Recycling and Sustainability for Emerging Technologies and Strategic Materials: E-Waste & Value Recovery
Sponsored by: TMS Extraction and Processing Division, TMS Light Metals Division, TMS: Recycling and Environmental Technologies Committee
Program Organizers: John Howarter, Purdue University; Mingming Zhang, Baowu Ouyeel Co. Ltd; Elsa Olivetti, Massachusetts Institute of Technology; Hong (Marco) Peng, University of Queensland
Tuesday 2:00 PM
March 16, 2021
Room: RM 24
Location: TMS2021 Virtual
Session Chair: John Howarter, Purdue University
2:00 PM Invited
Characterisation and Techno-economics of a Process to Recover Value from E-waste Materials: Khairul Islam1; Michael Somerville2; Nawshad Haque2; 1RMIT University; 2CSIRO
Printed circuit boards, collected from Bangladesh, were melted to determine the proportion of metal, ceramic and volatile components. The concentration and amount of valuable elements in the e-waste was calculated from the analysis of the metal and ceramic phases. This information was used to design a simple three stage process to recover the valuable components. The three stages included primary smelting, electro-refining of a crude copper rich anode and smelting of anode slimes. In this process copper would be recovered as a high purity cathode and silver and gold recovered as a precious metal bullion from the processed anode slimes. Tin and other valuable elements such as rare earth elements reported to a slag phase. The operating and capital costs of these three operations were estimated and the financial viability of the process estimated. The results showed that the process could be economical at present metal values.
2:30 PM
Recycling of Spent SCR Catalyst to Recover Vanadium and Tungsten by Hydrometallurgical Routes: Ana Belen Cueva-Sola1; Jin-Young Lee2; Rajesh Kumar Jyothi2; 1Korea University of Science and Technology (UST), Daejeon 34113, South Korea; 2Korea Inst of Geoscience & Mineral Resources
Currently selective catalytic reduction (SCR) catalyst is the most promising technology to reduce the air pollution caused by nitrogen oxides (NOx) emissions in industries. Due to the increasing demand of catalyst and the limited lifespan of them, after deactivation, they usually end up in landfills posing a major environmental issue. The most widely used catalyst for stationary applications contains around 0.5-1.5% wt V2O5 and 7-10% wt of WO3 in a TiO2 matrix and owing to the vast uses of vanadium and tungsten and the necessity of replacing primary ores with secondary sources makes the recovery of these metals a major motivation for this research. During this experimental study, the leach liquor obtained after titanium selective leaching containing only vanadium and tungsten was processed using liquid-liquid extraction. The optimum conditions for extraction and stripping were derived and separation of vanadium and tungsten was proposed in a variety of hydrometallurgical routes.
2:50 PM
The Separation of Nickel and Cobalt from Lithium-ion Battery Leachate: Mark Strauss1; Josh McNally1; Luis Aldana1; John Klaehn1; Tedd Lister1; 1Idaho National Laboratory
The separation of nickel and cobalt is essential to the technoeconomic success of a nickel laterite mining or lithium-ion battery recycling operation. The current standard for Ni/Co separation requires solvent extraction. This paper proposes a possibly less carbon intensive separation route via a solvent free method. An acidic leach solution from lithium ion battery scrap was used as the feed solution. Using several unit operations, a separation factor of more than 50 was attained for separate cobalt and nickel fractions. Finally, more than 95% pure nickel and 99% pure cobalt fractions were recovered from the separation.
3:10 PM
Rare Earth Magnet or Ferroalloy? What Steel Processing Can Teach Us about Magnet Sludge Recycling.: Mary Elizabeth Wagner1; Antoine Allanore1; 1Massachusetts Institute of Technology
Recycling rare-earth magnets poses a metallurgical challenge due to their high reactivity and the difficulty in separating individual rare-earth elements. These challenges are compounded when considering magnet machining sludge, which is more heavily oxidized and contaminated than typical end-of-life magnets. Drawing inspiration from steel processing, a thermodynamic study was undertaken to consider the oxidation behavior of rare-earth magnet sludge using a hybrid CALPHAD-classical method and a comprehensive 25 element model. Oxygen distribution in a rare-earth magnet, with a total O content ranging between 0.09% to 5.4wt%, was assessed. The theoretical minimum energy to reduce the whole magnet sludge, without separation and purification, was calculated. The model performance with respect to published experimental data is used to shed light into new possible processing methods for magnet recycling.