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Separation of plastic wastes using froth flotation - An overview. Adv Colloid Interface Sci 2022; 308:102769. [PMID: 36116142 DOI: 10.1016/j.cis.2022.102769] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Revised: 08/29/2022] [Accepted: 08/30/2022] [Indexed: 11/22/2022]
Abstract
Despite various initiatives and efforts, plastic solid waste (PSW) has become a major global problem due to decades of relentless use of plastics. Since non-biodegradable plastics can persist in the environment for hundreds of years, threatening animal and human life, discarding them into the environment is not a viable option. Plastic recycling is a critical research area that requires urgent attention since less than 10% of the seven billion tons of globally generated plastic waste has been recycled so far. With recent technological developments, it is now possible to recycle many types of PSW using a variety of methods. This review provides an overview of the froth flotation technology that is currently being researched for PSW recycling. Fundamental working principles, the current state of the development, and limitations of this technique are reviewed. It is suggested that froth flotation with continuous development has tremendous potential to result in a more efficient and environmentally friendly approach to PSW recycling.
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Meneses Quelal WO, Velázquez-Martí B, Ferrer Gisbert A. Separation of virgin plastic polymers and post-consumer mixed plastic waste by sinking-flotation technique. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:1364-1374. [PMID: 34350580 PMCID: PMC8724085 DOI: 10.1007/s11356-021-15611-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Accepted: 07/20/2021] [Indexed: 06/13/2023]
Abstract
The main objective of this research is to separate virgin polymers (PA, PC, PP, HDPE; PS, and ABS) and post-consumer plastic waste from municipal solid waste (MSW) using the sinking-flotation technique. Separation was carried out on a pilot scale in an 800-l useful volume container with 160 rpm agitation for one hour. Tap water, ethanol solutions, and sodium chloride at different concentrations were used as densification medium. Virgin polymers were separated into two groups: low-density (HDPE and PP) and high-density polymers groups (PS, ABS, PA, and PC). Polymers whose density was less than that of the medium solution floated to the surface, while those whose density was greater than those of the medium solution sank to the bottom. The experimental results showed that complete separation of HDPE from PP achieved 23% ethanol v/v, whereas high-density polymers separated up to 40% w/v sodium chloride. Polymer recovery ranged from 70 to 99.70%. In post-consumer recycled plastic waste, fractions of 29.6% polyolefins, 37.54% PS, 11% ABS, 8% PA, 12% PC PET, and PVC were obtained. Finally, cast plates were made of the post-consumer waste to properly identify the polymer type present in the separated fractions.
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Affiliation(s)
- Washington Orlando Meneses Quelal
- Departamento de Ingeniería Rural and Agroalimentaria, Universitat Politècnica de Valencia, 46022, Camino de Vera s/n, Valencia, Spain
| | - Borja Velázquez-Martí
- Departamento de Ingeniería Rural and Agroalimentaria, Universitat Politècnica de Valencia, 46022, Camino de Vera s/n, Valencia, Spain.
| | - Andrés Ferrer Gisbert
- Departamento de Ingeniería Rural and Agroalimentaria, Universitat Politècnica de Valencia, 46022, Camino de Vera s/n, Valencia, Spain
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3
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Du Y, Zhang Y, Jiang H, Li T, Luo M, Wang L, Wang C, Wang H. Hydrophilic modification of polycarbonate surface with surface alkoxylation pretreatment for efficient separation of polycarbonate and polystyrene by froth flotation. WASTE MANAGEMENT (NEW YORK, N.Y.) 2020; 118:471-480. [PMID: 32979778 DOI: 10.1016/j.wasman.2020.09.006] [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: 07/15/2020] [Revised: 09/02/2020] [Accepted: 09/06/2020] [Indexed: 06/11/2023]
Abstract
Waste polystyrene (PS) and polycarbonate (PC) are crucial components arising from mixtures of plastic products, whose recycling is significantly limited by separation efficiency. In this work, to assist the flotation separation of PC and PS, we proposed a novel modification technology of surface alkoxylation pretreatment (SAP) where PC surface reacted with glycerol and urea. The SAP could selectively transform the hydrophobic PC into hydrophilic plastic, while the PS remained its hydrophobic surface owing to the exclusion from SAP process. Benefiting from the hydrophilic PC, the separation efficiency of PS and PC could reach the maximum of 99.34% under optimum conditions (urea dosage of 5 g, pretreatment temperature of 130 °C, pretreatment time of 10 min, flotation time of 2.5 min, frother concentration of 16.5 mg/L, and airflow rate of 7.2 mL/min). The mechanism of SAP was systematically analyzed by wettability, surface morphology, molecular weight, and chemical reactions. Compared with PS plastic, the pretreated PC presented better wettability, rougher surface, and significantly reducing molecular weight. The improvement of PC hydrophilicity can be attributed to the cleavage of ester bonds on backbone chains and the introduction of hydrophilic hydroxyl groups. The effective SAP process proves that chemical recycling of waste plastic can provide a novel strategy for surface modification and flotation separation of PS and PC.
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Affiliation(s)
- Yichen Du
- College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China
| | - Yingshuang Zhang
- College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China
| | - Hongru Jiang
- College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China
| | - Tianshu Li
- Ansteel Mining Co. Ltd., Anshan 114001, China
| | - Maozhi Luo
- College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China
| | - Ling Wang
- College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China
| | - Chongqing Wang
- School of Chemical Engineering and Energy, Zhengzhou University, Zhengzhou 450001, China
| | - Hui Wang
- College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China.
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Zhang Y, Jiang H, Wang H, Wang C. Separation of hazardous polyvinyl chloride from waste plastics by flotation assisted with surface modification of ammonium persulfate: Process and mechanism. JOURNAL OF HAZARDOUS MATERIALS 2020; 389:121918. [PMID: 31879107 DOI: 10.1016/j.jhazmat.2019.121918] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Revised: 12/14/2019] [Accepted: 12/16/2019] [Indexed: 06/10/2023]
Abstract
Plastic separation becomes an effective method to improve the plastic recycling by concentrating a single component from complex plastic mixtures. Based on advanced oxidation process, surface modification assisted by ammonium persulfate ((NH4)2S2O8) was applied to selectively wet plastic surface, achieving the separation of hazardous polyvinyl chloride (PVC) from acrylonitrile butadiene styrene (ABS), polystyrene (PS), and polycarbonate (PC) in forth flotation. The mechanisms were investigated through contact angle, X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FT-IR), as well as scanning electron microscope (SEM). The floatability of PS, PC, and ABS reduces owing to the introduction of carbonyl (O = CO), hydroxyl (-OH), and amide (O = C-NH2) on plastic surfaces, which is the result of the oxidation by sulfate radical (SO4∙-) and the hydrolysis of nitrile group (CN) and butadiene (CC). Then, available reaction equations of ABS, PS, and PC were established to supplement the mechanisms of surface modification. The optimal conditions for flotation separation of PVC are (NH4)2S2O8 concentration 0.2 M, temperature 70 °C, pretreatment time 30 min, pH 10, flotation time 4 min, terpineol dosage 20 mg/L, and particle size 3-4 mm. The recovery and purity of PVC reach 100 % and 99.7 ± 0.2 % respectively, favoring the reuse of separated waste plastic.
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Affiliation(s)
- Yingshuang Zhang
- College of Chemistry and Chemical Engineering, Central South University, Changsha, 410083, China
| | - Hongru Jiang
- College of Chemistry and Chemical Engineering, Central South University, Changsha, 410083, China
| | - Hui Wang
- College of Chemistry and Chemical Engineering, Central South University, Changsha, 410083, China.
| | - Chongqing Wang
- School of Chemical Engineering and Energy, Zhengzhou University, Zhengzhou, 450001, China.
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5
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Pita F, Castilho A. Separation of PET from other plastics by flotation combined with alkaline pretreatment. POLIMEROS 2020. [DOI: 10.1590/0104-1428.03320] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Zhong Y, Wang H, Wang J, Zhang Y, Wang K, Guo C, Chen S, Luo M, Du Y, Wang L. Combination of sodium hypochlorite pretreatment and flotation towards separation of polycarbonate from waste plastic mixtures. WASTE MANAGEMENT (NEW YORK, N.Y.) 2019; 99:112-121. [PMID: 31476636 DOI: 10.1016/j.wasman.2019.08.040] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 07/15/2019] [Accepted: 08/25/2019] [Indexed: 06/10/2023]
Abstract
This study developed a novel method, surface pretreatment using sodium hypochlorite along with flotation, to facilitate separation of waste polycarbonate from plastic mixtures for recycling. Surface pretreatment was observed that has an obviously negative effect on the floating ratio of polycarbonate and the floating ratio of poly-methyl-methacrylate, polystyrene, and polyvinylchloride was not affected in flotation, and this difference in floating ratio can be expected to separate polycarbonate from plastic mixtures. The optimum conditions obtained included sodium hypochlorite concentration of 0.05 M, pretreatment temperature of 70.0 °C, pretreatment time of 60.0 min, frother dosage of 10.8 mg/L, and flotation time of 4.0 min. Under optimum conditions, polycarbonate was separated effectively from multiple plastic mixtures, and the purity and recovery were 99.8% and 100.0%, respectively. The major mechanism of surface pretreatment was ascertained by the aid of Fourier transform infrared, scanning electron microscope, energy dispersive spectrometer, and X-ray photoelectron spectroscopy, and the hydrophilic groups, pitting, and protuberances introduced on polycarbonate surface caused the reduced floating ratio of polycarbonate. Accordingly, this method can be expected to improve the recycling quality of waste plastics, and provides technological insights in the environmentally friendly disposal of waste plastics.
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Affiliation(s)
- Yiwei Zhong
- School of Chemistry and Chemical Engineering, Central South University, Changsha 410083, Hunan, PR China
| | - Hui Wang
- School of Chemistry and Chemical Engineering, Central South University, Changsha 410083, Hunan, PR China.
| | - Jianchao Wang
- School of Chemistry and Chemical Engineering, Central South University, Changsha 410083, Hunan, PR China; School of Environment, Tsinghua University, Beijing 100084, PR China.
| | - Yingshuang Zhang
- School of Chemistry and Chemical Engineering, Central South University, Changsha 410083, Hunan, PR China
| | - Kangyu Wang
- School of Chemistry and Chemical Engineering, Central South University, Changsha 410083, Hunan, PR China
| | - Chenchao Guo
- School of Chemistry and Chemical Engineering, Central South University, Changsha 410083, Hunan, PR China
| | - Shuaijun Chen
- School of Chemistry and Chemical Engineering, Central South University, Changsha 410083, Hunan, PR China
| | - Maozhi Luo
- School of Chemistry and Chemical Engineering, Central South University, Changsha 410083, Hunan, PR China
| | - Yichen Du
- School of Chemistry and Chemical Engineering, Central South University, Changsha 410083, Hunan, PR China
| | - Ling Wang
- School of Chemistry and Chemical Engineering, Central South University, Changsha 410083, Hunan, PR China
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Zhao Y, Yang S, Wen H, Shen Z, Han F. Adsorption behavior and selectivity mechanism of flotation reagents applied in ternary plastic mixtures. WASTE MANAGEMENT (NEW YORK, N.Y.) 2019; 87:565-576. [PMID: 31109557 DOI: 10.1016/j.wasman.2019.02.044] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Revised: 02/21/2019] [Accepted: 02/23/2019] [Indexed: 06/09/2023]
Abstract
Plastic flotation attracts increasing attention in the process of recycling and will bring potential application in industry after theoretical perfection. For a separated ternary system of polyethylene terephthalate (PET), polyvinyl chloride (PVC) and polyethylene (PE), adsorption behavior and selectivity mechanism of flotation reagents were investigated by multi-characterization tests and batch equilibrium adsorption method. Quantitative adsorption results indicate that frother polyethylene glycol (PEG) only acts on gas and liquid phases in the flotation system with negligible adsorption capacity onto solid phase. For depressant sodium lignosulphonate (SL), the pseudo-first-order and Langmuir isotherm models are suitable for corresponding kinetic and equilibrium data of PET or PVC. Thermodynamic parameters further indicate that the adsorption of SL is a spontaneous and endothermic process, which neither belongs to the pure physisorption nor to the pure chemisorption. Adsorption models of SL were established based on hydrogen bond, with three clear bonding types (OH…π*, OH…O, and OH…Cl). Selectivity mechanism can be attributed to the selective hydrogen bond acceptors and donors, which are provided by specific plastic and depressant, respectively. In the light of these theoretical fundings, new targeted reagents or pre-treatments are expected to be developed towards more complex flotation system.
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Affiliation(s)
- Yue Zhao
- Shaanxi Key Laboratory of Disaster Monitoring & Mechanism Simulating, College of Geography and Environment, Baoji University of Arts and Sciences, Baoji 721013, China.
| | - Shengke Yang
- Key Laboratory of Subsurface Hydrology and Ecology in Arid Areas, Ministry of Education, School of Environmental Science and Engineering, Chang'an University, Xi'an 710054, China
| | - Hao Wen
- Key Laboratory of Subsurface Hydrology and Ecology in Arid Areas, Ministry of Education, School of Environmental Science and Engineering, Chang'an University, Xi'an 710054, China
| | - Zhou Shen
- Université de Toulouse, INSA, UPS, INP, LISBP, 135 Avenue de Rangueil, F-31077 Toulouse, France
| | - Fengrong Han
- Laboratory of Intelligent Information Processing, School of Computer, Baoji University of Arts and Sciences, Baoji 721016, China
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Zhao P, Xie J, Gu F, Sharmin N, Hall P, Fu J. Separation of mixed waste plastics via magnetic levitation. WASTE MANAGEMENT (NEW YORK, N.Y.) 2018; 76:46-54. [PMID: 29506775 DOI: 10.1016/j.wasman.2018.02.051] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Revised: 02/11/2018] [Accepted: 02/24/2018] [Indexed: 05/15/2023]
Abstract
Separation becomes a bottleneck of dealing with the enormous stream of waste plastics, as most of the extant methods can only handle binary mixtures. In this paper, a novel method that based on magnetic levitation was proposed for separating multiple mixed plastics. Six types of plastics, i.e., polypropylene (PP), acrylonitrile butadiene styrene (ABS), polyamide 6 (PA6), polycarbonate (PC), polyethylene terephthalate (PET), and polytetrafluoroethylene (PTFE), were used to simulate the mixed waste plastics. The samples were mixed and immersed into paramagnetic medium that placed into a magnetic levitation configuration with two identical NdFeB magnets with like-poles facing each other, and Fourier transform infrared (FTIR) spectroscopy was employed to verify the separation outputs. Unlike any conventional separation methods such as froth flotation and hydrocyclone, this method is not limited by particle sizes, as mixtures of different size fractions reached their respective equilibrium positions in the initial tests. The two-stage separation tests demonstrated that the plastics can be completely separated with purities reached 100%. The method has the potential to be industrialised into an economically-viable and environmentally-friendly mass production procedure, since quantitative correlations are determined, and the paramagnetic medium can be reused indefinitely.
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Affiliation(s)
- Peng Zhao
- State Key Lab of Fluid Power Transmission and Control, School of Mechanical Engineering, Zhejiang University, Hangzhou, China; Key Laboratory of 3D Printing Process and Equipment of Zhejiang Province, School of Mechanical Engineering, Zhejiang University, Hangzhou, China
| | - Jun Xie
- State Key Lab of Fluid Power Transmission and Control, School of Mechanical Engineering, Zhejiang University, Hangzhou, China; Key Laboratory of 3D Printing Process and Equipment of Zhejiang Province, School of Mechanical Engineering, Zhejiang University, Hangzhou, China
| | - Fu Gu
- State Key Lab of Fluid Power Transmission and Control, School of Mechanical Engineering, Zhejiang University, Hangzhou, China; Department of Industrial Engineering, Zhejiang University, Hangzhou, China.
| | - Nusrat Sharmin
- Department of Chemical and Environmental Engineering, University of Nottingham, Ningbo, China
| | - Philip Hall
- Department of Chemical and Environmental Engineering, University of Nottingham, Ningbo, China
| | - Jianzhong Fu
- State Key Lab of Fluid Power Transmission and Control, School of Mechanical Engineering, Zhejiang University, Hangzhou, China; Key Laboratory of 3D Printing Process and Equipment of Zhejiang Province, School of Mechanical Engineering, Zhejiang University, Hangzhou, China
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9
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Kangal MO, Üçerler Z. Recycling of Virgin and Post-Consumer Polypropylene and High Density Polyethylene. INT POLYM PROC 2018. [DOI: 10.3139/217.3506] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Abstract
Recycling of plastics is becoming more important nowadays due to the increasing amount of waste that is generated worldwide. Post-consumer plastics have a large volume and their harmful effects must be considered. From this perspective, the option of recycling post-consumer plastics has become more and more necessary. The main objective of this research is the selective separation of polypropylene (PP) and high density polyethylene (HDPE). On this basis, various flotation parameters were tested on virgin plastics and optimized conditions were applied to post-consumer plastics. PP particles with a purity of 96.30% were obtained with a recovery rate of 97.4% in virgin polymer separation, while HDPE particles were obtained as the sunken product with 97.38% purity and a recovery rate of 96.3%. Besides, almost all PP and HDPE particles were selectively separated with the highest recovery rates when using 500 g/t calcium lignosulfonate (CLs) as a plasticizer in post-consumer polymer separation. Moreover, water reuse was investigated to determine the recovery and economy of plasticizer without adding extra water during the experiment. Therefore, it can be concluded that this process is environmentally friendly in terms of PP and HDPE recycling and reuse of process water.
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Affiliation(s)
- M. O. Kangal
- Faculty of Mines , Mineral Processing Engineering Department, Istanbul Technical University, Istanbul , Turkey
| | - Z. Üçerler
- Faculty of Mines , Mineral Processing Engineering Department, Istanbul Technical University, Istanbul , Turkey
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10
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Separation of polyvinylchloride (PVC), polystyrene (PS) and polyethylene terephthalate (PET) granules using various chemical agents by flotation technique. Sep Purif Technol 2018. [DOI: 10.1016/j.seppur.2017.11.062] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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11
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Wang JC, Wang H, Huang LL, Wang CQ. Surface treatment with Fenton for separation of acrylonitrile-butadiene-styrene and polyvinylchloride waste plastics by flotation. WASTE MANAGEMENT (NEW YORK, N.Y.) 2017; 67:20-26. [PMID: 28578857 DOI: 10.1016/j.wasman.2017.05.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Revised: 04/17/2017] [Accepted: 05/04/2017] [Indexed: 06/07/2023]
Abstract
Surface treatment with Fenton was applied to flotation separation of acrylonitrile-butadienestyrene (ABS) and polyvinylchloride (PVC). After treatment, the floatability of ABS has a dramatic decrease, while the floatability of PVC is not affected. Fourier transform infrared spectroscopy (FT-IR) spectra and X-ray photoelectron spectroscopy (XPS) spectra were recorded to ascertain the mechanism of Fenton treatment. FT-IR and XPS analysis confirms that the introduction of oxygen-containing group occurs on the surface of ABS. The optimum conditions are molar ration (H2O2:Fe2+) 10000, H2O2 concentration 0.4M/L, pH 5.8, treatment time 2min and temperature 25°C, frother concentration 15mg/L and flotation time 3min. Particle sizes and mixing ratios were also investigated. Plastic mixtures of ABS and PVC with different particle sizes and mixing ratios can be effectively separated. The purity of ABS and PVC are up to 100% and 99.78%, respectively; the recovery of ABS and PVC are up to 99.89% and 100%, respectively. A practical, environmentally friendly and effective reagent, namely Fenton, was originally applied to surface treatment of ABS and PVC waste plastics for flotation separation of their mixtures.
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Affiliation(s)
- Jian-Chao Wang
- School of Chemistry and Chemical Engineering, Central South University, Changsha, 410083 Hunan, China
| | - Hui Wang
- School of Chemistry and Chemical Engineering, Central South University, Changsha, 410083 Hunan, China.
| | - Luo-Luo Huang
- School of Chemistry and Chemical Engineering, Central South University, Changsha, 410083 Hunan, China
| | - Chong-Qing Wang
- School of Chemistry and Chemical Engineering, Central South University, Changsha, 410083 Hunan, China
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Wang CQ, Wang H, Huang LL. A novel process for separation of polycarbonate, polyvinyl chloride and polymethyl methacrylate waste plastics by froth flotation. WASTE MANAGEMENT (NEW YORK, N.Y.) 2017; 65:3-10. [PMID: 28400158 DOI: 10.1016/j.wasman.2017.04.006] [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] [Received: 01/09/2017] [Revised: 03/31/2017] [Accepted: 04/03/2017] [Indexed: 06/07/2023]
Abstract
A novel process was proposed for separation of ternary waste plastics by froth flotation. Pretreatment of plastics with potassium permanganate (KMnO4) solution was conducted to aid flotation separation of polycarbonate (PC), polyvinyl chloride (PVC) and polymethyl methacrylate (PMMA) plastics. The effect of pretreatment parameters including KMnO4 concentration, treatment time, temperature and stirring rate on flotation recovery were investigated by single factor experiments. Surface treatment with KMnO4 changes selectively the flotation behavior of PC, PVC and PMMA, enabling separation of the plastics by froth flotation. Mechanism of surface treatment was studied by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and X-ray photoelectron spectrum (XPS). Effect of frother concentration and flotation time on flotation behavior of plastic mixtures was further studied for flotation separation. The optimized conditions for separation of PC are KMnO4 concentration 2mmolL-1, treatment time 10min, temperature 60°C, stirring rate 300rpm, flotation time 1min and frother concentration 17.5mgL-1. Under optimum conditions, PVC and PMMA mixtures are also separated efficiently by froth flotation associated with KMnO4 treatment. The purity of PC, PVC and PMMA is up to 100%, 98.41% and 98.68%, while the recovery reaches 96.82%, 98.71% and 98.38%, respectively. Economic analysis manifests remarkable profits of the developed process. Reusing KMnO4 solution is feasible, enabling the process greener.
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Affiliation(s)
- Chong-Qing Wang
- School of Chemistry and Chemical Engineering, Central South University, Changsha, 410083 Hunan, China
| | - Hui Wang
- School of Chemistry and Chemical Engineering, Central South University, Changsha, 410083 Hunan, China.
| | - Luo-Luo Huang
- School of Chemistry and Chemical Engineering, Central South University, Changsha, 410083 Hunan, China
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Güney A, Özdilek C, Kangal MO, Burat F. Flotation characterization of PET and PVC in the presence of different plasticizers. Sep Purif Technol 2015. [DOI: 10.1016/j.seppur.2015.07.027] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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14
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Wang CQ, Wang H, Fu JG, Liu YN. Flotation separation of waste plastics for recycling-A review. WASTE MANAGEMENT (NEW YORK, N.Y.) 2015; 41:28-38. [PMID: 25869841 DOI: 10.1016/j.wasman.2015.03.027] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2014] [Revised: 03/16/2015] [Accepted: 03/18/2015] [Indexed: 06/04/2023]
Abstract
The sharp increase of plastic wastes results in great social and environmental pressures, and recycling, as an effective way currently available to reduce the negative impacts of plastic wastes, represents one of the most dynamic areas in the plastics industry today. Froth flotation is a promising method to solve the key problem of recycling process, namely separation of plastic mixtures. This review surveys recent literature on plastics flotation, focusing on specific features compared to ores flotation, strategies, methods and principles, flotation equipments, and current challenges. In terms of separation methods, plastics flotation is divided into gamma flotation, adsorption of reagents, surface modification and physical regulation.
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Affiliation(s)
- Chong-qing Wang
- School of Chemistry and Chemical Engineering, Key Laboratory of Resource Chemistry of Nonferrous Metals, Ministry of Education, Central South University, Changsha, 410083 Hunan, China.
| | - Hui Wang
- School of Chemistry and Chemical Engineering, Key Laboratory of Resource Chemistry of Nonferrous Metals, Ministry of Education, Central South University, Changsha, 410083 Hunan, China.
| | - Jian-gang Fu
- School of Chemistry and Chemical Engineering, Key Laboratory of Resource Chemistry of Nonferrous Metals, Ministry of Education, Central South University, Changsha, 410083 Hunan, China.
| | - You-nian Liu
- School of Chemistry and Chemical Engineering, Key Laboratory of Resource Chemistry of Nonferrous Metals, Ministry of Education, Central South University, Changsha, 410083 Hunan, China.
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