Rare Metal Extraction & Processing: Processing for Precious Metals and Rare Metals / Electrochemical Processing for Rare Metals
Sponsored by: TMS Extraction and Processing Division, TMS: Hydrometallurgy and Electrometallurgy Committee, TMS: Recycling and Environmental Technologies Committee
Program Organizers: Takanari Ouchi, University of Tokyo; Kerstin Forsberg, KTH Royal Institute of Technology; Gisele Azimi, University of Toronto; Shafiq Alam, University of Saskatchewan; Neale Neelameggham, IND LLC; Hojong Kim, Pennsylvania State University; Alafara Baba, University of Ilorin; Hong (Marco) Peng, University of Queensland; Athanasios Karamalidis, Pennsylvania State University; Shijie Wang, Coeur Mining, Inc
Monday 2:00 PM
March 20, 2023
Room: 30B
Location: SDCC
Session Chair: Athanasios Karamalidis, Pennsylvania State University; Shijie Wang, Coeur Mining, Inc; Hojong Kim, Pennsylvania State University; Takanari Ouchi, The University of Tokyo
2:00 PM Invited
An Innovated Hydrometallurgical Process for Recoveries of Critical and Rare Metals from Copper Anode Slimes: Shijie Wang1; 1Coeur Mining, Inc
During electrorefining, copper or lead are purified from impure anodes by dissolving in the electrolyte and plating on the cathodes while all insoluble components are precipitated to the bottom of electrolytic cells in the Tank house (or Cell House). These settled insoluble components are called anode slimes that contain copper, tellurium, selenium, bismuth, silver, gold, and traces of platinum group metals, such as platinum and palladium. Traditionally these valuable metals are recovered in partial pyro- and partial hydro- metallurgical processes. In this paper, it summarizes a 100% hydrometallurgical process (Wang’s process) that was innovatively developed for each of the critical metal’s recovery. This novel hydrometallurgical process would not only eliminate all by-products from current Precious Metals Plants, but also increase significant revenues in the copper or lead refinery operations.
2:30 PM
Eutectic Freeze Crystallization for Recovery of Cobalt Sulfate in the Recycling of Li-ion Batteries: Yiqian Ma1; Amanda Sjögren1; Michael Svärd1; Xiong Xiao1; James Gardner1; Richard Olsson1; Kerstin Forsberg1; 1KTH Royal Institute of Technology
The crystallization of cobalt sulfate within a typical hydrometallurgical process for the recycling of Li-ion batteries has been investigated. The cobalt sulfate salt was obtained by eutectic freeze crystallization (EFC) from a synthetic acidic strip liquor after solvent extraction. The ternary phase diagram of CoSO4-H2SO4-H2O was first established by the mixed-solvent electrolyte (MSE) model to predict and reveal the changes in the system during the freezing process and to assess the conditions required for EFC. Batch EFC experiments were then conducted for the cobalt strip liquor. It is shown that, with suitable control of supersaturation, seeding and stirring, pure ice and salt crystals can be recovered as separate phases at the eutectic temperatures, with the crystalline salts in the form of a heptahydrate. The crystallization process can be described using the ternary phase diagram. After washing, CoSO4·7H2O obtained usng EFC is shown to meet the standards of a battery-grade product.
2:50 PM
Studies on the Hydrometallurgical Recovery of Metals from Used and End of Life PCBs: Om Dinkar1; Rekha Panda1; Pankaj Choubey1; Manis Jha1; Balram Ambade1; 1CSIR-National Metallurgical Laboratory
In this era of modernisation, the demand of metals is increasing as well as limitation of primary resources created a huge gap between demand and supply. In this connection, attempt has been made to recover Pb, Sn and Cu from waste PCBs of computer hard disc using pre-treatment followed by hydrometallurgical techniques.In PCBs encapsulation of epoxy sheets hinders dissolution of metals.Therefore, initially PCBs were depopulated and then using pre-treatment techniques i.e. size reduction, wet gravity separation and mix metal concentrate was obtained.This obtained concentrate was used further for developing various metal recovery processes and optimisation of various process parameters. The experimental results indicate,~ 99%recovery of metals using suitable leachants and extractants.The obtained data is presented and validated to develop a process flow-sheet. This work will be productive for the researchers,students and industrialists working in this area.
3:10 PM
Extraction of Tungsten, Yttrium and Uranium from Tantalum – Niobium Ore from Muchinga Province in Zambia: Douglas Musowoya1; Yotamu Hara1; Fredrick Chilese1; Janet Mundundu1; Stephen Parirenyatwa1; 1Copperbelt University
A clean method of extracting tungsten, yttrium and uranium from tantalum - niobium ore located in the Muchinga province of Zambia has been developed. Tungsten is selectively extracted by roasting with alkaline at 700 and 750 degrees celcius followed by leaching in water to solubilize alkaline tungstate. The alkaline leach residue is cured with sulphuric acid to sulphate uranium and yttrium which are then leached out in acidic media. The effects of sulphation temperature, time and particle size were studied. Yttrium was recovered from leach solution via precipitation with oxalic acid in which yttrium oxalate with purity of more than 99 wt% was obtained. Uranium was recovered from the leach solution through precipitation with sodium hydroxide. Extraction of tungsten, yttrium and uranium from the material concentrated tantalum oxide by two times. A process flowsheet was developed based on optimised test works.
3:30 PM Break
3:50 PM
Production of High-purity Mg Metal from Various MgO Resources through a Novel Electrolytic Process Using a Cu Cathode and Vacuum Distillation: Hyeong-Jun Jeoung1; Tae-Hyuk Lee1; Youngjae Kim1; Jin-Young Lee1; Young Min Kim2; Toru H. Okabe3; Kyung-Woo Yi4; Jungshin Kang1; 1Korea Institute of Geoscience and Mineral Resources; 2Korea Institute of Materials Science; 3The University of Tokyo; 4Seoul National University
In this study, the feasibility of producing Mg metal from primary and secondary resources containing MgO with the novel Mg production process was investigated. The electrolysis of various MgO resources was conducted in a MgF2–LiF–KCl molten salt at 1043 K by applying an average current of 1.44 A for 12.5 h using Cu cathode and C anode. After electrolysis, 9.20–14.4 mass% Mg–Cu alloys with a mixture of MgCu2 and Cu (Mg) phases were obtained with 59.3–92.4 % current efficiency, and the average cell potential was 2.43–2.75 V. After vacuum distillation of the Mg alloys at 1300 K for 10 h, Mg metal with a purity of 99.994–99.999 % was obtained with 90.7–91.5 % of recovery efficiency. Therefore, the proposed electrolysis process using a Cu cathode followed by vacuum distillation is an effective method to produce high-purity Mg metal from various MgO resources.
4:10 PM
Recovery of Copper Metal from Discarded Printed Circuit Boards (PCBs) by Hydro and Electro Metallurgical Processes: Om Shankar Dinkar1; Rukshana Parween1; Rekha Panda1; Pankaj Kumar Choubey1; Balram Ambade2; Manis Kumar Jha1; 1CSIR-National Metallurgical Laboratory; 2National Institute of Technology
Limited metal resources and significant environmental hazards urged researchers for finding sustainable technology for recycling of waste printed circuit boards (PCBs) to recover metals. Therefore, present paper is focused on the recovery of copper (Cu) from waste PCBs using mechanical pre-treatment followed by hydrometallurgical processing. Initially, depopulated PCBs were pre-treated to get enrich copper in metallic concentrate. Further, experiments were carried out varying different process parameters i.e. acid concentration, oxidant concentration, time, etc., to obtain optimized condition for efficient Cu leaching from metallic concentrate. It was found that 99.9% Cu was leached using 15% H2SO4 at 75 oC in presence of 15% H2O2 within 120 min maintaining 100 g/L pulp density. The obtained leach liquor was used for electro-winning to recover pure copper metal. Result showed that 99.99% pure copper got deposited at cathode between 200-210 A/m2 current density with a current efficiency of ≥85%.