METHOD FOR PRODUCTION OF MAGNESIUM CHLORIDE TO BE USED FOR PRODUCTION OF MAGNESIUM METAL BY LEACHING MAGNESITE IN HYDROCHLORIC ACID

摘要

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 the first stage coarsly crushed magnesite lumps are dissolved by feeding hydrochloric acid. The reaction solution from the first stage is led to a second stage, 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.