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A Strong Acid-weak Acid Method for Producing Aluminum Chloride Hexahydrate from Kaolinitic Clay.
Bauer-DJ; Shanks-DE; Eisele-JA
MISSING :7 pages
The Bureau of Mines has conducted extensive studies on the recovery of alumina from kaolinitic clay by a hcl leaching-hcl sparging process. The current study reports a modification of the process, which involves a double-leaching system. The first leach of the calcined clay is made at as high a hcl acid strength as possible so that the dissolution of aluminum chloride hexahydrate (alcl3.6H2o) is suppressed. Most of the impurities, but very little aluminum, are soluble in the strong acid. After liquid-solid separation and washing, the solids are leached with recycled weak hcl, which dissolves the alcl3.6H2o. The pregnant liquor is separated from the gangue, and alcl3.6H2o is crystallized from solution by injecting hcl gas. A proposed flowsheet is presented, and the effect of bleedstream size on alcl3.6H2o purity is discussed.
IH; Report of Investigations
Page last reviewed: September 2, 2020
Content source: National Institute for Occupational Safety and Health Education and Information Division