Magnesium extraction from sea water using - surfactants and organic solvents

Selective Mg salt extraction from Mg-containing salt solutions (I), pref. sea water, takes place by mixing (I) with at least 1 mole of a water-soluble anionic surface active agent (II) consisting of Na-, K- or NH4 salts of high mol. wt. alkyl sulphates or-sulphonates, per mole Mg contained in (I); contacting mixtures of (I) and (II) with a water-immiscible liquid organic extractant consisting of alcohols, ethers, ketones and/r hydrocarbons and separating the Mg-enriched extractant from the salt solution. Pref. Mg-charged organic extractant is contacted with a water-soluble salt (such as NaCl) in sufficient amounts to release Mg, which is then separated from organic extractant with reduced Mg Content.