Patent US4500502A successfully refreshed from Google Patents.
US4500502A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for removing impurities from wet process of phosphoric acid
Assignee: Mississippi Chemical Corp
•
Filing: 1983-06-28
•
Granted: 1985-02-19
•
Expires: 2003-06-28
Abstract
Abstract A method of preparing a purified ammoniated phosphoric acid composition, comprising, reacting an aqueous wet process phosphoric acid with an ammonium ion source at a N/P 2 O 5 weight ratio ranging from about 0.06 to about 0.15 in the presence of solid phase metal ion containing impurities for a time sufficient to precipitate the majority of the impurities in the acid, the impurity precipitation comprising at least several complex metal salts at least one of which contains magnesium, aluminum and fluorine, and obtaining the purified ammoniated phosphoric acid by separating the precipitated impurities therefrom.
Inventors
- 👤 Daniel P. McDonald
- 👤 James C. Wade
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 23:04
CPC Classifications
C; C01; C01B; C01B25/00; C01B25/16; C01B25/26; C01B25/455; C01B25/18; C01B25/234; C01B25/237
Claims Analysis
Total Claims: 29
Claim 1
Independent Claim
104 words
A method of preparing a purified ammoniated phosphoric acid composition, comprising: reacting an aqueous wet process phosphoric acid having a P 2 O 5 content of 23-62% with an ammonium ion source at a N/P 2 O 5 weight ratio ranging from about 0.06 to about 0.15 in the presence of solid phase metal ion containing impurities for a time sufficient to precipitate the majority of the metal impurities in said acid, said impurity precipitation comprising at least several complex metal salts, one of which contains magnesium, aluminum and fluoride ions; and obtaining said purified ammoniated phosphoric acid by separating said precipitated impurities therefrom.
Claim 2
Independent Claim
104 words
A method of preparing a purified ammoniated phosphoric acid composition, comprising: reacting an aqueous wet process phosphoric acid having a P 2 O 5 content of 23-62% with an ammonium ion source at a N/P 2 O 5 weight ratio ranging from about 0.06 to about 0.15 in the presence of solid phase metal ion containing impurities for a time sufficient to precipitate the majority of the metal impurities in said acid, said impurity precipitation comprising at least several complex metal salts, one of which contains magnesium, aluminum and fluoride ions; and obtaining said purified ammoniated phosphoric acid by separating said precipitated impurities therefrom.
Claim 3
Dependent Claim
19 words
The method of claim 1, wherein the time for the precipitation of said impurities is at least one hour.
Claim 4
Dependent Claim
19 words
The method of claim 2, wherein the time of precipitation of said impurities ranges from 2 to 16 hours.
Claim 5
Dependent Claim
16 words
The method of claim 3, wherein said time of precipitation ranges from 3 to 8 hours.
Claim 6
Dependent Claim
17 words
The method of claim 1, wherein said N/P 2 O 5 ratio ranges from 0.08 to 0.13.
Claim 7
Dependent Claim
15 words
The method of claim 5, wherein said N/P 2 O 5 ratio ranges from 0.09-0.12.
Claim 8
Dependent Claim
17 words
The method of claim 1, wherein said impurity precipitation reaction occurs at a temperature of 52°-108° C.
Claim 9
Dependent Claim
12 words
The method of claim 7, wherein said temperature ranges from 60°-99° C.
Claim 10
Dependent Claim
12 words
The method of claim 8, wherein said temperature ranges from 77°-93° C.
Claim 11
Dependent Claim
20 words
The method of claim 1, wherein said precipitated complex metal salts include the following salts: Fe(NH.sub.4)(HPO.sub.4).sub.2.0.5 H.sub.2 O Al(NH.sub.4)(HPO.sub.4)F.sub.2.xH.sub.2 O
Claim 12
Dependent Claim
28 words
The method of claim 1, wherein said metal complex salt containing magnesium, aluminum and fluoride ions is MgAl(NH 4 )(HPO 4 ) 2 F 2 .4H 2 O.
Claim 13
Dependent Claim
29 words
The method of claim 1, wherein said solid phase metal ion containing impurities are present in said reaction medium in the form of added crude wet process monoammonium phosphate.
Claim 14
Dependent Claim
49 words
The method of claim 1, wherein said reaction is initiated by adding metal ion containing impurities obtained from crude wet process ammonium phosphate, to wet process phosphoric acid solution containing ammonium ions in an amount such that the N/P 2 O 5 weight ratio is within the stated range.
Claim 15
Dependent Claim
78 words
The method of claim 1, wherein said solid phase metal ion containing impurities are obtained by reacting wet process phosphoric acid with an ammonium ion source at a N/P 2 O 5 ratio of at least 0.15, thereby obtaining precipitation of said solid phase metal ion containing impurities; and recycling the precipitated solids to wet process phosphoric acid solution containing ammonium ions in an amount such that the N/P 2 O 5 ratio is within the stated range.
Claim 16
Dependent Claim
59 words
The method of claim 1, wherein said solid phase metal ion containing impurities are obtained as a slurry by reacting wet process phosphoric acid with an ammonium ion source for a prolonged period of time sufficient to obtain the impurities, and then adding the slurry to wet process phosphoric acid or ammoniated phosphoric acid to initiate the precipitation process.
Claim 17
Dependent Claim
25 words
The method of claim 1, wherein said wet process acid has a P 2 O 5 content ranging from 23-62% P 2 O 5 .
Claim 18
Dependent Claim
12 words
The method of claim 1, wherein said ammonium ion source is ammonia.
Claim 19
Dependent Claim
13 words
The method of claim 1, wherein said ammonium ion source is ammonium hydroxide.
Claim 20
Dependent Claim
18 words
The method of claim 1, wherein said ammonium ion source is monoammonium phosphate, diammonium phosphate or ammonium polyphosphate.
Claim 21
Dependent Claim
38 words
The method of claim 1, wherein a portion of the precipitated impurities which have been separated from the ammoniated phosphoric acid are recycled to the phosphoric acid - ammonia reactor, providing additional seed solids thus enhancing impurity precipitation.
Claim 22
Dependent Claim
19 words
The method of claim 1, wherein the precipitated, separated impurities are further processed into a solid phosphatic fertilizer material.
Claim 23
Dependent Claim
27 words
The method of claim 21, wherein the separated impurities are further processed by mixing with phosphoric and/or sulfuric acids and subsequently ammoniated in a fertilizer granulation process.
Claim 24
Dependent Claim
21 words
The method of claim 21, wherein the separated impurities are ammoniated further and dried to produce a powdered phosphatic fertilizer material.
Claim 25
Dependent Claim
15 words
The method of claim 21, wherein the solid phosphatic material is relatively high in micronutrients.
Claim 26
Independent Claim
105 words
A method of preparing a purified ammoniated phosphoric acid composition, comprising: (a) reacting an aqueous wet process phosphoric acid having a P 2 O 5 content of 23-62% with an ammonium ion source at a N/P 2 O 5 weight ratio ranging from about 0.06 to about 0.15; (b) seeding said aqueous acid with a mixture of complex metal salts one of which has the formula: MgAl(NH 4 )(HPO 4 ) 2 F 2 .4H 2 O in order to affect precipitation of contaminating metal ions in said wet process acid; and (c) obtaining said purified ammoniated phosphoric acid by separating said precipitated impurities therefrom.
Claim 27
Independent Claim
105 words
A method of preparing a purified ammoniated phosphoric acid composition, comprising: (a) reacting an aqueous wet process phosphoric acid having a P 2 O 5 content of 23-62% with an ammonium ion source at a N/P 2 O 5 weight ratio ranging from about 0.06 to about 0.15; (b) seeding said aqueous acid with a mixture of complex metal salts one of which has the formula: MgAl(NH 4 )(HPO 4 ) 2 F 2 .4H 2 O in order to affect precipitation of contaminating metal ions in said wet process acid; and (c) obtaining said purified ammoniated phosphoric acid by separating said precipitated impurities therefrom.
Claim 28
Independent Claim
178 words
A method of preparing a purified ammoniated phosphoric acid composition, comprising: reacting an aqueous wet process phosphoric acid having a P 2 O 5 -content of 23-62% with an ammonium ion source at a N/P 2 O 5 weight ratio ranging from about 0.06 to about 0.15 in the presence of solid phase metal ion containing impurities for a time sufficient to precipitate the majority of the metal impurities in said acid, said impurity precipitation comprising at least several complex metal salts, one of which contains magnesium, aluminum, ammonium, phosphate and fluoride ions and has the following X-ray diffraction pattern: ______________________________________
Position (20)
D (A°) I/I.sub.o
______________________________________
11.008 8.0311 100.0
13.303 6.6499 27.3
14.397 6.1471 5.7
19.730 4.4960 10.4
21.268 4.1742 10.4
21.954 4.0453 21.7
25.227 3.5274 44.7
26.782 3.3260 5.1
27.364 3.2565 32.0
29.081 3.0681 43.6
31.676 2.8224 5.8
33.468 2.6753 9.0
33.781 2.6512 33.1
35.870 2.5014 11.8
36.314 2.4718 6.0
38.960 2.3098 8.4
41.582 2.1701 6.6
44.745 2.0237 6.4
51.753 1.7650 16.7; and
______________________________________ obtaining said purified ammoniated phosphoric acid by separating said precipitated impurities therefrom.
Claim 29
Independent Claim
178 words
A method of preparing a purified ammoniated phosphoric acid composition, comprising: reacting an aqueous wet process phosphoric acid having a P 2 O 5 -content of 23-62% with an ammonium ion source at a N/P 2 O 5 weight ratio ranging from about 0.06 to about 0.15 in the presence of solid phase metal ion containing impurities for a time sufficient to precipitate the majority of the metal impurities in said acid, said impurity precipitation comprising at least several complex metal salts, one of which contains magnesium, aluminum, ammonium, phosphate and fluoride ions and has the following X-ray diffraction pattern: ______________________________________
Position (20)
D (A°) I/I.sub.o
______________________________________
11.008 8.0311 100.0
13.303 6.6499 27.3
14.397 6.1471 5.7
19.730 4.4960 10.4
21.268 4.1742 10.4
21.954 4.0453 21.7
25.227 3.5274 44.7
26.782 3.3260 5.1
27.364 3.2565 32.0
29.081 3.0681 43.6
31.676 2.8224 5.8
33.468 2.6753 9.0
33.781 2.6512 33.1
35.870 2.5014 11.8
36.314 2.4718 6.0
38.960 2.3098 8.4
41.582 2.1701 6.6
44.745 2.0237 6.4
51.753 1.7650 16.7; and
______________________________________ obtaining said purified ammoniated phosphoric acid by separating said precipitated impurities therefrom.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-02-19 | 1988-08-20 | 1989-02-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-02-19 | 1992-08-20 | 1993-02-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-02-19 | 1996-08-20 | 1997-02-19 | $7700.00 | Window Closed / Lapsed |