دورية أكاديمية
أعرض في EDS

Alkali-Induced Phase Transition to β-Spodumene along the LiAlSi 2 O 6 -LiAlSi 4 O 10 Join.

التفاصيل البيبلوغرافية
العنوان: Alkali-Induced Phase Transition to β-Spodumene along the LiAlSi 2 O 6 -LiAlSi 4 O 10 Join.
المؤلفون: Thibault, Yves, Gamage McEvoy, Joanne
المصدر: Crystals (2073-4352); Aug2023, Vol. 13 Issue 8, p1182, 21p
مصطلحات موضوعية: PHASE transitions, LITHIUM, FLUID inclusions, ION exchange (Chemistry), HEAT treatment, QUARTZ
مستخلص: Due to the refractory nature of α-spodumene (LiAlSi2O6) and petalite (LiAlSi4O10), two major lithium minerals, conventional lithium recovery processes involve a high-temperature pre-treatment (>1000 °C) to induce a phase transition to tetragonal β-spodumene, an open structure allowing easier access to lithium through ion exchange. Considering that these high temperatures are not dictated by thermodynamics but rather sluggish kinetics, the study investigates the mechanisms enhancing the rate of transformation to β-spodumene at lower temperatures while minimizing the growth of metastable hexagonal β-quartz typically observed at the onset of the conversion. The heat treatment of natural α-spodumene revealed that rapid growth of β-spodumene veinlets is achieved at ≤600 °C by activation of alkali-rich fluid inclusions, through a dissolution–recrystallization process. For petalite, the mechanism of the phase transition, initiated at ≈750 °C is a solid-state transformation keeping crystallographic coincidence with the mineral host. Synthetic growth experiments along the LiAlSi2O6-LiAlSi4O10 join indicate a compositional dependence on the resulting β-phase structure, where minor sodium doping strongly favors β-spodumene, as the tetrahedral framework of β-quartz does not allow the extent of deformation to accommodate the larger alkali. These findings open opportunities for energy-efficient lithium recovery pathways where the phase transition and ion exchange can be achieved simultaneously without a high-temperature pre-treatment. [ABSTRACT FROM AUTHOR]
Copyright of Crystals (2073-4352) is the property of MDPI and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
قاعدة البيانات: Complementary Index
كن أول من يترك تعليقا!
يجب تسجيل دخولك أولا