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US4381289A
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Process for preparing zirconium phosphate
Assignee: National Research Development Corp UK
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Filing: 1981-12-02
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Granted: 1983-04-26
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Expires: 2001-12-02
Abstract
Abstract Crystalline alpha zirconium phosphate Zr(HPO4) 2 .H 2 O, which can selectively remove ammonia and heavy metal ions from solution by ion exchange, is made by forming a room-temperature solution of zirconyl chloride ZrOCl 2 in hydrochloric acid and adding sodium fluoride; the pH is now at most 1.6, the zirconium concentration is about 0.1M and the molar ratio sodium:zirconium is 5:1. Then, with rapid mixing, this composition is added to 15M phosphoric acid H 3 PO 4 (molar ratio phosphate:zirconium at least 3:1). Zirconium phosphate is precipitated.
Inventors
- 👤 Derek V. Nowell
- 👤 Koteswararao Rentala
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 15:46
CPC Classifications
B; B01; B01J; B01J39/00; B01J39/08; B01J39/12; C; C01; C01B; C01B25/00; C01B25/16; C01B25/26; C01B25/37; C01B25/372; Y; Y02; Y02W; Y02W10/00; Y02W10/30; Y02W10/37
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
119 words
A process for preparing zirconium phosphate comprising: (1) forming a solution of zirconyl chloride in hydrochloric acid, the solution having a pH not exceeding 0.3; (2) adding sodium fluoride to a minimum molar ratio sodium:zirconium of 4:1 and subject to a maximum of 5.0:1 at a zirconium concentration of 0.1 M, of 5.2 at 0.07 M and 9 at 0.05 M; (3) ensuring that the solution is homogeneous, at a maximum pH of 1.6, and at a concentration of from 0.05 to 0.1 M in zirconium; (4) mixing the solution with phosphoric acid such that in the mixture the molar ratio phosphate:zirconium is substantially always at least 3, whereby zirconium phosphate precipitates; and (5) recovering said precipitated zirconium phosphate.
Claim 2
Dependent Claim
119 words
A process for preparing zirconium phosphate comprising: (1) forming a solution of zirconyl chloride in hydrochloric acid, the solution having a pH not exceeding 0.3; (2) adding sodium fluoride to a minimum molar ratio sodium:zirconium of 4:1 and subject to a maximum of 5.0:1 at a zirconium concentration of 0.1 M, of 5.2 at 0.07 M and 9 at 0.05 M; (3) ensuring that the solution is homogeneous, at a maximum pH of 1.6, and at a concentration of from 0.05 to 0.1 M in zirconium; (4) mixing the solution with phosphoric acid such that in the mixture the molar ratio phosphate:zirconium is substantially always at least 3, whereby zirconium phosphate precipitates; and (5) recovering said precipitated zirconium phosphate.
Claim 3
Dependent Claim
22 words
A process for preparing zirconium phosphate according to claim 1, wherein the said molar ratio phosphate:zirconium is substantially always at least 6.
Claim 4
Dependent Claim
22 words
A process for preparing zirconium phosphate according to claim 2, wherein the said molar ratio phosphate:zirconium is substantially always at least 12.
Claim 5
Dependent Claim
22 words
A process for preparing zirconium phosphate according to claim 3, wherein the said molar ratio phosphate:zirconium is substantially always at least 15.
Claim 6
Dependent Claim
29 words
A process for preparing zirconium phosphate according to claim 1, wherein the solution containing the zirconium, hydrochloric acid and fluoride is introduced into a volume of the phosphoric acid.
Claim 7
Dependent Claim
19 words
A process for preparing zirconium phosphate according to claim 1, wherein the molar ratio sodium:zirconium is at least 4.5:1.
Claim 8
Dependent Claim
19 words
A process for preparing zirconium phosphate according to claim 6, wherein the molar ratio sodium:zirconium is at least 5.0:1.
Claim 9
Dependent Claim
34 words
A process for preparing zirconium phosphate according to claim 1, wherein the molar ratio sodium:zirconium is at most 5.0:1 at 0.1 M zirconium, 5.1:1 at 0.07 M zirconium or 8:1 at 0.05 M zirconium.
Claim 10
Dependent Claim
29 words
A process for preparing zirconium phosphate according to claim 1, wherein the zirconyl chloride/hydrochloric acid solution before the addition of the sodium fluoride has a pH not exceeding 0.2.
Claim 11
Dependent Claim
24 words
A process for preparing zirconium phosphate acording to claim 9, wherein the said pH of the zirconyl chloride/hydrochloric acid solution does not exceed 0.1.
References Cited (Backward Citations)
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1986-04-25 | 1986-10-25 | 1987-04-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-04-25 | 1990-10-25 | 1991-04-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-04-25 | 1994-10-25 | 1995-04-26 | $7700.00 | Window Closed / Lapsed |