Solubility Product of Vanadinite Pb5(VO4)3Cl at 25 °C—A Comprehensive Approach to Incongruent Dissolution Modeling
| Autor: | Julia Sordyl, Bartosz Puzio, Maciej Manecki, Justyna Topolska, Olaf J. Borkiewicz |
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| Rok vydání: | 2021 |
| Předmět: |
lead apatite
lcsh:Mineralogy lcsh:QE351-399.2 Mineral Chemistry Thermodynamics Geology Sequestering Agent Solubility equilibrium 010501 environmental sciences Vanadinite engineering.material 010502 geochemistry & geophysics Geotechnical Engineering and Engineering Geology 01 natural sciences thermodynamics solubility product dissolution experiment engineering chervetite geochemical modeling Dissolution 0105 earth and related environmental sciences Geochemical modeling |
| Zdroj: | Minerals Volume 11 Issue 2 Minerals, Vol 11, Iss 135, p 135 (2021) |
| ISSN: | 2075-163X |
| Popis: | Although vanadinite (Pb5(VO4)3Cl) occurs in abundance in various terrestrial geochemical systems of natural and anthropogenic origin and is seriously considered as a potential nuclear waste sequestering agent, its actual application is severely limited by a lack of understanding of its basic thermodynamic parameters. In this regard, the greatest challenge is posed by its incongruent dissolution, which is a pivotal hurdle for effective geochemical modeling. Our paper presents an universal approach for geochemical computing of systems undergoing incongruent dissolution which, along with unique, long-term experiments on vanadinites&rsquo stability, allowed us to determine the mineral solubility constant. The dissolution experiments were carried out at pH = 3.5 for 12 years. Vanadinite has dissolved incongruently, continuously re-precipitating into chervetite (Pb2V2O7) with the two minerals remaining in mutual equilibrium until termination of the experiments. The empirically derived solubility constant KspV,298 = 10&ndash 91.89 ± 0.05 of vanadinite was determined for the first time. The proposed modeling method is versatile and can be adopted to other mineral systems undergoing incongruent dissolution. |
| Databáze: | OpenAIRE |
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