The Experts below are selected from a list of 4509 Experts worldwide ranked by ideXlab platform
Catherine Joulian - One of the best experts on this subject based on the ideXlab platform.
-
Quantitative Monitoring of Microbial Species during Bioleaching of a Copper Concentrate
Frontiers in Microbiology, 2016Co-Authors: Sabrina Hedrich, Axel Schippers, Anne-gwenaëlle Guezennec, Mickaël Charron, Catherine JoulianAbstract:Monitoring of the microbial community in bioleaching processes is essential in order to control process parameters and enhance the leaching efficiency. Suitable methods are, however, limited as they are usually not adapted to bioleaching samples and often no taxon-specific assays are available in the literature for these types of consortia. Therefore, our study focused on the development of novel quantitative real-time PCR (qPCR) assays for the quantification of Acidithiobacillus caldus, Leptospirillum ferriphilum, Sulfobacillus thermosulfidooxidans, and Sulfobacillus benefaciens and comparison of the results with data from other common molecular monitoring methods in order to evaluate their accuracy and specificity. Stirred tank bioreactors for the leaching of Copper Concentrate, housing a consortium of acidophilic, moderately thermophilic bacteria, relevant in several bioleaching operations, served as a model system. The microbial community analysis via qPCR allowed a precise monitoring of the evolution of total biomass as well as abundance of specific species. Data achieved by the standard fingerprinting methods, terminal restriction fragment length polymorphism (T-RFLP) and capillary electrophoresis single strand conformation polymorphism (CE-SSCP) on the same samples followed the same trend as qPCR data. The main added value of qPCR was, however, to provide quantitative data for each species whereas only relative abundance could be deduced from T-RFLP and CE-SSCP profiles. Additional value was obtained by applying two further quantitative methods which do not require nucleic acid extraction, total cell counting after SYBR Green staining and metal sulfide oxidation activity measurements via microcalorimetry. Overall, these complementary methods allow for an efficient quantitative microbial community monitoring in various bioleaching operations.
-
Relationship between bioleaching performance, bacterial community structure and mineralogy in the bioleaching of a Copper Concentrate in stirred-tank reactors
Applied Microbiology and Biotechnology, 2011Co-Authors: Pauline Spolaore, Catherine Joulian, Jérôme Gouin, Dominique Morin, Patrick D'huguesAbstract:During the Bioshale European project, a technoeconomic study of the bioleaching of a Copper Concentrate originating from a black shale ore was carried out. This Concentrate is a multi-mineral resource in which the Copper sulphides are mainly chalcocite, covellite, bornite and chalcopyrite. The experiments undertaken to produce the techno-economic data were also an opportunity to carry out more fundamental research. The objective of this work was to combine the results of the bioleaching experiments, in terms of Copper recovery, with the results of bacterial community monitoring and mineralogy residue analysis. Batch and continuous bioleaching tests were carried out with 10% solids, at 42 °C and with a pH between 1.2 and 1.6. Final Copper recovery was higher in batch cultures than in continuous mode (>95% vs. 91%). Mineralogical analysis showed that the limiting factor for Copper recovery was incomplete chalcopyrite dissolution in both cases. However, chalcopyrite was even less dissolved in continuous conditions. This was also related to a variation in bacterial community structure. The population in all tests was composed of Acidithiobacillus caldus, Leptospirillum ferriphilum and one or two species of Sulfobacillus (Sulfobacillus thermosulfidooxidans and sometimes Sulfobacillus benefaciens), but Sulfobacillus and more generally sulphur oxidizers were more represented in batch mode. It was proposed that due to their capacity to reduce inorganic compounds, sulphur oxidizers may be efficient in limiting chalcopyrite surface hindering. It may help to better dissolve this mineral and reach a better Copper recovery.
-
Non-traditional operating conditions for a Copper Concentrate continuous bioleaching
2010Co-Authors: Pauline Spolaore, Catherine Joulian, Yannick Menard, Patrick D'huguesAbstract:The Polish Copper Concentrate subject of this study is produced by flotation from a black shale organic rich ore. Due to ore specific properties, flotation indexes have always been poor in the Polish concentrator. Moreover, in the last 5-6 years, ore characteristics dramatically changed and the Concentrate grades (mostly Cu and As) degraded. As a consequence, research on alternative technologies to pyrometallurgy is necessary. Bioleaching efficiency was already demonstrated during the Bioshale FP6 European project. However, some improvements were still needed to be achieved in order to meet process economic viability. In the frame of Promine FP7 European project, our study aimed at improving the profitability of the continuous bioleaching of the Copper Concentrate in stirred tank reactors. Non traditional operating conditions were tested: high solids concentration (> 20% solids), reduced agitation and aeration rates. The follow-up of the experiment consisted in both physical parameters measurements (pH, Eh, oxygen uptake rates...) but also in the monitoring of the bacterial population using molecular biology techniques. Keywords: Sulphide ore, bioleaching, ore mineralogy
Sabrina Hedrich - One of the best experts on this subject based on the ideXlab platform.
-
Selective Chemical and Biological Metal Recovery from Cu-Rich Bioleaching Solutions
Solid State Phenomena, 2017Co-Authors: Sabrina Hedrich, René Kermer, Tim Aubel, Mirko Martin, Axel Schippers, D. Barrie Johnson, Eberhard JanneckAbstract:Pregnant leach solutions (PLS) resulting from bioleaching of Copper Concentrate from Kupferschiefer are characterized by low pH and high concentrations of Fe, Cu, Zn as well as significant amounts of Ni and Co. In order to recover the valuable metals for further processing, chemical methods and a novel biological-induced technique that promotes selective metal recovery and sulfate removal from acidic liquors were applied and a process scheme was developed.
-
Quantitative Monitoring of Microbial Species during Bioleaching of a Copper Concentrate
Frontiers in Microbiology, 2016Co-Authors: Sabrina Hedrich, Axel Schippers, Anne-gwenaëlle Guezennec, Mickaël Charron, Catherine JoulianAbstract:Monitoring of the microbial community in bioleaching processes is essential in order to control process parameters and enhance the leaching efficiency. Suitable methods are, however, limited as they are usually not adapted to bioleaching samples and often no taxon-specific assays are available in the literature for these types of consortia. Therefore, our study focused on the development of novel quantitative real-time PCR (qPCR) assays for the quantification of Acidithiobacillus caldus, Leptospirillum ferriphilum, Sulfobacillus thermosulfidooxidans, and Sulfobacillus benefaciens and comparison of the results with data from other common molecular monitoring methods in order to evaluate their accuracy and specificity. Stirred tank bioreactors for the leaching of Copper Concentrate, housing a consortium of acidophilic, moderately thermophilic bacteria, relevant in several bioleaching operations, served as a model system. The microbial community analysis via qPCR allowed a precise monitoring of the evolution of total biomass as well as abundance of specific species. Data achieved by the standard fingerprinting methods, terminal restriction fragment length polymorphism (T-RFLP) and capillary electrophoresis single strand conformation polymorphism (CE-SSCP) on the same samples followed the same trend as qPCR data. The main added value of qPCR was, however, to provide quantitative data for each species whereas only relative abundance could be deduced from T-RFLP and CE-SSCP profiles. Additional value was obtained by applying two further quantitative methods which do not require nucleic acid extraction, total cell counting after SYBR Green staining and metal sulfide oxidation activity measurements via microcalorimetry. Overall, these complementary methods allow for an efficient quantitative microbial community monitoring in various bioleaching operations.
-
Development of a Strategy for Selective Metal Recovery from Pregnant Leach Solutions of Kupferschiefer Bioleaching
Advanced Materials Research, 2015Co-Authors: Sabrina Hedrich, Axel Schippers, D. Barrie JohnsonAbstract:Pregnant leach solutions (PLS) resulting from bioleaching of Copper Concentrate from Kupferschiefer are characterized by low pH values and high concentrations of mainly ferric iron, Copper, zinc and sulfate, as well as significant amounts of nickel and cobalt. In order to recover the valuable metals for further processing, a novel technique that promotes selective metal recovery and sulfate removal from acidic liquors, described in this study, is proposed.
M J Garcia - One of the best experts on this subject based on the ideXlab platform.
-
leaching of a Copper zinc bulk sulphide Concentrate using an aqueous ferric sulphate dilute solution in a semicontinuous system kinetics of dissolution of zinc
Hydrometallurgy, 1990Co-Authors: I Palencia, F Carranza, M J GarciaAbstract:Abstract The selective dissolution of zinc from a Spanish Copper/zinc sulphide Concentrate using acidic ferric sulphate solution at low concentration was investigated. A semicontinuous operation was employed in the experiments. The dissolution rate of zinc follows a parabolic equation which fits the Crank-Ginstling and Brounshtein model well. Dissolution of zinc up to nearly 80% was achieved; the residue was a Copper Concentrate suitable for treatment by a conventional pyrometallurgical process after separation of solid sulphur and lead sulphate.
Patrick D'hugues - One of the best experts on this subject based on the ideXlab platform.
-
Relationship between bioleaching performance, bacterial community structure and mineralogy in the bioleaching of a Copper Concentrate in stirred-tank reactors
Applied Microbiology and Biotechnology, 2011Co-Authors: Pauline Spolaore, Catherine Joulian, Jérôme Gouin, Dominique Morin, Patrick D'huguesAbstract:During the Bioshale European project, a technoeconomic study of the bioleaching of a Copper Concentrate originating from a black shale ore was carried out. This Concentrate is a multi-mineral resource in which the Copper sulphides are mainly chalcocite, covellite, bornite and chalcopyrite. The experiments undertaken to produce the techno-economic data were also an opportunity to carry out more fundamental research. The objective of this work was to combine the results of the bioleaching experiments, in terms of Copper recovery, with the results of bacterial community monitoring and mineralogy residue analysis. Batch and continuous bioleaching tests were carried out with 10% solids, at 42 °C and with a pH between 1.2 and 1.6. Final Copper recovery was higher in batch cultures than in continuous mode (>95% vs. 91%). Mineralogical analysis showed that the limiting factor for Copper recovery was incomplete chalcopyrite dissolution in both cases. However, chalcopyrite was even less dissolved in continuous conditions. This was also related to a variation in bacterial community structure. The population in all tests was composed of Acidithiobacillus caldus, Leptospirillum ferriphilum and one or two species of Sulfobacillus (Sulfobacillus thermosulfidooxidans and sometimes Sulfobacillus benefaciens), but Sulfobacillus and more generally sulphur oxidizers were more represented in batch mode. It was proposed that due to their capacity to reduce inorganic compounds, sulphur oxidizers may be efficient in limiting chalcopyrite surface hindering. It may help to better dissolve this mineral and reach a better Copper recovery.
-
Non-traditional operating conditions for a Copper Concentrate continuous bioleaching
2010Co-Authors: Pauline Spolaore, Catherine Joulian, Yannick Menard, Patrick D'huguesAbstract:The Polish Copper Concentrate subject of this study is produced by flotation from a black shale organic rich ore. Due to ore specific properties, flotation indexes have always been poor in the Polish concentrator. Moreover, in the last 5-6 years, ore characteristics dramatically changed and the Concentrate grades (mostly Cu and As) degraded. As a consequence, research on alternative technologies to pyrometallurgy is necessary. Bioleaching efficiency was already demonstrated during the Bioshale FP6 European project. However, some improvements were still needed to be achieved in order to meet process economic viability. In the frame of Promine FP7 European project, our study aimed at improving the profitability of the continuous bioleaching of the Copper Concentrate in stirred tank reactors. Non traditional operating conditions were tested: high solids concentration (> 20% solids), reduced agitation and aeration rates. The follow-up of the experiment consisted in both physical parameters measurements (pH, Eh, oxygen uptake rates...) but also in the monitoring of the bacterial population using molecular biology techniques. Keywords: Sulphide ore, bioleaching, ore mineralogy
Axel Schippers - One of the best experts on this subject based on the ideXlab platform.
-
Selective Chemical and Biological Metal Recovery from Cu-Rich Bioleaching Solutions
Solid State Phenomena, 2017Co-Authors: Sabrina Hedrich, René Kermer, Tim Aubel, Mirko Martin, Axel Schippers, D. Barrie Johnson, Eberhard JanneckAbstract:Pregnant leach solutions (PLS) resulting from bioleaching of Copper Concentrate from Kupferschiefer are characterized by low pH and high concentrations of Fe, Cu, Zn as well as significant amounts of Ni and Co. In order to recover the valuable metals for further processing, chemical methods and a novel biological-induced technique that promotes selective metal recovery and sulfate removal from acidic liquors were applied and a process scheme was developed.
-
Quantitative Monitoring of Microbial Species during Bioleaching of a Copper Concentrate
Frontiers in Microbiology, 2016Co-Authors: Sabrina Hedrich, Axel Schippers, Anne-gwenaëlle Guezennec, Mickaël Charron, Catherine JoulianAbstract:Monitoring of the microbial community in bioleaching processes is essential in order to control process parameters and enhance the leaching efficiency. Suitable methods are, however, limited as they are usually not adapted to bioleaching samples and often no taxon-specific assays are available in the literature for these types of consortia. Therefore, our study focused on the development of novel quantitative real-time PCR (qPCR) assays for the quantification of Acidithiobacillus caldus, Leptospirillum ferriphilum, Sulfobacillus thermosulfidooxidans, and Sulfobacillus benefaciens and comparison of the results with data from other common molecular monitoring methods in order to evaluate their accuracy and specificity. Stirred tank bioreactors for the leaching of Copper Concentrate, housing a consortium of acidophilic, moderately thermophilic bacteria, relevant in several bioleaching operations, served as a model system. The microbial community analysis via qPCR allowed a precise monitoring of the evolution of total biomass as well as abundance of specific species. Data achieved by the standard fingerprinting methods, terminal restriction fragment length polymorphism (T-RFLP) and capillary electrophoresis single strand conformation polymorphism (CE-SSCP) on the same samples followed the same trend as qPCR data. The main added value of qPCR was, however, to provide quantitative data for each species whereas only relative abundance could be deduced from T-RFLP and CE-SSCP profiles. Additional value was obtained by applying two further quantitative methods which do not require nucleic acid extraction, total cell counting after SYBR Green staining and metal sulfide oxidation activity measurements via microcalorimetry. Overall, these complementary methods allow for an efficient quantitative microbial community monitoring in various bioleaching operations.
-
Development of a Strategy for Selective Metal Recovery from Pregnant Leach Solutions of Kupferschiefer Bioleaching
Advanced Materials Research, 2015Co-Authors: Sabrina Hedrich, Axel Schippers, D. Barrie JohnsonAbstract:Pregnant leach solutions (PLS) resulting from bioleaching of Copper Concentrate from Kupferschiefer are characterized by low pH values and high concentrations of mainly ferric iron, Copper, zinc and sulfate, as well as significant amounts of nickel and cobalt. In order to recover the valuable metals for further processing, a novel technique that promotes selective metal recovery and sulfate removal from acidic liquors, described in this study, is proposed.