Verfahren zur Gewinnung von Magnesium durch elektrothermische Reduktion von calciniertem Dolomit

摘要

In the production of magnesium by the electrothermal reduction of dolomite with ferro-silicon or other metallic reducing agent, the reaction mixture contains dolomite in 50-200% excess over that theoretically required. Reduction is carried out under reduced pressure at a temperature above the solidus of the reducing agent, and the mixture is heated by radiation on to its surface. Excess dolomite is recovered from the residue by sieving preferably at a temperature below 675 DEG C. and is recycled. A suitable apparatus illustrated consists of a furnace 1 having a grating 2 to support the reaction mixture which is introduced through feeder 6, the residue being discharged at 4. Heat is supplied by means 8 and the magnesium vapour is transported by a stream of inert gas from pipe 20 through purification chamber 12 to the condenser where the major part is condensed to liquid which forms barometric column 15, the remainder solidifying in condenser 17 from which it is subsequently removed by heating coil 18.