Claims
- 1. A process for producing synthetic stevensite, which comprises hydrothermally treating a fluorine-ion-free aqueous composition containing as metallic components only basic magnesium carbonate and a silica-sodium component selected from the group consisting of (i) sodium silicate, (ii) sodium silicate and amorphous silica, and (iii) amorphous silica and sodium hydroxide, the solids concentration of the aqueous composition being 5 to 15% by weight, the hydrothermal treatment being carried out at a temperature of 100.degree. to 300.degree. C. under a pressure of 0 to 100 kg/cm.sup.2 .multidot.G, and the resulting synthetic stevensite being non-toxic to humans.
- 2. The process of claim 1 wherein the basic magnesium carbonate is hydromagnesite.
- 3. The process of claim 1 wherein the magnesium component and the silica component are used in substantially stoichiometric proportions.
- 4. The process of claim 1 wherein the hydrothermal treatment is carried out at a temperature of 150.degree. to 200.degree. C. under a pressure of 6 to 40 kg/cm.sup.2.
Priority Claims (1)
Number |
Date |
Country |
Kind |
62-20476 |
Feb 1987 |
JPX |
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Parent Case Info
This is a division of application Ser. No. 07/150,613, filed on 2/1/88.
US Referenced Citations (3)
Number |
Name |
Date |
Kind |
3586478 |
Neumann |
Jun 1971 |
|
4040974 |
Wright et al. |
Aug 1977 |
|
4054537 |
Wright et al. |
Oct 1977 |
|
Foreign Referenced Citations (3)
Number |
Date |
Country |
13009382 |
Jul 1982 |
JPX |
61-275126 |
Dec 1986 |
JPX |
62-59518 |
Mar 1987 |
JPX |
Non-Patent Literature Citations (2)
Entry |
Brindley, G. W. and Brown, G., Crystal Structures of Clay Minerals and Their X-Ray Identification, Mineralogical Society Monograph No. 5, pp. 169-170 (1980). |
Grim, R. E., Structure of the Clay Minerals, Clay Mineralogy, pp. 83-87 (1968). |
Divisions (1)
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Number |
Date |
Country |
Parent |
150613 |
Feb 1988 |
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