Key Laboratory of Solid Waste Treatment and Resource Recycle, Ministry of Education, and §School of Manufacturing Science and Technology, Southwest University of Science and Technology (SWUST) , 59 Qinglong Road, Mianyang, Sichuan 621010, People's Republic of China.
Environ Sci Technol. 2013;47(21):12409-16. doi: 10.1021/es402102t. Epub 2013 Oct 15.
Waste printed circuit boards (WPCBs) are resource-rich but hazardous, demanding innovative strategies for post-consumer collection, recycling, and mining for economically precious constituents. A novel technology for disassembling electronic components from WPCBs is proposed, using hot air to melt solders and to separate the components and base boards. An automatic heated-air disassembling equipment was designed to operate at a heating source temperature at a maximum of 260 °C and an inlet pressure of 0.5 MPa. A total of 13 individual WPCBs were subjected to disassembling tests at different preheat temperatures in increments of 20 °C between 80 and 160 °C, heating source temperatures ranging from 220 to 300 °C in increments of 20 °C, and incubation periods of 1, 2, 4, 6, or 8 min. For each experimental treatment, the disassembly efficiency was calculated as the ratio of electronic components released from the board to the total number of its original components. The optimal preheat temperature, heating source temperature, and incubation period to disassemble intact components were 120 °C, 260 °C, and 2 min, respectively. The disassembly rate of small surface mount components (side length ≤ 3 mm) was 40-50% lower than that of other surface mount components and pin through hole components. On the basis of these results, a reproducible and sustainable industrial ecological protocol using steam produced by industrial exhaust heat coupled to electronic-waste recycling is proposed, providing an efficient, promising, and green method for both electronic component recovery and industrial exhaust heat reutilization.
废弃印刷电路板（WPCBs）是一种资源丰富但具有危害性的物质，需要采用创新的策略来进行消费者后收集、回收和采矿，以提取经济上有价值的成分。提出了一种从 WPCBs 上拆卸电子元件的新技术，使用热空气熔化焊料并分离元件和基板。设计了一种自动加热空气拆卸设备，可在最高 260°C 的加热源温度和 0.5 MPa 的入口压力下运行。总共对 13 个单独的 WPCBs 进行了拆卸测试，在 80 至 160°C 之间以 20°C 的增量预热温度，在 220 至 300°C 之间以 20°C 的增量加热源温度，以及 1、2、4、6 或 8 分钟的孵育期。对于每个实验处理，拆卸效率计算为从板上释放的电子元件与原始元件总数的比率。完整组件的最佳预热温度、加热源温度和孵育时间分别为 120°C、260°C 和 2 分钟。小表面贴装元件（边长≤3mm）的拆卸率比其他表面贴装元件和引脚通孔元件低 40-50%。基于这些结果，提出了一种使用工业废气余热与电子废物回收相结合产生的蒸汽的可重复和可持续的工业生态协议，为电子元件回收和工业废气余热再利用提供了一种高效、有前途和绿色的方法。
