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Cédric Carteret - One of the best experts on this subject based on the ideXlab platform.
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Remineralization of ferrous carbonate from bioreduction of natural goethite in the Lorraine Iron ore (Minette) by Shewanella putrefaciens
Chemical Geology, 2015Co-Authors: Baptiste Maitte, Frederic P. A. Jorand, Dragan Grgic, Mustapha Abdelmoula, Cédric CarteretAbstract:Bacterial Iron oxide reduction has been extensively studied over recent decades with the aim of improving knowledge of Fe-bearing mineral transformations. Chemically synthesized Fe(III) oxides such as ferrihydrite or goethite have mainly been used as Iron oxide models but very few studies have focused on natural oxides. The scope of our work was to evaluate the ability of Iron-reducing bacteria to transform Iron ore and to identify the nature and outcome of the reduced phases. For this purpose, Lothringen (minette), the oolitic Iron ore type found in the Lorraine area (North-East of France), was incubated with Shewanella putrefaciens CIP 80.40 as a model Iron-reducing bacteria. Chemical and mineralogical analyses (ferrozine assay, X-ray diffraction, diffuse reflectance infrared Fourier transform spectroscopy, Mossbauer spectroscopy, transmission electron microscopy) were performed on both aged (i.e. Iron ore oxidized by air during similar to 80 years of mining exploitation) and intact Iron ores, before and after bioreduction in anoxic conditions. The oolites of intact Iron ore were composed of goethite (alpha-FeOOH), with siderite (FeCO3) and phyllosilicates as cement. Oolites of the aged Iron ore contained hematite (alpha-Fe2O3), as well as goethite and significantly less siderite. We observed that 26% and 20% of goethite was bio-reduced for aged and intact Iron ore respectively. No other Fe(III) phase was significantly reduced. Natural Iron oxides constituting the Iron ore can now be considered more available for Iron-reducing bacteria than chemically synthesized oxides. The nano-crystallinity of Iron ore goethite and the presence of sorption sites for Fe(II) were suggested as explanations for this discrepancy. Finally, a poorly crystalline ferrous carbonate was the main Fe(II) phase formed during the bio-reduction process of the Iron ore (aged and intact). In the context of Iron Mines, the neo-formed ferrous carbonate could be a precursor of siderite and could recreate the diagenetic links and the inter-oolitic cohesion lost by the Iron ore during its oxidizing process. The long-term stability of Iron ore pillars would therefore be ensured.
Baptiste Maitte - One of the best experts on this subject based on the ideXlab platform.
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Remineralization of ferrous carbonate from bioreduction of natural goethite in the Lorraine Iron ore (Minette) by Shewanella putrefaciens
Chemical Geology, 2015Co-Authors: Baptiste Maitte, Frederic P. A. Jorand, Dragan Grgic, Mustapha Abdelmoula, Cédric CarteretAbstract:Bacterial Iron oxide reduction has been extensively studied over recent decades with the aim of improving knowledge of Fe-bearing mineral transformations. Chemically synthesized Fe(III) oxides such as ferrihydrite or goethite have mainly been used as Iron oxide models but very few studies have focused on natural oxides. The scope of our work was to evaluate the ability of Iron-reducing bacteria to transform Iron ore and to identify the nature and outcome of the reduced phases. For this purpose, Lothringen (minette), the oolitic Iron ore type found in the Lorraine area (North-East of France), was incubated with Shewanella putrefaciens CIP 80.40 as a model Iron-reducing bacteria. Chemical and mineralogical analyses (ferrozine assay, X-ray diffraction, diffuse reflectance infrared Fourier transform spectroscopy, Mossbauer spectroscopy, transmission electron microscopy) were performed on both aged (i.e. Iron ore oxidized by air during similar to 80 years of mining exploitation) and intact Iron ores, before and after bioreduction in anoxic conditions. The oolites of intact Iron ore were composed of goethite (alpha-FeOOH), with siderite (FeCO3) and phyllosilicates as cement. Oolites of the aged Iron ore contained hematite (alpha-Fe2O3), as well as goethite and significantly less siderite. We observed that 26% and 20% of goethite was bio-reduced for aged and intact Iron ore respectively. No other Fe(III) phase was significantly reduced. Natural Iron oxides constituting the Iron ore can now be considered more available for Iron-reducing bacteria than chemically synthesized oxides. The nano-crystallinity of Iron ore goethite and the presence of sorption sites for Fe(II) were suggested as explanations for this discrepancy. Finally, a poorly crystalline ferrous carbonate was the main Fe(II) phase formed during the bio-reduction process of the Iron ore (aged and intact). In the context of Iron Mines, the neo-formed ferrous carbonate could be a precursor of siderite and could recreate the diagenetic links and the inter-oolitic cohesion lost by the Iron ore during its oxidizing process. The long-term stability of Iron ore pillars would therefore be ensured.
Chantal Dion - One of the best experts on this subject based on the ideXlab platform.
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o32 6 elongate mineral particles in Iron and gold Mines is there an increased risk of cancer
Occupational and Environmental Medicine, 2016Co-Authors: Felix Gervais, Ginette Truchon, Guy Perrault, Chantal DionAbstract:Background Recent studies in Minnesota showed an increased risk of mesothelioma among Iron miners, and a significant dose-response relationship with cumulative exposure to elongate mineral particles (EMPs). This prompted us to assess the state of knowledge on potential contribution of EMPs in the aetiology of occupational lung diseases in Iron and gold miners. Methods We first systematically reviewed epidemiologic studies on Iron and gold miners’ health, and animal studies on health effects of EMPs (published since 1990), and then conducted an exploratory study of the geological characteristics of Iron and gold Mines in Quebec. Following a literature review of Mines for which health problems have been reported worldwide, a petrographic study was done on rock-specimens from several active and inactive Mines in Quebec to identify mineral species that could have an EMP morphology. Results Between January 1990 and February 2016, 24 epidemiological articles published in 7 countries mentioned cancer risks: only the Minnesota studies reported an increased risk of mesothelioma in Iron miners, whereas 2 articles mentioned a few mesothelioma cases in gold miners. Three available animal studies and 4 toxicological literature reviews inferred that other parameters than dimension may modulate toxicity. The geological literature review indicated that EMPs are expected in host rocks of gold Mines (tremolite and actinolite), and in rock-deposits of Iron Mines (grunerite). The identification of amphibole-EMPs in several specimens during our petrographic study confirmed these expectations. Conclusion The epidemiological literature does not describe adequately dimensional characteristics of the particles, and animal studies point to possible toxicity of cleavage fragments that meet dimensional criteria of WHO fibres. Geological settings of Iron and gold Mines in Quebec seem to favour the formation of amphibole EMPs. In the absence of fibre measurements in the Mines, the precautionary principle should be applied in order to protect workers adequately.
Frederic P. A. Jorand - One of the best experts on this subject based on the ideXlab platform.
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Remineralization of ferrous carbonate from bioreduction of natural goethite in the Lorraine Iron ore (Minette) by Shewanella putrefaciens
Chemical Geology, 2015Co-Authors: Baptiste Maitte, Frederic P. A. Jorand, Dragan Grgic, Mustapha Abdelmoula, Cédric CarteretAbstract:Bacterial Iron oxide reduction has been extensively studied over recent decades with the aim of improving knowledge of Fe-bearing mineral transformations. Chemically synthesized Fe(III) oxides such as ferrihydrite or goethite have mainly been used as Iron oxide models but very few studies have focused on natural oxides. The scope of our work was to evaluate the ability of Iron-reducing bacteria to transform Iron ore and to identify the nature and outcome of the reduced phases. For this purpose, Lothringen (minette), the oolitic Iron ore type found in the Lorraine area (North-East of France), was incubated with Shewanella putrefaciens CIP 80.40 as a model Iron-reducing bacteria. Chemical and mineralogical analyses (ferrozine assay, X-ray diffraction, diffuse reflectance infrared Fourier transform spectroscopy, Mossbauer spectroscopy, transmission electron microscopy) were performed on both aged (i.e. Iron ore oxidized by air during similar to 80 years of mining exploitation) and intact Iron ores, before and after bioreduction in anoxic conditions. The oolites of intact Iron ore were composed of goethite (alpha-FeOOH), with siderite (FeCO3) and phyllosilicates as cement. Oolites of the aged Iron ore contained hematite (alpha-Fe2O3), as well as goethite and significantly less siderite. We observed that 26% and 20% of goethite was bio-reduced for aged and intact Iron ore respectively. No other Fe(III) phase was significantly reduced. Natural Iron oxides constituting the Iron ore can now be considered more available for Iron-reducing bacteria than chemically synthesized oxides. The nano-crystallinity of Iron ore goethite and the presence of sorption sites for Fe(II) were suggested as explanations for this discrepancy. Finally, a poorly crystalline ferrous carbonate was the main Fe(II) phase formed during the bio-reduction process of the Iron ore (aged and intact). In the context of Iron Mines, the neo-formed ferrous carbonate could be a precursor of siderite and could recreate the diagenetic links and the inter-oolitic cohesion lost by the Iron ore during its oxidizing process. The long-term stability of Iron ore pillars would therefore be ensured.
Dragan Grgic - One of the best experts on this subject based on the ideXlab platform.
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Remineralization of ferrous carbonate from bioreduction of natural goethite in the Lorraine Iron ore (Minette) by Shewanella putrefaciens
Chemical Geology, 2015Co-Authors: Baptiste Maitte, Frederic P. A. Jorand, Dragan Grgic, Mustapha Abdelmoula, Cédric CarteretAbstract:Bacterial Iron oxide reduction has been extensively studied over recent decades with the aim of improving knowledge of Fe-bearing mineral transformations. Chemically synthesized Fe(III) oxides such as ferrihydrite or goethite have mainly been used as Iron oxide models but very few studies have focused on natural oxides. The scope of our work was to evaluate the ability of Iron-reducing bacteria to transform Iron ore and to identify the nature and outcome of the reduced phases. For this purpose, Lothringen (minette), the oolitic Iron ore type found in the Lorraine area (North-East of France), was incubated with Shewanella putrefaciens CIP 80.40 as a model Iron-reducing bacteria. Chemical and mineralogical analyses (ferrozine assay, X-ray diffraction, diffuse reflectance infrared Fourier transform spectroscopy, Mossbauer spectroscopy, transmission electron microscopy) were performed on both aged (i.e. Iron ore oxidized by air during similar to 80 years of mining exploitation) and intact Iron ores, before and after bioreduction in anoxic conditions. The oolites of intact Iron ore were composed of goethite (alpha-FeOOH), with siderite (FeCO3) and phyllosilicates as cement. Oolites of the aged Iron ore contained hematite (alpha-Fe2O3), as well as goethite and significantly less siderite. We observed that 26% and 20% of goethite was bio-reduced for aged and intact Iron ore respectively. No other Fe(III) phase was significantly reduced. Natural Iron oxides constituting the Iron ore can now be considered more available for Iron-reducing bacteria than chemically synthesized oxides. The nano-crystallinity of Iron ore goethite and the presence of sorption sites for Fe(II) were suggested as explanations for this discrepancy. Finally, a poorly crystalline ferrous carbonate was the main Fe(II) phase formed during the bio-reduction process of the Iron ore (aged and intact). In the context of Iron Mines, the neo-formed ferrous carbonate could be a precursor of siderite and could recreate the diagenetic links and the inter-oolitic cohesion lost by the Iron ore during its oxidizing process. The long-term stability of Iron ore pillars would therefore be ensured.