Development of a Model to Estimate the Thermodynamic Stability of Organic Substances in Leaching Processes
The leaching processes for metals using organic substances represent a sustainable approach to recover precious minerals from solid matrices. However, the generation of organometallic species and the lack of thermodynamic diagrams make it difficult to advance the understanding of their behavior and...
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| Format: | Article |
| Language: | English |
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MDPI AG
2022-08-01
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| Series: | Metals |
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| Online Access: | https://www.mdpi.com/2075-4701/12/9/1424 |
| _version_ | 1797484812193234944 |
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| author | Carlos Ocampo-López Álvaro Ospina-Sanjuan Margarita Ramírez-Carmona Leidy Rendón-Castrillón |
| author_facet | Carlos Ocampo-López Álvaro Ospina-Sanjuan Margarita Ramírez-Carmona Leidy Rendón-Castrillón |
| author_sort | Carlos Ocampo-López |
| collection | DOAJ |
| description | The leaching processes for metals using organic substances represent a sustainable approach to recover precious minerals from solid matrices. However, the generation of organometallic species and the lack of thermodynamic diagrams make it difficult to advance the understanding of their behavior and optimize the process. In this work, a thermodynamically and stoichiometrically consistent mathematical model was developed to estimate the thermodynamic stability of organic substances during the leaching process, and iron leaching with oxalic acid was used as a case study. The Pourbaix and the global thermodynamic stability diagrams for the system were developed in this study. Using a Gaussian<sup>®</sup>, it was estimated that the Gibbs free energy formation for <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>Fe</mi><msubsup><mrow><mrow><mo>(</mo><mrow><msub><mi mathvariant="normal">C</mi><mn>2</mn></msub><msub><mi mathvariant="normal">O</mi><mn>4</mn></msub></mrow><mo>)</mo></mrow></mrow><mn>2</mn><mrow><mn>2</mn><mo>−</mo></mrow></msubsup></mrow></semantics></math></inline-formula>, <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>Fe</mi><msubsup><mrow><mrow><mo>(</mo><mrow><msub><mi mathvariant="normal">C</mi><mn>2</mn></msub><msub><mi mathvariant="normal">O</mi><mn>4</mn></msub></mrow><mo>)</mo></mrow></mrow><mn>2</mn><mrow><mn>1</mn><mo>−</mo></mrow></msubsup><mo>,</mo></mrow></semantics></math></inline-formula> and <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>Fe</mi><msubsup><mrow><mrow><mo>(</mo><mrow><msub><mi mathvariant="normal">C</mi><mn>2</mn></msub><msub><mi mathvariant="normal">O</mi><mn>4</mn></msub></mrow><mo>)</mo></mrow></mrow><mn>3</mn><mrow><mn>3</mn><mo>−</mo></mrow></msubsup></mrow></semantics></math></inline-formula> was −1407.51, −2308.38, and −3068.89 kcal/mol. A set of eleven independent reactions was formulated for the sixteen species involved in the leaching process, and its stability functions in terms of E<sub>h</sub> and pH were calculated to generate a 3D global thermodynamic stability diagram. According to the E<sub>h</sub>-pH diagrams for the leaching process, ferrioxalate was identified as the most stable and predominant species in the leaching process at pH above 6.6 under reductive conditions. The mathematical model developed in this work resulted in a thermodynamic tool for predicting leaching processes. |
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| format | Article |
| id | doaj.art-7cc24d9a517649598755ba458b21065c |
| institution | Directory Open Access Journal |
| issn | 2075-4701 |
| language | English |
| last_indexed | 2024-03-09T23:10:48Z |
| publishDate | 2022-08-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Metals |
| spelling | doaj.art-7cc24d9a517649598755ba458b21065c2023-11-23T17:45:48ZengMDPI AGMetals2075-47012022-08-01129142410.3390/met12091424Development of a Model to Estimate the Thermodynamic Stability of Organic Substances in Leaching ProcessesCarlos Ocampo-López0Álvaro Ospina-Sanjuan1Margarita Ramírez-Carmona2Leidy Rendón-Castrillón3Faculty of Chemical Engineering, Centro de Estudios y de Investigación en Biotecnología (CIBIOT), Universidad Pontificia Bolivariana, Circular 1A No. 70-01, Bloque 11, Medellín 050031, ColombiaFaculty of Electric and Electronic Engineering, Grupo de Investigaciones en Bioingeniería y Microelectrónica, Universidad Pontificia Bolivariana, Circular 1A No. 70-01, Bloque 11, Medellín 050031, ColombiaFaculty of Chemical Engineering, Centro de Estudios y de Investigación en Biotecnología (CIBIOT), Universidad Pontificia Bolivariana, Circular 1A No. 70-01, Bloque 11, Medellín 050031, ColombiaFaculty of Chemical Engineering, Centro de Estudios y de Investigación en Biotecnología (CIBIOT), Universidad Pontificia Bolivariana, Circular 1A No. 70-01, Bloque 11, Medellín 050031, ColombiaThe leaching processes for metals using organic substances represent a sustainable approach to recover precious minerals from solid matrices. However, the generation of organometallic species and the lack of thermodynamic diagrams make it difficult to advance the understanding of their behavior and optimize the process. In this work, a thermodynamically and stoichiometrically consistent mathematical model was developed to estimate the thermodynamic stability of organic substances during the leaching process, and iron leaching with oxalic acid was used as a case study. The Pourbaix and the global thermodynamic stability diagrams for the system were developed in this study. Using a Gaussian<sup>®</sup>, it was estimated that the Gibbs free energy formation for <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>Fe</mi><msubsup><mrow><mrow><mo>(</mo><mrow><msub><mi mathvariant="normal">C</mi><mn>2</mn></msub><msub><mi mathvariant="normal">O</mi><mn>4</mn></msub></mrow><mo>)</mo></mrow></mrow><mn>2</mn><mrow><mn>2</mn><mo>−</mo></mrow></msubsup></mrow></semantics></math></inline-formula>, <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>Fe</mi><msubsup><mrow><mrow><mo>(</mo><mrow><msub><mi mathvariant="normal">C</mi><mn>2</mn></msub><msub><mi mathvariant="normal">O</mi><mn>4</mn></msub></mrow><mo>)</mo></mrow></mrow><mn>2</mn><mrow><mn>1</mn><mo>−</mo></mrow></msubsup><mo>,</mo></mrow></semantics></math></inline-formula> and <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>Fe</mi><msubsup><mrow><mrow><mo>(</mo><mrow><msub><mi mathvariant="normal">C</mi><mn>2</mn></msub><msub><mi mathvariant="normal">O</mi><mn>4</mn></msub></mrow><mo>)</mo></mrow></mrow><mn>3</mn><mrow><mn>3</mn><mo>−</mo></mrow></msubsup></mrow></semantics></math></inline-formula> was −1407.51, −2308.38, and −3068.89 kcal/mol. A set of eleven independent reactions was formulated for the sixteen species involved in the leaching process, and its stability functions in terms of E<sub>h</sub> and pH were calculated to generate a 3D global thermodynamic stability diagram. According to the E<sub>h</sub>-pH diagrams for the leaching process, ferrioxalate was identified as the most stable and predominant species in the leaching process at pH above 6.6 under reductive conditions. The mathematical model developed in this work resulted in a thermodynamic tool for predicting leaching processes.https://www.mdpi.com/2075-4701/12/9/1424organic leachingE<sub>h</sub>-pH diagramsstabilityPourbaixironfree energy |
| spellingShingle | Carlos Ocampo-López Álvaro Ospina-Sanjuan Margarita Ramírez-Carmona Leidy Rendón-Castrillón Development of a Model to Estimate the Thermodynamic Stability of Organic Substances in Leaching Processes Metals organic leaching E<sub>h</sub>-pH diagrams stability Pourbaix iron free energy |
| title | Development of a Model to Estimate the Thermodynamic Stability of Organic Substances in Leaching Processes |
| title_full | Development of a Model to Estimate the Thermodynamic Stability of Organic Substances in Leaching Processes |
| title_fullStr | Development of a Model to Estimate the Thermodynamic Stability of Organic Substances in Leaching Processes |
| title_full_unstemmed | Development of a Model to Estimate the Thermodynamic Stability of Organic Substances in Leaching Processes |
| title_short | Development of a Model to Estimate the Thermodynamic Stability of Organic Substances in Leaching Processes |
| title_sort | development of a model to estimate the thermodynamic stability of organic substances in leaching processes |
| topic | organic leaching E<sub>h</sub>-pH diagrams stability Pourbaix iron free energy |
| url | https://www.mdpi.com/2075-4701/12/9/1424 |
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