Obtaining lithium metal
Lithium metallurgy

Lithium metal is obtained from LiCl obtained from Li₂CO₃.

Lithium carbonate is first purified to remove impurities interfering with electrolysis and the purity of the final lithium, in particular sodium, calcium, magnesium and sulfate ions. The most widely used process is the CO₂ process. It involves solubilizing lithium in bicarbonate form by adding CO₂ operating on a suspension of lithium carbonate in water. After filtration to remove precipitated impurities, lithium is precipitated from the filtrate in the form of carbonate by thermal decomposition at 90°C of the bicarbonate. The purified carbonate is converted to chloride by reaction with hydrochloric acid. Due to the strong corrosion resulting from this reaction, reactors are made of special steels or titanium. Lithium chloride is crystallized, wrung out and dried. It is extremely hygroscopic,...