Transport numbers in the molten system NaF-KF-AlF3-Al2O3

被引：17

作者：

Hives, Jan ^{[1
]}

Fellner, Pavel ^{[1
]}

Thonstad, Jomar ^{[2
]}

机构：

[1] Slovak Univ Technol Bratislava, SK-81237 Bratislava, Slovakia

[2] Norwegian Univ Sci & Technol, N-7034 Trondheim, Norway

来源：

IONICS | 2013年 / 19卷 / 02期

关键词：

Molten cryolite; Charge transport; Acid bath; BN cell; HITTORF METHOD; ALUMINUM; ELECTROLYSIS;

D O I：

10.1007/s11581-012-0736-6

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

Transport numbers in the molten system NaF-KF-AlF3 (Al2O3, CaF2) were investigated by the Hittorf method. It was confirmed that in molten cryolite, Na3AlF6, 1,010 A degrees C, the current is transported almost exclusively by the Na+ cations (t(Na+) = 0.99). When AlF3 was added to a Na3AlF6 melt, the transport number of sodium cations decreased to 0.74 at the composition corresponding to NaAlF4. In molten K3AlF6, the transport number of K+ cations equals 0.836 at 1,005 A degrees C. In melts containing both Na+ and K+, the cations contribute to the charge transport approximately in the ratio of the squares of their ionic radii. When 5 mass % of CaF2 was added to the molten NaF-KF-AlF3 system, it remarkably influenced the transport numbers of potassium and fluoride anions.

引用

页码：315 / 319

页数：5

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