GB518949A - Process for the production of magnesium and of magnesium alloys - Google Patents

Abstract

518,949. Magnesium alloys. SERI HOLDING SOC. ANON. Sept. 10, 1938, Nos. 26499 and 26500. Convention dates, Sept. 11, 1937, and Aug. 17, 1938. Drawings to Specification. [Class 82 (i)] A cyclic process for obtaining magnesium from its ores, such as magnesite, dolomite &c. comprises treating the ore with hydrofluoric acid, heating the resulting magnesium fluoride with a reducing agent in a non-oxidizing atmosphere at a temperature between the melting point of magnesium fluoride and 1260‹C. condensing the magnesium vapours, treating the fluorinated residue to regenerate hydrofluoric acid, and so on. The reducing agent may be calcium, or a tetravalent element such as silicon, or a compound or alloy of a tetravalent element such as calcium carbide, a calciumsilicon alloy, an iron-silicon alloy, or an ironsilicon-aluminium alloy. The magnesium fluoride to be reduced may be mixed with calcium fluoride, with or without magnesium carbonate. magnesium oxide, or calcium carbonate, or with an alkali-metal fluoride to lower the reaction temperature. Hydrofluoric acid may be supplied to the cycle to make up losses. Metals to be alloyed with magnesium may be introduced into the cycle as metals, ores, or compounds such as fluorides, or added in molten form to the magnesium at the condensation phase ; or if silicon is used as the reducing agent, a magnesium-silicon alloy may be formed and removed from the cycle before the distillation phase. The production of alloys of magnesium with the following metals and pairs of metals is referred to : lithium, cobalt, zirconium, cadmium, lead, aluminium, tin, silver-aluminium, silver-cadmium, silver-copper, silver-antimony, silvertin, aluminium-beryllium, aluminium-copper, aluminium-tin, aluminium-zinc, copper-beryllium, cadmium-antimony, cadmium-tin, cadmium-zinc, copper-antimony, copper-tin, copperzinc, iron-zinc, lithium-tin, lithium-zinc, antimony-tin, antimony-zinc, tin-zinc.