Flotation separation of polyvinyl chloride and polyethylene terephthalate plastics combined with surface modification for recycling. (November 2015)

• Record Type: Journal Article
• Authors: Wang, Chongqing; Wang, Hui; Fu, Jiangang; Zhang, Lingling; Luo, Chengcheng; Liu, Younian
• Is Part Of: Waste management. Volume 45(2015)
• Page Start: 112
• Page End: 117
• Publication Date: 2015-11
• Subjects: Flotation -- Plastics recycling -- Polyvinyl chloride -- Surface modification; Hazardous wastes -- Periodicals; Refuse and refuse disposal -- Periodicals; 363.728
• DOI: 10.1016/j.wasman.2015.07.053
• Languages: English
• ISSNs: 0956-053X

Abstract

Abstract : Graphical abstract: Surface modification with KMnO4 solutions increased the wettability of PVC plastic, while PET was unaffected. A process was developed for flotation separation of PVC and PET waste plastics combined with surface modification. Highlights: A simple and practical method was developed for separation of waste plastics. Surface modification increases selectively the wettability of PVC. Mechanism of surface modification may be due to oxidization reactions. Flotation separation of PVC and PET was obtained efficiently. A flotation process was designed for flotation separation of PVC and PET plastics. Abstract: Surface modification with potassium permanganate (KMnO4 ) solution was developed for separation of polyvinyl chloride (PVC) and polyethylene terephthalate (PET) waste plastics. The floatability of PVC decreases with increasing of KMnO4 concentration, treatment time, temperature and stirring rate, while that of PET is unaffected. Fourier transform infrared (FT-IR) analysis confirms that mechanism of surface modification may be due to oxidization reactions occurred on PVC surface. The optimum conditions are KMnO4 concentration 1.25 mM/L, treatment time 50 min, temperature 60 °C, stirring rate 300 r/min, frother concentration 17.5 g/L and flotation time 1 min. PVC and PET with different particle sizes were separated efficiently through two-stage flotation. Additionally, after ultrasonic assisted surface modification, separation of PVC and PET with different mass ratios was obtained efficiently through one-stage flotation. The purity and the recovery of the obtained products after flotation separation are up to 99.30% and 99.73%, respectively. A flotation process was designed for flotation separation of PVC and PET plastics combined with surface modification. This study provides technical insights into physical separation of plastic wastes for recycling industry.