Team:British Columbia/ProjectBiomining

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A Separation Problem:
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'''A Separation Problem''':
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Our access to easily extractable copper is gradually diminishing as demands for copper continues to grow worldwide. To meet these demands, non-traditional, metallurgically challenging deposits are expected to become more prevalent, thereby forcing us to deal with more complex, and lower-grade ores containing higher levels of impurities.  Arsenic-challenged deposits is a concern for the copper mining industry as arsenic produces hazardous fumes and oxide dusts during the smelting process. Smelting with arsenic therefore poses a significant risk to the health of the workers and to the environment. Furthermore, safe removal and disposal of stabilized arsenic is often difficult and costly.  With stricter legislation in place, the mining industry is facing increasing pressure to progressively reduce the amount of allowable arsenic concentrations for smelters. Consequently, fines and penalties are set for arsenic concentrations exceeding 0.2%, while ores past 0.5% arsenic concentrations are rejected by smelters. Therefore, there is increasing precedence for removing arsenic-containing minerals such as enargite (Cu3AsS4)from relevant minerals, such as chalcopyrite (CuFeS2), during the flotation process. However, separation is often conflicted with shared flotation properties between enargite and the associated valuable minerals. The mining industry has developed several methods for dealing with arsenic impurities, which includes precipitation with scorodite and pressure hydrometallurgical procedures (150C and 1380kPa) for processing high concentration of arsenic while extracting copper in parallel. However, many procedures requires an enormous amount of energy or additional acidic chemicals to help selectively separate arensic-containing minerals in the ore mixtures.
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Our access to easily extractable copper is gradually diminishing as demands for copper continues to grow worldwide. To meet these demands, non-traditional, metallurgically challenging deposits are expected to become more prevalent, thereby forcing us to deal with more complex, and lower-grade ores containing higher levels of impurities.  Arsenic-challenged deposits is a concern for the copper mining industry as arsenic produces hazardous fumes and oxide dusts during the smelting process. Smelting with arsenic therefore poses a significant risk to the health of the workers and to the environment. Furthermore, safe removal and disposal of stabilized arsenic is often difficult and costly.  With stricter legislation in place, the mining industry is facing increasing pressure to progressively reduce the amount of allowable arsenic concentrations for smelters. Consequently, fines and penalties are set for arsenic concentrations exceeding 0.2%, while ores past 0.5% arsenic concentrations are rejected by smelters. Therefore, there is increasing precedence for removing arsenic-containing minerals such as enargite (Cu3AsS4)from relevant sulfide minerals, such as chalcopyrite (CuFeS2), during the flotation process. However, separation is often conflicted with shared flotation properties between enargite and the associated valuable minerals. The mining industry has developed several methods for dealing with arsenic impurities, which includes precipitation with scorodite and pressure hydrometallurgical procedures (150C and 1380kPa) for processing high concentration of arsenic while extracting copper in parallel. However, many procedures requires an enormous amount of energy or additional acidic chemicals to help selectively separate arensic-containing minerals in the ore mixtures.
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Our solution:
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'''Our solution''':
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We, the UBC iGEM team, feel that separation can be done other ways that does not have to  
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We, the UBC iGEM team, feel that separation and enrichment can be done in other ways that does not rely on energy or chemically-intensive methods. Our solution involves the use of small surface heptapeptides, which have been demonstrated in M13 bacteriophage to selectively bind  to chalcopyrite. Our goal is to sink these
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TPTTYKV,
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Here we show the first application of phage biotechnology to the processing of economically important minerals in ore slurries. A random heptapeptide library was screened for peptide sequences that bind selectively to the minerals sphalerite (ZnS) and chalcopyrite (CuFeS2). After several rounds of enrichment, cloned phage containing the surface peptide loops KPLLMGS and QPKGPKQ bound specifically to sphalerite. Phage containing the peptide loop TPTTYKV bound to both sphalerite and chalcopyrite. By using an enzyme-linked immunosorbant assay (ELISA), the phage was characterized as strong binders compared to wild-type phage. Specificity of binding was confirmed by immunochemical visualization of phage bound to mineral particles but not to silica (a waste mineral) or pyrite. The current study focused primarily on the isolation of ZnS-specific phage that could be utilized in the separation of sphalerite from silica. At mining sites where sphalerite and chalcopyrite are not found together in natural ores, the separation of sphalerite from silica would be an appropriate enrichment step. At mining sites where sphalerite and chalcopyrite do occur together, more specific phage would be required. This bacteriophage has the potential to be used in a more selective method of mineral separation and to be the basis for advanced methods of mineral processing.
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2014 UBC iGEM

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