Selective Extraction of Lithium Chloride from Brines

Lithium chloride can be recovered from brines by liquid-liquid extraction with alcohols such as n-butanol or isoamyl alcohol as well as by precipitation of the lithium aluminate complex (1–3). In most cases, however, certain amounts of magnesium chloride and calcium chloride are coextracted. In order to obtain pure lithium chloride, separation of alkaline earth compounds by special precipitation (4) or extraction procedures (5) is necessary. On the other side, coextraction of alkaline earth chlorides with alcohols can be suppressed by the addition of ammonia (6) or urea (7). For the separation of lithium from magnesium and sodium, extraction with mixtures of butanol and hexanediols is also recommended (8).