| abstract |
Siliceous materials produced by thermally treating Bayer process liquors are obtained in modified form when produced in the presence of ammonium, aromatic amine, and amine compounds, or compounds bearing ammonium, aromatic amine or amine moieties, such as N-propylamine, pyridine and tetramethylammonium hydroxide. These modified siliceous materials possess morphologies which confer upon them a reduced tendency to deposit on surfaces throughout the process. |