A thermodynamic analysis of the system LiAlSiO4-NaAlSiO4-Al2O3-SiO2-H2O based on new heat capacity, thermal expansion, and compressibility data for selected phases
A thermodynamic analysis of the system LiAlSiO4-NaAlSiO4-Al2O3-SiO2-H2O based on new heat capacity, thermal expansion, and compressibility data for selected phases
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基于选定相的新热容、热膨胀和压缩性数据对 LiAlSiO4-NaAlSiO4-Al2O3-SiO2-H2O 系统进行热力学分析
DOI：
10.1007/s004100050446
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发表时间：
1998
期刊：
影响因子：
--
通讯作者：
L. Cemič
中科院分区：
文献类型：
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作者：
D. W. Fasshauer;N. Chatterjee;L. Cemič
已经获得了 NaAlSiO4-LiAlSiO4-Al2O3-SiO2-H2O 系统的许多选定相的热容、热膨胀和压缩性数据。所有 Cp 测量均由 DSC 在 133–823 K 温度范围内执行。T≥ 223 K 的数据已拟合至函数 Cp(T) =a+cT−2+dT−0.5+fT−3，拟合参数为 热膨胀数据（最高 525 °C）已拟合至函数V0(T) =V0(T) [1 +v1(T−T0) +v2(T−T0)2]，其中T0= 298.15 K。室温压缩性数据（高达6 GPa）已通过Murnaghan状态方程进行平滑处理。所得参数为 这些数据以及文献中的其他相性质和反应逆转数据，同时通过贝叶斯方法进行处理，以获得 NaAlSiO4-LiAlSiO4-Al2O3-SiO2-H2O 五元的内部一致的热力学数据集（参见表 6 和表 7）。从该数据集生成的相图与在变铝土矿和常见变沉积岩中观察到的含库克石、石蜡石和钠长石的组合兼容。从同一数据库获得的相图也与已知在含锂伟晶岩重结晶的亚固相线相中形成的不含炊石、透锂长石、锂辉石、锂霞石和锂钛矿的组合一致。令人欣慰的是，Vidal 和 Goffé (1991) 早期在 Li2O-Al2O3-SiO2-H2O 系统中预测的库硅石相关系总体上与我们的结果一致。
Heat capacity, thermal expansion, and compressibility data have been obtained for a number of selected phases of the system NaAlSiO4-LiAlSiO4-Al2O3-SiO2-H2O. AllCpmeasurements have been executed by DSC in the temperature range 133–823 K. The data forT≥ 223 K have been fitted to the functionCp(T) =a+cT−2+dT−0.5+fT−3, the fit parameters being The thermal expansion data (up to 525 °C) have been fitted to the functionV0(T) =V0(T) [1 +v1(T−T0) +v2(T−T0)2], withT0= 298.15 K. The room-temperature compressibility data (up to 6 GPa) have been smoothed by the Murnaghan equation of state. The resulting parameters are These data, along with other phase property and reaction reversal data from the literature, have been simultaneously processed by the Bayes method to derive an internally consistent thermodynamic dataset (see Tables 6 and 7) for the NaAlSiO4-LiAlSiO4-Al2O3-SiO2-H2O quinary. Phase diagrams generated from this dataset are compatible with cookeite-, ephesite-, and paragonite-bearing assemblages observed in metabauxites and common metasediments. Phase diagrams obtained from the same database are also in agreement with the cookeite-free, petalite-, spodumene-, eucryptite-, and bikitaite-bearing assemblages known to develop in the subsolidus phase of recrystallization of␣lithium-bearing pegmatites. It is gratifying to note that the cookeite phase relations predicted earlier by Vidal and Goffé (1991) in the context of the system Li2O-Al2O3-SiO2-H2O agree with our results in a general way.