Process for recovery of alumina from high-silica ore
 Back reactions of dissolved alumina from a high caustic-lime digest of anorthosite and other alumina-containing siliceous materials can be eliminated or mitigated by control of particle size of digestible material; and time and temperature of separation of the alumina-bearing liquid from the solid residues. In one embodiment the back reaction is further controlled by adjustment of the caustic concentration of the digest effluent. 
Aluminum Company of America
C
C01F
inventional
Lawrence Keith John M. Kenneth I.
Hudson Stinson, Jr. Savage