Study on energy-saving demagging process without air pollution

Magnesium-containing aluminum alloy is electrolyzed as anode using a tungsten rod as cathode and a ceramic fiber cylinder permeated by molten chlorides as electrolyte and diaphragm at 720 °C. Demagging current efficiency was tested in the range of current density from 0.18 to 0.71 A/cm2. Effect of magnesium chloride content of the electrolyte on demagging efficiency was also studied in the range 0∼40 wt.% in NaCl 50 wt.%-KCl 50 wt.% mixtures and proved to have no relation. Magnesium content of the aluminum alloy decreased to less than 0.1% from initial content of 1.0%. Demagging current efficiency falls as current density increases as the result of partial chlorination of aluminum on the surface of anode.