Novel dry process for the recovery of magnesium metal from cell sludge

Sludge obtained during the production of magnesium (Mg) from molten MgCl sub 2 by electrolysis contains entrapped magnesium particles. The sludge containing the magnesium particle is a friable, continuous matrix of frozen salts that may also contain some oxides and impurities. Due to the high reactivity of magnesium metal with water, a dry process was developed to recover magnesium metal from the sludge. The process utilizes mineral-processing unit operations. The steps include selective comminution, screening, attritioning and tabling. Recovery of the high-grade ( > 90%) metal was in the 70% range. The novel process was also successfully applied to a magnesium-alloy for the recovery of metal from the sludges.