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Huo Q, Li R, Chen M, Zhou R, Li B, Chen C, Liu X, Xiao Z, Qin G, Huang J, Long T. Mechanism for leaching of fluoride ions from carbon dross generated in high-temperature and low-lithium aluminum electrolytic systems. JOURNAL OF HAZARDOUS MATERIALS 2024; 469:133838. [PMID: 38430589 DOI: 10.1016/j.jhazmat.2024.133838] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Revised: 02/05/2024] [Accepted: 02/18/2024] [Indexed: 03/05/2024]
Abstract
Carbon dross, a hazardous solid waste generated during aluminum electrolysis, contains large amounts of soluble fluoride ions for the main components of the electrolyte (such as Na3AlF6 and NaF). Response surface methodology (RSM) was used to investigate the mechanism for fluoride ion leaching from carbon dross via water leaching, acid leaching and alkali leaching, and the kinetic and thermodynamic principles of the leaching process were revealed. The RSM predicted the optimum conditions of water leaching, alkali leaching and acid leaching, and the conditions are as follows: temperature, 50 °C; shaking speed, 213 r·min-1; particle size, 0.075 mm; shaking speed, 194 r·min-1; liquid-solid ratio, 12.6 mg·L-1; sodium hydroxide concentration, 1.53 mol·L-1; liquid-solid ratio, 25.0 mg·L-1; sulfuric acid concentration, 2.00 mol·L-1; and temperature, 60 °C,and actual results which were almost consistent with the predicted results were gained. The fluoride ions in the alkaline and acid leaching solutions were mainly the dissociation products of fluorides such as Na3AlF6, Na5Al3F14 and CaF2, as indicated by thermodynamics calculations. In particular, the fluoride compounds dissolved in alkali solution were Na3AlF6, Na5Al3F14, AlF3, ZrF4, K3AlF6, while the acid solution could dissolve only Na3AlF6 and CaF2. The leaching kinetics experiments showed that the leaching rate fit the unreacted shrinking core model [1-2/3α-(1-α)2/3 =kt] and that the leaching process was controlled by internal diffusion. This study provides theoretical guidance for the removal of soluble fluoride ions from carbon dross and will also assist in the separation of electrolytes from carbon dross. ENVIRONMENTAL IMPLICATION: Carbon dross, a hazardous waste generated during the aluminum electrolysis production process, contains a large amount of soluble fluoride. Improper storage will lead the fluoride ions pollution in soil, surface water or groundwater under the direct contact between carbon dross and rainfall, snow or surface runoff. The influence of wind will cause carbon dross dust to pollute further areas. With the human body long-term contact with fluoride ion contaminated soil or water, human health will be seriously harmed.
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Affiliation(s)
- Qiang Huo
- Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education - Guangxi Key Laboratory of Landscape Resources Conservation and Sustainable Utilisation in Lijiang River Basin, Guilin, Guangxi 541006, China; Guangxi Key Laboratory of Environmental Processes and Remediation in Ecologically Fragile Regions, Guilin, Guangxi 541006, China; College of Environment and Resources, Guangxi Normal University, Guilin, Guangxi 541006, China
| | - Ruoyang Li
- Guangxi Key Laboratory of Environmental Processes and Remediation in Ecologically Fragile Regions, Guilin, Guangxi 541006, China; College of Environment and Resources, Guangxi Normal University, Guilin, Guangxi 541006, China
| | - Mingyan Chen
- Guangxi Key Laboratory of Environmental Processes and Remediation in Ecologically Fragile Regions, Guilin, Guangxi 541006, China; College of Environment and Resources, Guangxi Normal University, Guilin, Guangxi 541006, China
| | - Runyou Zhou
- College of Environment and Resources, Guangxi Normal University, Guilin, Guangxi 541006, China
| | - Bin Li
- College of Environment and Resources, Guangxi Normal University, Guilin, Guangxi 541006, China
| | - Chunqiang Chen
- College of Environment and Resources, Guangxi Normal University, Guilin, Guangxi 541006, China
| | - Xi Liu
- Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education - Guangxi Key Laboratory of Landscape Resources Conservation and Sustainable Utilisation in Lijiang River Basin, Guilin, Guangxi 541006, China; School of Economics and Management, Guangxi Normal University, Guilin 541006, China
| | - Zeqi Xiao
- College of Environment and Resources, Guangxi Normal University, Guilin, Guangxi 541006, China
| | - Guozhao Qin
- College of Environment and Resources, Guangxi Normal University, Guilin, Guangxi 541006, China
| | - Jianghui Huang
- College of Environment and Resources, Guangxi Normal University, Guilin, Guangxi 541006, China
| | - Tengfa Long
- Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education - Guangxi Key Laboratory of Landscape Resources Conservation and Sustainable Utilisation in Lijiang River Basin, Guilin, Guangxi 541006, China; Guangxi Key Laboratory of Environmental Processes and Remediation in Ecologically Fragile Regions, Guilin, Guangxi 541006, China; College of Environment and Resources, Guangxi Normal University, Guilin, Guangxi 541006, China.
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Dong L, Jiao F, Liu W, Wang D, Chen Wang, Qin W. Selective preparation of lithium carbonate from overhaul slag by high temperature sulfuric acid roasting - Water leaching. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2024; 359:120963. [PMID: 38728980 DOI: 10.1016/j.jenvman.2024.120963] [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: 11/27/2023] [Revised: 03/30/2024] [Accepted: 04/19/2024] [Indexed: 05/12/2024]
Abstract
An efficient recycling process is developed to recover valuable materials from overhaul slag and reduce its harm to the ecological environment. The high temperature sulfuric acid roasting - water leaching technology is innovatively proposed to prepare Li2CO3 from overhaul slag. Under roasting conditions, fluorine volatilizes into the flue gas with HF, lithium is transformed into NaLi(SO4), aluminum is firstly transformed into NaAl(SO4)2, and then decomposed into Al2O3, so as to selective extraction of lithium. Under the optimal roasting - leaching conditions, the leaching rate of lithium and aluminum are 95.6% and 0.9%, respectively. Then the processes of impurity removal, and settling lithium are carried out. The Li2CO3 with recovery rate of 72.6% and purity of 98.6% could be obtained under the best settling lithium conditions. Compared with the traditional process, this work has short flow, high controllability, remarkable technical, economic, and environmental benefits. This comprehensive recycling technology is suitable for overhaul slag, and has great practical application potential for the disposal of other hazardous wastes in electrolytic aluminum industry.
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Affiliation(s)
- Liangmin Dong
- School of Minerals Processing and Bioengineering, Central South University, Changsha, 410083, China; Key Laboratory of Hunan Province for Clean and Efficient Utilization of Strategic Calcium-containing Mineral Resources, Central South University, Changsha, 410083, China
| | - Fen Jiao
- School of Minerals Processing and Bioengineering, Central South University, Changsha, 410083, China; Key Laboratory of Hunan Province for Clean and Efficient Utilization of Strategic Calcium-containing Mineral Resources, Central South University, Changsha, 410083, China.
| | - Wei Liu
- School of Minerals Processing and Bioengineering, Central South University, Changsha, 410083, China; Key Laboratory of Hunan Province for Clean and Efficient Utilization of Strategic Calcium-containing Mineral Resources, Central South University, Changsha, 410083, China.
| | - Dakun Wang
- School of Minerals Processing and Bioengineering, Central South University, Changsha, 410083, China; Key Laboratory of Hunan Province for Clean and Efficient Utilization of Strategic Calcium-containing Mineral Resources, Central South University, Changsha, 410083, China
| | - Chen Wang
- School of Minerals Processing and Bioengineering, Central South University, Changsha, 410083, China; Key Laboratory of Hunan Province for Clean and Efficient Utilization of Strategic Calcium-containing Mineral Resources, Central South University, Changsha, 410083, China
| | - Wenqing Qin
- School of Minerals Processing and Bioengineering, Central South University, Changsha, 410083, China; Key Laboratory of Hunan Province for Clean and Efficient Utilization of Strategic Calcium-containing Mineral Resources, Central South University, Changsha, 410083, China
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3
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Wang T, Li M, Gu Z, Qu C, Segervald J, Salh R, Wågberg T, Wang J, Kou W. Fluoride releasing in polymer blends of poly(ethylene oxide) and poly(methyl methacrylate). Front Chem 2024; 12:1356029. [PMID: 38406557 PMCID: PMC10884178 DOI: 10.3389/fchem.2024.1356029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Accepted: 01/26/2024] [Indexed: 02/27/2024] Open
Abstract
Introduction: Polymethyl methacrylate is a polymer commonly used in clinical dentistry, including denture bases, occlusal splints and orthodontic retainers. Methods: To augment the polymethyl methacrylate-based dental appliances in counteracting dental caries, we designed a polymer blend film composed of polymethyl methacrylate and polyethylene oxide by solution casting and added sodium fluoride. Results: Polyethylene oxide facilitated the dispersion of sodium fluoride, decreased the surface average roughness, and positively influenced the hydrophilicity of the films. The blend film made of polymethyl methacrylate, polyethylene oxide and NaF with a mass ratio of 10: 1: 0.3 showed sustained release of fluoride ions and acceptable cytotoxicity. Antibacterial activity of all the films to Streptococcus mutans was negligible. Discussion: This study demonstrated that the polymer blends of polyethylene oxide and polymethyl methacrylate could realize the relatively steady release of fluoride ions with high biocompatibility. This strategy has promising potential to endow dental appliances with anti-cariogenicity.
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Affiliation(s)
- Tianxiao Wang
- Department of Odontology, Umeå University, Umeå, Sweden
| | - Menghong Li
- Department of Odontology, Umeå University, Umeå, Sweden
| | - Ziyan Gu
- Department of Odontology, Umeå University, Umeå, Sweden
| | - Chengjuan Qu
- Department of Odontology, Umeå University, Umeå, Sweden
| | | | - Roushdey Salh
- Department of Physics, Umeå University, Umeå, Sweden
| | | | - Jia Wang
- Department of Physics, Umeå University, Umeå, Sweden
| | - Wen Kou
- Department of Odontology, Umeå University, Umeå, Sweden
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Wang C, Mao S. Study on the effect of an ultrasound assisted reaction on the crystallization properties of recovered cryolite. RSC Adv 2023; 13:35359-35368. [PMID: 38053682 PMCID: PMC10695192 DOI: 10.1039/d3ra06661d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2023] [Accepted: 11/29/2023] [Indexed: 12/07/2023] Open
Abstract
During the treatment of spent cathode carbon from electrolytic aluminum, a large amount of fluoride containing wastewater is generated. By adding different sodium source and aluminum source reagents, under the conditions of different addition order, pH, temperature and time, the effects of conventional static reaction, stirring reaction and ultrasonic assisted reaction on the crystallization properties of recovered cryolite were investigated. The results showed that under the optimum reaction conditions (sodium source: NaCl, aluminum source: AlCl3, the molar ratio of AlCl3 to NaCl is 1 : 3, addition order: first addition of AlCl3 and then NaCl, pH is 8.57, time is 40 min, temperature at room temperature), the removal efficiency of fluoride ions was the highest when ultrasound assisted treatment was used. The cryolite products with ultrasound assisted crystallization and without ultrasound assisted crystallization were characterized using SEM and TEM. The results showed that the crystal particles obtained by ultrasound assisted crystallization were relatively concentrated, and the morphology was regular and the surface was smooth. Design Expert orthogonal software was used to design the response surface test, it was found that ultrasound time has the most significant impact on the content of recovered cryolite among single factors, and the interaction between ultrasound frequency and ultrasound power, ultrasound power and ultrasound time was highly significant among multiple factors.
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Affiliation(s)
- Chenchen Wang
- Mining College, Guizhou University Guiyang 550025 China
- National & Local Joint Laboratory of Engineering for Effective Utilization of Regional Mineral Resources from Karst Areas Guiyang 550025 China
- Guizhou Key Laboratory of Comprehensive Utilization of Nonmetallic Mineral Resources Guiyang 550025 China
| | - Song Mao
- Mining College, Guizhou University Guiyang 550025 China
- National & Local Joint Laboratory of Engineering for Effective Utilization of Regional Mineral Resources from Karst Areas Guiyang 550025 China
- Guizhou Key Laboratory of Comprehensive Utilization of Nonmetallic Mineral Resources Guiyang 550025 China
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Li X, Liu Y, Zhang TA. A comprehensive review of aluminium electrolysis and the waste generated by it. WASTE MANAGEMENT & RESEARCH : THE JOURNAL OF THE INTERNATIONAL SOLID WASTES AND PUBLIC CLEANSING ASSOCIATION, ISWA 2023; 41:1498-1511. [PMID: 37052310 DOI: 10.1177/0734242x231164321] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Aluminium is produced by electrolysis using alumina (Al2O3) as raw material and cryolite (Na3AlF6) as electrolyte. In this Hall-Héroult process, the energy consumption is relatively large, and solid wastes such as spent anodes and spent pot liner, flue gas and waste heat are generated. Therefore, this article discusses from the perspective of high energy consumption and high pollution and summarizes the methods to reduce energy consumption and solve pollution problems. The functions of carbon anode, carbon cathode, refractory material and sidewall in aluminium electrolysis cells are discussed in detail. The process of aluminium electrolysis and the ways to improve the current efficiency of aluminium electrolysis cells and reduce their energy consumption are outlined. The causes and treatment methods of spent anodes, spent cathodes, spent refractories and spent spot liner are reviewed. The research progress of waste heat recovery and aluminium electrolysis flue gas purification are analysed. And the future research directions of aluminium electrolysis flue gas are provided.
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Affiliation(s)
- Xueke Li
- Key Laboratory of Ecological Metallurgy of Multi-metal Intergrown Ores of Ministry of Education, School of Metallurgy, Northeastern University, Shenyang, Liaoning, China
| | - Yan Liu
- Key Laboratory of Ecological Metallurgy of Multi-metal Intergrown Ores of Ministry of Education, School of Metallurgy, Northeastern University, Shenyang, Liaoning, China
| | - Ting-An Zhang
- Key Laboratory of Ecological Metallurgy of Multi-metal Intergrown Ores of Ministry of Education, School of Metallurgy, Northeastern University, Shenyang, Liaoning, China
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Wang C, Mao S, Li L. Study on ultrasonic leaching and recovery of fluoride from spent cathode carbon of aluminum electrolysis. RSC Adv 2023; 13:16300-16310. [PMID: 37266505 PMCID: PMC10230273 DOI: 10.1039/d3ra02088f] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Accepted: 05/22/2023] [Indexed: 06/03/2023] Open
Abstract
Under the assistance of ultrasound, the fluoride in the spent cathode carbon of aluminum electrolysis was recovered by the process of washing first and then leaching. The effects of time, temperature, liquid-solid ratio, ultrasonic power, alkali amount and acid concentration on the leaching rate of fluoride were investigated. The useful components in the leaching solution were recovered by evaporation crystallization and cryolite regeneration. The tests of X-ray diffraction (XRD), X-ray fluorescence spectroscopy (XRF), and scanning electron microscopy combined with energy dispersive spectroscopy (SEM-EDS) showed that under the optimal experimental conditions (water washing: 50 s, 3 : 1, 420 W; alkaline leaching: alkali amount 1 g, 60 min, 70 °C, 7 : 1, 480 W; acid leaching: acid concentration 0.6 mol L-1, 60 min, 5 : 1, 70 °C, 480 W), the leaching rate of fluoride was 82.99%, and the fluoride contents recovered in the water washing and leaching processes are 94.67% and 95%, respectively. There is no solid waste and waste water in the whole experimental process.
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Affiliation(s)
- Chenchen Wang
- College of Mining, Guizhou University Guiyang 550025 China
- Guizhou Key Laboratory of Comprehensive Utilization of Non-metallic Mineral Resources Guiyang 550025 China
- National & Local Joint Laboratory of Engineering for Effective Utilization of Regional Mineral Resources from Karst Areas Guiyang 550025 China
| | - Song Mao
- College of Mining, Guizhou University Guiyang 550025 China
- Guizhou Key Laboratory of Comprehensive Utilization of Non-metallic Mineral Resources Guiyang 550025 China
- National & Local Joint Laboratory of Engineering for Effective Utilization of Regional Mineral Resources from Karst Areas Guiyang 550025 China
| | - Longjiang Li
- College of Mining, Guizhou University Guiyang 550025 China
- Guizhou Key Laboratory of Comprehensive Utilization of Non-metallic Mineral Resources Guiyang 550025 China
- National & Local Joint Laboratory of Engineering for Effective Utilization of Regional Mineral Resources from Karst Areas Guiyang 550025 China
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7
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Chen Y, Li P, Bu X, Wang L, Liang X, Chehreh Chelgani S. In-depth purification of spent pot-lining by oxidation-expansion acid leaching – A comparative study. Sep Purif Technol 2022. [DOI: 10.1016/j.seppur.2022.122313] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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9
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Zhang L, Xiao J, Yao Z, Yuan J, Ye S, Zhong Q. Complementary advantages of spent pot lining and coal gangue in the detoxification and valuable components recovery process. CHEMOSPHERE 2022; 307:136064. [PMID: 35981622 DOI: 10.1016/j.chemosphere.2022.136064] [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: 06/23/2022] [Revised: 08/04/2022] [Accepted: 08/10/2022] [Indexed: 06/15/2023]
Abstract
As a hazardous solid waste rich in carbon and fluorine, spent pot lining (SPL) is a huge threat to sustainable production and environmental security. As abundant carbon and fluorine resources, the use of such valuable components has great practical and economic significance. Based on the environmental concerns and the component characteristics of SPL, coal gangue (CG), the largest output of solid wastes in the coal-producing industry and rich in aluminum and silicon, was introduced in the utilization and detoxification process of SPL in this work. The substance flow of the co-utilization process presents a circular economy and complementary advantages of SPL and CG. Pure regular fibrous silicon carbides were obtained owing to the synergy effect of SPL and CG. Aluminum from CG and SPL was utilized to prepare dawsonite combined with the sodium from the impurities removal process. Pure cryolite was obtained via mixing wastewater from the silicon carbide purification process and the dawsonite extraction process. Almost all components in SPL and CG were converted into valuable products, and no wastewater and residue was discharged. Thus, a sustainable process of trash to treasure and circular economy for treating CG and SPL was established here with environmental and economically friendly characteristics, which gave a new insight into utilizing wastes with complementary advantages.
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Affiliation(s)
- Liuyun Zhang
- School of Metallurgy and Environment, National Engineering Laboratory of Efficient Utilization of Refractory Nonferrous Metal Resources, Central South University, Changsha, 410083, PR China
| | - Jin Xiao
- School of Metallurgy and Environment, National Engineering Laboratory of Efficient Utilization of Refractory Nonferrous Metal Resources, Central South University, Changsha, 410083, PR China.
| | - Zhen Yao
- School of Materials and Architectural Engineering, Guizhou Normal University, Guiyang, 550001, PR China
| | - Jie Yuan
- School of Chemistry and Materials Engineering, Liupanshui Normal University, Liupanshui, 553004, PR China
| | - Shengchao Ye
- School of Metallurgy and Environment, National Engineering Laboratory of Efficient Utilization of Refractory Nonferrous Metal Resources, Central South University, Changsha, 410083, PR China
| | - Qifan Zhong
- School of Metallurgy and Environment, National Engineering Laboratory of Efficient Utilization of Refractory Nonferrous Metal Resources, Central South University, Changsha, 410083, PR China.
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Xiao Y, Li L, Huang M, Liu Y, Xu J, Xu Z, Lei Y. Treating waste with waste: Metals recovery from electroplating sludge using spent cathode carbon combustion dust and copper refining slag. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 838:156453. [PMID: 35660588 DOI: 10.1016/j.scitotenv.2022.156453] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 05/21/2022] [Accepted: 05/31/2022] [Indexed: 06/15/2023]
Abstract
Electroplating sludge is a hazardous waste and secondary metal resource because of its heavy metal content, which poses a huge threat to environmental safety if not properly disposed. An innovative process of oxidizing roasting followed by water leaching and smelting reduction to recover Cr, Cu, and Ni from electroplating sludge was proposed in this research, in which other two hazardous wastes of spent cathode carbon combustion dust and copper refining slag were co-treated. The NaF from spent cathode carbon combustion dust could convert Cr2O3 to Na2CrO4 using the oxidizing roasting process, resulting in a Cr recovery through the subsequent water leaching. The Na2CrO4 formation was promoted by CaO owing to it transferring the Cr spinel phase of FeCr2O4 [1+] to CaCrO4 and then to Na2CrO4. Under optimal conditions, the Cr recovery reached 97.1 %, and most 'F' was solidified into CaF2. In the next smelting reduction of the leaching residue, the Cu and Ni were recovered mainly in the form of Cu-Ni alloy. The addition of copper refining slag promoted their recovery, due to it modifying the molten slag and alloy structures and increasing the Cu-Ni alloy separation from molten slag. Some generated high-melting-point Cu-Ni-Fe and Ni-Fe alloys were converted to a Cu-Ni alloy with a low melting point in presence of Co from the copper refining slag, simultaneously with which the Fe was transferred out from Cu-Ni-Fe and Ni-Fe alloys and combined with Co to form a Fe-Co alloy. It increased Cu-Ni alloy droplets aggregation from molten slag and decreased their contents in the residual slag. Under optimized conditions, the Cu and Ni contents in the residual slag decreased to 0.37 and 0.06 wt%, respectively. Besides, the residual slag mainly composed of CaO, CaF2 and SiO2 could be used to prepare building materials rendering it harmless.
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Affiliation(s)
- Yang Xiao
- College of Environmental Science and Engineering, Donghua University, Shanghai 201620, PR China
| | - Lei Li
- College of Environmental Science and Engineering, Donghua University, Shanghai 201620, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, PR China.
| | - Manhong Huang
- College of Environmental Science and Engineering, Donghua University, Shanghai 201620, PR China
| | - Yanbiao Liu
- College of Environmental Science and Engineering, Donghua University, Shanghai 201620, PR China
| | - Jingzhuang Xu
- College of Environmental Science and Engineering, Donghua University, Shanghai 201620, PR China
| | - Zhipeng Xu
- College of Environmental Science and Engineering, Donghua University, Shanghai 201620, PR China
| | - Yun Lei
- Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming 650093, PR China
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11
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Zhang Z, Zhu X, Hou H, Tang L, Xiao J, Zhong Q. Regeneration and utilization of graphite from the spent lithium-ion batteries by modified low-temperature sulfuric acid roasting. WASTE MANAGEMENT (NEW YORK, N.Y.) 2022; 150:30-38. [PMID: 35792439 DOI: 10.1016/j.wasman.2022.06.037] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Revised: 06/20/2022] [Accepted: 06/27/2022] [Indexed: 06/15/2023]
Abstract
Recycling spent graphite in spent lithium-ion batteries (LIBs) is crucial for lacking high-quality graphite and environmental protection. Here, an environmentally friendly and economical modified method based on sulfate roasting was proposed to recycle spent graphite via low temperature roasting at 250 °C with sodium fluoride as an assistant additive. Recycling leads to graphite with a high purity of 99.55 % and chemical structures for energy storage. Batteries manufactured in regenerated graphite deliver a high initial charge capacity of 333.9 mAh/g with an initial columbic efficiency of 85.71% and excellent capacity retention of 91.2% after 400 cycles. In addition, the waste produced in the method could be well treated, and by-products 177 g of sodium sulfate would be collected per 1 kg spent graphite and NaF, equivalent to 78.95% of the added amount obtained through wastewater and exhaust gas, respectively. The regenerated sodium fluoride will be re-applied to the recovery spent graphite. The loop-closed method shows great promise for the industrial-scale recycling of spent graphite for energy storage applications.
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Affiliation(s)
- Zhenghua Zhang
- School of Metallurgy and Environment, Central South University, Changsha 410083, China
| | - Xiangdong Zhu
- School of Metallurgy and Environment, Central South University, Changsha 410083, China
| | - Huiliang Hou
- School of Metallurgy and Environment, Central South University, Changsha 410083, China
| | - Lei Tang
- School of Metallurgy and Environment, Central South University, Changsha 410083, China
| | - Jin Xiao
- School of Metallurgy and Environment, Central South University, Changsha 410083, China; National Engineering Laboratory for Efficient Utilization of Refractory Nonferrous Metal Resources, Central South University, Changsha 410083, China
| | - Qifan Zhong
- School of Metallurgy and Environment, Central South University, Changsha 410083, China.
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Yong Y, Jianhang H, Yongkui L, Dapeng Z, Hua W. A new method for simultaneous separation and solidification of arsenic from arsenic-bearing gypsum sludge using waste carbon cathodes. Sep Purif Technol 2022. [DOI: 10.1016/j.seppur.2022.120656] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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13
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Zhang B, Qu X, Chen X, Liu D, Zhao Z, Xie H, Wang D, Yin H. A sodium salt-assisted roasting approach followed by leaching for recovering spent LiFePO 4 batteries. JOURNAL OF HAZARDOUS MATERIALS 2022; 424:127586. [PMID: 34808449 DOI: 10.1016/j.jhazmat.2021.127586] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Revised: 10/18/2021] [Accepted: 10/20/2021] [Indexed: 06/13/2023]
Abstract
Mild-temperature (<1000 °C) carbothermic reduction has been proven as an effective way to recover Li and transition metals by converting lithium transition metal oxides to transition metals/alloys and Li2CO3. However, LiFePO4 cannot be reduced by carbon because of its thermodynamically stable olivine structure. Herein, LiFePO4 is converted to Fe and lithium salts by carbon with the assistance of Na2CO3 that acts as an activating agent to break down the chemical bonds of LiFePO4 and thereby enable the carbothermic reduction. Using Na2CO3 as the activating agent, LiFePO4 was reduced to Fe, NaLi2PO4, and LiNa5(PO4)2 which can be separated by magnetic separation with a Li recovery rate of 99.2%. Using NaOH as the activating agent, LiFePO4 was oxidized to Fe3O4, NaLi2PO4 and LiNa5(PO4)2 at 600 °C, and the roasted products can be separated by magnetic separation process with a Li recovery rate of 92.7%. Various sodium salts were tested to screen proper salts for the reduction process, and a 400-g scale roasting-separation process has been demonstrated. Overall, the salt-assisted roasting is a promising way to recycle spent LiFePO4 batteries without using strong mineral acids and shows great potential for the industrial-scale implementation.
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Affiliation(s)
- Beilei Zhang
- Key Laboratory for Ecological Metallurgy of Multimetallic Mineral of Ministry of Education, School of Metallurgy, Northeastern University, Shenyang 110819, PR China
| | - Xin Qu
- Key Laboratory for Ecological Metallurgy of Multimetallic Mineral of Ministry of Education, School of Metallurgy, Northeastern University, Shenyang 110819, PR China
| | - Xiang Chen
- Key Laboratory for Ecological Metallurgy of Multimetallic Mineral of Ministry of Education, School of Metallurgy, Northeastern University, Shenyang 110819, PR China
| | - Dongxu Liu
- Key Laboratory for Ecological Metallurgy of Multimetallic Mineral of Ministry of Education, School of Metallurgy, Northeastern University, Shenyang 110819, PR China
| | - Zhuqing Zhao
- Key Laboratory for Ecological Metallurgy of Multimetallic Mineral of Ministry of Education, School of Metallurgy, Northeastern University, Shenyang 110819, PR China
| | - Hongwei Xie
- Key Laboratory for Ecological Metallurgy of Multimetallic Mineral of Ministry of Education, School of Metallurgy, Northeastern University, Shenyang 110819, PR China
| | - Dihua Wang
- School of Resource and Environmental Science, Wuhan University, Wuhan 430072, PR China
| | - Huayi Yin
- Key Laboratory for Ecological Metallurgy of Multimetallic Mineral of Ministry of Education, School of Metallurgy, Northeastern University, Shenyang 110819, PR China,; School of Resource and Environmental Science, Wuhan University, Wuhan 430072, PR China.
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14
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Huang P, Zhu R, Zhang X, Zhang W. A milliseconds flash joule heating method for the regeneration of spent cathode carbon. JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART A, TOXIC/HAZARDOUS SUBSTANCES & ENVIRONMENTAL ENGINEERING 2022; 57:33-44. [PMID: 35389829 DOI: 10.1080/10934529.2021.2022422] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Revised: 12/10/2021] [Accepted: 12/12/2021] [Indexed: 06/14/2023]
Abstract
Spent cathode carbon (SCC) blocks of aluminum electrolytic cell were hazardous waste produced in the production of electrolytic aluminum. In this present work, a facile, rapid, and economical strategy was proposed to remove fluoride and other toxic substances in the SCC block by the flash joule heating method. SCC after flash joule heating (F-SCC) were prepared in different flash voltages and number of passes; the chemical composition, microscopic morphology and carbon configuration of the SCC and F-SCC were described in detail. The results show that the purification efficiency depends upon the flash voltages and pass number. In terms of flash voltage, 150 V (5.62 kJ/g) is the optimal voltage to maintain the micro-expansion characteristics of the cathode carbon. Multiple flash joule heating can not only maintain its high-graphitization carbon, but also improve its micro-expansion characteristics. In addition, the electrochemical performance of F-SCC was characterized, and F-SCC displayed excellence capacitance performance. The low-cost, rapid -regeneration method based on the flash joule heating provides an effective method for the clean recycling and high-value utilization of carbonized solid waste.
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Affiliation(s)
- Pengfei Huang
- Key Laboratory of Coal Processing and Efficient Utilization of Ministry of Education, China University of Mining and Technology, Xuzhou, Jiangsu, China
| | - Rongtao Zhu
- Key Laboratory of Coal Processing and Efficient Utilization of Ministry of Education, China University of Mining and Technology, Xuzhou, Jiangsu, China
- School of Chemical Engineering and Technology, China University of Mining and Technology, Xuzhou, Jiangsu, China
| | - Xinxi Zhang
- Key Laboratory of Coal Processing and Efficient Utilization of Ministry of Education, China University of Mining and Technology, Xuzhou, Jiangsu, China
- School of Chemical Engineering and Technology, China University of Mining and Technology, Xuzhou, Jiangsu, China
| | - Wenjun Zhang
- School of Chemical Engineering and Technology, China University of Mining and Technology, Xuzhou, Jiangsu, China
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15
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Yong Y, Hua W, Jianhang H. Co-treatment of electroplating sludge, copper slag, and spent cathode carbon for recovering and solidifying heavy metals. JOURNAL OF HAZARDOUS MATERIALS 2021; 417:126020. [PMID: 33992022 DOI: 10.1016/j.jhazmat.2021.126020] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2021] [Revised: 04/24/2021] [Accepted: 04/25/2021] [Indexed: 06/12/2023]
Abstract
Electroplating sludge, a hazardous solid waste product of the electroplating industry, presents a serious environmental pollution risk. In this study, an environmentally friendly process for solidifying and recovering heavy metals from electroplating sludge using copper slag and spent cathode carbon is proposed. Combining the results of toxicity characteristic leaching procedure tests, thermodynamic analysis, chemical analysis, X-ray diffraction analysis, and electron probe microanalysis, the Cr, Ni, Cu, Fe, and F transformation mechanisms were first probed during vitrification. Under optimal experimental conditions, the Cr, Ni, and Cu recovery ratios reached 75.56 wt%, 98.41 wt%, and 99.25 wt%, and they increased by 40%, 5%, and 5%, respectively compared with the currently utilized technique. Moreover, the toxicity leaching results of the slag indicate that the Cr, F, and Cu are stable, while Ni is easily leached from the (Fe,Ni)(Fe,Cr)2O4 and alloy phases. Under the optimal metal recovery conditions, the leaching concentrations of Cr, Cu, F, and Ni were 0.57 mg/L, 4.45 mg/L, 1.52 mg/L, and 1.85 mg/L, respectively, which can be reused in other materials, minimizing the environmental risk. The electroplating sludge, copper slag, and spent cathode carbon co-treatment process achieves waste disposal with waste and significantly reduces electroplating sludge processing costs.
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Affiliation(s)
- Yu Yong
- Engineering Research Center of Metallurgical Energy Conservation and Emission Reduction, Ministry of Education, Kunming University of Science and Technology, Kunming, China; National Local Joint Engineering Research Center of Energy Saving and Environmental Protection Technology in Metallurgy and Chemical Engineering Industry, Kunming University of Science and Technology, Kunming, China; State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization, Kunming University of Science and Technology, Kunming, China; Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming, China
| | - Wang Hua
- Engineering Research Center of Metallurgical Energy Conservation and Emission Reduction, Ministry of Education, Kunming University of Science and Technology, Kunming, China; National Local Joint Engineering Research Center of Energy Saving and Environmental Protection Technology in Metallurgy and Chemical Engineering Industry, Kunming University of Science and Technology, Kunming, China; State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization, Kunming University of Science and Technology, Kunming, China; Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming, China.
| | - Hu Jianhang
- Engineering Research Center of Metallurgical Energy Conservation and Emission Reduction, Ministry of Education, Kunming University of Science and Technology, Kunming, China; National Local Joint Engineering Research Center of Energy Saving and Environmental Protection Technology in Metallurgy and Chemical Engineering Industry, Kunming University of Science and Technology, Kunming, China; State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization, Kunming University of Science and Technology, Kunming, China; Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming, China
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