Method of producing a high purity aluminum-lithium mother alloy

Abstract

A method of producing high purity aluminum-lithium mother alloys essentially free from sodium, potassium and calcium, which comprises electrolyzing mixed molten salts consisting essentially of lithium chloride and potassium chloride preferably under a cathodic current density in the range of 0.005 to 1 A/cm.sup.2, using one or more hollow cylindrical solid aluminum cathodes, and thereby producing an aluminum-lithium alloy on the cathodes. In the method, the mixed molten salts may be composed essentially of 34 to 64 wt. % of lithium chloride and 66 to 36 wt. % of potassium chloride, and, optionally, 1 to 20 wt. % of sodium chloride based on a combined weight of the aforesaid two components. Preferably, throughout the electrolysis, the potential difference between the cathode and a two-phase (.alpha.+.beta.) aluminum-lithium alloy reference electrode is continuously measured and differentiated with respect to time and at the point of a sudden change in the differentiated value, the electrolysis is stopped.