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4 Regenerated from Failed Commercial Li-Ion Batteries for Na-Ion Battery Applications
Published in Ram K. Gupta, Tuan Anh Nguyen, Energy from Waste, 2022
Dona Susan Baji, Anjali V. Nair, Shantikumar Nair, Dhamodaran Santhanagopalan
The aim of all the recycling methods is to retrieve the resources by eco-friendly, safe, and environmentally feasible processes [13]. Active material extraction methods are classified as hydrometallurgy, pyrometallurgy, direct recycling, and biometallurgy. The primary one involves the most well-known and long chemical process in the field of valuable metal recovery from spent LIBs. This process depends on solid-to-liquid ratio, leachant and reductant species, leaching time, temperature, concentration, etc. [4,14]. Pyrometallurgy, also called smelting, reduces valuable metals using high temperatures. This is a three-step process: pyrolysis or thermal degradation of spent LIBs, metal reduction at 1,500 °C using proper reductant, and finally, gas incineration at 1,000 °C to prevent dioxins liberation. Although a simple technique, it is not eco-friendly due to the release of toxic gases, high energy consumption, and secondary pollution [14,15]. Direct recycling involves non-destructive methods, which include mechanical, electrochemical, cathode-to-cathode, and cathode healing techniques without decomposition of cathode material. The main challenges in this process are the isolation of electrodes and their purification and toxic gases such as HF liberation [16]. Biometallurgy is known to be the most relevant technique due to its low cost and mild reaction conditions. The main challenge during the recycling process is the identification of battery type. If the chemistry of battery is identified, then the process will be very simple and efficient [13,17].
Pyrometallurgical Process for Recycling of Valuable Materials and Waste Management: Valorisation Applications of Blast Furnace Slags
Published in Hossain Md Anawar, Vladimir Strezov, Abhilash, Sustainable and Economic Waste Management, 2019
Sara Yasipourtehrani, Vladimir Strezov, Tim Evans, Hossain Md Anawar
Pyrometallurgical and hydrometallurgical processes are the two main metal extraction and recovery technologies generally used to produce refined metals. The pyrometallurgy is a process that utilises high temperatures to alter the mineral chemically, separate desired metals from other materials and ultimately reduce the metal oxides to free metals. This process applies high temperature reactions, roasting, smelting and conversion of metal oxide to metal (Ramachandra Rao, 2006). The differences between oxidation potentials, melting points, vapour pressures, densities and/or miscibility of the ore components are used in these processes (Roto, 1998). Pyrometallurgical processes are also used to recycle iron, copper, lead, steel and other scrap metals (Espinosa et al., 2015). After beneficiation (crushing, grinding, floating and drying), an ore is sintered or roasted (calcined) with other materials, such as baghouse dust and flux, during pyrometallurgical processing and then smelted, or melted, in a blast furnace in order to fuse the desired metals into an impure molten bullion. The various metals, such as gold and silver, may also be produced as by-products depending on the origin of the ore and its residual metal contents. Cobalt and zinc are produced by roasting, which is an important pyrometallurgical process, and then undergo further hydrometallurgical processing.
Recovery of Metal from Electronic Waste for Sustainable Development (through Microbial Leaching/Bioprocesses)
Published in V. Sivasubramanian, Bioprocess Engineering for a Green Environment, 2018
Shankar Nalinakshan, Aneesh Vasudevan, J. Kanimozhi, V. Sivasubramanian
Pyrometallurgy is a branch of extractive metallurgy that includes treating minerals and metallurgical ores and concentrates to change materials so that valuable metals can be recovered. The various processes in pyrometallurgy include incineration, smelting in a plasma arc furnace or blast furnace, sintering, melting, and reactions in a gas phase at high temperatures. In the process, the crushed scraps are burned in a furnace or in a molten bath to remove plastics, and the refractory oxides form a slag phase together with some metal oxides (Figure 16.4).
Is Near-zero Waste Production of Copper and Its Geochemically Scarce Companion Elements Feasible?
Published in Mineral Processing and Extractive Metallurgy Review, 2022
In pyrometallurgy, firstly matte (containing substantial amounts of S and 45–85 (weight)% Cu) is generated in flash or bath smelters. In 2015 about 72% of copper ore smelting capacity regarded flash smelter-based production of matte (ICSG (International Copper Study Group) 2016). Flash smelting requires a dry input of particles <100 micrometer, whereas bath smelters can also process larger sized materials and have a less strict drying requirement (Forsén, Aromaa and Lindström 2017). A higher matte grade and a higher temperature in flash smelting increase solubility of Cu in slag (Forsén, Aromaa and Lindström 2017; Klaffenbach et al. 2021). Subsequently, through oxidative treatment in converters, matte is turned into blister copper with >90 (weight)% Cu (e. g. ICSG (International Copper Study Group) 2016). In the presence of tailored slag systems direct concentrate-to-blister copper smelting is an option (Voigt et al. 2017). Blister copper in turn is refined in an anode furnace (fire refining), to generate copper anodes with >99 (weight)% Cu (e. g. Dupont et al. 2016; Gregurek et al. 2018; Li et al. 2016). Subsequently, anode copper is subjected to electrolytic treatment. This implies dissolution of anode-Cu in the electrolyte and the generation of anode slime (mainly precipitates, also called anode mud). Cu is removed from the electrolyte, generating cathodes with high purity (>99.9 (weight)%) copper (Forsén, Aromaa and Lindström 2017; Norgate and Jahanshahi 2010; Rönnlund et al. 2016).
Toward the Implementation of Circular Economy Strategies: An Overview of the Current Situation in Mineral Processing
Published in Mineral Processing and Extractive Metallurgy Review, 2022
Luis A. Cisternas, Javier I. Ordóñez, Ricardo I. Jeldres, Rodrigo Serna-Guerrero
On the other hand, pyrometallurgical operations encompass the processes of calcination, roasting, smelting, and refining. Because metal grades in the ore are typically low, direct smelting treatment is not economically feasible. For this reason, as was indicated, minerals must be previously concentrated. For example, in the production of zinc, the sulfide mineral named sphalerite is firstly processed by flotation and the obtained concentrate is subsequently roasted and converted to metallic zinc in several furnaces. In a similar approach, chalcopyrite, a copper sulfide ore, is also treated by flotation-smelting-refining. Pyrometallurgical operations can produce several environmental problems, especially air pollution, due to the emission of toxic gases such as SO2, and metals/metalloids particulate matter (Adamczyk and Nowińska 2019; Dimitrijević et al. 2009; Serbula et al. 2017). Also, pyrometallurgy is an energy-intensive technology that further contributes to greenhouse gas (GHG) emissions (Kulczycka et al. 2016; Liddell et al. 2011). Another pollution problem associated with smelting is the generation of slags that contain heavy metals (Agnello et al. 2018).
Valorization of resources from end-of-life lithium-ion batteries: A review
Published in Critical Reviews in Environmental Science and Technology, 2022
Francine Duarte Castro, Mentore Vaccari, Laura Cutaia
Pyrometallurgy requires high temperatures to extract metals from ores, scrap, and concentrates by physical-chemical transformations. At first, the input is smelted in the presence of slag formers at temperatures >1400 °C (Liu, Lin, et al., 2019). According to Guoxing et al. (2016), CaO-SiO2-Al2O3 or FeO-CaO-SiO2-Al2O3 is generally used for slag formation in the processing of spent LIBs. Subsequently, reduction takes place, usually promoted by graphite (from the anode or external source). Cobalt from the cathode is, then, reduced by graphite and CO to its metallic form, and Li is converted into Li2CO3, which accumulates in the slag phase with Al, Ca, and Si (Dang et al., 2018; Liu, Lin, et al., 2019; Lv et al., 2018). During the process, target metals such as Co, Ni, Cu, and Fe are converted into alloys, whereas organics are burnt (Dang et al., 2018). Outputs of the smelter are slag, gases, flue dust (which may contain halogens), and metal alloys (Weyhe & Pan, 2016).