Claims
- 1. A process for preparing a modified amorphous silica having a surface area of less than 30 m.sup.2 /g, a unimodal pore distribution with pores of about 300 .ANG. to about 25,000 .ANG., at least about 10% of Q3 silanols as measured by nuclear magnetic resonance spectroscopy, and less than about 0.5% of Q2 silanols as measured by nuclear magnetic resonance spectroscopy, the process comprising combining a silica slurry and a mineralizing agent to form a mixture, heating the mixture to a temperature of about 85.degree. C. to about 300.degree. C. for a time of about 4 hours to about 10 days and isolating the modified silica produced thereby.
- 2. The process of claim 1 where the mineralizing agent is selected from the group consisting of compounds of inorganic anions, organic complexing agents and mixtures thereof.
- 3. The process of claim 2 where the inorganic anion is selected from the group consisting of hydroxide, carbonate, and fluoride anions.
- 4. The process of claim 3 where the anion is derived from a compound where the cation is selected from the group consisting of alkali metal cations, ammonium ion, quaternary ammonium cations, magnesium and mixtures thereof.
- 5. The process of claim 4 where the alkali metal cation is sodium.
- 6. The process of claim 2 where the organic complexing agent is selected from the group consisting of diphenols, amines, xanthanates, ketones, and polyfunctional complexing agents.
- 7. The process of claim 6 where the organic complexing agent is selected from the group consisting of catechol, ethylenediamine, 2, 2'-bipyridine, acetylacetonate, ethylenediamine tetraacetic acid and nitrilotriacetic acid.
- 8. The process of claim 1 where the modified silica has a median pore size of at least 1,000 .ANG..
- 9. The process of claim 1 where the modified silica has a pore size in the range of about 800 .ANG. to about 10,000 .ANG..
- 10. The process of claim 1 where the modified silica has at least 13% of Q3 silanols.
CROSS REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of U.S. application Ser. No. 08/998,766 filed on Dec. 11, 1997 now U.S. Pat. No. 5,897,849, which in turn is a continuation-in-part of U.S. application Ser. No. 08/774,751, filed Dec. 30, 1996, now abandoned, all of which are incorporated herein by reference.
US Referenced Citations (6)
Continuation in Parts (2)
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Number |
Date |
Country |
Parent |
998766 |
Dec 1997 |
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Parent |
774751 |
Dec 1996 |
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