Liquid distribution in drip irrigated heap bioleaching of ore and its influence on microbial colonization
| dc.contributor.author | Fagan, M A | |
| dc.contributor.author | Ngoma, E | |
| dc.contributor.author | Chiume, R A | |
| dc.contributor.author | Harrison, S T L | |
| dc.date | 2014-10-22 | |
| dc.date.accessioned | 2016-08-22T12:41:19Z | |
| dc.date.available | 2016-08-22T12:41:19Z | |
| dc.date.issued | 2016-08-22 | |
| dc.date.updated | 2016-08-22T11:53:59Z | |
| dc.description.abstract | Heap bioleaching is an unsaturated hydrometallurgical extraction process which is commonly applied to the recovery of copper from low grade sulfide ores as well as for preparatory treatment of gold ores. The leaching reactions occur in the liquid phase, catalysed by iron and/or sulfur oxidising micro-organisms. Contact of the mineral grains with the leaching solution is consequently essential for metal recovery. Additionally, the liquid is responsible for the transport of the liberated metal out of the heap under gravitation-driven flow. However, the highly inhomogeneous structure of the heaps coupled with low irrigation rates cause the flow to vary between being gravitationally and capillary dominated, resulting in non-uniform wetting of the ore. In this study a 132 kg agglomerated ore ‘slice’ is used to examine the effect of liquid distribution on microbial colonisation and mineral recovery in a long term bioleach (> 500 days) when irrigation from a single drip emitter source is employed. The novel setup enabled sample collection from ports positioned along the length and height of the ore bed, so that 2D maps of the degree of wetting and microbial colonisation could be generated at different times in the leach. Lateral movement of the liquid increased with bed depth; the majority of flow was below the irrigation point while the top corner of the bed that was not irrigated remained the driest region of the heap throughout the experiment duration. The lowest cell numbers were also recorded in the driest regions. Specifically, cell numbers in the top corner of the bed, 400mm from the irrigation point, remained at undetectable levels until the 283rd day measurement, in line with typical heap operation durations. This indicates that slow colonisation of the heap in the regions between irrigation points may be a significant issue in heap optimisation. | en_ZA |
| dc.identifier.apacitation | Fagan, M. A., Ngoma, E., Chiume, R. A., & Harrison, S. T. L. (2016). <i>Liquid distribution in drip irrigated heap bioleaching of ore and its influence on microbial colonization</i>. Chile, International Mineral Processing. http://hdl.handle.net/11427/21435 | en_ZA |
| dc.identifier.chicagocitation | Fagan, M A, E Ngoma, R A Chiume, and S T L Harrison. "Liquid distribution in drip irrigated heap bioleaching of ore and its influence on microbial colonization." 2014-10-22, Chile. International Mineral Processing. http://hdl.handle.net/11427/21435. | en_ZA |
| dc.identifier.citation | Fagan, M. A., Ngoma, E., Chiume, R. A. & Harrison, S. T. L. 2014. Liquid distribution in drip irrigated heap bioleaching of ore and its influence on microbial colonization. Proceedings of 27th International Mineral Processing Congress. 20 - 24th October. Santiago: Chile. | en_ZA |
| dc.identifier.ris | TY - Conference Paper AU - Fagan, M A AU - Ngoma, E AU - Chiume, R A AU - Harrison, S T L AB - Heap bioleaching is an unsaturated hydrometallurgical extraction process which is commonly applied to the recovery of copper from low grade sulfide ores as well as for preparatory treatment of gold ores. The leaching reactions occur in the liquid phase, catalysed by iron and/or sulfur oxidising micro-organisms. Contact of the mineral grains with the leaching solution is consequently essential for metal recovery. Additionally, the liquid is responsible for the transport of the liberated metal out of the heap under gravitation-driven flow. However, the highly inhomogeneous structure of the heaps coupled with low irrigation rates cause the flow to vary between being gravitationally and capillary dominated, resulting in non-uniform wetting of the ore. In this study a 132 kg agglomerated ore ‘slice’ is used to examine the effect of liquid distribution on microbial colonisation and mineral recovery in a long term bioleach (> 500 days) when irrigation from a single drip emitter source is employed. The novel setup enabled sample collection from ports positioned along the length and height of the ore bed, so that 2D maps of the degree of wetting and microbial colonisation could be generated at different times in the leach. Lateral movement of the liquid increased with bed depth; the majority of flow was below the irrigation point while the top corner of the bed that was not irrigated remained the driest region of the heap throughout the experiment duration. The lowest cell numbers were also recorded in the driest regions. Specifically, cell numbers in the top corner of the bed, 400mm from the irrigation point, remained at undetectable levels until the 283rd day measurement, in line with typical heap operation durations. This indicates that slow colonisation of the heap in the regions between irrigation points may be a significant issue in heap optimisation. CY - Chile DA - 2016-08-22 DB - OpenUCT DP - University of Cape Town LK - https://open.uct.ac.za PB - University of Cape Town PP - Chile PY - 2016 T1 - Liquid distribution in drip irrigated heap bioleaching of ore and its influence on microbial colonization TI - Liquid distribution in drip irrigated heap bioleaching of ore and its influence on microbial colonization UR - http://hdl.handle.net/11427/21435 ER - | en_ZA |
| dc.identifier.uri | http://hdl.handle.net/11427/21435 | |
| dc.identifier.vancouvercitation | Fagan MA, Ngoma E, Chiume RA, Harrison STL, Liquid distribution in drip irrigated heap bioleaching of ore and its influence on microbial colonization. ; 2014-10-22; Chile. International Mineral Processing; 2016. http://hdl.handle.net/11427/21435 . | en_ZA |
| dc.language | eng | en_ZA |
| dc.publisher | International Mineral Processing | en_ZA |
| dc.publisher.institution | University of Cape Town | |
| dc.publisher.location | Chile | en_ZA |
| dc.relation.ispartofseries | International Mineral Processing Congress | en_ZA |
| dc.subject.other | Mineral Bioprocess Engineering | |
| dc.title | Liquid distribution in drip irrigated heap bioleaching of ore and its influence on microbial colonization | en_ZA |
| dc.type | Conference Paper | en_ZA |
| uct.type.filetype | Text | |
| uct.type.filetype | Image | |
| uct.type.publication | Research | en_ZA |
| uct.type.resource | Conference paper | en_ZA |