FIELD: chemical technology. SUBSTANCE: reduction is carried out in the presence of calcium oxide from the charge with excess of reducing agent - aluminium at ratio 1.1-1.5 with respect to stoichiometric necessary quantity in reaction, at 890-910 C and residual pressure 0.05 mm mercury column, not more. Charge is reduced at the rate 0.67-0.75 g/h, and charge can be calcined preliminary under vacuum at 600-620 C. Under these conditions of charge reduction metal prepared does not contain calcium impurity. Extraction is 96-99% that provides high quantitative efficacy of conversion of initial isotopic oxide (for example, Mg-26) to the metallic state. EFFECT: enhanced degree of magnesium extraction, increased purity. 3 cl, 2 tbl
