Claims
- 1. A process for producing a shaped calcium silicate product, comprising:
- (a) forming an aqueous slurry of calcium silicate hydrate obtained by heating and reacting a calcareous source with a siliceous source in water as a dispersion;
- (b) molding said aqueous slurry into a shaped object;
- (c) heat treating said molded product under the conditions specified by the relationships (I) and (II):
- 10.ltoreq..theta..multidot. T (I)
- 50.ltoreq..theta..ltoreq.300 (II)
- wherein .theta. represents the temperature (.degree.C.) of the interior of said molded product and T represents the time (hrs), with the proviso that the amount of water loss during said heat treatment is less than 25 wt.%;
- (d) optionally steam curing said treated product; and
- (e) drying the cured product.
- 2. The process of claim 1, wherein said aqueous slurry contains a calcium silicate hydrate of the tobermorite structure having been reacted at a temperature of greater than 130.degree. C. and having a wet volume of more than 15 cm.sup.3 /g as defined by the equation:
- wet volume=V/W,
- wherein W represents the total weight of the calcareous source and the siliceous source and V represents the volume of the solid components after the aqueous slurry has settled for 24 hours.
- 3. The process of claim 1, wherein said aqueous slurry of calcium silicate hydrate is admixed with a reinforcing fibrous material and the resulting mixture is molded by press filter-molding and cured.
- 4. The process of claim 1, wherein said aqueous slurry of calcium silicate hydrate is prepared by mixing the siliceous source and the calcareous source with a reinforcing fibrous material and heating the resulting mixture in water followed by completing the preparation of said molded product by press filter-molding said aqueous slurry and curing the molded product.
- 5. The process of claim 1, wherein the reaction of the siliceous source and the calcaerous source is conducted at a temperature of 150.degree. to 230.degree. C.
- 6. The process of claim 1, wherein the heat treating conditions of step (c) are defined by the relationships (I') and (II'):
- 100.ltoreq..theta..multidot.T.ltoreq.1,000 (I')
- 70.ltoreq..theta..ltoreq.230 (II')
- 7. The process of claim 1, wherein said heat treatment of step (c) is conducted under the provisions in which less than 10 wt.% of the water is removed.
- 8. The process of claim 1, wherein said heat treatment of step (c) is conducted under the provisions in which the amount of water removed is less than 5 wt.%.
- 9. The process of claim 1, wherein the steam pressure during steam curing of the molded and heat treated product is conducted at a pressure ranging from 5 to 50 kg/cm.sup.2 G.
- 10. The process of claim 1, wherein the steam pressure during steam curing of the molded and heat treated product is conducted at a pressure ranging from 6 to 30 kg/cm.sup.2 G.
- 11. A process for producing a shaped calcium silicate product, comprising:
- (a) forming an aqueous slurry of calcium silicate hydrate obtained by heating and reacting a calcareous source with a siliceous source in water as a dispersion;
- (b) molding said aqueous slurry into a shaped object;
- (c) heat treating said molded product under the conditions specified by the relationships (I) and (II):
- 100.ltoreq..theta..ltoreq..multidot.T (I)
- 50.ltoreq..theta..ltoreq.300 (II)
- wherein .theta. represents the temperature (.degree.C.) of the heat treatment and T represents the time (hrs) of heat treatment, with the proviso that the amount of water loss during said heat treatment is less than 25 wt.%;
- (d) optionally steam curing said treated product; and
- (e) drying the cured product.
- 12. The process of claim 11, wherein said aqueous slurry contains a calcium silicate hydrate of the tobermorite structure having been reacted at a temperature of greater than 130.degree. C. and having a wet volume of more than 15 cm.sup.3 /g as defined by the equation:
- wet volume=V/W,
- wherein W represents the total weight of the calcareous source and the siliceous source and V represents the volume of the solid components after the aqueous slurry has settled for 24 hours.
- 13. The process of claim 11, wherein said aqueous slurry of calcium silicate hydrate is admixed with a reinforcing fibrous material and the resulting mixture is molded by press filter-molding and cured.
- 14. The process of claim 11, wherein said aqueous slurry of calcium silicate hydrate is prepared by mixing the siliceous source and the calcareous source with a reinforcing fibrous material and heating the resulting mixture in water followed by completing the preparation of said molded product by press filter-molding said aqueous slurry and curing the molded product.
- 15. The process of claim 11, wherein the reaction of the siliceous source and the calcareous source is conducted at a temperature of 150.degree. to 230.degree. C.
- 16. The process of claim 11, wherein the heat treating conditions of step (c) are defined by the relationships (I') and (II'):
- 100.ltoreq..theta..multidot.T.ltoreq.1,000 (I')
- 70.ltoreq..theta..ltoreq.230 (II')
- 17. The process of claim 11, wherein said heat treatment of step (c) is conducted under the provisions in which less than 10 wt.% of the water is removed.
- 18. The process of claim 11, wherein said heat treatment of step (c) is conducted under the provisions in which the amount of water removed is less than 5 wt.%.
- 19. The process of claim 11, wherein the steam pressure during steam curing of the molded and heat treated product is conducted at a pressure ranging from 5 to 50 kg/cm.sup.2 G.
- 20. The process of claim 11, wherein the steam pressure during steam curing of the molded and heat treated product is conducted at a pressure ranging from 6 to 30 kg/cm.sup.2 G.
Priority Claims (1)
Number |
Date |
Country |
Kind |
55-12161 |
Feb 1980 |
JPX |
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Parent Case Info
This is a continuation of application Ser. No. 227,697, filed Jan. 23, 1981 abandoned.
US Referenced Citations (2)
Number |
Name |
Date |
Kind |
3231657 |
Kalousek |
Jan 1966 |
|
3505439 |
Moorehead |
Apr 1970 |
|
Foreign Referenced Citations (1)
Number |
Date |
Country |
1043015 |
Sep 1966 |
GBX |
Continuations (1)
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Number |
Date |
Country |
Parent |
227697 |
Jan 1981 |
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