| abstract |
An amorphous aluminosilicate sol with uniform size particles is prepared by a process comprising (1) preparing a sol of discrete colloidal particles of uniform size, the surface of which consists of a coating of an aluminosilicate by separately and simultaneously adding a silica sol or an alkali metal silicate solution and an alkali metal aluminate solution to a heel sol of uniform-sized colloidal particles of aluminosilicate, silica or refractory metal oxide(s) at a certain rate of addition at constant pH of 9 to 12 and T of 50 DEG to 100 DEG C. to deposit or coat aluminosilicate onto surface of heel sol particles, (2) ion exchanging the alkali metal ions of the sol from (1) for ammonium ions, and (3) filtering the sol from (2) to remove the cation exchange resin and optionally concentrating the sol to a solids content of up to 60% by weight. |