College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China.
J Hazard Mater. 2010 Mar 15;175(1-3):823-8. doi: 10.1016/j.jhazmat.2009.10.083. Epub 2009 Oct 30.
Waste printed circuit boards (WPCBs) contain lots of valuable resources together with plenty of hazardous materials, which are considered both an attractive secondary resource and an environmental contaminant. In this research, a new process of "centrifugal separation+vacuum pyrolysis" for the combined recovery of solder and organic materials from WPCBs was investigated. The results of centrifugal separation indicated that the separation of solder from WPCBs was complete when WPCBs were heated at 240 degrees C, and the rotating drum was rotated at 1400 rpm for 6 min intermittently. The results of vacuum pyrolysis showed that the type-A of WPCBs without solder pyrolysed to form an average of 69.5 wt% residue, 27.8 wt% oil, and 2.7 wt% gas; and pyrolysis of the type-B of WPCBs without solder led to an average mass balance of 75.7 wt% residue, 20.0 wt% oil, and 4.3 wt% gas. The pyrolysis residues contain various metals, glass fibers and other inorganic materials, which could be recycled for further processing. The pyrolysis oils can be used for fuel or chemical feedstock and the pyrolysis gases can be collected and combusted for the pyrolysis self-sustain. This clean and non-polluting technology offers a new way to recycle valuable materials from WPCBs and prevent the environmental pollution of WPCBs effectively.
废弃印刷电路板（WPCBs）中含有大量有价值的资源和大量危险物质，被认为既是有吸引力的二次资源，也是环境污染物。本研究采用“离心分离+真空热解”新工艺，从 WPCBs 中联合回收焊料和有机材料。离心分离结果表明，当 WPCBs 在 240°C 下加热，并以 1400rpm 的转速间歇旋转 6 分钟时，可实现 WPCBs 中焊料的完全分离。真空热解结果表明，无焊料的 A 型 WPCBs 热解后形成平均 69.5wt%的残渣、27.8wt%的油和 2.7wt%的气体；无焊料的 B 型 WPCBs 热解后平均质量平衡为 75.7wt%的残渣、20.0wt%的油和 4.3wt%的气体。热解残渣中含有各种金属、玻璃纤维和其他无机材料，可回收进一步加工。热解油可作为燃料或化工原料，热解气可收集燃烧，实现热解自维持。这种清洁无污染的技术为从 WPCBs 中回收有价值的材料提供了一种新途径，并能有效防止 WPCBs 的环境污染。
