Environmentally Benign, Rapid, and Selective Extraction of Gold from Ores and Waste Electronic Materials

• Published in: Angewandte Chemie 2017-08, Vol.129 (32), p.9459-9463
• Main Authors: Yue, Chunlin, Sun, Huaming, Liu, Wen‐Jing, Guan, Binbin, Deng, Xudong, Zhang, Xu, Yang, Peng
• Format: Article
• Language: English
• Subjects: Aquatic animals; Benign; Chemistry; Electronic materials; Electronic waste; Elektronikschrott; Energy consumption; Environmental impact; Extraction; Gold; Goldlaugung; Goldrückgewinnung; Heavy metals; Koordinationskomplexe; Leaching; Mammalian cells; Minerals; N-Bromosuccinimide; Ores; Oxidation; pH effects; Pyridines; Reagents; Selectivity; Selektive Extraktion; Temperature effects; Toxicity; Water pollution
• ISSN: 0044-8249; 1521-3757
• DOI: 10.1002/ange.201703412

The extraction of gold from ores and electronic waste is an important topic worldwide, as this precious metal has immense value in a variety of fields. However, serious environmental pollution and high energy consumption due to the use of toxic oxidation reagents and harsh reaction conditions is a well‐known problem in the gold industry. Herein, we report a new chemical method based on the combined use of N‐bromosuccinimide (NBS) and pyridine (Py), which has a greatly decreased environmental impact and reagent cost, as well as mild reaction requirements. This method can directly leach Au0 from gold ore and electronic waste to form AuIII in water. The process is achieved in a yield of approximately 90 % at room temperature and a nearly neutral pH. The minimum dose of NBS/Py is as low as 10 mm, which exhibits low toxicity towards mammalian cells and animals as well as aquatic creatures. The high leaching selectivity of Au over other metals during gold leaching is demonstrated, showing that this method has great potential for practical industrial application towards the sustainable refining of gold from ores and electronic waste. Milde Goldlaugung: Eine chemische Methode basierend auf einer wässrigen Lösung aus N‐Bromsuccinimid (NBS) und Pyridin (Py) kann genutzt werden, um Au0 selektiv aus Golderz und Elektronikschrott auszulaugen, wobei Au3+ gebildet wird. Eine Ausbeute von knapp 90 % wird bei Raumtemperatur und fast neutralem pH erzielt.