Claims
- 1. An integrated process for production of zeolite 4A from bauxite which comprises:
- 1) digesting bauxite at atmospheric pressure at a temperature of from 90.degree. to 100.degree. C. by use of aqueous sodium hydroxide solution having a concentration at least 11%;
- 2) filtering the product obtained;
- 3) passing the filtrate through a bed of hydrophobic resin to remove organic material;
- 4) reacting the treated filtrate at a temperature of from 60.degree. to 70.degree. C. with an alkaline solution of silica having a molar ratio of SiO.sub.2 :Na.sub.z O in the range 2.0 to 2.5 in an agitated reaction to produce a sodium silica aluminate gel;
- 5) crystallizing said gel to produce the desired zeolite;
- 6) treating the residue from step (2) with sulfuric acid to recover metal values therefore as aqueous metal sulfate and recycling the silica residue for preparation of the alkaline solution of silica used in step (4) and
- 7) recycling the mother liquor remaining after crystallization of the gel to the digestion step (1).
- 2. A process according to claim 1 wherein said dissolution of bauxite is effected in a rotating reactor.
- 3. A process according to claim 1 wherein residues left after dissolution of the bauxite are treated with boiling sulfuric acid to recover metal values therein as sulfates, the separating silica residues from dissolved sulfates and recycling said silica for production of the alkaline solution of silica used for production of the gel.
Parent Case Info
This is a continuation of application Ser. No. 07/801,260, filed on Dec. 3, 1991, now abandoned.
US Referenced Citations (6)
Foreign Referenced Citations (2)
Number |
Date |
Country |
712963 |
Jul 1965 |
CAX |
2722535 |
Nov 1978 |
DEX |
Continuations (1)
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Number |
Date |
Country |
Parent |
801260 |
Dec 1991 |
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