Patent ID: 6338785
Filing Date: 2002-01-15
Classification: C25C

Abstract:
A method of starting-up a cell for the electrowinning of aluminium by the electrolysis of alumina dissolved in a fluoride-based melt, the cell comprising a cathode on which, in use, aluminium is produced and forms a layer or pool, said method comprising the steps of:applying one or more aluminium-containing start-up layers on the cathode surface to protect temporarily the cathode surface during start-up, said applied start-up layer(s) comprising at least one of a pliable foil of aluminium having a thickness of from 0.03 to 0.1 mm, which comes into and remains in intimate matching contact with the cathode surface during preheating the cell and an aluminium-containing metallization which is applied to and remains in intimate matching contact with the cathode surface during preheating the cell; and preheating the cell, the cathode being temporarily protected by the start-up layer(s) against chemical attack by reaction with gases and/or fluids such as melting electrolyte during the preheating of the cell.