Transference coefficients and transference numbers in salt mixtures relevant for the aluminium electrolysis

✍ Scribed by Signe Kjelstrup Ratkje; Habiba Rajabu; Tormod Førland

• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 882 KB
• Volume: 38
• Category: Article
• ISSN: 0013-4686
• DOI: 10.1016/0013-4686(93)85159-v

✦ Synopsis

A new procedure is proposed for determination of transference numbers from etnj measurements. The procedure is applied to molten fluorides using literature data. We show that eqfmeasurements reported for a cell containing NaF and AIF, give transference numbers which are physically unlikely. The transference number reported for Na+, t,, , in pure NaF is of no thermodynamic significance in the absence of pressure gradients. Data for the system NaF-AlFs-Al,O,(sat)

give the movement of one ion with respect to all others, and t,, is discussed for several choices of frame of reference.

Inconsistency of some experimental results is pointed out. The thermodynamic significance of the findings is pointed out, and new experiments are suggested.