| 摘要 |
1519452 Alumina purification JOHNSON MATTHEY & CO Ltd 1 July 1975 [10 July 1974] 30490/74 Heading C1A [Also in Division C7] Recovery of gallium and alumina from bauxite ore by: (a) dissolving the ore in caustic soda solution under pressure, (b) precipitation of alumina hydrate from the caustic soda solution by reduction of pressure and temperature, (c) subjecting the molten liquor from (b) to a temperature of 60‹ to 450‹C and a pressure of 2 to 100 atmos. in the presence of an O 2 containing atmosphere, (d) cementing the Ga remaining in solution by contact with Al. The process in steps (a) and (b) may be repeated by recycling before the liquor is passed to steps (c) and (d). |
