Patent · US Expired

Process for removing reactive silica from a bayer process feedstock

US6309615A · kind A · utility

1Cited by
8References
17Claims
0Family size

Assignee

Inventors

Key dates

Filing dateOct 15, 1999
Grant dateOct 30, 2001
Priority date
Expiry dateOct 15, 2019

Classification

  • Technology area (CPC C)Chemistry; Metallurgy
  • CPC primaryC01F7/062
  • WIPO fieldMaterials, metallurgy
  • WIPO sectorChemistry

Abstract

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

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.