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Li XG, Gao Q, Jiang SQ, Nie CC, Zhu XN, Jiao TT. Review on the gentle hydrometallurgical treatment of WPCBs: Sustainable and selective gradient process for multiple valuable metals recovery. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2023; 348:119288. [PMID: 37864943 DOI: 10.1016/j.jenvman.2023.119288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Revised: 09/20/2023] [Accepted: 10/06/2023] [Indexed: 10/23/2023]
Abstract
The metal resource crisis and the inherent need for a low-carbon circular economy have driven the rapid development of e-waste recycling technology. High-value waste printed circuit boards (WPCBs) are an essential component of e-waste. However, WPCBs are considered hazardous to the ecosystem due to the presence of heavy metals and brominated organic polymers. Therefore, achieving the recycling of metals in WPCBs is not only a strategic requirement for building a green ecological civilization but also an essential guarantee for achieving a safe supply of mineral resources. This review systematically analyzes the hydrometallurgical technology of metals in WPCBs in recent years. Firstly, the different unit operations of pretreatment in the hydrometallurgical process, which contain disassembly, crushing, and pre-enrichment, were analyzed. Secondly, environmentally friendly hydrometallurgical leaching systems and high-value product regeneration technologies used in recent years to recover metals from WPCBs were evaluated. The leaching techniques, including cyanidation, halide, thiourea, and thiosulfate for precious metals, and inorganic acid, organic acid, and other leaching methods for base metals such as copper and nickel in WPCBs, were outlined, and the leaching performance and greenness of each leaching system were summarized and analyzed. Eventually, based on the advantages of each leaching system and the differences in chemical properties of metals in WPCBs, an integrated and multi-gradient green process for the recovery of WPCBs was proposed, which provides a sustainable pathway for the recovery of metals in WPCBs. This paper provides a reference for realizing the gradient hydrometallurgical recovery of metals from WPCBs to promote the recycling metal resources.
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Affiliation(s)
- Xi-Guang Li
- College of Chemical and Biological Engineering, Shandong University of Science and Technology, Qingdao, Shandong 266590, China
| | - Qiang Gao
- College of Chemical and Biological Engineering, Shandong University of Science and Technology, Qingdao, Shandong 266590, China
| | - Si-Qi Jiang
- College of Chemical and Biological Engineering, Shandong University of Science and Technology, Qingdao, Shandong 266590, China
| | - Chun-Chen Nie
- College of Chemical and Biological Engineering, Shandong University of Science and Technology, Qingdao, Shandong 266590, China
| | - Xiang-Nan Zhu
- College of Chemical and Biological Engineering, Shandong University of Science and Technology, Qingdao, Shandong 266590, China.
| | - Tian-Tian Jiao
- College of Chemical and Biological Engineering, Shandong University of Science and Technology, Qingdao, Shandong 266590, China.
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He H, Yang B, Wu D, Gao X, Fei X. Applications of crushing and grinding-based treatments for typical metal-containing solid wastes: Detoxification and resource recovery potentials. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2022; 314:120034. [PMID: 36030964 DOI: 10.1016/j.envpol.2022.120034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Revised: 08/14/2022] [Accepted: 08/20/2022] [Indexed: 06/15/2023]
Abstract
Metal-containing solid wastes can induce serious environmental pollution if managed improperly, but contain considerable resources. The detoxification and resource recoveries of these wastes are of both environmental and economic significances, being indispensable for circular economy. In the past decades, attempts have been made worldwide to treat these wastes. Crushing and grinding-based treatments have been increasingly applied, the operating apparatus and parameters of which depend on the waste type and treatment purpose. Based on the relevant studies, the applications of crushing and grinding on four major types of solid wastes, namely spent lithium-ion batteries (LIBs) cathode, waste printed circuit boards (WPCBs), incineration bottom ash (IBA), and incineration fly ash (IFA) are here systematically reviewed. These types of solid wastes are generated in increasing amounts, and have the potentials to release various organic and inorganic pollutants. Despite of the widely different texture, composition, and other physicochemical properties of the solid wastes, crushing and grinding have been demonstrated to be universally applicable. For each of the four wastes, the technical route that involving crushing and grinding is described with the advantages highlighted. The crushing and grinding serve either mainstream or auxiliary role in the processing of the solid wastes. This review summarizes and highlights the developments and future directions of crushing and grinding-based treatments.
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Affiliation(s)
- Hongping He
- College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen 518060, PR China; School of Civil and Environmental Engineering, Nanyang Technological University, 639798, Singapore
| | - Bo Yang
- College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen 518060, PR China
| | - Deli Wu
- State Key Laboratory of Pollution Control and Resources Reuse, School of Environmental Science & Engineering, Tongji University, Shanghai, 200092, PR China; Shanghai Institute of Pollution Control Ecological Security, Shanghai, 200092, PR China
| | - Xiaofeng Gao
- Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing, 400045, China
| | - Xunchang Fei
- School of Civil and Environmental Engineering, Nanyang Technological University, 639798, Singapore; Residues and Resource Reclamation Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, 1 Cleantech Loop, 637141, Singapore.
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Faraji F, Golmohammadzadeh R, Pickles CA. Potential and current practices of recycling waste printed circuit boards: A review of the recent progress in pyrometallurgy. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2022; 316:115242. [PMID: 35588669 DOI: 10.1016/j.jenvman.2022.115242] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 04/22/2022] [Accepted: 05/04/2022] [Indexed: 06/15/2023]
Abstract
Over the last few decades, a substantial amount of e-waste including waste printed circuit boards (WPCBs) has been produced and is accumulating worldwide. More recently, the rate of production has increased significantly, and this trend has raised some serious concerns regarding the need to develop viable recycling methods. The presence of other materials in the WPCBs, such as ceramics and polymers, and the multi-metal nature of WPCBs all contribute to the increased complexity of any recycling process. Among the viable techniques, pyrometallurgy, with the inherent ability to process the waste independent of its composition, is a promising candidate for both rapid and large-scale treatment. In the present study, firstly, the principles of the pyrometallurgical methods for WPCB recycling are discussed. Secondly, the different unit operations of thermochemical pretreatment including incineration, pyrolysis, and molten salt processing are reviewed. Thirdly, the smelting processes for the recovery of metals from WPCBs, as well as the issues surrounding slag formation and subsequent treatment are explained. Fourthly, alternative methods for the recovery of polymers and ceramics, in addition to metal recycling, are elucidated. Fifthly, emission control techniques and the potential for energy recovery are evaluated.
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Affiliation(s)
- Fariborz Faraji
- The Robert M. Buchan Department of Mining, Queen's University, Kingston, ON, K7L 3N6, Canada.
| | - Rabeeh Golmohammadzadeh
- Department of Chemical Engineering, Monash University, Clayton, Victoria, 3800, Australia; Institute for Frontier Materials, Deakin University, Geelong, Victoria 3200, Australia
| | - Christopher A Pickles
- The Robert M. Buchan Department of Mining, Queen's University, Kingston, ON, K7L 3N6, Canada.
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Mariyam S, Zuhara S, Al-Ansari T, Mackey H, McKay G. Novel high capacity model for copper binary ion exchange on e-waste derived adsorbent resin. ADSORPTION 2022. [DOI: 10.1007/s10450-022-00360-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Abstract
AbstractHeavy metal water pollution is a global concern in recent years. Copper is a toxic metal at higher concentrations (> 20 μg /g) and needs to be removed using ion exchanger systems. This study investigates the removal efficiencies of copper by the non-metallic fraction (NMF) waste printed circuit boards (PCBs). The high maximum adsorption capacity of copper by the PCB-derived material after activation with KOH was 2.65 mmol/g, and the experimental isotherm was best correlated by the Temkin model. Finally, this study presents a novel dual site adsorption/ion exchange mechanism, wherein the potassium (from the activation) and calcium (present in the structure) served as ion exchange sites for the copper in the solution. Therefore, this recycling study, focusing on cyclic environmental management, converts a major waste material to an activated ion exchange resin (high capacity) for the removal of copper from wastewater solutions and successfully regenerates the resin for re-use while producing an acidic copper solution for recovery by electrolysius or chemical salt precipitation.
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Hao J, Wang X, Wang Y, Wu Y, Guo F. Optimizing the Leaching Parameters and Studying the Kinetics of Copper Recovery from Waste Printed Circuit Boards. ACS OMEGA 2022; 7:3689-3699. [PMID: 35128277 PMCID: PMC8811881 DOI: 10.1021/acsomega.1c06173] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Accepted: 12/17/2021] [Indexed: 05/31/2023]
Abstract
The study of copper (Cu) recovery is crucial for the entire recovery process of waste printed circuit boards (WPCBs), and Cu can be leached efficiently via a sulfuric acid-hydrogen peroxide (H2SO4-H2O2) system. To achieve high Cu recovery, it is important to evaluate the parameters of the leaching process and understand the Cu leaching kinetics. Applying statistical and mathematical techniques to the leaching process will further benefit the optimization of the Cu leaching parameters. Moreover, the leaching kinetics of Cu in the H2SO4-H2O2 solution is yet to be fully understood. Hence, in the present work, process parameters, such as temperature, H2SO4 and H2O2 concentrations, solid-liquid ratio, particle size, and stirring speed, were optimized statistically by the response surface methodology (RSM). The results showed that the leaching kinetics conformed to the Avrami model. The maximum Cu leaching efficiency was 99.47%, and it was obtained based on the following optimal conditions: 30.98 °C, 2.6 mol/L H2SO4, 1.87 mol/L H2O2, a solid-liquid ratio of 0.05 g/mL, 135 mesh, and 378 rpm. RSM was used for the optimization of the process parameters, and the leaching kinetics in this system was clarified. This study provides an important pathway for the investigation of other metal recoveries from WPCBs.
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Affiliation(s)
- Juanjuan Hao
- Faculty
of Materials and Manufacturing, Beijing
University of Technology, Beijing 100124, P. R. China
| | - Xiaolu Wang
- Faculty
of Materials and Manufacturing, Beijing
University of Technology, Beijing 100124, P. R. China
| | - Yishu Wang
- Faculty
of Materials and Manufacturing, Beijing
University of Technology, Beijing 100124, P. R. China
| | - Yufeng Wu
- Faculty
of Materials and Manufacturing, Beijing
University of Technology, Beijing 100124, P. R. China
| | - Fu Guo
- Faculty
of Materials and Manufacturing, Beijing
University of Technology, Beijing 100124, P. R. China
- Key
Laboratory of Advanced Functional Materials, Ministry of Education, Beijing 100124, P. R. China
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Jadhao PR, Pandey A, Pant KK, Nigam KDP. Efficient recovery of Cu and Ni from WPCB via alkali leaching approach. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2021; 296:113154. [PMID: 34216905 DOI: 10.1016/j.jenvman.2021.113154] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 05/22/2021] [Accepted: 06/22/2021] [Indexed: 06/13/2023]
Abstract
The large generation of electronic waste (e-waste) is posing a serious threat to society. It is important to develop sustainable technology for the effective management of e-waste and the recovery of valuable metals from it. The present study employed hydrometallurgical approach for Cu and Ni extraction from waste printed circuit boards (WPCB) of mobile phones. This study demonstrates the application of ammonia-ammonium sulfate leaching for the maximum recovery of Cu and Ni. Investigations revealed that the most favourable reaction parameters for efficient metal extraction are - ammonia concentration - 90 g/L, ammonium sulfate concentration - 180 g/L, H2O2 concentration - 0.4 M, time - 4 h, liquid to solid ratio - 20 mL/g, temperature - 80 °C and agitation speed - 700 rpm. Under these conditions, 100% Cu and 90% Ni were extracted. Furthermore, the kinetic study was performed using the shrinking core model which revealed that the internal diffusion is the rate-controlling step for Cu and Ni extraction. The activation energies for Cu and Ni extraction were found out to be 4.5 and 5.7 kJ/mol, respectively. Finally, Cu was recovered with 98.38% purity using electrowinning at a constant DC voltage of 2.0 V at Al cathode. The present study provides a solution for concurrent extraction of Cu and Ni from the raw WPCB of mobile phones and selective recovery of Cu from metal leached solution. The process has the potential to recover the resources from WPCB while minimising the pollution caused by mismanagement of WPCB.
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Affiliation(s)
- Prashant Ram Jadhao
- Chemical Engineering Department, Indian Institute of Technology Delhi, New Delhi, 110016, India
| | - Ashish Pandey
- Chemical Engineering Department, Indian Institute of Technology Delhi, New Delhi, 110016, India
| | - K K Pant
- Chemical Engineering Department, Indian Institute of Technology Delhi, New Delhi, 110016, India.
| | - K D P Nigam
- Chemical Engineering Department, Indian Institute of Technology Delhi, New Delhi, 110016, India
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Das SK, Ellamparuthy G, Kundu T, Ghosh MK, Angadi SI. Critical analysis of metallic and non-metallic fractions in the flotation of waste printed circuit boards. POWDER TECHNOL 2021. [DOI: 10.1016/j.powtec.2021.05.061] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Uptake and Recovery of Gold from Simulated Hydrometallurgical Liquors by Adsorption on Pine Bark Tannin Resin. WATER 2020. [DOI: 10.3390/w12123456] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The recovery of critical and precious metals from waste electrical and electronic equipment (WEEE) is an environmental and economic imperative. Biosorption has been considered a key technology for the selective extraction of gold from hydrometallurgical liquors obtained in the chemical leaching of e-waste. In this work, the potential of tannin resins prepared from Pinus pinaster bark to sequester and recover gold(III) from hydrochloric acid and aqua regia solutions was assessed. Equilibrium isotherms were experimentally determined and maximum adsorption capacities of 343 ± 38 and 270 ± 19 mg g−1 were found for Au uptake from HCl and HCl/HNO3 (3:1 v/v) solutions containing 1.0 mol L−1 H+. Higher levels of acidity (and chloride ligands) significantly impaired the adsorption of gold from both kinds of leaching solutions, especially in the aqua regia system, in which the adsorbent underperformed. Pseudo-first and pseudo-second order models successfully described the kinetic data. The adsorbent presented high selectivity towards gold. Actually, in simulated aqua regia WEEE liquors, Au(III) was extensively adsorbed, compared to Cu(II), Fe(III), Ni(II), Pd(II), and Zn(II). In three adsorption–desorption cycles, the adsorption capacity of the regenerated adsorbent moderately decreased (19%), although the gold elution in acidic thiourea solution had been quite limited. Future research is needed to examine more closely the elution of gold from the exhausted adsorbents. The results obtained in this work show good perspectives as regards the application of pine bark tannin resins for the selective extraction of Au from electronic waste leach liquors.
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Zhu XN, Zhang YK, Zhang YQ, Yan ZQ, Nie CC, Lyu XJ, Tao YJ, Qiu J, Li L. Flotation dynamics of metal and non-metal components in waste printed circuit boards. JOURNAL OF HAZARDOUS MATERIALS 2020; 392:122322. [PMID: 32097856 DOI: 10.1016/j.jhazmat.2020.122322] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Revised: 02/11/2020] [Accepted: 02/14/2020] [Indexed: 06/10/2023]
Abstract
Flotation is an effective and clean separation technology to realize the recovery of metal in waste printed circuit boards (WPCBs). The flotation kinetic of metal and non-metal components was concerned in this study. In addition, the loading of bubbles, the collision and shedding of particles and bubbles were used to assist in proving the particle dynamics results. By analyzing the force on the particles, the load of bubbles on particles was analyzed, and the appropriate volume ratio of bubbles to particles was 1.5-8.0, depending on the particle density. Moreover, Clift model and Schiller-Naumann model has high fitting accuracy for the final bubble velocity. In addition, metal particles have greater settling velocity, which results in shorter collision time with bubbles. In the process of bubble-particle rising, the shedding probability gradually decreases, and the shedding probability of metal particles is much higher than that of non-metal particles. The results of flotation kinetics show that the removal of impurity particles represented by silicon mainly occurs in the initial stage of flotation process. The loss of copper increases with flotation time and collector dosage. This study reveals the flotation kinetics of particles from the perspectives of bubble loading, bubble-particle collision and shedding.
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Affiliation(s)
- Xiang-Nan Zhu
- College of Chemical and Environmental Engineering, Shandong University of Science and Technology, Qingdao, Shandong 266590, China.
| | - Yuan-Kang Zhang
- College of Chemical and Environmental Engineering, Shandong University of Science and Technology, Qingdao, Shandong 266590, China
| | - Yi-Qing Zhang
- College of Chemical and Environmental Engineering, Shandong University of Science and Technology, Qingdao, Shandong 266590, China
| | - Zheng-Qing Yan
- College of Chemical and Environmental Engineering, Shandong University of Science and Technology, Qingdao, Shandong 266590, China
| | - Chun-Chen Nie
- College of Chemical and Environmental Engineering, Shandong University of Science and Technology, Qingdao, Shandong 266590, China
| | - Xian-Jun Lyu
- College of Chemical and Environmental Engineering, Shandong University of Science and Technology, Qingdao, Shandong 266590, China
| | - You-Jun Tao
- School of Chemical Engineering and Technology, China University of Mining & Technology, Xuzhou, Jiangsu 221116, China
| | - Jun Qiu
- College of Chemical and Environmental Engineering, Shandong University of Science and Technology, Qingdao, Shandong 266590, China
| | - Lin Li
- College of Chemical and Environmental Engineering, Shandong University of Science and Technology, Qingdao, Shandong 266590, China
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Zhu XN, Zhang LY, Dong SL, Kou WJ, Nie CC, Lyu XJ, Qiu J, Li L, Liu ZX, Wu P. Mechanical activation to enhance the natural floatability of waste printed circuit boards. WASTE MANAGEMENT (NEW YORK, N.Y.) 2020; 109:222-230. [PMID: 32416564 DOI: 10.1016/j.wasman.2020.05.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Revised: 04/10/2020] [Accepted: 05/06/2020] [Indexed: 06/11/2023]
Abstract
The metal in the waste printed circuit boards (WPCBs) is an excellent secondary metal resource. WPCBs were ground to dissociate, and impurities in the dissociated product were removed by gradient flotation to recover valuable metals in this study. The effects of crushing methods on size composition and dissociation state of the crushed products were studied. Then the gradient flotation experiment was designed to verify the natural floatability of ground materials. Grinding test shows that impact crushing has greater grinding fineness (-0.074 mm) than shear crushing, which is 42.14% and 26.18% respectively with 5 min grinding. The flotation test results illustrate that the natural floatability of impurities increases with the grinding fineness, that is, the yield of floats increases without flotation reagents. For impact crushing and shear crushing, the floats yields are 38.48% and 31.75% respectively, accompanied by 70.53% and 65.46% impurity removal for ground materials with 5 min grinding. Subsequently, 21.61% and 26.35% of impurities can be further removed with the aid of collector. Finally, the recovery of Cu in concentrate reaches 67.84% and 65.75%, respectively. FT-IR proves that the excellent floatability of particles is caused by the significant hydrophobic group. Mechanical grinding has been proved to have double effects of improving dissociation and natural floatability.
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Affiliation(s)
- Xiang-Nan Zhu
- College of Chemical and Environmental Engineering, Shandong University of Science and Technology, Qingdao, Shandong 266590, China.
| | - Li-Ye Zhang
- College of Chemical and Environmental Engineering, Shandong University of Science and Technology, Qingdao, Shandong 266590, China
| | - Shu-Ling Dong
- College of Chemical and Environmental Engineering, Shandong University of Science and Technology, Qingdao, Shandong 266590, China
| | - Wen-Jia Kou
- College of Chemical and Environmental Engineering, Shandong University of Science and Technology, Qingdao, Shandong 266590, China
| | - Chun-Chen Nie
- College of Chemical and Environmental Engineering, Shandong University of Science and Technology, Qingdao, Shandong 266590, China
| | - Xian-Jun Lyu
- College of Chemical and Environmental Engineering, Shandong University of Science and Technology, Qingdao, Shandong 266590, China
| | - Jun Qiu
- College of Chemical and Environmental Engineering, Shandong University of Science and Technology, Qingdao, Shandong 266590, China
| | - Lin Li
- College of Chemical and Environmental Engineering, Shandong University of Science and Technology, Qingdao, Shandong 266590, China
| | - Zhen-Xue Liu
- College of Chemical and Environmental Engineering, Shandong University of Science and Technology, Qingdao, Shandong 266590, China.
| | - Peng Wu
- College of Chemical and Environmental Engineering, Shandong University of Science and Technology, Qingdao, Shandong 266590, China.
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