Silica gel with covalently attached bambusuril macrocycle for dicyanoaurate sorption from water

• Michaela Šusterová and
• Vladimír Šindelář

Beilstein J. Org. Chem. 2025, 21, 2604–2611, doi:10.3762/bjoc.21.201

• remains a major challenge due to the strong hydration of anions. Here, we report the preparation of silica gel functionalized with covalently anchored bambusuril macrocycles. In aqueous solution, this material efficiently sorbs dicyanoaurate(I), the key anion in gold mining, even in the presence of

• ; gold mining; macrocycles; Introduction Inorganic anions play essential roles in a variety of biological and biochemical mechanisms and are also involved in many industrial and manufacturing processes. Due to their significant environmental impact, it is important to monitor their presence and control

• is able to remove dicyanoaurate(I) anion from water, the principal cyanide-based species generated during gold mining processes. However, the use of the SG-BnBU material is problematic as BnBU can leach from the material into the solution. To address this limitation, we have developed and herein

Gold extraction at the molecular level using α- and β-cyclodextrins

• Susana Santos Braga

Beilstein J. Org. Chem. 2025, 21, 1116–1125, doi:10.3762/bjoc.21.89

• the constant composition of 2:1 for α-CD to KAuBr4, in consistency with the single-crystal X-ray data. Application studies in gold mining facilities Process patenting and scale-up pilot trials in the United States: The discovery that α-CD can quickly precipitate gold, as detailed in the previous

• , α-CD·cyanoauride. Moreover, the use of α-CD offers the benefit of a selective isolation of Au(CN)2. The path is open for the integration of the α-CD stripping method into commercial gold mining protocols, with expected reductions in costs, energy consumption, and environmental impact. Research on

• recovery, revolve around the ability of α-CD·bromoaurate complexes to form infinite channels that self-aggregate and spontaneously precipitate as needle-shaped crystals. The discovery, serendipitous in its essence, has opened a new area of research and ended up bringing significant impact on the gold