| abstract |
New crystalline silicas are synthesized from a sodium silicate or other silica source solution having a Na2O/SiO2 ratio of about 0.3 up to 7. These new silicas are formed at elevated temperatures wherein the precursor solution is at a pH of at least about 10. The precursor solution is aged for from 15-75 days, preferably with a promotor which is a metal salt of group 3A, 5B or 6B. Depending on the reaction period the silica is either of a very fine particle (<.2 Mu ) or of a platelet form. |