LEPMI, UMR 5279, CNRS - Grenoble INP-Université de Savoie, Université Joseph Fourier, BP75, 38402 Saint Martin d'Hères, France.
J Hazard Mater. 2012 Apr 30;213-214:485-90. doi: 10.1016/j.jhazmat.2012.02.037. Epub 2012 Feb 21.
Recycling of waste electrical and electronic equipments (WEEE) has been taken into consideration in the literature due to the large quantity of concerned wastes and their hazardous contents. The situation is so critical that EU published European Directives imposing collection and recycling with a minimum of material recovery [1]. Moreover, WEEEs contain precious metals, making the recycling of these wastes economically interesting, but also some critical metals and their recycling leads to resource conservation. This paper reports on a new approach for recycling waste printed circuit boards (WPCBs). Molten salts and specifically molten KOH-NaOH eutectic is used to dissolve glasses, oxides and to destruct plastics present in wastes without oxidizing the most valuable metals. This method is efficient for recovering a copper-rich metallic fraction, which is, moreover, cleared of plastics and glasses. In addition, analyses of gaseous emission show that this method is environmentally friendly since most of the process gases, such as carbon monoxide and dioxide and halogens, are trapped in the highly basic molten salt. In other respects, under operation without oxygen, a large quantity of hydrogen is produced and might be used as fuel gas or as synthesis gas, leading to a favourable energy balance for this new process.
由于相关废物数量庞大且含有有害物质，废弃电气电子设备（WEEE）的回收已在文献中得到考虑。情况非常危急，欧盟发布了欧洲指令，强制要求进行收集和回收，最低限度地实现材料回收[1]。此外，WEEEs 中含有贵金属，使得这些废物的回收具有经济意义，但也有一些关键金属，其回收有助于资源节约。本文报告了一种回收废弃印刷电路板（WPCBs）的新方法。熔融盐，特别是熔融的 KOH-NaOH 共晶，用于溶解玻璃、氧化物，并破坏废物中的塑料，而不会氧化最有价值的金属。这种方法对于回收富含铜的金属部分非常有效，而且该金属部分还清除了塑料和玻璃。此外，气体排放分析表明，由于大多数工艺气体（如一氧化碳、二氧化碳和卤素）被捕获在高碱性熔融盐中，因此该方法对环境友好。另一方面，在没有氧气的情况下操作时，会产生大量的氢气，可作为燃料气或合成气使用，为新工艺带来有利的能量平衡。
