Olli Tuovinen - Academia.edu (original) (raw)
Papers by Olli Tuovinen
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Journal of Cleaner Production, Aug 1, 2020
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Oil Shale, 1998
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Irrigation and Drainage Systems Engineering, 2016
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Science of The Total Environment, Sep 1, 2023
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Frontiers in Microbiology, Feb 9, 2023
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Advanced Materials Research, Nov 1, 2015
This study was undertaken to determine the leaching of Cu and Zn from a smelter slag in acidic, s... more This study was undertaken to determine the leaching of Cu and Zn from a smelter slag in acidic, sulfate-rich solutions with, and without, mesophilic Fe-and S-oxidizing bacteria. Cu in the slag was mostly distributed in fayalite, Fe-deficient Cu-sulfides and metallic Cu, and Zn was associated with fayalite, magnetite and glassy silicates. The test culture was enriched from acid mine water using mineral salt growth media supplemented with 4.5 g Fe2+ L-1 and 10 g S0 L-1. The bioleaching experiments were carried out in shake flasks at 27 °C and chemical controls were included. The slag sample was pre-leached for 24 h to partially satisfy the acid demand before the leaching experiments at 10% pulp density. In the bioleaching experiments, 69-83% Cu and 4.1-14% Zn were dissolved in 25 days at pH 2.0-2.2. The highest extent of bioleaching was with S0 as the substrate. The efficiency of the bioleaching depended on H2SO4 generation from the added S0. The activities of the bacteria were not adversely affected by the dissolved metals. The maximum yields of chemical leaching were 68% Cu and 3.7% Zn.
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Applied Microbiology and Biotechnology, Jul 1, 1986
ABSTRACT
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Minerals Engineering, May 1, 2017
Abstract Pyrometallurgical processes for sulfide concentrates produce slag waste materials that c... more Abstract Pyrometallurgical processes for sulfide concentrates produce slag waste materials that contain multiple metals as carry-over impurities. Varied quantities of the metal content can be solubilized from the slag through chemical acid leaching or bioleaching. In this study, copper smelter slags were leached with and without iron- and sulfur-oxidizing bacteria in acid, sulfate-rich solutions and solid phase changes were determined. The samples (10% pulp density) were leached at 28 °C in stirred tanks at pH 2.5 and 3.0. The duration of the experiment was 37 d and the adjusted pH decreased to 2.3 in both sets of experiments. The primary metals of interest in the slag were Cu and Zn, with minor amounts of Ni and Co, and As, Sb, and Pb at trace levels. The metals in the slag were distributed in fayalite, glassy silicates and magnetite phases as well as minor amounts in oxides, metallic Cu and sulfides. Based on the solution analyses, the dissolution yields were 44% and 34% for Cu, 14% and 13% for Zn and Co, and 4.5% and 4.0% for Ni at initial pH values of 2.5 and 3.0, respectively. Fayalite was the most reactive mineral and Cu-sulfides were particularly refractory. The elemental composition of leached residues was matched with solid phase changes and the distribution of metals in the mineral phases.
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Microbial biotechnology, Sep 21, 2011
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Revista De Microbiologia, 1997
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Ohio State University. Water Resources Center eBooks, 1983
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Coal science and technology, 1986
Ferrus iron oxidation by growing cultures of Thiobacillus ferrooxidans was sensitive to negative ... more Ferrus iron oxidation by growing cultures of Thiobacillus ferrooxidans was sensitive to negative catalysis (inhibition) by selected oxyanios of sulfur. The relative order of negative catalytic activity for the sulfoxyanions was S_20_5^(2-) > S_20_3^(2-) > S_20_4^(2-) > S_40_6^(2-). Inhibition by the sulfoxyanions was greater at μm 1.5 than at pH 2.0. A mechanism involving the formation of radical intermediates, HO_2,-OH, HSO_3, HSO_5, H_2O_4, and HS_3O_3, induced by Fe(II) and Fe(III) complexes is proposed to account for the observed inhibitory effects. Orthophosphate, pyrophosphate, and tripolyphosphate compounds were also inhibitory to ferrous iron oxidation by T. ferrooxidans. Orthophosphates were increasingly at high concentrations (200-300 mM) whereas the apparent toxicity of pyrophosphate and tripolyphosphate was inversely related to concentration over the range of 50-300 mM with no apparent at pH dependency at pH ≤ 2. Equilibrium models are presented to explain the relative effect of the phosphates in terms of phosphate precipitates, which were actually observed , and soluble complexes, which have an effect on the thermodynamics of electron transfer.
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Journal American Water Works Association, Feb 1, 1981
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Biotechnology for Biofuels, 2011
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Phytopathology, 1988
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Journal of Cleaner Production, Aug 1, 2020
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Oil Shale, 1998
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Irrigation and Drainage Systems Engineering, 2016
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Science of The Total Environment, Sep 1, 2023
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Frontiers in Microbiology, Feb 9, 2023
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International Journal of Hydrogen Energy, Jun 1, 2019
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Advanced Materials Research, Nov 1, 2015
This study was undertaken to determine the leaching of Cu and Zn from a smelter slag in acidic, s... more This study was undertaken to determine the leaching of Cu and Zn from a smelter slag in acidic, sulfate-rich solutions with, and without, mesophilic Fe-and S-oxidizing bacteria. Cu in the slag was mostly distributed in fayalite, Fe-deficient Cu-sulfides and metallic Cu, and Zn was associated with fayalite, magnetite and glassy silicates. The test culture was enriched from acid mine water using mineral salt growth media supplemented with 4.5 g Fe2+ L-1 and 10 g S0 L-1. The bioleaching experiments were carried out in shake flasks at 27 °C and chemical controls were included. The slag sample was pre-leached for 24 h to partially satisfy the acid demand before the leaching experiments at 10% pulp density. In the bioleaching experiments, 69-83% Cu and 4.1-14% Zn were dissolved in 25 days at pH 2.0-2.2. The highest extent of bioleaching was with S0 as the substrate. The efficiency of the bioleaching depended on H2SO4 generation from the added S0. The activities of the bacteria were not adversely affected by the dissolved metals. The maximum yields of chemical leaching were 68% Cu and 3.7% Zn.
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Applied Microbiology and Biotechnology, Jul 1, 1986
ABSTRACT
Bookmarks Related papers MentionsView impact
Minerals Engineering, May 1, 2017
Abstract Pyrometallurgical processes for sulfide concentrates produce slag waste materials that c... more Abstract Pyrometallurgical processes for sulfide concentrates produce slag waste materials that contain multiple metals as carry-over impurities. Varied quantities of the metal content can be solubilized from the slag through chemical acid leaching or bioleaching. In this study, copper smelter slags were leached with and without iron- and sulfur-oxidizing bacteria in acid, sulfate-rich solutions and solid phase changes were determined. The samples (10% pulp density) were leached at 28 °C in stirred tanks at pH 2.5 and 3.0. The duration of the experiment was 37 d and the adjusted pH decreased to 2.3 in both sets of experiments. The primary metals of interest in the slag were Cu and Zn, with minor amounts of Ni and Co, and As, Sb, and Pb at trace levels. The metals in the slag were distributed in fayalite, glassy silicates and magnetite phases as well as minor amounts in oxides, metallic Cu and sulfides. Based on the solution analyses, the dissolution yields were 44% and 34% for Cu, 14% and 13% for Zn and Co, and 4.5% and 4.0% for Ni at initial pH values of 2.5 and 3.0, respectively. Fayalite was the most reactive mineral and Cu-sulfides were particularly refractory. The elemental composition of leached residues was matched with solid phase changes and the distribution of metals in the mineral phases.
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Microbial biotechnology, Sep 21, 2011
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Revista De Microbiologia, 1997
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Ohio State University. Water Resources Center eBooks, 1983
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Coal science and technology, 1986
Ferrus iron oxidation by growing cultures of Thiobacillus ferrooxidans was sensitive to negative ... more Ferrus iron oxidation by growing cultures of Thiobacillus ferrooxidans was sensitive to negative catalysis (inhibition) by selected oxyanios of sulfur. The relative order of negative catalytic activity for the sulfoxyanions was S_20_5^(2-) > S_20_3^(2-) > S_20_4^(2-) > S_40_6^(2-). Inhibition by the sulfoxyanions was greater at μm 1.5 than at pH 2.0. A mechanism involving the formation of radical intermediates, HO_2,-OH, HSO_3, HSO_5, H_2O_4, and HS_3O_3, induced by Fe(II) and Fe(III) complexes is proposed to account for the observed inhibitory effects. Orthophosphate, pyrophosphate, and tripolyphosphate compounds were also inhibitory to ferrous iron oxidation by T. ferrooxidans. Orthophosphates were increasingly at high concentrations (200-300 mM) whereas the apparent toxicity of pyrophosphate and tripolyphosphate was inversely related to concentration over the range of 50-300 mM with no apparent at pH dependency at pH ≤ 2. Equilibrium models are presented to explain the relative effect of the phosphates in terms of phosphate precipitates, which were actually observed , and soluble complexes, which have an effect on the thermodynamics of electron transfer.
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Journal American Water Works Association, Feb 1, 1981
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Biotechnology for Biofuels, 2011
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Phytopathology, 1988
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