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Updated: Jun 25, 2025
09:04
A Direct, Early Stage Guanidinylation Protocol for the Synthesis of Complex Aminoguanidine-containing Natural Products
Published on: September 9, 2016
10.6K
Effectively adsorb Au(S2O3)23- using aminoguanidine as trapping group from thiosulfate solutions
Yihuai Yang1, Xianzhi Hu2, Futing Zi1
1Faculty of Science, Kunming University of Science and Technology, Kunming, 650500, Yunnan, China.
Summary
Aminoguanidine-functionalized microspheres (AGMs) efficiently recover gold(I) from thiosulfate solutions. This green extraction method shows promise for sustainable gold recovery, with AGMs demonstrating good cyclic stability and adsorption capacity.
Area of Science:
- Materials Science
- Chemical Engineering
- Environmental Science
Background:
- Thiosulfate leaching offers a greener alternative to cyanide for gold extraction.
- Efficient recovery of gold(I) from thiosulfate solutions remains a significant challenge.
- Developing novel adsorbents is crucial for advancing cyanide-free gold processing.
Purpose of the Study:
- To develop and evaluate aminoguanidine-functionalized microspheres (AGMs) for adsorbing gold(I) from thiosulfate solutions.
- To investigate the adsorption performance and mechanism of AGMs for gold recovery.
- To assess the cyclic application potential and practical applicability of AGMs.
Main Methods:
- Synthesis of AGMs via nucleophilic substitution.
- Characterization of AGMs using SEM, BET, FTIR, and XPS.
- Adsorption experiments to determine the effects of pH, temperature, and concentrations.
- Kinetic and isotherm modeling (pseudo-second-order and Langmuir).
- Desorption studies using acidic thiourea and cyclic testing.
- Density functional theory (DFT) calculations for mechanism elucidation.
Main Results:
- AGMs demonstrated efficient Au(I) adsorption across a wide pH range.
- The adsorption process followed pseudo-second-order kinetics and Langmuir isotherm models.
- Maximum adsorption capacity reached 22.03 kg/t.
- AGMs showed good cyclic stability with 78.63% adsorption after four cycles.
- Anion exchange was identified as the primary adsorption mechanism.
- Satisfactory performance was observed in complex practical systems.
Conclusions:
- AGMs are effective adsorbents for Au(I) recovery from thiosulfate leachates.
- The developed adsorbent exhibits high capacity, good recyclability, and a well-defined adsorption mechanism.
- This study provides a viable pathway for sustainable and efficient gold recovery using thiosulfate leaching.
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