Abstract:
The metal resource crisis and the inherent need for a low-carbon circular economy have driven the rapid development of e-waste recycling technology. High-value waste printed circuit boards (WPCBs) are an essential component of e-waste. However, WPCBs are considered hazardous to the ecosystem due to the presence of heavy metals and brominated organic polymers. Therefore, achieving the recycling of metals in WPCBs is not only a strategic requirement for building a green ecological civilization but also an essential guarantee for achieving a safe supply of mineral resources. This review systematically analyzes the hydrometallurgical technology of metals in WPCBs in recent years. Firstly, the different unit operations of pretreatment in the hydrometallurgical process, which contain disassembly, crushing, and pre-enrichment, were analyzed. Secondly, environmentally friendly hydrometallurgical leaching systems and high-value product regeneration technologies used in recent years to recover metals from WPCBs were evaluated. The leaching techniques, including cyanidation, halide, thiourea, and thiosulfate for precious metals, and inorganic acid, organic acid, and other leaching methods for base metals such as copper and nickel in WPCBs, were outlined, and the leaching performance and greenness of each leaching system were summarized and analyzed. Eventually, based on the advantages of each leaching system and the differences in chemical properties of metals in WPCBs, an integrated and multi-gradient green process for the recovery of WPCBs was proposed, which provides a sustainable pathway for the recovery of metals in WPCBs. This paper provides a reference for realizing the gradient hydrometallurgical recovery of metals from WPCBs to promote the recycling metal resources.
摘要:
金属资源危机和低碳循环经济的内在需求推动了电子垃圾回收技术的快速发展。高价值的废弃印刷电路板(WPCB)是电子垃圾的重要组成部分。然而,由于重金属和溴化有机聚合物的存在,WPCB被认为对生态系统有害。因此,实现多氯联苯中金属的循环利用,不仅是建设绿色生态文明的战略要求,也是实现矿产资源安全供应的重要保证。本文系统地分析了近年来WPCB中金属的湿法冶金技术。首先,湿法冶金过程中预处理的不同单元操作,包含拆卸,压碎,和预富集,进行了分析。其次,对近年来用于从WPCB中回收金属的环保湿法冶金浸出系统和高价值产品再生技术进行了评估。浸出技术,包括氰化,卤化物,卤化物硫脲,和贵金属的硫代硫酸盐,无机酸,有机酸,以及其他对WPCB中的铜和镍等贱金属的浸出方法,概述了,并对各浸出系统的浸出性能和绿度进行了总结和分析。最终,基于每个浸出系统的优点和WPCB中金属化学性质的差异,提出了一种用于回收WPCB的集成多梯度绿色工艺,这为回收WPCB中的金属提供了可持续的途径。为实现湿法湿法湿法湿法湿法湿法回收WPCB中金属,促进金属资源循环利用提供参考。