Patent ID: 6723212
Filing Date: 2004-04-20
Classification: C25C

Abstract:
A method of making an impregnated graphite cathode for electrolysis of aluminum, comprising:(a) forming a carbon-containing body; (b) graphitizing said body at above 2400Â° C. to form a porous graphite body; (c) heating at least one impregnant comprising at least one substance selected from the group consisting of coal pitches and petroleum pitches to an impregnant temperature sufficient to reduce its viscosity below 150 cP; (d) impregnating at least a portion of the pores of said porous graphite body with said at least one heated impregnant; and (e) heating said impregnated body at a temperature below 1600Â° C. for a time sufficient to coke said substance.