Claims
- 1. A process for preparing a crystalline, potassium-containing L zeolite having a composition, in terms of mole ratios of oxides, in the range:
- 0. 9 to 1.3(M.sub.2 O):Al.sub.2 O.sub.3 :5.2 to 6.9SiO.sub.2 :0.9H.sub.2 O
- where M is either K or a mixture of K and Na where Na is no more than 20 mole percent of the mixture, which process comprises:
- (a) preparing with agitation a reaction mixture comprising water, and feed materials of potassium silicate, metakaolin, KOH and up to about 30% by mole fraction of NaOH based on total KOH and NaOH, and whereon potassium silicate and metakaolin are the only sources of silica in the reaction mixture, said reaction mixture having a composition, in terms of mole ratios of oxides, within the following ranges:
- ______________________________________K.sub.2 O:Al.sub.2 O.sub.3 1.0 to 3.0Na.sub.2 O:Al.sub.2 O.sub.3 0 to 1.0SiO.sub.2 :Al.sub.2 O.sub.3 5 to 9H.sub.2 O:Al.sub.2 O.sub.3 110 to 140______________________________________
- said ratios being selected to permit recovery of essentially a stoichiometric amount of L zeolite crystals in step (c);
- (b) maintaining the reaction mixture in a substantially homogeneous state, at between about 80.degree. and 260.degree. C. for between about 1 and 10 days until essentially a stoichiometric amount of crystals of said L zeolite are formed, and
- (c) recovering L zeolite crystals.
- 2. The process of claim 1 wherein NaOH is not employed in the reaction mixture.
- 3. The process of claim 1 wherein after step (a) but before step (b) the reaction mixture is blended sufficiently to form a substantially homogeneous mixture.
- 4. The process of claim 1 wherein the reaction mixture is maintained between 80.degree. and 100.degree. C.
- 5. The process of claim 1 wherein prior to step (b) microcrystals of an L type zeolite are added to the blended reaction mixture in an amount of from 0.1 to 20% by weight based on silica and alumina.
- 6. The process of claim 1 wherein prior to step (b) the blended reaction mixture is maintained at about 10.degree. to 100.degree. C. for from about 6 hours to 6 days.
- 7. A process for preparing a crystalline, potassium-containing L zeolite having a composition, in terms of mole ratios of oxides in the range:
- 0.9 to 1.3K.sub.2 O:Al.sub.2 O.sub.3 : 5.2 to 6.9SiO.sub.2 :0.9H.sub.2 O
- which comprises:
- (a) preparing a reaction mixture comprising water, and feed materials of KOH, potassium silicate and metakaolin, and wherein potassium silicate and metakaolin are the only sources of silica in the reaction mixture, said reaction mixture having a composition, in terms of mole ratios of oxides, within the following ranges:
- ______________________________________K.sub.2 O:Al.sub.2 O.sub.3 1.0 to 3.0SiO.sub.2 :Al.sub.2 O.sub.3 5 to 9H.sub.2 O:Al.sub.2 O.sub.3 110 to 140______________________________________
- said ratios being selected to permit recovery in step (d) of essentially a stoichiometric amount of type L zeolite crystals,
- (b) blending the reaction mixture sufficiently to form a substantially homogeneous mixture;
- (c) maintaining the blended reaction mixture at between 80.degree. and 100.degree. C. for a sufficient period of time to produce essentially a stoichiometric amount of crystals of said L zeolite; and
- (d) recovering type L zeolite crystals.
Parent Case Info
This applicaion is a continuation of application Ser. No. 550,896, filed 11/10/83, now abandoned.
US Referenced Citations (11)
Foreign Referenced Citations (3)
Number |
Date |
Country |
1202511 |
Aug 1970 |
GBX |
1393365 |
May 1975 |
GBX |
1394163 |
May 1975 |
GBX |
Non-Patent Literature Citations (1)
Entry |
Breck "Zeolite Molecular Sieves", 1974, pp. 313-320. |
Continuations (1)
|
Number |
Date |
Country |
Parent |
550896 |
Nov 1983 |
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