{"title":"α-FeOOH (goethite)-ScOOH 固溶体的热力学","authors":"Juraj Majzlan","doi":"10.1007/s00269-024-01298-1","DOIUrl":null,"url":null,"abstract":"<div><p>Scandium (Sc) is a rare element that finds uses in modern technologies. Thermodynamic properties of Sc phases could help in the development of innovative technologies to extract Sc from mining waste. In this work, we investigated the FeOOH–ScOOH solid solution with the goethite structure. The end members and five intermediate compositions were synthesized and characterized. The lattice parameters show that the solid solution is non-ideal, with complex behavior induced by the Fe–Sc substitution. The excess unit-cell volume deviates negatively for the Sc-rich region, and positively for the Fe-rich region from the ideal behavior (Vegard’s law). Enthalpies of dissolution were determined by acid-solution calorimetry in 5 mol<span>\\(\\cdot \\hbox {dm}^{-3}\\)</span> HCl at <i>T</i> = 343.15 K. Enthalpies of mixing (<span>\\(\\Delta _{mix}H\\)</span>), calculated from the experimental data, are small and positive. The available data allow for fitting the data as <span>\\(\\Delta _{mix}H = W x (1-x)\\)</span>, with the mixing parameter <span>\\(W = 15.2\\pm\\)</span>1.0 kJ<span>\\(\\cdot \\hbox {mol}^{-1}\\)</span>. Using <span>\\(\\Delta _fG^o\\)</span> of ScOOH from earlier literature, we calculated a Lippmann diagram that shows that Sc should strongly partition into the aqueous phase upon goethite precipitation. The field observations from lateritic profiles show that Sc is primarily harbored by goethite <i>via</i> adsorption. It seems that under weathering conditions, thermodynamically driven partitioning of <span>\\(\\hbox {Sc}^{3+}\\)</span> into the aqueous phases and its subsequent adsorption onto goethite surfaces controls the mobility of Sc in the weathering profiles.</p></div>","PeriodicalId":20132,"journal":{"name":"Physics and Chemistry of Minerals","volume":"51 4","pages":""},"PeriodicalIF":1.2000,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00269-024-01298-1.pdf","citationCount":"0","resultStr":"{\"title\":\"Thermodynamics of the α-FeOOH (goethite)-ScOOH solid solution\",\"authors\":\"Juraj Majzlan\",\"doi\":\"10.1007/s00269-024-01298-1\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>Scandium (Sc) is a rare element that finds uses in modern technologies. Thermodynamic properties of Sc phases could help in the development of innovative technologies to extract Sc from mining waste. In this work, we investigated the FeOOH–ScOOH solid solution with the goethite structure. The end members and five intermediate compositions were synthesized and characterized. The lattice parameters show that the solid solution is non-ideal, with complex behavior induced by the Fe–Sc substitution. The excess unit-cell volume deviates negatively for the Sc-rich region, and positively for the Fe-rich region from the ideal behavior (Vegard’s law). Enthalpies of dissolution were determined by acid-solution calorimetry in 5 mol<span>\\\\(\\\\cdot \\\\hbox {dm}^{-3}\\\\)</span> HCl at <i>T</i> = 343.15 K. Enthalpies of mixing (<span>\\\\(\\\\Delta _{mix}H\\\\)</span>), calculated from the experimental data, are small and positive. The available data allow for fitting the data as <span>\\\\(\\\\Delta _{mix}H = W x (1-x)\\\\)</span>, with the mixing parameter <span>\\\\(W = 15.2\\\\pm\\\\)</span>1.0 kJ<span>\\\\(\\\\cdot \\\\hbox {mol}^{-1}\\\\)</span>. Using <span>\\\\(\\\\Delta _fG^o\\\\)</span> of ScOOH from earlier literature, we calculated a Lippmann diagram that shows that Sc should strongly partition into the aqueous phase upon goethite precipitation. The field observations from lateritic profiles show that Sc is primarily harbored by goethite <i>via</i> adsorption. It seems that under weathering conditions, thermodynamically driven partitioning of <span>\\\\(\\\\hbox {Sc}^{3+}\\\\)</span> into the aqueous phases and its subsequent adsorption onto goethite surfaces controls the mobility of Sc in the weathering profiles.</p></div>\",\"PeriodicalId\":20132,\"journal\":{\"name\":\"Physics and Chemistry of Minerals\",\"volume\":\"51 4\",\"pages\":\"\"},\"PeriodicalIF\":1.2000,\"publicationDate\":\"2024-10-02\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://link.springer.com/content/pdf/10.1007/s00269-024-01298-1.pdf\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Physics and Chemistry of Minerals\",\"FirstCategoryId\":\"89\",\"ListUrlMain\":\"https://link.springer.com/article/10.1007/s00269-024-01298-1\",\"RegionNum\":4,\"RegionCategory\":\"地球科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q4\",\"JCRName\":\"MATERIALS SCIENCE, MULTIDISCIPLINARY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Physics and Chemistry of Minerals","FirstCategoryId":"89","ListUrlMain":"https://link.springer.com/article/10.1007/s00269-024-01298-1","RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"MATERIALS SCIENCE, MULTIDISCIPLINARY","Score":null,"Total":0}
Thermodynamics of the α-FeOOH (goethite)-ScOOH solid solution
Scandium (Sc) is a rare element that finds uses in modern technologies. Thermodynamic properties of Sc phases could help in the development of innovative technologies to extract Sc from mining waste. In this work, we investigated the FeOOH–ScOOH solid solution with the goethite structure. The end members and five intermediate compositions were synthesized and characterized. The lattice parameters show that the solid solution is non-ideal, with complex behavior induced by the Fe–Sc substitution. The excess unit-cell volume deviates negatively for the Sc-rich region, and positively for the Fe-rich region from the ideal behavior (Vegard’s law). Enthalpies of dissolution were determined by acid-solution calorimetry in 5 mol\(\cdot \hbox {dm}^{-3}\) HCl at T = 343.15 K. Enthalpies of mixing (\(\Delta _{mix}H\)), calculated from the experimental data, are small and positive. The available data allow for fitting the data as \(\Delta _{mix}H = W x (1-x)\), with the mixing parameter \(W = 15.2\pm\)1.0 kJ\(\cdot \hbox {mol}^{-1}\). Using \(\Delta _fG^o\) of ScOOH from earlier literature, we calculated a Lippmann diagram that shows that Sc should strongly partition into the aqueous phase upon goethite precipitation. The field observations from lateritic profiles show that Sc is primarily harbored by goethite via adsorption. It seems that under weathering conditions, thermodynamically driven partitioning of \(\hbox {Sc}^{3+}\) into the aqueous phases and its subsequent adsorption onto goethite surfaces controls the mobility of Sc in the weathering profiles.
期刊介绍:
Physics and Chemistry of Minerals is an international journal devoted to publishing articles and short communications of physical or chemical studies on minerals or solids related to minerals. The aim of the journal is to support competent interdisciplinary work in mineralogy and physics or chemistry. Particular emphasis is placed on applications of modern techniques or new theories and models to interpret atomic structures and physical or chemical properties of minerals. Some subjects of interest are:
-Relationships between atomic structure and crystalline state (structures of various states, crystal energies, crystal growth, thermodynamic studies, phase transformations, solid solution, exsolution phenomena, etc.)
-General solid state spectroscopy (ultraviolet, visible, infrared, Raman, ESCA, luminescence, X-ray, electron paramagnetic resonance, nuclear magnetic resonance, gamma ray resonance, etc.)
-Experimental and theoretical analysis of chemical bonding in minerals (application of crystal field, molecular orbital, band theories, etc.)
-Physical properties (magnetic, mechanical, electric, optical, thermodynamic, etc.)
-Relations between thermal expansion, compressibility, elastic constants, and fundamental properties of atomic structure, particularly as applied to geophysical problems
-Electron microscopy in support of physical and chemical studies
-Computational methods in the study of the structure and properties of minerals
-Mineral surfaces (experimental methods, structure and properties)