Recycle technology for recovering resources and products from waste printed circuit boards
Recycle technology for recovering resources and products from waste printed circuit boards
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DOI：
10.1021/es0618245
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发表时间：
2007-03-15
影响因子：
11.4
通讯作者：
Zhou, Yaohe
中科院分区：
文献类型：
--
作者：
Li, Jia;Lu, Hongzhou;Zhou, Yaohe
印刷电路板（PCB）中含有近28%的金属，其中含有丰富的铜、铝、锡等有色金属。多氯联苯中贵金属的纯度比富含矿物质的纯度高10倍以上。因此，多氯联苯的回收利用是一个重要的课题，不仅从废物的处理，而且从有价物质的回收。化学法和机械法是两种传统的多氯联苯回收方法。然而，化学方法的前景有限，因为在此过程中有毒液体或气体的排放会给环境带来二次污染。机械工艺，如形状分离、跳汰、密度分离、静电分离等已广泛应用于回收工业。但是，废弃多氯联苯的回收才刚刚开始。在本研究中，通过回收技术处理了400 kg的废弃多氯联苯，对环境没有负面影响。该工艺包括机械两步破碎、电晕静电分离和回收。结果表明：(1)两步破碎是将金属从底板上完全剥离的有效工艺；(2)工业应用中，粒径在0.6 ~ 1.2 mm之间的颗粒适合电晕静电分离；（三）废旧多氯联苯的非金属达到了一种非金属板材重量的80%，扩大了废旧非金属材料的应用前景。
The printed circuit board (PCB) contains nearly 28% metals that are abundant non-ferrous metals such as Cu, Al, Sn, etc. The purity of precious metals in PCBs is more than 10 times higher than that of rich-content minerals. Therefore, recycling of PCBs is an important subject not only from the treatment of waste but also from the recovery of valuable materials. Chemical and mechanical methods are two traditional recycling processes for waste PCBs. However, the prospect of chemical methods will be limited since the emission of toxic liquid or gas brings secondary pollution to the environment during the process. Mechanical processes, such as shape separation, jigging, density-based separation, and electrostatic separation have been widely utilized in the recycling industry. But, recycling of waste PCBs is only beginning. In this study, a total of 400 kg of waste PCBs was processed by a recycle technology without negative impact to the environment. The technology contained mechanical two-step crushing, corona electrostatic separating, and recovery. The results indicated that (i) two-step crushing was an effect process to strip metals from base plates completely; (ii) the size of particles between 0.6 and 1.2 mm was suitable for corona electrostatic separating during industrial application; and (iii) the nonmetal of waste PCBs attained 80% weight of a kind of nonmetallic plate that expanded the applying prospect of waste nonmetallic materials.