| 摘要 |
<p>1339670 Distilling magnesium J M AVERY 19 April 1971 [6 April 1970] 26381/71 Heading C7D Magnesium vapour produced by the reaction of a metallic or silicon reducing agent with magnesium oxide, in the presence of a molten oxidic slag and an "inert" gas, is passed to a condensor predominantly by diffusion by ensuring that the molar flow rate of magnesium is greater than that of the "inert" gas. The "inert" gas may be H 2 , He, Ar, Ne or mixtures thereof. The magnesium oxide may be present as calcined dolomite, magnesia, mixtures thereof, or as serpentine. The reducing agent may be Si, Al metal or Al/Si, Ce/Si/Al, Ca/Si or Ca/Si/Al alloys. Al 2 O 3 may be added as a flux. The preferred operating conditions are an "inert" gas partial pressure of at least 0À05 atmospheres, a lower magnesium vapour partial pressure of at least 0À05 atmospheres and a temperature of at least 1300‹C. The final slag composition is preferably 10-60 wt per cent CaO, 0-35 per cent Al 2 O 3 , 20-50 per cent SiO 2 and 2-25 per cent MgO.</p> |
