Selective recovery of PVC-free polymers from ASR polymers by ozonation and froth flotation
Selective recovery of PVC-free polymers from ASR polymers by ozonation and froth flotation
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DOI：
10.1016/j.resconrec.2008.02.003
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发表时间：
2008-04
影响因子：
13.2
通讯作者：
M. Reddy;K. Kurose;T. Okuda;W. Nishijima;M. Okada
中科院分区：
文献类型：
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作者：
M. Reddy;K. Kurose;T. Okuda;W. Nishijima;M. Okada
研究了臭氧氧化-泡沫浮选法从汽车粉碎残渣中选择性回收不含聚氯乙烯（PVC）的聚合物。使用三种不同的重ASR聚合物样品。进行适当的碱洗作为从ASR聚合物表面去除污染物的预处理。比较了两种不同粉碎方法（双轴剪切粉碎机和单轴旋转粉碎机）粉碎的样品在泡沫浮选过程中PVC的行为。与未用碱溶液预洗涤的PVC聚合物相比，已发现ASR中用PVC聚合物的碱溶液预洗涤的臭氧化显著改变了亲水性。而碱洗并不改变其它重质聚合物的表面疏水性。结果表明，臭氧氧化（碱洗）使PVC的接触角由80.7°变为55.7°，82.4°变为59.1°，82°变为59.6°，而对其它重质ASR聚合物的接触角几乎没有降低。该结果表明，在不同ASR组合物中，通过臭氧化后的泡沫浮选，成功地回收了93.5-96.4%的不含PVC的ASR聚合物，其中PVC小于0.1-0.2%。臭氧氧化加碱溶液预洗的ASR可显著提高PVC纯度。
The present study focused on the selective recovery of poly(vinyl chloride) (PVC)-free polymers from automobile shredder residue (ASR) polymers by ozonation and froth flotation. Three different heavy ASR polymer samples were used. Appropriate alkaline washing was done as a pretreatment for the removal of the pollutants from the ASR polymer surface. The samples grinded by two different methods (two-shaft shear shredder and single-shaft rotary grinder) were compared for the behavior of PVC in the froth flotation. Ozonation with pre-washed by alkaline solution of PVC polymer in ASR has been found to significantly modify the hydrophilicity when compared to PVC polymer without pre-washing with alkaline solution. Whereas, alkaline washing did not change the surface hydrophobicity of other heavy polymers. It is found from the results that ozonation (with alkaline washing) has changed the contact angle of PVC from 80.7° to 55.7°, 82.4° to 59.1° and 82° to 59.6°, whereas little decrease of the contact angle was observed on other heavy ASR polymers. This result indicates that 93.5–96.4% PVC-free ASR polymer was successfully recovered with less than 0.1–0.2% of PVC by the froth flotation after ozonation in different ASR compositions. Ozonation with pre-washed by alkaline solution of ASR has significantly improved the PVC purity.