Wang Jianchao, Wang Hui, Wang Chongqing, Zhang Lingling, Wang Tao, Zheng Long
School of Chemistry and Chemical Engineering, Central South University, Changsha, 410083 Hunan, China.
School of Chemistry and Chemical Engineering, Central South University, Changsha, 410083 Hunan, China.
Waste Manag. 2017 Nov;69:59-65. doi: 10.1016/j.wasman.2017.07.049. Epub 2017 Aug 8.
A novel method, calcium hypochlorite (CHC) treatment, was proposed for separation of hazardous poly(vinyl chloride) (PVC) plastic from mixed plastic wastes (MPWs) by froth flotation. Flotation behavior of single plastic indicates that PVC can be separated from poly(ethylene terephthalate) (PET), poly(acrylonitrile-co-butadiene-co-styrene) (ABS), polystyrene (PS), polycarbonate (PC) and poly(methyl methacrylate) (PMMA) by froth flotation combined with CHC treatment. Mechanism of CHC treatment was examined by contact angle measurement, scanning electron microscopy, Fourier transform infrared and X-ray photoelectron spectroscopy. Under the optimum conditions, separation of PVC from binary plastics with different particle sizes is achieved efficiently. The purity of PC, ABS, PMMA, PS and PET is greater than 96.8%, 98.5%, 98.8%, 97.4% and 96.3%, respectively. Separation of PVC from multi-plastics was further conducted by two-stage flotation. PVC can be separated efficiently from MPWs with residue content of 0.37%. Additionally, reusing CHC solution is practical. This work indicates that separation of hazardous PVC from MPWs is effective by froth flotation.
提出了一种新方法——次氯酸钙（CHC）处理法，用于通过泡沫浮选从混合塑料废物（MPW）中分离有害的聚氯乙烯（PVC）塑料。单一塑料的浮选行为表明，通过泡沫浮选结合CHC处理，可以将PVC与聚对苯二甲酸乙二酯（PET）、丙烯腈-丁二烯-苯乙烯共聚物（ABS）、聚苯乙烯（PS）、聚碳酸酯（PC）和聚甲基丙烯酸甲酯（PMMA）分离。通过接触角测量、扫描电子显微镜、傅里叶变换红外光谱和X射线光电子能谱研究了CHC处理的机理。在最佳条件下，能够高效地从不同粒径的二元塑料中分离出PVC。PC、ABS、PMMA、PS和PET的纯度分别大于96.8%、98.5%、98.8%、97.4%和96.3%。通过两段浮选进一步从多种塑料中分离PVC。PVC可以从残留量为0.37%的混合塑料废物中高效分离出来。此外，CHC溶液的重复使用是可行的。这项工作表明，通过泡沫浮选从混合塑料废物中分离有害的PVC是有效的。
