| 摘要 |
<PICT:1115576/C1/1> Magnesium chloride is dehydrated by contacting a film of hydrous MgCl2 not above 20 m thickness at 500-700 DEG F., in an HCl atmosphere wherein, at the temperature of the reaction, the partial pressure of HCl exceeds the equilibrium partial pressure and the ratio of partial pressures of HCl to H2O exceeds the equilibrium ratio. The film may be formed by spraying the hydrous MgCl2 on to a fluidized bed of anhydrous MgCl2 of 50 to 300 m size, or by coating it on the inner surface of a heated cylinder by a rotary wiper. A solution of MgCl2 may be concentrated to 50% to 60% by evaporating in boiler 20 (see drawing) at 345 DEG to 365 DEG F., and then injected at 9 into the fluidized bed in drier 30 heated with HCl at e.g. 1220 DEG F. The dehydrated MgCl2 may be fused in a second zone 80 in HCl wherein the ratio of HCl to H2O exceeds the equilibrium partial pressure at the temperature of operation of the second zone, and a part of this MgCl2 recycled to the fluidized bed. The fluidizing HCl gas may be dried after use, heated and recycled.
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