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Wang F, Xu B, Yang B, Shi T. The lead removal evolution from hazardous waste cathode ray tube funnel glass under enhancement of red mud melting and synthesizing value-added glass-ceramics via reutilization of silicate resources. JOURNAL OF HAZARDOUS MATERIALS 2022; 429:128334. [PMID: 35091191 DOI: 10.1016/j.jhazmat.2022.128334] [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: 11/28/2021] [Revised: 01/19/2022] [Accepted: 01/20/2022] [Indexed: 06/14/2023]
Abstract
Waste CRT funnel glass (FG) is a typical hazardous waste produced by the electronics industry that contains toxic lead oxide, red mud (RM) is the first waste produced during alumina production. Both of these are extremely difficult to reuse. Here, we report a method to control FG waste, in which RM was used to enhance the removal of Pb from FG via a vacuum thermal process. The removed residual glass was utilized to create glass-ceramics. The results showed that RM can enhance the lead removal from waste CRT funnel glass by the vacuum thermal process. When 30% RM was added, the removal rate reached 98.54%. A significant mechanism of enhancing delead is investigated by a Fourier transform infrared (FTIR) spectrometer and X-ray photoelectron spectroscopy (XPS). The results showed that the -Pb-O-Si-O- network structure was broken by the free calcium ions of RM. Afterward, valuable glass-ceramics with tetragonal-KAlSi2O6 and triclinic-CaSiO3 crystals were synthesized using the residual glass. The Pb, Ba, Cr, and Cu leaching concentrations of the glass-ceramics were well below the regulatory limit (5 mg/L) of the CA-EPA, as measured by the toxicity characteristic leaching procedure (TCLP) test. Overall, the results indicated that RM enhanced the removal of lead during the vacuum thermal process. The synthesis of value-added glass-ceramics reutilized silicate resources from waste cathode ray tube (CRT) funnel glass and RM.
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Affiliation(s)
- Fengkang Wang
- State Key Laboratory of Complex Nonferrous Metal Resources Clear Utilization, Kunming 650093, PR China; National Engineering Laboratory for Vacuum Metallurgy, Kunming 650093, PR China; Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming 650093, PR China; School of Metallurgy and Environment, Central South University, Changsha, PR China
| | - Baoqiang Xu
- State Key Laboratory of Complex Nonferrous Metal Resources Clear Utilization, Kunming 650093, PR China; National Engineering Laboratory for Vacuum Metallurgy, Kunming 650093, PR China; Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming 650093, PR China.
| | - Bin Yang
- State Key Laboratory of Complex Nonferrous Metal Resources Clear Utilization, Kunming 650093, PR China; National Engineering Laboratory for Vacuum Metallurgy, Kunming 650093, PR China; Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming 650093, PR China
| | - Tengteng Shi
- State Key Laboratory of Complex Nonferrous Metal Resources Clear Utilization, Kunming 650093, PR China; National Engineering Laboratory for Vacuum Metallurgy, Kunming 650093, PR China; Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming 650093, PR China
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Lu X, Ning XA, Chen D, Chuang KH, Shih K, Wang F. Lead extraction from Cathode Ray Tube (CRT) funnel glass: Reaction mechanisms in thermal reduction with addition of carbon (C). WASTE MANAGEMENT (NEW YORK, N.Y.) 2018; 76:671-678. [PMID: 29650298 DOI: 10.1016/j.wasman.2018.04.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Revised: 03/27/2018] [Accepted: 04/06/2018] [Indexed: 06/08/2023]
Abstract
This study quantitatively determined the extraction of lead from CRT funnel glass and examined the mechanisms of thermally reducing lead in the products of sintering Pb-glass with carbon in the pre-heated furnace. The experimentally derived results indicate that a 90.3 wt% lead extraction efficiency can be achieved with 20 wt% of C addition at 950 °C for 3 min under air. The formation of viscous semi-liquid glass blocked the oxygen supply between the interaction of C and Pb-glass, and was highly effective for the extraction of metallic Pb. A maximum of 87.3% lead recover was obtained with a C to Na2CO3 ratio of 1/3 at 1200 °C. The decrease of C/Na2CO3 ratio enhanced the metallic lead recovery by increasing the glass viscosity for effective sedimentation of metallic lead in the bottom. However, with the further increase of temperature and treatment time, re-vitrification of lead back to silicate-glass matrix was detected in both Pb-glass/C and Pb-glass/C/Na2CO3 systems. The findings indicated that with proper controls, using C as an inexpensive reagent can effectively reduce treatment time and energy, which is crucial to a waste-to-resource technology for economically recovering lead from the waste CRT glass.
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Affiliation(s)
- Xingwen Lu
- School of Environmental Science and Engineering and Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China; Department of Civil Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong Special Administrative Region
| | - Xun-An Ning
- School of Environmental Science and Engineering and Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China
| | - Da Chen
- School of Environment, Guangzhou Key Laboratory of Environmental Exposure and Health, and Guangdong Key Laboratory of Environmental Pollution and Health, Jinan University, Guangzhou 510632, China
| | - Kui-Hao Chuang
- Department of Safety Health and Environmental Engineering, Central Taiwan University of Science and Technology, Taichung 406, Taiwan, ROC
| | - Kaimin Shih
- Department of Civil Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong Special Administrative Region
| | - Fei Wang
- Department of Civil Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong Special Administrative Region; School of Environment, Guangzhou Key Laboratory of Environmental Exposure and Health, and Guangdong Key Laboratory of Environmental Pollution and Health, Jinan University, Guangzhou 510632, China.
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Wang C, Yao D, Liu Y, Wu Y, Shen J. Development of a novel recycling system for waste cathode ray tube funnel glass based on the integration of nanoscale Fe 0 with ball milling. WASTE MANAGEMENT (NEW YORK, N.Y.) 2018; 76:679-686. [PMID: 29643009 DOI: 10.1016/j.wasman.2018.04.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Revised: 04/02/2018] [Accepted: 04/04/2018] [Indexed: 06/08/2023]
Abstract
A novel and effective system was developed for recycling cathode ray tube (CRT) funnel glass wastes. Initially, the combination of nanoscale Fe0 with ball milling promoted lead transfer that was strongly encapsulated in the glass inner structure to the surface of funnel glass and/or adhere to iron substance due to the collapse of SiO bonds. This condition enhanced the dissolution of lead in the acid solution. A high lead extraction rate of 97.8% from funnel glass was achieved through nitric acid leaching by optimizing the operational parameters (Fe0/funnel glass mass ratio, 0.5:1; ball milling time; 72 h). Subsequently, lead sulfate, iron hydroxides, and sodium nitrate were gradually recovered from the acid leachate by using three simple operations, namely, sulfation, alkali neutralization, and salt evaporation. Meanwhile, the leaching results of short-term toxicity characteristic leaching (TCLP) and long-term multiple extraction procedures (MEP) clearly demonstrated that the residual high silica products (after acid leaching) had no impact on the environment and could be used to synthesize high value-added zeolites as raw materials. With the addition of Al sources, the complete conversion of high silica residues into high crystalline zeolites with high cation exchange capacity value was realized by applying an alkaline fusion method during the hydrothermal treatment. Furthermore, lead, NO-3, and SO2-4 concentrations of the resulting drainage were considerably lower than the relevant standard for surface water quality. Therefore, the proposed recycling system provided an eco-friendly and feasible technique for complete reutilization of obsolete CRT funnel glass.
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Affiliation(s)
- Chunfeng Wang
- Henan Key Laboratory for Environmental Pollution Control and Key Laboratory for Yellow River and Huai River Water Environment and Pollution Control, Ministry of Education, School of Environment, Henan Normal University, 46 East Jianshe Road, Xinxiang, Henan Province 453007, China; Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, China.
| | - Dan Yao
- Henan Key Laboratory for Environmental Pollution Control and Key Laboratory for Yellow River and Huai River Water Environment and Pollution Control, Ministry of Education, School of Environment, Henan Normal University, 46 East Jianshe Road, Xinxiang, Henan Province 453007, China
| | - Yang Liu
- Henan Key Laboratory for Environmental Pollution Control and Key Laboratory for Yellow River and Huai River Water Environment and Pollution Control, Ministry of Education, School of Environment, Henan Normal University, 46 East Jianshe Road, Xinxiang, Henan Province 453007, China
| | - Yufan Wu
- Henan Key Laboratory for Environmental Pollution Control and Key Laboratory for Yellow River and Huai River Water Environment and Pollution Control, Ministry of Education, School of Environment, Henan Normal University, 46 East Jianshe Road, Xinxiang, Henan Province 453007, China
| | - Jinyou Shen
- Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, China.
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Lv J, Yang H, Jin Z, Zhao M. Lead extraction and glass-ceramics synthesis from waste cathode ray tube funnel glass through cooperative smelting process with coal fly ash. WASTE MANAGEMENT (NEW YORK, N.Y.) 2018; 76:687-696. [PMID: 29550068 DOI: 10.1016/j.wasman.2018.03.019] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Revised: 02/09/2018] [Accepted: 03/09/2018] [Indexed: 06/08/2023]
Abstract
In this study, a novel process was developed for extracting lead from the hazardous waste cathode ray tube (CRT) funnel glass and simultaneously producing glass-ceramics. CRT funnel glass was mixed with coal fly ash and subjected to carbon thermal reduction with the addition of CaO. The homogeneous glass melt and reduced metallic lead were quenched in water. Glass-ceramics were produced from the parent glass through an appropriate heat treatment. The optimum carbon loading amount (calculated as the molar ratio of C/PbO), CaO/SiO2 ratio, smelting temperature and holding time for lead recovery were 1.0, 0.3-0.6, 1450 °C and 2 h, respectively. Under these conditions, more than 95% of lead can be extracted from the funnel glass and a low lead content of the resultant parent glass below 0.6 wt% was successfully achieved. CaO behaved as a network modifier to reduce the viscosity of the glass and also acted as a substitution to release lead oxide from the silicate network structure, resulting in a high lead separation efficiency. X-ray diffraction (XRD) analysis revealed that the main crystalline phase was gehlenite when 50-70 wt% funnel glass was added. Scanning electron microscopy (SEM) observation showed that well-crystallized crystals occurred in the specimens with 50-70 wt% funnel glass additions, whereas the specimens with 40 wt% and 80 wt% glass additions exhibited a relative low crystallization degree. Furthermore, property measurements, chemical resistance tests and leaching characteristics of heavy metals confirmed the possibility of engineering and construction applications of the superior glass-ceramic products. Overall results indicate that the process proposed in this paper is an effective and promising approach for reutilization of obsolete CRT funnel glass.
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Affiliation(s)
- Jianfang Lv
- School of Metallurgy, Northeastern University, Shenyang 110819, Liaoning, China
| | - Hongying Yang
- School of Metallurgy, Northeastern University, Shenyang 110819, Liaoning, China
| | - Zhenan Jin
- School of Metallurgy, Northeastern University, Shenyang 110819, Liaoning, China.
| | - Minglei Zhao
- School of Metallurgy, Northeastern University, Shenyang 110819, Liaoning, China
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Hu B, Hui W. Extraction of lead from waste CRT funnel glass by generating lead sulfide - An approach for electronic waste management. WASTE MANAGEMENT (NEW YORK, N.Y.) 2017; 67:253-258. [PMID: 28587804 DOI: 10.1016/j.wasman.2017.05.048] [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: 02/25/2017] [Revised: 05/22/2017] [Accepted: 05/29/2017] [Indexed: 06/07/2023]
Abstract
Waste cathode ray tube (CRT) funnel glass is the key and difficult points in waste electrical and electronic equipment (WEEE) disposal. In this paper, a novel and effective process for the detoxification and reutilization of waste CRT funnel glass was developed by generating lead sulfide precipitate via a high-temperature melting process. The central function in this process was the generation of lead sulfide, which gathered at the bottom of the crucible and was then separated from the slag. Sodium carbonate was used as a flux and reaction agent, and sodium sulfide was used as a precipitating agent. The experimental results revealed that the lead sulfide recovery rate initially increased with an increase in the amount of added sodium carbonate, the amount of sodium sulfide, the temperature, and the holding time and then reached an equilibrium value. The maximum lead sulfide recovery rate was approximately 93%, at the optimum sodium carbonate level, sodium sulfide level, temperature, and holding time of 25%, 8%, 1200°C, and 2h, respectively. The glass slag can be made into sodium and potassium silicate by hydrolysis in an environmental and economical process.
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Affiliation(s)
- Biao Hu
- School of Management, Tianjin University of Technology, Tianjin, China; School of Environmental Science and Safety Engineering, Tianjin University of Technology, Tianjin, China
| | - Wenlong Hui
- School of Environmental Science and Safety Engineering, Tianjin University of Technology, Tianjin, China.
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Bursi E, Barbieri L, Lancellotti I, Saccani A, Bignozzi M. Lead waste glasses management: Chemical pretreatment for use in cementitious composites. WASTE MANAGEMENT & RESEARCH : THE JOURNAL OF THE INTERNATIONAL SOLID WASTES AND PUBLIC CLEANSING ASSOCIATION, ISWA 2017; 35:958-966. [PMID: 28681661 DOI: 10.1177/0734242x17715098] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
This article investigates the effect of a low-impact chemical treatment based on a nitrilotriacetic acid chelating agent on the reactivity of funnel glass derived from discarded cathode ray tubes. Treated and untreated glass has been recycled either as a supplementary cementing material or as a fine aggregate in cementitious mortars. The effect of the treatment on the chemical and morphological properties of cullets, as well as on the solubility in an alkaline environment has been evaluated. Data so far collected underline a change in glass cullets characteristics that consequently affects their behaviour in cementitious mortars, reducing the pozzolanic activity as supplementary cementing material, but strongly decreasing the tendency towards alkali silica reactions when added as a fine aggregate. The leaching behaviour of lead on treated and untreated glass and on derived composites has been determined to verify the sustainability of the prepared materials.
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Affiliation(s)
- Elena Bursi
- 1 Dipartimento di Ingegneria "Enzo Ferrari" Università di Modena e Reggio Emilia, Modena, Italy
| | - Luisa Barbieri
- 1 Dipartimento di Ingegneria "Enzo Ferrari" Università di Modena e Reggio Emilia, Modena, Italy
| | - Isabella Lancellotti
- 1 Dipartimento di Ingegneria "Enzo Ferrari" Università di Modena e Reggio Emilia, Modena, Italy
| | - Andrea Saccani
- 2 Dipartimento di Ingegneria Civile, Chimica, Ambientale e dei Materiali Università di Bologna, Bologna, Italy
| | - Maria Bignozzi
- 2 Dipartimento di Ingegneria Civile, Chimica, Ambientale e dei Materiali Università di Bologna, Bologna, Italy
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Xu Z, Okada T, Nishimura F, Yonezawa S. Recovery of palladium, cesium, and selenium from heavy metal alkali borosilicate glass by combination of heat treatment and leaching processes. JOURNAL OF HAZARDOUS MATERIALS 2017; 331:171-181. [PMID: 28273566 DOI: 10.1016/j.jhazmat.2017.02.032] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Revised: 01/23/2017] [Accepted: 02/19/2017] [Indexed: 06/06/2023]
Abstract
Reductive heat-treatment and leaching process were applied to a simulated lead or bismuth soda-potash-borosilicate glass with palladium, cesium, and selenium to separate these elements. In the reductive heat treatment, palladium is extracted in liquid heavy metal phase generated by the reduction of the heavy metal oxides, whereas cesium and selenium are concentrated in phase separated Na-K-rich materials on the glass surface. From the materials, cesium and selenium can be extracted in water, and the selenium extraction was higher in the treatment of the bismuth containing glass. The chemical forms of palladium in the glass affected the extraction efficiencies of cesium and selenium. Among the examined conditions, in the bismuth glass treatment, the cesium and selenium extraction efficiencies in water were over 80%, and that of palladium in liquid bismuth was over 80%.
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Affiliation(s)
- Zhanglian Xu
- Headquarters for Innovative Society-Academic Cooperation, University of Fukui, Bunkyo 3-9-1, Fukui 910-8507, Japan
| | - Takashi Okada
- Headquarters for Innovative Society-Academic Cooperation, University of Fukui, Bunkyo 3-9-1, Fukui 910-8507, Japan.
| | - Fumihiro Nishimura
- Headquarters for Innovative Society-Academic Cooperation, University of Fukui, Bunkyo 3-9-1, Fukui 910-8507, Japan
| | - Susumu Yonezawa
- Headquarters for Innovative Society-Academic Cooperation, University of Fukui, Bunkyo 3-9-1, Fukui 910-8507, Japan
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Yao Z, Wu D, Liu J, Wu W, Zhao H, Tang J. Recycling of typical difficult-to-treat e-waste: Synthesize zeolites from waste cathode-ray-tube funnel glass. JOURNAL OF HAZARDOUS MATERIALS 2017; 324:673-680. [PMID: 27876241 DOI: 10.1016/j.jhazmat.2016.11.041] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Revised: 11/13/2016] [Accepted: 11/14/2016] [Indexed: 06/06/2023]
Abstract
The disposal of waste cathode ray-tubes (CRTs) from old televisions and discarded computer monitors has become a major environmental concern worldwide. In this work, an open-loop recycling method was developed to synthesize zeolites using CRT funnel glass as the raw material. The effects of hydrothermal temperatures and pressure, n(SiO2/Al2O3) molar ratios and hydrothermal time on the resulting products were investigated. The results indicated that hydrothermal temperatures and pressure played critical roles in zeolite synthesis. Amorphous phases were detected at lower temperatures (80-100°C) and pressure (0.47-1.01bar) with n(SiO2/Al2O3)=2.0. At the temperature of 110°C (pressure 1.43bar), NaA formed with a mixture of NaP1 and Faujasite. With further increase in the temperature and pressure, the unstable NaA and Faujasite disappeared, and Hydroxysodalite developed. The influence of n(SiO2/Al2O3) ratios on resulting products revealed a single phase of NaA was formed at the ratio of 1.5 and a mixture of NaA and Faujasite at the ratio of 2.0. Prolonging hydrothermal time, however, could promote zeolite crystallization, and NaA gradually developed with an increase in the time from 2 to 6h at n(SiO2/Al2O3)=1.5. By comparison, crystallization phases were observed only when the time was longer than 8h at n(SiO2/Al2O3)=2.0.
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Affiliation(s)
- Zhitong Yao
- College of Materials Science and Environmental Engineering, Hangzhou Dianzi University, Hangzhou 310018, China
| | - Daidai Wu
- Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640, China.
| | - Jie Liu
- College of Materials Science and Environmental Engineering, Hangzhou Dianzi University, Hangzhou 310018, China
| | - Weihong Wu
- College of Materials Science and Environmental Engineering, Hangzhou Dianzi University, Hangzhou 310018, China
| | - Hongting Zhao
- College of Materials Science and Environmental Engineering, Hangzhou Dianzi University, Hangzhou 310018, China
| | - Junhong Tang
- College of Materials Science and Environmental Engineering, Hangzhou Dianzi University, Hangzhou 310018, China.
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Li Z, Chen M, Zhang Q, Liu X, Saito F. Mechanochemical processing of molybdenum and vanadium sulfides for metal recovery from spent catalysts wastes. WASTE MANAGEMENT (NEW YORK, N.Y.) 2017; 60:734-738. [PMID: 27422050 DOI: 10.1016/j.wasman.2016.06.035] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Revised: 06/27/2016] [Accepted: 06/27/2016] [Indexed: 06/06/2023]
Abstract
This work describes the mechanochemical transformations of molybdenum and vanadium sulfides into corresponding molybdate and vanadate, to serve as a new environment-friendly approach for processing hazardous spent hydrodesulphurization (HDS) catalysts solid waste to achieve an easy recovery of not only molybdenum and vanadium but also nickel and cobalt. Co-grinding the molybdenum and vanadium sulfides with oxidants and sodium carbonate stimulates solid-state reactions without any heating aid to form metal molybdates and vanadates. The reactions proceed with an increase in grinding time and were enhanced by using more sodium carbonate and stronger oxidant. The necessary conditions for the successful transformation can be explained on the basis of thermodynamic analyses, namely a negative change in Gibbs free energy.
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Affiliation(s)
- Zhao Li
- School of Resources and Environmental Engineering, Wuhan University of Technology, Wuhan 430070, China
| | - Min Chen
- School of Resources and Environmental Engineering, Wuhan University of Technology, Wuhan 430070, China
| | - Qiwu Zhang
- School of Resources and Environmental Engineering, Wuhan University of Technology, Wuhan 430070, China.
| | - Xinzhong Liu
- College of Ecological Environment and Urban Construction, Fujian University of Technology, Fuzhou 350118, China
| | - Fumio Saito
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577, Japan
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Xing M, Fu Z, Wang Y, Wang J, Zhang Z. Lead recovery and high silica glass powder synthesis from waste CRT funnel glasses through carbon thermal reduction enhanced glass phase separation process. JOURNAL OF HAZARDOUS MATERIALS 2017; 322:479-487. [PMID: 27745960 DOI: 10.1016/j.jhazmat.2016.10.012] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Revised: 10/04/2016] [Accepted: 10/05/2016] [Indexed: 06/06/2023]
Abstract
In this study, a novel process for the removal of toxic lead from the CRT funnel glass and synchronous preparation of high silica glass powder was developed by a carbon-thermal reduction enhanced glass phase separation process. CRT funnel glass was remelted with B2O3 in reducing atmosphere. In the thermal process, a part of PbO contained in the funnel glass was reduced into metallic Pb and detached from the glass phase. The rest of PbO and other metal oxides (including Na2O, K2O, Al2O3, BaO and CaO) were mainly concentrated in the boric oxide phase. The metallic Pb phase and boric oxide phase were completely leached out by 5mol/L HNO3. The lead removal rate was 99.80% and high silica glass powder (SiO2 purity >95wt%) was obtained by setting the temperature, B2O3 added amount and holding time at 1000°C, 20% and 30mins, respectively. The prepared high silicate glass powders can be used as catalyst carrier, semipermeable membranes, adsorbents or be remelted into high silicate glass as an ideal substitute for quartz glass. Thus this study proposed an eco-friendly and economical process for recycling Pb-rich electronic glass waste.
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Affiliation(s)
- Mingfei Xing
- Henan Key Laboratory Cultivation Base of Mine Environmental Protection and Ecological Remediation, Henan Polytechnic University, Jiaozuo 454000 Henan China; Institute of Resource and Environment, Henan Polytechnic University, Jiaozuo 454000 Henan China
| | - Zegang Fu
- Institute of Resource and Environment, Henan Polytechnic University, Jiaozuo 454000 Henan China
| | - Yaping Wang
- School of Surveying and Land Information Engineering, Henan Polytechnic University, Jiaozuo 454000, Henan China.
| | - Jingyu Wang
- Institute of Resource and Environment, Henan Polytechnic University, Jiaozuo 454000 Henan China
| | - Zhiyuan Zhang
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
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Xu Z, Okada T, Nishimura F, Yonezawa S. Phase separation of cesium from lead borosilicate glass by heat treatment under a reducing atmosphere. JOURNAL OF HAZARDOUS MATERIALS 2016; 317:622-631. [PMID: 27368086 DOI: 10.1016/j.jhazmat.2016.06.031] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Revised: 06/14/2016] [Accepted: 06/15/2016] [Indexed: 06/06/2023]
Abstract
A phase-separation technique for removing sodium from glass using a heat-treatment method under a reducing atmosphere was previously developed for sodium recovery from waste glass. In this study, this technique was applied to cesium-containing lead borosilicate glass to concentrate the cesium in phase-separated sodium-rich materials for efficient cesium extraction. The theoretical phase-separation temperature of the sodium-rich phase was simulated by thermodynamic equilibrium calculations and was predicted to occur below 700°C for lead borosilicate glass. Experimentally, a simulated lead borosilicate glass was melted at 1000°C and subsequently annealed below 700°C under a CO-containing reducing atmosphere. The phase separation of cesium was found to occur with sodium enrichment on the glass surface that was in contact with the gas phase, promoting cesium extraction from the treated glass using water. The cesium extraction efficiency was affected by the surface area of the treated glass that was in contact with water, and under the examined conditions, the cesium extraction efficiency was up to 66%. Phase separation using reductive heat treatment, combined with a water leaching technique, is suggested to be effective for extracting cesium incorporated in borosilicate glass waste.
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Affiliation(s)
- Zhanglian Xu
- Headquarters for Innovative Society-Academic Cooperation, University of Fukui, Bunkyo 3-9-1, Fukui 910-8507, Japan
| | - Takashi Okada
- Headquarters for Innovative Society-Academic Cooperation, University of Fukui, Bunkyo 3-9-1, Fukui 910-8507, Japan.
| | - Fumihiro Nishimura
- Headquarters for Innovative Society-Academic Cooperation, University of Fukui, Bunkyo 3-9-1, Fukui 910-8507, Japan
| | - Susumu Yonezawa
- Headquarters for Innovative Society-Academic Cooperation, University of Fukui, Bunkyo 3-9-1, Fukui 910-8507, Japan
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Li J, Dong Q, Liu L, Song Q. Measuring treatment costs of typical waste electrical and electronic equipment: A pre-research for Chinese policy making. WASTE MANAGEMENT (NEW YORK, N.Y.) 2016; 57:36-45. [PMID: 26970844 DOI: 10.1016/j.wasman.2016.02.025] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Revised: 02/06/2016] [Accepted: 02/21/2016] [Indexed: 06/05/2023]
Abstract
Waste Electrical and Electronic Equipment (WEEE) volume is increasing, worldwide. In 2011, the Chinese government issued new regulations on WEEE recycling and disposal, establishing a WEEE treatment subsidy funded by a levy on producers of electrical and electronic equipment. In order to evaluate WEEE recycling treatment costs and revenue possibilities under the new regulations, and to propose suggestions for cost-effective WEEE management, a comprehensive revenue-expenditure model (REM), were established for this study, including 7 types of costs, 4 types of fees, and one type of revenue. Since TV sets dominated the volume of WEEE treated from 2013 to 2014, with a contribution rate of 87.3%, TV sets were taken as a representative case. Results showed that the treatment cost varied from 46.4RMB/unit to 82.5RMB/unit, with a treatment quantity of 130,000 units to 1,200,000 units per year in China. Collection cost accounted for the largest portion (about 70.0%), while taxes and fees (about 11.0 %) and labor cost (about 7.0 %) contributed less. The average costs for disposal, sales, and taxes had no influence on treatment quantity (TQ). TQ might have an adverse effect on average labor and management costs; while average collection and purchase fees, and financing costs, would vary with purchase price, and the average sales fees and taxes would vary with the sales of dismantled materials and other recycled products. Recycling enterprises could reduce their costs by setting up online and offline collection platforms, cooperating with individual collectors, creating door-to-door collection channels, improving production efficiency and reducing administrative expenditures. The government could provide economic incentives-such as subsidies, low-cost loans, tax cuts and credits-and could also raise public awareness of waste management and environmental protection, in order to capture some of the WEEE currently discarded into the general waste stream. Foreign companies with advanced WEEE utilization technology could invest or participate in this area, producing profits for themselves while helping to develop and implement environmentally friendly and energy-saving technologies applicable to the Chinese market.
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Affiliation(s)
- Jinhui Li
- School of Environment, Tsinghua University, Beijing 100084, China; State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China.
| | - Qingyin Dong
- Basel Convention Regional Centre for Asia and the Pacific, Beijing 100084, China; State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Lili Liu
- Basel Convention Regional Centre for Asia and the Pacific, Beijing 100084, China; State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Qingbin Song
- School of Environment, Tsinghua University, Beijing 100084, China; State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
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Okada T. Water-soluble lead in cathode ray tube funnel glass melted in a reductive atmosphere. JOURNAL OF HAZARDOUS MATERIALS 2016; 316:43-51. [PMID: 27209518 DOI: 10.1016/j.jhazmat.2016.05.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Revised: 04/28/2016] [Accepted: 05/04/2016] [Indexed: 06/05/2023]
Abstract
In the reduction-melting process, lead can be recovered from cathode ray tube funnel glass (PbO=25wt%); however, resulting glass residues still contain approximately 1-2wt% of unrecovered lead. For environmental protection in the residue disposal or recycling, it is important to evaluate the quantities of water-soluble species among the unrecovered lead. This study examined water-soluble lead species generated in the reduction-melting process of the funnel glass and factors determining their generation. In the reduction-melting, metallic lead was generated by reducing lead oxides in the glass, and a part of the metallic lead remained in the glass residue. Such unrecovered metallic lead can dissolve in water depending on its pH level and was regarded as water-soluble lead. When 10g Na2CO3 was added to 20g funnel glass during reduction-melting, the resulting glass contained high concentrations of sodium. In a water leaching of the glass, the obtained leachate was alkalized by the sodium-rich glass (pH=12.7-13.0). The unrecovered metallic lead in the glass was extracted in the alkalized leachate. The quantity of the unrecovered metallic lead (water-soluble lead) in the glass decreased when the melting time, melting temperature, and carbon dosage were controlled during reduction-melting.
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Affiliation(s)
- Takashi Okada
- Laboratory of Mineral Processing and Resources Recycling, Graduate School of Engineering, Hokkaido University, Kita 13, Nishi 8, Kita-ku, Sapporo, 060-8628 Japan.
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15
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Mingfei X, Yaping W, Jun L, Hua X. Lead recovery and glass microspheres synthesis from waste CRT funnel glasses through carbon thermal reduction enhanced acid leaching process. JOURNAL OF HAZARDOUS MATERIALS 2016; 305:51-58. [PMID: 26642446 DOI: 10.1016/j.jhazmat.2015.11.032] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Revised: 11/14/2015] [Accepted: 11/17/2015] [Indexed: 06/05/2023]
Abstract
In this study, a novel process for detoxification and reutilization of waste cathode ray tube (CRT) funnel glass was developed by carbon thermal reduction enhanced acid leaching process. The key to this process is removal of lead from the CRT funnel glass and synchronous preparation of glass microspheres. Carbon powder was used as an isolation agent and a reducing agent. Under the isolation of the carbon powder, the funnel glass powder was sintered into glass microspheres. In thermal reduction, PbO in the funnel glass was first reduced to elemental Pb by carbon monoxide and then located on the surface of glass microspheres which can be removed easily by acid leaching. Experimental results showed that temperature, carbon adding amount and holding time were the major parameters that controlled lead removal rate. The maximum lead removal rate was 94.80% and glass microspheres that measured 0.73-14.74μm were obtained successfully by setting the temperature, carbon adding amount and holding time at 1200°C, 10% and 30min, respectively. The prepared glass microspheres may be used as fillers in polymer materials and abrasive materials, among others. Accordingly, this study proposed a practical and economical process for detoxification and recycling of waste lead-containing glass.
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Affiliation(s)
- Xing Mingfei
- Henan Key Laboratory Cultivation Base of Mine Environmental Protection and Ecological Remediation, Henan Polytechnic University, Jiaozuo 454000, Henan, China; Institute of Resource and Environment, Henan Polytechnic University, Jiaozuo 454000, Henan, China.
| | - Wang Yaping
- School of Surveying and Land Information Engineering, Henan Polytechnic University, Jiaozuo 454000, Henan, China
| | - Li Jun
- Institute of Resource and Environment, Henan Polytechnic University, Jiaozuo 454000, Henan, China
| | - Xu Hua
- Mengzhou talents exchange center, Jiaozuo 454000, Henan, China
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