A comparison of the thermal behaviour of α-AIF3 and aluminium fluoride hydrates

Menz, Dirk–Henning; Zacharias, Adway O.; Kolditz, Lothar

doi:10.1007/bf02138592

Cited by 17 publications

(10 citation statements)

References 6 publications

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“…The endothermic peaks at 312.9 and 372.6 • C at 180 min could be distributed to the decomposition of Na 2 SiF 6 and KNaSiF 6 [33]. The mass decrease at 644.0 • C was mainly caused by the decomposition of AlF 3 [34]. The thermal decomposition behaviors were consistent with our speculation on the generated intermediates.…”

Section: Tg-dsc Analysessupporting

confidence: 88%

Investigation of Enhanced Leaching of Lithium from α-Spodumene Using Hydrofluoric and Sulfuric Acid

et al. 2017

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An effective method using hydrofluoric and sulfuric acid was proposed to enhance the leaching of lithium from α-spodumene, without calcination that is subjected to 1000 • C for phase transformation. The thermodynamic feasibility of the reactions was firstly verified. Dissolution conditions were tested to maximize the leaching efficiency of lithium and with efficient utilization of hydrofluoric acid (HF) served as evaluation criteria. The results showed that 96% of lithium could be transferred into lixivium with an ore/HF/H 2 SO 4 ratio of 1:3:2 (g/mL/mL), at 100 • C for 3 h. Due to the fact that HF molecules were the main reaction form, the dissolution behaviors were theoretically represented and investigated by dissolution in HF/H 2 SO 4 . When combined with chemical elements analyses and characterizations, the results of the dissolution behaviors revealed that α-spodumene and albite were preferentially dissolved over quartz. Insoluble fluoroaluminates, such as

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Section: Tg-dsc Analysessupporting

confidence: 88%

Investigation of Enhanced Leaching of Lithium from α-Spodumene Using Hydrofluoric and Sulfuric Acid

et al. 2017

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“…The complex nature of thermal phase transitions in aluminum fluoride hydrates , gave strong evidence for the formation of AlF 3 −OH - or AlF 3 −H 2 O complexes. (The existence of HF−AlF 3 and 2HF−AlF 3 was directly proven during such processes. , ) Thermally induced processes such as water loss, hydrolysis occurring after the main water content was given up, and the formation of the highly reactive species HF accompanied by a complex chemical and physical reorganization of the solid cause the appearance of a spontaneous catalytic active β-AlF 3 phase above 450 °C. − Menz et al assumed that the intermediate formation of solid and gaseous aluminum fluoride oxides plays a crucial role for the reorganization processes taking place in the solid. F/OH - exchange processes could be proven during dehydration processes .…”

Section: Experimental Challenge and Dilemmamentioning

confidence: 99%

“…However, there is much empirical chemical knowledge and many spectroscopic results that imply the existence and reaction of such complexes. The complex nature of thermal phase transitions in aluminum fluoride hydrates 28,29 gave strong evidence for the formation of AlF 3 -OHor AlF 3 -H 2 O complexes. (The existence of HF-AlF 3 and 2HF-AlF 3 was directly proven during such processes.…”

Section: Experimental Challenge and Dilemmamentioning

confidence: 99%

Oxygen-Bridged Adducts Formed by Chemical Reactions of Solid Aluminum Halides. Experimental Dilemma and ab Initio Calculations of Heterodimer Complexes AlX₃−Y (X = F, Cl; Y = OH^-, H₂O)

1996

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Starting from new experimental facts given by ESR, MS, and other physical and chemical methods, the role of bridged intermediates in the formation of catalytic active solids by thermal chemical reactions including the gaseous phase is discussed. Structures of oxygen-bridged adducts of AlF 3 and AlCl 3 with OH -and H 2 O have been explored at the HF and MP2 levels using 6-31G*, 6-31+G*, and 6-311G** basis sets. The reaction enthalpies of complex formation are calculated for several temperatures. Both hydroxyl and water complexes were found to be energetically stable complexes that have a real chance to take part in high-temperature heterogeneous reactions like the formation of activated aluminum halide catalysts.

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“…Meanwhile, Fig. 18 It should be noted that infrared spectra of dry AlF 3 films, which have been exposed to the air for a few days, exhibit the O-H absorption band with a magnitude intermediate between Figs. The existence of the O-H absorption band in Fig.…”

Section: Resultsmentioning

confidence: 92%

Investigation of electron-beam-induced phase transitions in amorphous aluminum trifluoride thin films using transmission electron microscopy

Chen

1999

Journal of Vacuum Science &Amp; Technology A: Vacuum, Surfaces, and Films

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A comparison of the thermal behaviour of α-AIF3 and aluminium fluoride hydrates

Cited by 17 publications

References 6 publications

Investigation of Enhanced Leaching of Lithium from α-Spodumene Using Hydrofluoric and Sulfuric Acid

Investigation of Enhanced Leaching of Lithium from α-Spodumene Using Hydrofluoric and Sulfuric Acid

Oxygen-Bridged Adducts Formed by Chemical Reactions of Solid Aluminum Halides. Experimental Dilemma and ab Initio Calculations of Heterodimer Complexes AlX₃−Y (X = F, Cl; Y = OH^-, H₂O)

Investigation of electron-beam-induced phase transitions in amorphous aluminum trifluoride thin films using transmission electron microscopy

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A comparison of the thermal behaviour of α-AIF3 and aluminium fluoride hydrates

Cited by 17 publications

References 6 publications

Investigation of Enhanced Leaching of Lithium from α-Spodumene Using Hydrofluoric and Sulfuric Acid

Investigation of Enhanced Leaching of Lithium from α-Spodumene Using Hydrofluoric and Sulfuric Acid

Oxygen-Bridged Adducts Formed by Chemical Reactions of Solid Aluminum Halides. Experimental Dilemma and ab Initio Calculations of Heterodimer Complexes AlX3−Y (X = F, Cl; Y = OH-, H2O)

Investigation of electron-beam-induced phase transitions in amorphous aluminum trifluoride thin films using transmission electron microscopy

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Product

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About

Oxygen-Bridged Adducts Formed by Chemical Reactions of Solid Aluminum Halides. Experimental Dilemma and ab Initio Calculations of Heterodimer Complexes AlX₃−Y (X = F, Cl; Y = OH^-, H₂O)