Extraction of Gold and Copper from Flotation Tailings Using Glycine-Ammonia Solutions in the Presence of Permanganate
This study presents the novel idea of a cyanide-free leaching method, i.e., glycine-ammonia leaching in the presence of permanganate, to treat a low-grade and copper-bearing gold tailing. Ammonia played a key role as a pH modifier, lixiviant and potential catalyst (as cupric ammine) in this study. R...
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MDPI AG
2022-05-01
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Online Access: | https://www.mdpi.com/2075-163X/12/5/612 |
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author | Huan Li Elsayed Oraby Jacques Eksteen Tanmay Mali |
author_facet | Huan Li Elsayed Oraby Jacques Eksteen Tanmay Mali |
author_sort | Huan Li |
collection | DOAJ |
description | This study presents the novel idea of a cyanide-free leaching method, i.e., glycine-ammonia leaching in the presence of permanganate, to treat a low-grade and copper-bearing gold tailing. Ammonia played a key role as a pH modifier, lixiviant and potential catalyst (as cupric ammine) in this study. Replacing ammonia with other pH modifiers (i.e., sodium hydroxide or lime) made the extractions infeasibly low (<30%). The increased additions of glycine (23–93 kg/t), ammonia (30–157 kg/t) and permanganate (5–20 kg/t) enhanced gold and copper extractions considerably. Increasing the solids content from 20 to 40% did not make any obvious changes to copper extraction. However, gold leaching kinetics was slightly better at lower solids content. It was indicated that the staged addition of permanganate was unnecessary under the leaching conditions. Recovery of gold by CIL was shown to be feasible, and it improved gold extraction by 15%, but no effect was observed for copper extraction. Percentages of 76.5% gold and 64.5% copper were extracted in 48 h at 20 g/L glycine, 10 kg/t permanganate, 20 g/L carbon, pH 10.5 and 30% solids. Higher extractions could be potentially achieved by further optimization, such as by increasing permanganate addition, extending leaching time and ultra-fine grinding. |
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language | English |
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spelling | doaj.art-e9e9666581184c26a19dde9cc6099c712023-11-23T12:19:25ZengMDPI AGMinerals2075-163X2022-05-0112561210.3390/min12050612Extraction of Gold and Copper from Flotation Tailings Using Glycine-Ammonia Solutions in the Presence of PermanganateHuan Li0Elsayed Oraby1Jacques Eksteen2Tanmay Mali3Western Australian School of Mines: Minerals, Energy and Chemical Engineering, Curtin University, Bentley, WA 6102, AustraliaWestern Australian School of Mines: Minerals, Energy and Chemical Engineering, Curtin University, Bentley, WA 6102, AustraliaWestern Australian School of Mines: Minerals, Energy and Chemical Engineering, Curtin University, Bentley, WA 6102, AustraliaWestern Australian School of Mines: Minerals, Energy and Chemical Engineering, Curtin University, Bentley, WA 6102, AustraliaThis study presents the novel idea of a cyanide-free leaching method, i.e., glycine-ammonia leaching in the presence of permanganate, to treat a low-grade and copper-bearing gold tailing. Ammonia played a key role as a pH modifier, lixiviant and potential catalyst (as cupric ammine) in this study. Replacing ammonia with other pH modifiers (i.e., sodium hydroxide or lime) made the extractions infeasibly low (<30%). The increased additions of glycine (23–93 kg/t), ammonia (30–157 kg/t) and permanganate (5–20 kg/t) enhanced gold and copper extractions considerably. Increasing the solids content from 20 to 40% did not make any obvious changes to copper extraction. However, gold leaching kinetics was slightly better at lower solids content. It was indicated that the staged addition of permanganate was unnecessary under the leaching conditions. Recovery of gold by CIL was shown to be feasible, and it improved gold extraction by 15%, but no effect was observed for copper extraction. Percentages of 76.5% gold and 64.5% copper were extracted in 48 h at 20 g/L glycine, 10 kg/t permanganate, 20 g/L carbon, pH 10.5 and 30% solids. Higher extractions could be potentially achieved by further optimization, such as by increasing permanganate addition, extending leaching time and ultra-fine grinding.https://www.mdpi.com/2075-163X/12/5/612glycineammonianon-cyanidegoldcopperlow-grade |
spellingShingle | Huan Li Elsayed Oraby Jacques Eksteen Tanmay Mali Extraction of Gold and Copper from Flotation Tailings Using Glycine-Ammonia Solutions in the Presence of Permanganate Minerals glycine ammonia non-cyanide gold copper low-grade |
title | Extraction of Gold and Copper from Flotation Tailings Using Glycine-Ammonia Solutions in the Presence of Permanganate |
title_full | Extraction of Gold and Copper from Flotation Tailings Using Glycine-Ammonia Solutions in the Presence of Permanganate |
title_fullStr | Extraction of Gold and Copper from Flotation Tailings Using Glycine-Ammonia Solutions in the Presence of Permanganate |
title_full_unstemmed | Extraction of Gold and Copper from Flotation Tailings Using Glycine-Ammonia Solutions in the Presence of Permanganate |
title_short | Extraction of Gold and Copper from Flotation Tailings Using Glycine-Ammonia Solutions in the Presence of Permanganate |
title_sort | extraction of gold and copper from flotation tailings using glycine ammonia solutions in the presence of permanganate |
topic | glycine ammonia non-cyanide gold copper low-grade |
url | https://www.mdpi.com/2075-163X/12/5/612 |
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