Deportment of Metals from E-Waste PCBs towards Alloy and Slag Phases during Smelting Using CaO-Al<sub>2</sub>O<sub>3</sub>-SiO<sub>2</sub>-B<sub>2</sub>O<sub>3</sub> Slags
Printed circuit boards (PCBs) from antiquated electronic goods were processed by a pyrometallurgical route to produce and separate alloy and slag phases. The process involved initial size reduction of PCBs, followed by pyrolysis at 500 °C for 6 h and finally smelting of the solid materials in an ele...
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MDPI AG
2023-05-01
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| Series: | Minerals |
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| Online Access: | https://www.mdpi.com/2075-163X/13/6/727 |
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| author | Md Khairul Islam Michael Somerville Mark I. Pownceby James Tardio Nawshad Haque Suresh Bhargava |
| author_facet | Md Khairul Islam Michael Somerville Mark I. Pownceby James Tardio Nawshad Haque Suresh Bhargava |
| author_sort | Md Khairul Islam |
| collection | DOAJ |
| description | Printed circuit boards (PCBs) from antiquated electronic goods were processed by a pyrometallurgical route to produce and separate alloy and slag phases. The process involved initial size reduction of PCBs, followed by pyrolysis at 500 °C for 6 h and finally smelting of the solid materials in an electric furnace. A preliminary smelting test was performed at 1600 °C to estimate the composition of the slag generated. In later kilogram-scale smelting experiments, B<sub>2</sub>O<sub>3</sub> flux was added along with CaO and SiO<sub>2</sub> to decrease the liquidus temperature required to smelt the PCBs. The level of fluxing was adapted from earlier phase equilibria studies of the CaO-Al<sub>2</sub>O<sub>3</sub>-SiO<sub>2</sub>-B<sub>2</sub>O<sub>3</sub> slag system. Results showed that the flux decreased the melting temperature and assisted the recovery of most valuable metals within the alloy phase at 1350 °C smelting temperature. The alloy phase recovered 99.8% of Cu, 99% of Sn, and 100% of precious metals (Au, Ag, Pt). A fluxing strategy for smelting high Al<sub>2</sub>O<sub>3</sub> containing e-waste PCBs was proposed based on the experimental findings of this research. |
| first_indexed | 2024-03-11T02:06:59Z |
| format | Article |
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| institution | Directory Open Access Journal |
| issn | 2075-163X |
| language | English |
| last_indexed | 2024-03-11T02:06:59Z |
| publishDate | 2023-05-01 |
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| series | Minerals |
| spelling | doaj.art-2244d796e03c499d997395888d6fabba2023-11-18T11:44:43ZengMDPI AGMinerals2075-163X2023-05-0113672710.3390/min13060727Deportment of Metals from E-Waste PCBs towards Alloy and Slag Phases during Smelting Using CaO-Al<sub>2</sub>O<sub>3</sub>-SiO<sub>2</sub>-B<sub>2</sub>O<sub>3</sub> SlagsMd Khairul Islam0Michael Somerville1Mark I. Pownceby2James Tardio3Nawshad Haque4Suresh Bhargava5Centre for Advanced Materials & Industrial Chemistry (CAMIC), School of Science, RMIT University, Melbourne, VIC 3001, AustraliaCSIRO Mineral Resources, Clayton South, Melbourne, VIC 3169, AustraliaCSIRO Mineral Resources, Clayton South, Melbourne, VIC 3169, AustraliaCentre for Advanced Materials & Industrial Chemistry (CAMIC), School of Science, RMIT University, Melbourne, VIC 3001, AustraliaCSIRO Energy, Clayton South, Melbourne, VIC 3169, AustraliaCentre for Advanced Materials & Industrial Chemistry (CAMIC), School of Science, RMIT University, Melbourne, VIC 3001, AustraliaPrinted circuit boards (PCBs) from antiquated electronic goods were processed by a pyrometallurgical route to produce and separate alloy and slag phases. The process involved initial size reduction of PCBs, followed by pyrolysis at 500 °C for 6 h and finally smelting of the solid materials in an electric furnace. A preliminary smelting test was performed at 1600 °C to estimate the composition of the slag generated. In later kilogram-scale smelting experiments, B<sub>2</sub>O<sub>3</sub> flux was added along with CaO and SiO<sub>2</sub> to decrease the liquidus temperature required to smelt the PCBs. The level of fluxing was adapted from earlier phase equilibria studies of the CaO-Al<sub>2</sub>O<sub>3</sub>-SiO<sub>2</sub>-B<sub>2</sub>O<sub>3</sub> slag system. Results showed that the flux decreased the melting temperature and assisted the recovery of most valuable metals within the alloy phase at 1350 °C smelting temperature. The alloy phase recovered 99.8% of Cu, 99% of Sn, and 100% of precious metals (Au, Ag, Pt). A fluxing strategy for smelting high Al<sub>2</sub>O<sub>3</sub> containing e-waste PCBs was proposed based on the experimental findings of this research.https://www.mdpi.com/2075-163X/13/6/727e-wastesmeltingborate fluxprecious metalsslagphase equilibria |
| spellingShingle | Md Khairul Islam Michael Somerville Mark I. Pownceby James Tardio Nawshad Haque Suresh Bhargava Deportment of Metals from E-Waste PCBs towards Alloy and Slag Phases during Smelting Using CaO-Al<sub>2</sub>O<sub>3</sub>-SiO<sub>2</sub>-B<sub>2</sub>O<sub>3</sub> Slags Minerals e-waste smelting borate flux precious metals slag phase equilibria |
| title | Deportment of Metals from E-Waste PCBs towards Alloy and Slag Phases during Smelting Using CaO-Al<sub>2</sub>O<sub>3</sub>-SiO<sub>2</sub>-B<sub>2</sub>O<sub>3</sub> Slags |
| title_full | Deportment of Metals from E-Waste PCBs towards Alloy and Slag Phases during Smelting Using CaO-Al<sub>2</sub>O<sub>3</sub>-SiO<sub>2</sub>-B<sub>2</sub>O<sub>3</sub> Slags |
| title_fullStr | Deportment of Metals from E-Waste PCBs towards Alloy and Slag Phases during Smelting Using CaO-Al<sub>2</sub>O<sub>3</sub>-SiO<sub>2</sub>-B<sub>2</sub>O<sub>3</sub> Slags |
| title_full_unstemmed | Deportment of Metals from E-Waste PCBs towards Alloy and Slag Phases during Smelting Using CaO-Al<sub>2</sub>O<sub>3</sub>-SiO<sub>2</sub>-B<sub>2</sub>O<sub>3</sub> Slags |
| title_short | Deportment of Metals from E-Waste PCBs towards Alloy and Slag Phases during Smelting Using CaO-Al<sub>2</sub>O<sub>3</sub>-SiO<sub>2</sub>-B<sub>2</sub>O<sub>3</sub> Slags |
| title_sort | deportment of metals from e waste pcbs towards alloy and slag phases during smelting using cao al sub 2 sub o sub 3 sub sio sub 2 sub b sub 2 sub o sub 3 sub slags |
| topic | e-waste smelting borate flux precious metals slag phase equilibria |
| url | https://www.mdpi.com/2075-163X/13/6/727 |
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