS technique has been conducted

Improvement of the supercapacitor characteristics of perovskite oxides upon impregnation by RuO2

The supercapacitive charging/discharging (C/DC) response of lanthanum-based perovskite oxides, obtained by ultrasonic spray pyrolysis (USP), was discussed according to galvanostatic and the dynamic ac impedance C/DC data. We have synthesized perovskite type lanthanum strontium cobalt oxide (LSCO, La0.6Sr0.4CoO3) by USP and mixed LSCO/RuO2 by subsequent hydrothermal impregnation method. The obtained composites were investigated as electrode for electrochemical supercapacitors and their electrochemical performances have been investigated. Microstructures and surface morphologies, observed by scanning electron microscopy, appears crystalline with spherically-shaped nm-sized particles. The aim of our work was study of structural and electrochemical properties of ternary perovskite and LSCO/RuO2 as a supecapacitive material of improved stability with respect to carbonaceous ones. Potentiostatic ac impedance analysis has indicated lower charge transfer resistance of the LSCO/RuO2 sample confirming its enhanced electrochemical performances. The measurements indicated that nanocomposite LSCO/RuO2 is more suitable catalytic material with improved electrochemical performances