大学化学 >> 2023, Vol. 38 >> Issue (4): 216-226.doi: 10.3866/PKU.DXHX202211081

所属专题： 第3届全国大学生化学实验创新设计竞赛

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淀粉提金——电子废料中金的绿色特异性回收

简亚军(), 陈端睿, 郑蘅言, 韦婉瑶, 高玲香, 张伟强, 魏灵灵, 高子伟()   

  • 收稿日期:2022-11-26 录用日期:2023-01-11 发布日期:2023-03-20
  • 通讯作者: 简亚军,高子伟 E-mail:yajunjian@snnu.edu.cn;zwgao@snnu.edu.cn

Gold Extraction with Strach: Green Specific Recovery of Gold from Electronic Scrap

Yajun Jian(), Duanrui Chen, Hengyan Zheng, Wanyao Wei, Lingxiang Gao, Weiqiang Zhang, Lingling Wei, Ziwei Gao()   

  • Received:2022-11-26 Accepted:2023-01-11 Published:2023-03-20
  • Contact: Yajun Jian, Ziwei Gao E-mail:yajunjian@snnu.edu.cn;zwgao@snnu.edu.cn

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摘要：

以学生和公众倍感兴趣的废金回收为实验主题，紧跟科学前沿，基于α-环糊精特异性识别[AuBr4]-原理实现电子废料中金的特异性回收，以此为基础设计新创综合实验。实验通过四步反应实现废弃CPU中金的高效回收：稀硝酸除杂富集金(富金)，溴化钾-醋酸-硝酸-水体系温和氧化金(溶金)，α-环糊精选择性识别[AuBr4]- (萃金)，无毒非金属还原剂焦亚硫酸钠还原得金单质(成金)。本实验涉及无机化学、超分子化学和分析化学等多学科内容，涵盖反应监测、结构表征、纯度分析在内的合成反应与分析测定的重要操作；实验现象明显且可重复性强，回收金的纯度高达90%以上，教学时长约为6–8 h，适用于本科生综合化学实验教学；融入绿色化学理念，所用试剂环境友好、安全性高，展现了化学解决国计民生实际问题的重要价值；采取线上线下混合式教学，强化探究性环节，培养了学生科研思维和创新意识，提升了化学专业本科生解决复杂问题的综合能力，夯实了化学类人才的培养质量。

关键词: 新创综合实验, α-环糊精, 超分子识别, 电子废弃物, 绿色提金

Abstract:

In this study, we develop an innovative and comprehensive method for extracting Au from electronic scrap. Au recycling from electronic waste is a popular topic for chemistry students and the general public. To implement the latest scientific knowledge and methods, herein, Au recovery via the reaction of α-cyclodextrin with [AuBr4]- is used as the basic principle. The procedure used to recycle Au from electronic waste comprises four steps: dilute nitric acid is used to decrease the unwanted metal content of electronic waste (Au enrichment); Au is subjected to mild oxidation using a potassium bromide-acetic acid-nitric acid system (Au dissolution); α-cyclodextrin is reacted with [AuBr4]- (Au extraction); Au(Ⅲ) is reduced to Au(0) using sodium metabisulfite, a non-toxic and non-metallic reducing agent (Au formation). The experiments involve multi-disciplinary principles, such as inorganic, supramolecular, and analytical chemistry concepts. Furthermore, they cover the basic operations of synthesis and analytical experiments including reaction monitoring, structural characterization, and purity analysis. The experimental results are conspicuous, the experiments are repeatable, and the purity of Au is above 90%. Moreover, the time required to perform the experiments ranges between 6 and 8 h. Therefore, the experiments are suitable for undergraduate comprehensive chemistry laboratory teaching. In addition, green chemistry concepts and experimental methods are incorporated as the reagents are environmentally friendly and safe to handle. This experiment demonstrates the critical role of chemistry in solving national economy problems and improving the livelihood of humankind. Through a thorough teaching approach comprising online and offline modules, this experiment cultivates the scientific thinking patterns and innate curiosity of students, improves the ability of undergraduate chemistry students to solve complex synthetic chemistry problems, and consolidates the knowledge of chemistry trainees.

Key words: Innovative comprehensive experiments, α-cyclodextrin, Supramolecular recognition, Electronic waste, Green Au extraction