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Title: Bath for electrolytic reduction of alumina and method therefor

Abstract

An electrolytic bath for use during the electrolytic reduction of alumina to aluminum. The bath comprises a molten electrolyte having the following ingredients: (a) AlF.sub.3 and at least one salt selected from the group consisting of NaF, KF, and LiF; and (b) about 0.004 wt. % to about 0.2 wt. %, based on total weight of the molten electrolyte, of at least one transition metal or at least one compound of the metal or both. The compound may be, for example, a fluoride, oxide, or carbonate. The metal can be nickel, iron, copper, cobalt, or molybdenum. The bath can be employed in a combination that includes a vessel for containing the bath and at least one non-consumable anode and at least one dimensionally stable cathode in the bath. Employing the bath of the present invention during electrolytic reduction of alumina to aluminum can improve the wetting of aluminum on a cathode by reducing or eliminating the formation of non-metallic deposits on the cathode. Removing sulfur from the bath can also minimize cathode deposits. Aluminum formed on the cathode can be removed directly from the cathode.

Inventors:
 [1];  [1];  [2];  [3]
  1. (Seattle, WA)
  2. (Lynnwood, WA)
  3. (Bulleen, AU)
Issue Date:
Research Org.:
Pacific Northwest National Laboratory (PNNL), Richland, WA
OSTI Identifier:
874896
Patent Number(s):
6485628
Application Number:
09/721,836
Assignee:
Northwest Aluminum Technology (The Dalles, OR) PNNL
DOE Contract Number:  
310468-A-UF
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
bath; electrolytic; reduction; alumina; method; aluminum; molten; electrolyte; following; ingredients; alfsub3; salt; selected; consisting; naf; kf; lif; 0004; wt; 02; based; total; weight; transition; metal; compound; example; fluoride; oxide; carbonate; nickel; iron; copper; cobalt; molybdenum; employed; combination; vessel; containing; non-consumable; anode; dimensionally; stable; cathode; employing; improve; wetting; reducing; eliminating; formation; non-metallic; deposits; removing; sulfur; minimize; formed; removed; directly; transition metal; removing sulfur; electrolytic bath; /205/

Citation Formats

Brown, Craig W., Brooks, Richard J., Frizzle, Patrick B., and Juric, Drago D. Bath for electrolytic reduction of alumina and method therefor. United States: N. p., 2002. Web.
Brown, Craig W., Brooks, Richard J., Frizzle, Patrick B., & Juric, Drago D. Bath for electrolytic reduction of alumina and method therefor. United States.
Brown, Craig W., Brooks, Richard J., Frizzle, Patrick B., and Juric, Drago D. Tue . "Bath for electrolytic reduction of alumina and method therefor". United States. https://www.osti.gov/servlets/purl/874896.
@article{osti_874896,
title = {Bath for electrolytic reduction of alumina and method therefor},
author = {Brown, Craig W. and Brooks, Richard J. and Frizzle, Patrick B. and Juric, Drago D.},
abstractNote = {An electrolytic bath for use during the electrolytic reduction of alumina to aluminum. The bath comprises a molten electrolyte having the following ingredients: (a) AlF.sub.3 and at least one salt selected from the group consisting of NaF, KF, and LiF; and (b) about 0.004 wt. % to about 0.2 wt. %, based on total weight of the molten electrolyte, of at least one transition metal or at least one compound of the metal or both. The compound may be, for example, a fluoride, oxide, or carbonate. The metal can be nickel, iron, copper, cobalt, or molybdenum. The bath can be employed in a combination that includes a vessel for containing the bath and at least one non-consumable anode and at least one dimensionally stable cathode in the bath. Employing the bath of the present invention during electrolytic reduction of alumina to aluminum can improve the wetting of aluminum on a cathode by reducing or eliminating the formation of non-metallic deposits on the cathode. Removing sulfur from the bath can also minimize cathode deposits. Aluminum formed on the cathode can be removed directly from the cathode.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {2002},
month = {11}
}

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