Rare Metal Extraction & Processing: V, Mn, Co, Zn, Mo, Cu, REEs
Sponsored by: TMS Extraction and Processing Division, TMS: Hydrometallurgy and Electrometallurgy Committee
Program Organizers: Gisele Azimi, University of Toronto; Takanari Ouchi, University of Tokyo; Hojong Kim, Pennsylvania State University; Shafiq Alam, University of Saskatchewan; Kerstin Forsberg, KTH Royal Institute of Technology; Alafara Baba, University of Ilorin
Tuesday 2:00 PM
February 25, 2020
Room: 13
Location: San Diego Convention Ctr
Session Chair: Alafara Baba, University of Ilorin; Kerstin Forsberg, KTH Royal Institute of Technology
2:00 PM Keynote
Secondary and Byproduct Sources of Rare Earth Metals: Gabrielle Gaustad1; Alexandra Leader2; Eric Williams2; Saptarshi Das2; 1Alfred University; 2Rochester Institute of Technology
Current concerns about lack of diversity in supply of critical materials have spurred research into utilizing domestic sources, particularly from waste streams. This work combines material flow analysis and techno-economic modelling to explore the resource and economic potential for byproducts (coal combustion products, red mud) and secondary sources (waste electronics) to become a valuable source of rare earth elements (REE). Results show while REE concentrations in coal ash are significantly lower than currently economically extractable ores in most mines, the magnitude of materials available could meet current REE demand even at fairly low extraction yield rates. For many waste electronics, the concentration is much higher than economically extractable ores, but volumes may not meet demand depending on geographic location. Furthermore, infrastructure for collection and processing may not be in place. A combination of higher REE commodity prices which seems likely, improved yields, and enhanced infrastructure is required for economic profitability.
2:20 PM
Indian Coal Ash: a Potential Alternative Resource for Rare Earth Metals (REMs): Archana Kumari1; Manis Kumar Jha1; Devendra Deo Pathak2; 1CSIR-National Metallurgical Laboratory; 2Indian Institute of Technology (Indian School of Mines), Dhanbad, India
Huge scarcity of rare earth metals (REMs) globally, lack of good natural resources and generation of tremendous coal ash containing REMs generated by power plant attracted the researchers to work in this area. The analysis of geologically distributed heterogeneous coal samples at CSIR-NML, India reports the presence of 0.5 to 1.5 Kg/ Ton REMs in particular seam of coal at Indian eastern part. In this regard, systematic leaching studies were made to recover REMs from Indian coal ash using hydrometallurgical technique. Maximum dissolution of REMs from coal ash take place using HCl of concentration ranging between 3.5 to 5M at elevated temperature. From the obtained leach liquor, more than 90% REMs were recovered using oxalate precipitation. The process developed has tremendous potential to be a thrust area for any country to commercialized in industry after feasibility studies.
2:40 PM
Recovery of Manganese and Cobalt from Discarded Batteries of Toys: Pankaj Choubey1; Manis Kumar Jha1; Devendra Deo Pathak2; 1CSIR-National Metallurgical Laboratory; 2Indian Institute of Technology (Indian School of Mines), Dhanbad, India
Compared to other electronic goods life spam of children’s toys are very less, which resulted in the generation of huge amount of batteries and environmental pollution. Initially the batteries are discharged, dismantled, crushed and physically beneficiated to get black powder, metallic fraction and plastics. Further, the black powder of batteries was processed for systematic leaching studies and found 95.6% Mn and 86.05% Co were leached in 2 mol/L H2SO4 at 25 oC in 120 min using the 10% H2O2(v/v) as an oxidant, while maintaining the pulp density 75 g/L. From the leach liquor at various pH 5-8 and above 12, the oxides of Co and Mn were obtained, respectively. The developed process has potential to be transferred in an industry after scale-up studies.
3:00 PM
Recovery of Rare Earths from Waste Permanent Magnets Leach Liquors: Rajesh Kumar Jyothi1; Kyeong Woo Chung1; Chul-Joo Kim1; Ho-Sung Yoon1; 1Korea Institute of Geoscience & Mineral Resources (KIGAM)
Scraps are become a good source for demand metals recovery, as per the DoE, USA some of the rare earths such as neodymium, praseodymium, dysprosium and terbium are recognized as critical situation for future demands. In the 21st century the hi-tech industrialization is very fast growing all over the globe at the same time the human generated waste also being a big burden for environment. In this experimental study is concern with processing of the permanent magnets scraps for rare earths extraction with possible separation from each other. The leach liquor contains following rare earths: praseodymium, dysprosium, neodymium and terbium. In a leaching stage oxidation and roasting process applied to prevent the iron interference as much as possible. The leach liquor was processed with liquid-liquid extraction processing. The proper extractant with proper experimental conditions were optimized for above said rare earths separation was optimized.
3:20 PM Cancelled
Study on Vanadium Phase Evolution Law in Vanadium Slag during the Interface Reaction Process of Sodium Roasting: Dan-Qing Li1; Yang Yang1; Bing Xie1; Hong-Yi Li1; 1Chongqing University
Vanadium slag is composed of many complex phases with various kinds of elements, occurrence forms and chemical forms. At present, sodium roasting–water leaching can effectively extract vanadium, this technology has been widely used in industrial production, but the current researches to evolution law of the V-concentrating phase in V-slag during the roasting process focus on the macro level, not directly on micro level and especially at interface reaction process. Consequently, the micro structure, phase compositions, mineralogical morphology and elements distribution on the surface of V-slag during the roasting process were investigated by various surface analysis technologies. It is essential to truly understand and control the sodium roasting-water extraction process, so the atomic evolution law can be of a great significance to optimize operating conditions in order to raise vanadium recovery rate.Key words: Vanadium, Sodium roasting, Interface reaction, Surface analysis
3:40 PM Break
3:55 PM Cancelled
Phosphate-intensified Alkali Leaching to Recover Molybdenum from a Volatilizing Residue: Dapeng Shi1; Li Guanghui1; Hu Sun1; Jun Luo1; Tao Jiang1; 1Central South University
With the development of industry, the demand for molybdenum resources are increasing, however, the molybdenum ores are gradually decreasing. Therefore, it is urgent to seek an efficient method for of Mo from molybdate tailings. In this study, the feasibility of recovering Mo from molybdate tailing containing rare earths by NaOH and Na2CO3 leaching was verified. The effects of leaching agent concentration, temperature,time,and liquid-to-solid ratio on the leaching of Mo were investigated comprehensively. The results shown that the leaching of Mo in the NaOH and Na2CO3 combined solution was much higher than that in NaOH solution. Under the optimum conditions of leaching time of 1 h, leaching temperature of 140℃, liquid-to-solid ratio of 6 g/mL, the NaOH concentration of 1mol/L, and the Na2CO3 mass fraction of 30%. 96.4% of Mo was leached with 0.2% of Al and 12.6% of Si. Meanwhile, the rare earths were enriched in the leaching residue.
4:15 PM
Extraction of Rare and High-valued Metals from Blast Furnace Dust: Xiong Xiao1; Shengfu Zhang1; Hua Zhang1; Guibao Qiu1; Yuntao Xin1; Jintao Wang1; 1Chongqing university
The treatments of blast furnace dust such as returning to blast furnace sintering, using as flocculants and cement raw materials and adsorbents, recycling carbon and iron as well as recovering rare and high-valued metals were discussed. The current processing status of blast furnace dust in the iron and steel industry and the research trend of rare precious metals represented by indium was investigated. Finally, some advanced research directions on dealing with blast furnace dust were analyzed in the context of solid waste recycling, in the meanwhile, the advantages and disadvantages of pyrometallurgy and hydrometallurgy in metallurgical industry were analyzed by means of the process of indium extraction.
4:35 PM Cancelled
Mechanism of Extraction of Vanadium from Vanadium Slag with MgO: Cheng-Jie Wang1; Yi-Heng Yuan1; Bing Xie1; Hong-Yi Li1; 1Chongqing University
The widely-applied methods to extract vanadium are sodium roasting and calcified roasting. However, these roasting methods have difficulties in recycling of wastewater and efficient utilization of leaching residue, which contains high concentration of sodium or calcium sulfate, due to the variety of roasting additives radically. Therefore, a novelty extraction medium by roasting with MgO and leaching with sulfuric acid was introduced in this study. The oxidation with MgO and roasting mechanism were systematically studied, providing a theoretical basis for industrial extraction of vanadium. The result shows that under the optimum conditions, the roasting temperature of 900℃, the Mg/V molar ratio of 0.6 and the roasting time of 1.5h, the leaching efficiency of vanadium is above 90%. In the processes, vanadium spinel is converted into Mg2V2O7 and MgV2O6.Key words: Vanadium slag, MgO, Roasting mechanism
4:55 PM Cancelled
Effect of Sulfuric Acid Concentration on Marmatite Dissolution in the Presence of Cupric Ions: Xiaoyu Meng1; 1Central South University
Marmatite often associates with copper sulfide ore, the role of Cu2+ in marmatite dissolution is important in hydrometallurgy. In this work, we found that high concentration of cupric ions (Cu2) can accelerate marmatite dissolution, regardless of sulfuric acid concentration (pH 0.5-3.5). However, the consumption of Cu2+ was low at high acid concentration (pH below 1.5), but Cu2+ consumption increased significantly at low acid concentration (pH above 2.5). In addition, the acceleration effect of high concentration of Cu2+ improved obviously at low acid concentration (pH above 2.5) when compared with low concentration of Cu2+. X-ray diffraction (XRD) of the leaching residues proved that no copper containing mineralogical phase was produced at high acid concentration, but copper containing products were formed at low acid concentration. Kinetic analysis showed that marmatite dissolution was mainly controlled by surface reaction. The reaction between Cu2+ and marmatite should be different at different concentration of sulfuric acid.