Quantitative X-ray µCT Measurement of the Effect of Ore Characteristics on Non-Surface Mineral Grain Leaching
In heap (bio)leaching processes, a substantial fraction of the valuable mineral is positioned below the ore particle surface. X-ray micro-computed tomography (μCT) was used to quantify the effect of ore type and structure and operating temperature on the leaching of this mineral, to investigate the...
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| Format: | Article |
| Language: | English |
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MDPI AG
2020-08-01
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| Series: | Minerals |
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| Online Access: | https://www.mdpi.com/2075-163X/10/9/746 |
| _version_ | 1797556155382235136 |
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| author | Mahdi Ghadiri Susan T.L. Harrison Marijke A. Fagan-Endres |
| author_facet | Mahdi Ghadiri Susan T.L. Harrison Marijke A. Fagan-Endres |
| author_sort | Mahdi Ghadiri |
| collection | DOAJ |
| description | In heap (bio)leaching processes, a substantial fraction of the valuable mineral is positioned below the ore particle surface. X-ray micro-computed tomography (μCT) was used to quantify the effect of ore type and structure and operating temperature on the leaching of this mineral, to investigate the rate-controlling factors. Mini-leaching columns containing agglomerated chalcopyrite, pyrite, and malachite ores were scanned by X-ray μCT (13.40 µm resolution) at select time intervals. The leaching of a relatively porous malachite ore was reaction-controlled, with no leaching penetration limitation into the ore particles. For two less porous ore types, the structure and higher porosity of the agglomerate rim and conditions that resulted in the degradation of the full ore matrix structure were found to be the determining variables of the leaching extent and time. In the case of a chalcopyrite ore, an enhancement of copper recovery and sulphide mineral dissolution with increasing temperature was attributable to the increased leaching penetration distance and crack development in addition to thermodynamically expected increased leaching rate. Increasing temperature did not affect the maximum penetration distance for the waste rock containing pyrite, with no crack development observed. Overall increases in iron recovery were due to accelerated leaching rates, though diffusion or mineral access limitations were evident at a higher temperature. |
| first_indexed | 2024-03-10T16:57:57Z |
| format | Article |
| id | doaj.art-53e670cc07164c50a864961d46364fc0 |
| institution | Directory Open Access Journal |
| issn | 2075-163X |
| language | English |
| last_indexed | 2024-03-10T16:57:57Z |
| publishDate | 2020-08-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Minerals |
| spelling | doaj.art-53e670cc07164c50a864961d46364fc02023-11-20T11:04:16ZengMDPI AGMinerals2075-163X2020-08-0110974610.3390/min10090746Quantitative X-ray µCT Measurement of the Effect of Ore Characteristics on Non-Surface Mineral Grain LeachingMahdi Ghadiri0Susan T.L. Harrison1Marijke A. Fagan-Endres2Institute of Research and Development, Duy Tan University, Da Nang 550000, VietnamCentre for Bioprocess Engineering Research, Department of Chemical Engineering, University of Cape Town, South Lane, Rondebosch, Cape Town 7700, South AfricaCentre for Bioprocess Engineering Research, Department of Chemical Engineering, University of Cape Town, South Lane, Rondebosch, Cape Town 7700, South AfricaIn heap (bio)leaching processes, a substantial fraction of the valuable mineral is positioned below the ore particle surface. X-ray micro-computed tomography (μCT) was used to quantify the effect of ore type and structure and operating temperature on the leaching of this mineral, to investigate the rate-controlling factors. Mini-leaching columns containing agglomerated chalcopyrite, pyrite, and malachite ores were scanned by X-ray μCT (13.40 µm resolution) at select time intervals. The leaching of a relatively porous malachite ore was reaction-controlled, with no leaching penetration limitation into the ore particles. For two less porous ore types, the structure and higher porosity of the agglomerate rim and conditions that resulted in the degradation of the full ore matrix structure were found to be the determining variables of the leaching extent and time. In the case of a chalcopyrite ore, an enhancement of copper recovery and sulphide mineral dissolution with increasing temperature was attributable to the increased leaching penetration distance and crack development in addition to thermodynamically expected increased leaching rate. Increasing temperature did not affect the maximum penetration distance for the waste rock containing pyrite, with no crack development observed. Overall increases in iron recovery were due to accelerated leaching rates, though diffusion or mineral access limitations were evident at a higher temperature.https://www.mdpi.com/2075-163X/10/9/746leachingnon-surface mineralcopperore typetemperatureporosity |
| spellingShingle | Mahdi Ghadiri Susan T.L. Harrison Marijke A. Fagan-Endres Quantitative X-ray µCT Measurement of the Effect of Ore Characteristics on Non-Surface Mineral Grain Leaching Minerals leaching non-surface mineral copper ore type temperature porosity |
| title | Quantitative X-ray µCT Measurement of the Effect of Ore Characteristics on Non-Surface Mineral Grain Leaching |
| title_full | Quantitative X-ray µCT Measurement of the Effect of Ore Characteristics on Non-Surface Mineral Grain Leaching |
| title_fullStr | Quantitative X-ray µCT Measurement of the Effect of Ore Characteristics on Non-Surface Mineral Grain Leaching |
| title_full_unstemmed | Quantitative X-ray µCT Measurement of the Effect of Ore Characteristics on Non-Surface Mineral Grain Leaching |
| title_short | Quantitative X-ray µCT Measurement of the Effect of Ore Characteristics on Non-Surface Mineral Grain Leaching |
| title_sort | quantitative x ray µct measurement of the effect of ore characteristics on non surface mineral grain leaching |
| topic | leaching non-surface mineral copper ore type temperature porosity |
| url | https://www.mdpi.com/2075-163X/10/9/746 |
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