Abstract: Process for production of magnesium chloride with sufficient purity for the production of magnesium metal, by leaching a magnesium containing raw material in hydrochloric acid. It is essential to keep the ratio between acid soluble iron and nickel greater than 120 and the ratio between acid soluble iron and phosphorus greater than 20 in the primary magnesium chloride solution, to obtain a sufficiently pure product. The acid soluble iron can partly or completely be substituted by an equal, molar amount of acid soluble aluminium. It is especially preferred to use mixtures of macro- and crypto-crystalline magnesites in the ratio 1:10-10:1 as raw material.

Abstract: Method for production of magnesium chloride, to be used for production of magnesium, by leaching of magnesite in hydrochloric acid. A two-stage leaching process is used where in a first reactor magnesite lumps are dissolved in hydrochloric acid. The magnesium chloride containing solution is led to a second reactor, where finely ground magnesite or hydrochloric acid is added to obtain approximate equivalence between magnesium and chlorine. To precipitate the impurities an excess of magnesium oxide or magnesium hydroxide is added in one or several purification stages.