Material Characterization and Physical Processing of a General Type of Waste Printed Circuit Boards
Material Characterization and Physical Processing of a General Type of Waste Printed Circuit Boards
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DOI：
10.3390/su142013479
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发表时间：
2022-10-01
期刊：
影响因子：
3.9
通讯作者：
Yang, Xinbo
中科院分区：
文献类型：
--
作者：
Lin, Peijia;Werner, Joshua;Yang, Xinbo
由于电子设备的快速发展及其寿命的缩短，废弃电气和电子设备（WESTERN）或电子废物被认为是增长最快的废物之一。在电子废物的种类中，废弃印刷电路板（WPCB）被认为是最复杂的废物材料，因为它们的组成多种多样，例如塑料，电容器，布线和金属镀层。迄今为止，已经开发和研究了各种加工技术。然而，由于多氯联苯的异质性，需要对材料特性和物理分离进行全面研究，以更好地了解材料处理，并在下游化学工艺之前制备合适的原料。在本研究中，集成的大小和密度分离进行了解所包含的金属，特别是铜和Au，从塑料基板的解放。通过有价金属在不同粒度和密度组分中的元素浓度、分布和富集率来评价分离性能。此外，对密度分离产物进行SEM-EDS以表征表面形态、元素分布和定量元素含量。此外，通过热重分析研究了废弃PCB的热重特性，以了解温度对热处理过程中挥发分和可燃性组分的影响。
Due to the rapid development of electronic devices and their shortened lifespans, waste electrical and electronic equipment (WEEE), or E-waste, is regarded as one of the most fast-growing wastes. Among the categories of E-waste, waste printed circuit boards (WPCBs) are considered the most complex waste materials, owing to their various constitutes, such as plastics, capacitors, wiring, and metal plating. To date, a variety of processing technologies have been developed and studied. However, due to the heterogeneous nature of WPCBs, a thorough study on both material characterization and physical separation was needed to provide a better understanding in material handling, as well as to prepare a suitable feedstock prior to the downstream chemical process. In the present study, integrated size and density separations were performed to understand the liberation of contained metals, particularly Cu and Au, from the plastic substrates. The separation performance was evaluated by the elemental concentration, distribution, and enrichment ratio of valuable metals in different size and density fractions. Further, SEM-EDS on the density separation products was carried out to characterize the surface morphology, elemental mapping, and quantified elemental contents. Moreover, thermo-gravimetric properties of waste PCBs were investigated by TGA, in order to understand the effect of temperature on volatile and combustible fractions during the thermal processing.