Faculty of Environmental Science and Engineering, Guangdong University of Technology, 100 Waihuan Xi Road, Guangzhou Higher Education Mega Center, Guangzhou 510006, PR China.
J Hazard Mater. 2010 May 15;177(1-3):626-32. doi: 10.1016/j.jhazmat.2009.12.078. Epub 2009 Dec 24.
The constant growth in generation of waste printed circuit boards (WPCB) poses a huge disposal problem because they consist of a heterogeneous mixture of organic and metallic chemicals as well as glass fiber. Also the presence of heavy metals, such as Pb and Cd turns this scrap into hazardous waste. Therefore, recycling of WPCB is an important subject not only from the recovery of valuable materials but also from the treatment of waste. The aim of this study was to present a recycling process without negative impact to the environment as an alternative for recycling WPCB. In this work, a process technology containing vacuum pyrolysis and mechanical processing was employed to recycle WPCB. At the first stage of this work, the WPCB was pyrolyzed under vacuum in a self-made batch pilot-scale fixed bed reactor to recycle organic resins contained in the WPCB. By vacuum pyrolysis the organic matter was decomposed to gases and liquids which could be used as fuels or chemical material resources, however, the inorganic WPCB matter was left unaltered as solid residues. At the second stage, the residues obtained at the first stage were investigated to separate and recover the copper through mechanical processing such as crushing, screening, and gravity separation. The copper grade of 99.50% with recovery of 99.86% based on the whole WPCB was obtained. And the glass fiber could be obtained by calcinations in a muffle furnace at 600 degrees C for 10 min. This study had demonstrated the feasibility of vacuum pyrolysis and mechanical processing for recycling WPCB.
电路板废料（WPCB）的产量不断增加，造成了巨大的处理问题，因为它们由有机和金属化学品以及玻璃纤维的不均匀混合物组成。此外，重金属如铅和镉的存在使这种废料变成了危险废物。因此，回收 WPCB 不仅是从有价值的材料中回收的重要课题，也是处理废物的重要课题。本研究旨在提出一种对环境无负面影响的回收工艺，作为回收 WPCB 的替代方法。在这项工作中，采用了包含真空热解和机械加工的工艺技术来回收 WPCB。在这项工作的第一阶段，WPCB 在自制的间歇式固定床反应器中进行真空热解，以回收 WPCB 中含有的有机树脂。通过真空热解，有机物分解为气体和液体，可以用作燃料或化学材料资源，而无机的 WPCB 物质则作为固体残留物不变。在第二阶段，研究了第一阶段得到的残留物，通过机械加工，如粉碎、筛选和重力分离，分离和回收铜。以整个 WPCB 为基准，铜的品位达到 99.50%，回收率达到 99.86%。玻璃纤维可以通过在马弗炉中在 600 摄氏度下煅烧 10 分钟来获得。本研究证明了真空热解和机械加工回收 WPCB 的可行性。
