Patent Number: 6,309,615

Title: Process for removing reactive silica from a bayer process feedstock

Abstract: A process for the removal of reactive silica from a feedstock to thedigestion step of the Bayer process for the manufacture of alumina, inwhich (a) the feedstock is contacted with a caustic liquor under processconditions which result in dissolving and stabilizing at least 50% of thesilica into solution at a level of at least 3 gpL and without significantprecipitation from solution of dissolved silica, (b) the silica bearingliquor is separated from solid residue of step (a) under conditions whichdo not promote significant precipitation of the silica; and (c)aluminosilicates are precipitated from the separated silica bearing liquorfrom step (b), to form a solid aluminosilicate product which is free of amajority of all other components of the feedstock.

Inventors: Hollitt; Michael John (Graceville, AU), Crisp; Anthony John (Toowong, AU), Staker; Warren Scott (Thomastown, AU), Roe; Gerard Marcus (Preston, AU), Rodda; Darren Paul (Greensborough, AU)


International Classification:

Expiration Date: 10/32013