Uncharted biotechnologies for gold exploration and processing
Maintaining the current state of the metal mining industry relies on the continual improvement of mineral exploration and processing technologies, enabling the economic recovery of low-grade and/or complex ore. In recent years, a paradigm shift in our understanding of the geomicrobiology of gold has occurred. This has been made possible byimprovements in micro-analytical technologies, experimental geochemistry and environmental metagenomics, which have allowed researchers to study gold geochemistry and geomicrobiology at a molecular level. Focused ion beam-scanning electron microscopy ( FIB-SEM) is used to characterise the three-dimensional distribution of gold in ores at nano- to micron-scales. Synchrotron spectroscopic techniques can unravel the geochemistry and speciation of gold within hydrothermal environments, mine dumps and tailings, and within individual microbial cells. Molecular techniques are bringing to light the dynamics of microbial communities associated with gold in environments of key interest to mining companies, such as prospects, waste rock piles and tailings. This fundamental understanding of gold geomicrobiology serves as a gateway for the development of a wide range of new applications, with the potential for transforming the whole mining chain, from exploration to production, tailing reprocessing and environmental rehabilitation. Advancements to the understanding of gold detoxification mechanisms in soil microorganisms are underpinning the development of molecular biosensors. This will allow for in-field/in-line measurements of gold at exploration sites and in processing plants. The processing of gold-containing ores traditionally relies on physicochemical mechanisms, such as roasting and cyanide-leaching, which are becoming technically and legislatively more problematic. Microbially assisted processing of gold ores is currently limited to the pre-processing of sulfidecontaining ores (i. e. , BIOX? process). The understanding of biogeochemical processes involving the dispersion and re-concentration of gold in natural environments can lead not only to the identification of new biological agents for use as bioindicators in mineral exploration, but also to the isolation and cultivation of novel microbial agents for use in selective biosolubilisation and in bioprecipitation. This will provide a greener technology for gold extraction, but also allow for economical metal recovery from low-grade gold ores and tailings. Abbreviations; CDRR: coupled dissolution replacement reaction; DGGE; denaturing gradient gel electrophoresis; EBSD; electron back-scattered diffraction; FIB; focused ion beam; FIB-SEMS; focused ion beam-scanning electron microscopy; HR-TEM; highresolution transmission electron microscopy; LMCE; low melting-point chalcophile elements; TEM; transmission electron microscopy; TGGE: thermal gradient gel electrophoresis; T-RFLP; terminalrestriction length polymorphism; RISC; reduced inorganic sulfur compounds; ROM; run-of-mine; SSCP: single strand conformation polymorphism; VMS: volcanogenic massive sulfide; μ-XRF : μ-X-ray fluorescence.
gold geomicrobiology ore processing mineralogy exploration
CarlaZammit Davide Quaranta Nigel Cook Joel Brugger Frank Reith
The University of Adelaide, School of Earth and Environmental Sciences, Centre of Tectonics,Resource University of Nebraska-Lincoln School of Biological Sciences, Lincoln, 68588, Nebraska, USA The University of Adelaide, School of Earth and Environmental Sciences, Centre of Tectonics,Resource
国际会议
The 19th International Biohydrometallurgy Symposium(第19届国际生物湿法冶金大会 IBS2011)
长沙
英文
491-498
2011-09-18（万方平台首次上网日期，不代表论文的发表时间）