The mechanism and kinetics of DTPA-promoted dissolution of barite
The dissolution rate of natural barite, BaSO4, was measured in solutions of DTPA (diethylene triamine penta-acetic acid) to investigate the mechanism of ligand-promoted dissolution using a strong chelating agent. Experiments were carried out over a range of DTPA concentrations 0.5-0.0001 M solutions...
| Main Authors: | , , |
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| Format: | Journal Article |
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Pergamon
2008
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| Online Access: | http://hdl.handle.net/20.500.11937/45921 |
| _version_ | 1848757418433970176 |
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| author | Putnis, Christine Kowacz, M. Putnis, Andrew |
| author_facet | Putnis, Christine Kowacz, M. Putnis, Andrew |
| author_sort | Putnis, Christine |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | The dissolution rate of natural barite, BaSO4, was measured in solutions of DTPA (diethylene triamine penta-acetic acid) to investigate the mechanism of ligand-promoted dissolution using a strong chelating agent. Experiments were carried out over a range of DTPA concentrations 0.5-0.0001 M solutions, at room temperature (22 °C), as well as a range of temperatures, 22-80 °C at 1 atm. The dissolution rate is inversely related to the DTPA concentration in solution. A more dilute DTPA solution is shown to be more efficient as a solvent in terms of the approach to the equilibrium saturation value for the dissolution of Ba2+. An analysis of the temperature dependence of the dissolution rate at high pH by the determination of activation energies indicates that the reaction is probably controlled by the pre-exponential term in the rate constant. This indicates that reaction frequency mostly controls differences in reactivity and suggests an explanation for the results in terms of stearic hindrance due to adsorbed DTPA molecules at the barite surface. The effect of DTPA on the solvation of the Ba2+ ion may also influence the dissolution rate. © 2008 Elsevier Ltd. All rights reserved. |
| first_indexed | 2025-11-14T09:27:47Z |
| format | Journal Article |
| id | curtin-20.500.11937-45921 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-14T09:27:47Z |
| publishDate | 2008 |
| publisher | Pergamon |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-459212017-09-13T14:24:11Z The mechanism and kinetics of DTPA-promoted dissolution of barite Putnis, Christine Kowacz, M. Putnis, Andrew The dissolution rate of natural barite, BaSO4, was measured in solutions of DTPA (diethylene triamine penta-acetic acid) to investigate the mechanism of ligand-promoted dissolution using a strong chelating agent. Experiments were carried out over a range of DTPA concentrations 0.5-0.0001 M solutions, at room temperature (22 °C), as well as a range of temperatures, 22-80 °C at 1 atm. The dissolution rate is inversely related to the DTPA concentration in solution. A more dilute DTPA solution is shown to be more efficient as a solvent in terms of the approach to the equilibrium saturation value for the dissolution of Ba2+. An analysis of the temperature dependence of the dissolution rate at high pH by the determination of activation energies indicates that the reaction is probably controlled by the pre-exponential term in the rate constant. This indicates that reaction frequency mostly controls differences in reactivity and suggests an explanation for the results in terms of stearic hindrance due to adsorbed DTPA molecules at the barite surface. The effect of DTPA on the solvation of the Ba2+ ion may also influence the dissolution rate. © 2008 Elsevier Ltd. All rights reserved. 2008 Journal Article http://hdl.handle.net/20.500.11937/45921 10.1016/j.apgeochem.2008.07.006 Pergamon restricted |
| spellingShingle | Putnis, Christine Kowacz, M. Putnis, Andrew The mechanism and kinetics of DTPA-promoted dissolution of barite |
| title | The mechanism and kinetics of DTPA-promoted dissolution of barite |
| title_full | The mechanism and kinetics of DTPA-promoted dissolution of barite |
| title_fullStr | The mechanism and kinetics of DTPA-promoted dissolution of barite |
| title_full_unstemmed | The mechanism and kinetics of DTPA-promoted dissolution of barite |
| title_short | The mechanism and kinetics of DTPA-promoted dissolution of barite |
| title_sort | mechanism and kinetics of dtpa-promoted dissolution of barite |
| url | http://hdl.handle.net/20.500.11937/45921 |