The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 14, 2006
Filed:
Feb. 27, 2002
Oliver Bonnardel, Saint Martin d'arc, FR;
Claude Vanvoren, Saint Jean de Maurienne, FR;
Oliver Bonnardel, Saint Martin d'arc, FR;
Claude Vanvoren, Saint Jean de Maurienne, FR;
Aluminum Pechiney, Paris, FR;
Abstract
The invention relates to a regulation method for an electrolytic cell for the production of aluminium by means of reduction of alumina dissolved in a molten cryolite bath and comprises the addition, in the electrolyte bath, during pre-determined time intervals p referred to as 'periods', of a determined quantity Q(p) of aluminium trifluoride (AlF) determined by the following equation: Q(p)=Qint(p)−Qc1(p)+Qt(p), where Qint(p) is an integral (or 'self-adaptive') term which represents the total actual AlFrequirements of the cell and which is calculated from a mean Qm(p) of the actual AlFsupplies made during the last N periods, Qc1 is a compensating term corresponding to the so-called “equivalent” quantity of AlFcontained in the alumina added to the cell during the period p, and Qt(p) is a corrective term which is a typically increasing function of the difference between the measured bath temperature T(p) and the set-point temperature To. The method according to the invention makes it possible to regulate effectively the acidity of an electrolytic cell at intensities of up to 500 kA with an electrolyte bath having an AlFcontent greater than 11%.