GB634799A - Methods of and plant for producing magnesium powder or powder metal mixtures containing magnesium - Google Patents

Abstract

634,799. Distilling metals; magnesium. AMERICAN ELECTRO METAL CORPORATION. June 4, 1947, No. 14804. Convention date, June 8, 1946. [Class 82(i)] A method of producing magnesium powder by condensation from the vapour phase is characterized by the steps of passing an inert carrier gas through a melt of magnesium, heated to a temperature below the boiling point of magnesium, so that the carrier gas is heated and loaded with magnesium vapours of a pressure substantially corresponding to the temperature of the melt, admixing inert chilling gas with the loaded carrier gas outside the melt so as to reduce the temperature of the carrier gas and to condense a substantial portion of the magnesium vapours to magnesium powder. Predetermined relative quantities of carrier gas and chilling gas may be used to produce magnesium powder of desired particle size. The method may be applied to the production of powder of constituents of magnesium alloys, where all the said constituents boil below 1600‹C, the carrier gas being passed through a melt containing the constituents and being loaded with vapours of the said constituents in succession. The inert carrier and chilling gases may be helium, argon, neon and/or purified hydrogen of dew point below -40‹C. The apparatus shown in Fig. 1 comprises a vessel 10 for containing magnesium or the constituents of magnesium alloy up to a level 15, the vessel being heated by heating means 16 surrounded by a refractory container 12. Inert carrier gas enters the molten charge near the bottom of vessel 10 through pipe 21, valve 24 and pipe 25. The loaded carrier gas leaves the vessel through pipe 17 which is connected to vessel 10 above the level 15 of the melt. The carrier gas is mixed with inert chilling gas injected through nozzle 27 and supplied through pipe 23, cooler 32 and valve 22 from pipe 21. Gas containing metal powder is fed to a cyclone 18 where the powder is separated and periodically removed through valves 39 and 41. Gas leaving the cyclone passes through cooler 36 and a filter 48, which removes any remaining metal particles, before being recirculated by fan 20. Losses of inert gas are made up by fresh gas introduced through valve 42. after passing a moisture trap 43, a trap 44 containing heated magnesium and a cooler 47.