High-Pressure Oxidative Leaching and Iodide Leaching Followed by Selective Precipitation for Recovery of Base and Precious Metals from Waste Printed Circuit Boards Ash
This paper deals with the recovery of gold from waste printed circuit boards (WPCBs) ash by high-pressure oxidative leaching (HPOL) pre-treatment and iodide leaching followed by reduction precipitation. Base metals present in WPCB ash were removed via HPOL using a diluted sulfuric acid solution at e...
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MDPI AG
2019-03-01
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| Series: | Metals |
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| Online Access: | https://www.mdpi.com/2075-4701/9/3/363 |
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| author | Altansukh Batnasan Kazutoshi Haga Hsin-Hsiung Huang Atsushi Shibayama |
| author_facet | Altansukh Batnasan Kazutoshi Haga Hsin-Hsiung Huang Atsushi Shibayama |
| author_sort | Altansukh Batnasan |
| collection | DOAJ |
| description | This paper deals with the recovery of gold from waste printed circuit boards (WPCBs) ash by high-pressure oxidative leaching (HPOL) pre-treatment and iodide leaching followed by reduction precipitation. Base metals present in WPCB ash were removed via HPOL using a diluted sulfuric acid solution at elevated temperatures. Effects of potassium iodide concentration, hydrogen peroxide concentration, sulfuric acid concentration, leaching temperature, and leaching time on gold extraction from pure gold chips with KI–H<sub>2</sub>O<sub>2</sub>–H<sub>2</sub>SO<sub>4</sub> were investigated. The applicability of the optimized iodide leaching process for the extraction of gold from the leach residue obtained after HPOL were examined at different pulp densities ranging from 50 g/t to 200 g/t. Results show that the removal efficiency was 99% for Cu, 95.7% for Zn, 91% for Ni, 87.3% for Al, 82% for Co, and 70% for Fe under defined conditions. Under the optimal conditions, the percentage of gold extraction from the gold chips and the residue of WPCBs was 99% and 95%, respectively. About 99% of the gold was selectively precipitated from the pregnant leach solution by sequential precipitation with sodium hydroxide and L-ascorbic acid. Finally, more than 93% of gold recovery was achieved from WPCB ash by overall combined processes. |
| first_indexed | 2024-12-11T22:08:12Z |
| format | Article |
| id | doaj.art-1cfa5ab5dccc45fbae69a1420c23d3b1 |
| institution | Directory Open Access Journal |
| issn | 2075-4701 |
| language | English |
| last_indexed | 2024-12-11T22:08:12Z |
| publishDate | 2019-03-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Metals |
| spelling | doaj.art-1cfa5ab5dccc45fbae69a1420c23d3b12022-12-22T00:48:53ZengMDPI AGMetals2075-47012019-03-019336310.3390/met9030363met9030363High-Pressure Oxidative Leaching and Iodide Leaching Followed by Selective Precipitation for Recovery of Base and Precious Metals from Waste Printed Circuit Boards AshAltansukh Batnasan0Kazutoshi Haga1Hsin-Hsiung Huang2Atsushi Shibayama3Graduate School of International Resource Sciences, Akita University, 1-1 Tegata-Gakuen machi, Akita 010-8502, JapanGraduate School of International Resource Sciences, Akita University, 1-1 Tegata-Gakuen machi, Akita 010-8502, JapanDepartment of Metallurgy and Materials Engineering, Montana Technological University, 1300 West Park Street, Butte, MT 59701, USAGraduate School of International Resource Sciences, Akita University, 1-1 Tegata-Gakuen machi, Akita 010-8502, JapanThis paper deals with the recovery of gold from waste printed circuit boards (WPCBs) ash by high-pressure oxidative leaching (HPOL) pre-treatment and iodide leaching followed by reduction precipitation. Base metals present in WPCB ash were removed via HPOL using a diluted sulfuric acid solution at elevated temperatures. Effects of potassium iodide concentration, hydrogen peroxide concentration, sulfuric acid concentration, leaching temperature, and leaching time on gold extraction from pure gold chips with KI–H<sub>2</sub>O<sub>2</sub>–H<sub>2</sub>SO<sub>4</sub> were investigated. The applicability of the optimized iodide leaching process for the extraction of gold from the leach residue obtained after HPOL were examined at different pulp densities ranging from 50 g/t to 200 g/t. Results show that the removal efficiency was 99% for Cu, 95.7% for Zn, 91% for Ni, 87.3% for Al, 82% for Co, and 70% for Fe under defined conditions. Under the optimal conditions, the percentage of gold extraction from the gold chips and the residue of WPCBs was 99% and 95%, respectively. About 99% of the gold was selectively precipitated from the pregnant leach solution by sequential precipitation with sodium hydroxide and L-ascorbic acid. Finally, more than 93% of gold recovery was achieved from WPCB ash by overall combined processes.https://www.mdpi.com/2075-4701/9/3/363waste printed circuit boardgoldiodideiodineascorbic acidleachingprecipitation |
| spellingShingle | Altansukh Batnasan Kazutoshi Haga Hsin-Hsiung Huang Atsushi Shibayama High-Pressure Oxidative Leaching and Iodide Leaching Followed by Selective Precipitation for Recovery of Base and Precious Metals from Waste Printed Circuit Boards Ash Metals waste printed circuit board gold iodide iodine ascorbic acid leaching precipitation |
| title | High-Pressure Oxidative Leaching and Iodide Leaching Followed by Selective Precipitation for Recovery of Base and Precious Metals from Waste Printed Circuit Boards Ash |
| title_full | High-Pressure Oxidative Leaching and Iodide Leaching Followed by Selective Precipitation for Recovery of Base and Precious Metals from Waste Printed Circuit Boards Ash |
| title_fullStr | High-Pressure Oxidative Leaching and Iodide Leaching Followed by Selective Precipitation for Recovery of Base and Precious Metals from Waste Printed Circuit Boards Ash |
| title_full_unstemmed | High-Pressure Oxidative Leaching and Iodide Leaching Followed by Selective Precipitation for Recovery of Base and Precious Metals from Waste Printed Circuit Boards Ash |
| title_short | High-Pressure Oxidative Leaching and Iodide Leaching Followed by Selective Precipitation for Recovery of Base and Precious Metals from Waste Printed Circuit Boards Ash |
| title_sort | high pressure oxidative leaching and iodide leaching followed by selective precipitation for recovery of base and precious metals from waste printed circuit boards ash |
| topic | waste printed circuit board gold iodide iodine ascorbic acid leaching precipitation |
| url | https://www.mdpi.com/2075-4701/9/3/363 |
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