A process for recovering alumina values from a first liquor having an
initial concentration of aluminate ions and hydroxyl ions in solution is
described. The first liquor is treated with a hydroxide of a metal other
than aluminium to form an aluminium-bearing layered double hydroxide and
produce a treated stream of first liquor, the treated stream of first
liquor having a final concentration of aluminate ions less than the
initial concentration of aluminate ions. The aluminium-bearing layered
double hydroxide is separated from the treated stream of first liquor.
Thereafter the clarified treated stream of first liquor is returned to a
first location within an alumina refinery. The separated
aluminium-bearing layered double hydroxide is contacted with a solution
containing carbonate ions to form a slurry comprising an insoluble salt
of the metal other than aluminium and a second liquor comprising
aluminate ions released from the aluminium-bearing layered double
hydroxide.