Patent · US Expired

Process and apparatus for controlling solid electrolyte additions to electrolytic cells for aluminum production

US4857157A · kind A · utility

3Cited by
4References
9Claims
0Family size

Assignee

Inventors

Key dates

Filing dateApr 18, 1988
Grant dateAug 15, 1989
Priority date
Expiry dateApr 18, 2008

Classification

  • Technology area (CPC C)Chemistry; Metallurgy
  • CPC primaryC25C3/20
  • WIPO fieldSurface technology, coating
  • WIPO sectorChemistry

Abstract

Process and apparatus for controlling solid electrolyte additions to electrolytic cells for aluminum production. The invention relates to a process for controlling solid electrolyte additions to a cell for producing aluminum by the electrolysis of alumina dissolved in a molten cryolitic bath according to the Hall-Heroult process. According to this process a nominal value HBC is fixed for the bath height, the level of the bath in the cell is periodically determined on the basis of a fixed dimension point PF known relative to the carbon-containing cathode substrate, from it is deduced the total height HT of the electrolytic bath layer HB and the liquid aluminum layer HM, the thickness HM of the liquid aluminum layer on the cathode substrate is determined, from it is deduced the bath layer height HB, HB=HT-HM and Hb is compared with the nominal value HBC. If this comparison reveals a bath deficiency, a ground bath addition is initiated from a storage means through at least one opening made in the solidified electrolyte crust normally covering the cell. If this comparison reveals a bath excess, an alarm is triggered in order to bring about a bath tapping operation.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.