US4207302A
Expired / Lapsed
US
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Method of treating phosphoric acid to prevent crud formation during solvent extraction
Assignee: Freeport Mcmoran Resource Partners Ltd
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Filing: 1976-02-10
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Granted: 1980-06-10
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Expires: 1996-02-10
Abstract
Abstract A method for pretreating phosphoric acid to prevent the formation of a mass of suspended solids (i.e., "crud") during solvent extraction of the acid is described. Prior to solvent extraction, the acid is contacted with a liquid hydrocarbon such as kerosene which collects the crud-forming agents. The mixture of liquid hydrocarbon and collected crud-forming agents is separated from the acid and the liquid hydrocarbon is regenerated for reuse in the first step of the method.
Inventors
- 👤 Jay C. Smith
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 14:50
CPC Classifications
C; C01; C01B; C01B25/00; C01B25/16; C01B25/46; C01B25/461; C01B25/18; C01B25/234
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
222 words
A method of treating wet-process phosphoric acid to remove crud-forming agents, prior to treating the phosphoric acid with an organic extraction solvent, comprising the steps of: (a) mixing the phosphoric acid with a liquid consisting of a hydrocarbon, the volume ratio of liquid hydrocarbon to phosphoric acid being in the range of from about 0.1 to 10, to remove a substantial portion of the crud-forming agents from the phosphoric acid by entraining the crud-forming agents in the liquid hydrocarbon but without dissolving at least the major portion of the removed crud-forming agents in the liquid hydrocarbon; the liquid hydrocarbon being essentially insoluble and immiscible in the phosphoric acid and having a boiling point above the temperature at which the steps of said method are carried out; (b) separating the liquid hydrocarbon, containing entrained crud-forming agents, from the phosphoric acid; (c) mixing the liquid hydrocarbon with an aqueous base in an amount and concentration effective to transfer substantially all of the crud-forming agents mostly in the form of suspended matter from the liquid hydrocarbon to the aqueous base; the volume of aqueous base to the volume of the mixture of liquid hydrocarbon and crud-forming agents being at least about 0.3; and then (d) separating the aqueous base from the liquid hydrocarbon to regenerate the liquid hydrocarbon for reuse in mixing with phosphoric acid.
Claim 2
Independent Claim
222 words
A method of treating wet-process phosphoric acid to remove crud-forming agents, prior to treating the phosphoric acid with an organic extraction solvent, comprising the steps of: (a) mixing the phosphoric acid with a liquid consisting of a hydrocarbon, the volume ratio of liquid hydrocarbon to phosphoric acid being in the range of from about 0.1 to 10, to remove a substantial portion of the crud-forming agents from the phosphoric acid by entraining the crud-forming agents in the liquid hydrocarbon but without dissolving at least the major portion of the removed crud-forming agents in the liquid hydrocarbon; the liquid hydrocarbon being essentially insoluble and immiscible in the phosphoric acid and having a boiling point above the temperature at which the steps of said method are carried out; (b) separating the liquid hydrocarbon, containing entrained crud-forming agents, from the phosphoric acid; (c) mixing the liquid hydrocarbon with an aqueous base in an amount and concentration effective to transfer substantially all of the crud-forming agents mostly in the form of suspended matter from the liquid hydrocarbon to the aqueous base; the volume of aqueous base to the volume of the mixture of liquid hydrocarbon and crud-forming agents being at least about 0.3; and then (d) separating the aqueous base from the liquid hydrocarbon to regenerate the liquid hydrocarbon for reuse in mixing with phosphoric acid.
Claim 3
Dependent Claim
34 words
The method defined in claim 1 wherein the wet-process phosphoric acid is treated with an organic extraction solvent comprising di(2-ethylhexyl)phosphoric acid and trioctylphosphine oxide after being separated from the liquid hydrocarbon in step b).
Claim 4
Dependent Claim
42 words
The method defined in claim 1 wherein, in step a), said liquid hydrocarbon is selected from the group consisting of kerosene, diesel fuel, number 1 heating oil, number 2 heating oil, naphtha, hexane, nonane, decane, dodecane, benzene, heptane, chlorodecane, and mixtures thereof.
Claim 5
Dependent Claim
15 words
The method defined in claim 1 wherein, in step a), said liquid hydrocarbon is kerosene.
Claim 6
Dependent Claim
29 words
The method defined in claim 1 wherein, in step a), the volume ratio of liquid hydrocarbon to phosphoric acid is in the range of from about 0.2 to 2.
Claim 7
Dependent Claim
36 words
The method defined in claim 1 wherein, in step c), said aqueous base is selected from the group consisting of NH 4 OH, NaOH, KOH, Na 2 CO 3 , and K 2 CO 3 .
Claim 8
Dependent Claim
48 words
The method defined in claim 1 wherein, in step c), the volume ratio of aqueous base to liquid hydrocarbon, containing crud-forming agents, is at least about 0.3 and wherein the strength of the aqueous base is in the range of from about 0.3 to 30 percent by weight.
Claim 9
Dependent Claim
53 words
The method defined in claim 1 wherein, in step c), the volume ratio of aqueous base to liquid hydrocarbon, containing crud-forming agents, is in the range of from about 0.5 to 2 and wherein the strength of the aqueous base is in the range of from about 1 to 10 percent by weight.
Claim 10
Dependent Claim
40 words
The method defined in claim 1 further comprising the step of clarifying the phosphoric acid to a solids content of less than about 0.5 percent by volume prior to mixing the phosphoric acid with the liquid hydrocarbon in step a).
Claim 11
Dependent Claim
40 words
The method defined in claim 1 further comprising the step of clarifying the phosphoric acid to a solids content of less than about 0.3 percent by volume prior to mixing the phosphoric acid with the liquid hydrocarbon in step a).
Claim 12
Independent Claim
225 words
A method of treating wet-process phosphoric acid to remove crud-forming agents, prior to treating the phosphoric acid with an organic extraction solvent, comprising the steps of: (a) mixing the phosphoric acid with a liquid consisting essentially of a hydrocarbon, the volume ratio of liquid hydrocarbon to phosphoric acid being in the range of from about 0.1 to 10, to remove a substantial portion of the crud-forming agents from the phosphoric acid by entraining the crud-forming agents in the liquid hydrocarbon but without dissolving at least the major portion of the removed crud-forming agents in the liquid hydrocarbon; the liquid hydrocarbon being essentially insoluble and immiscible in the phosphoric acid and having a boiling point above the temperature at which the steps of said method are carried out; (b) separating the liquid hydrocarbon, containing entrained crud-forming agents, from the phosphoric acid; (c) washing the liquid hydrocarbon with an immiscible liquid washing agent selected from the group consisting of water and aqueous acid to recover additional phosphoric acid entrained in the liquid hydrocarbon; (d) mixing the liquid hydrocarbon with an aqueous base in an amount and concentration effective to transfer substantially all of the crud-forming agents from the liquid hydrocarbon to the aqueous base; and then (e) separating the aqueous base from the liquid hydrocarbon to regenerate the liquid hydrocarbon for reuse in mixing with phosphoric acid.
Claim 13
Independent Claim
225 words
A method of treating wet-process phosphoric acid to remove crud-forming agents, prior to treating the phosphoric acid with an organic extraction solvent, comprising the steps of: (a) mixing the phosphoric acid with a liquid consisting essentially of a hydrocarbon, the volume ratio of liquid hydrocarbon to phosphoric acid being in the range of from about 0.1 to 10, to remove a substantial portion of the crud-forming agents from the phosphoric acid by entraining the crud-forming agents in the liquid hydrocarbon but without dissolving at least the major portion of the removed crud-forming agents in the liquid hydrocarbon; the liquid hydrocarbon being essentially insoluble and immiscible in the phosphoric acid and having a boiling point above the temperature at which the steps of said method are carried out; (b) separating the liquid hydrocarbon, containing entrained crud-forming agents, from the phosphoric acid; (c) washing the liquid hydrocarbon with an immiscible liquid washing agent selected from the group consisting of water and aqueous acid to recover additional phosphoric acid entrained in the liquid hydrocarbon; (d) mixing the liquid hydrocarbon with an aqueous base in an amount and concentration effective to transfer substantially all of the crud-forming agents from the liquid hydrocarbon to the aqueous base; and then (e) separating the aqueous base from the liquid hydrocarbon to regenerate the liquid hydrocarbon for reuse in mixing with phosphoric acid.
Claim 14
Dependent Claim
48 words
The method defined in claim 11 wherein, in step a), said liquid hydrocarbon is selected from the group consisting of kerosene, diesel fuel, number 1 heating oil, number 2 heating oil, naphtha, hexane, nonane, decane, dodecane, benzene, heptane, octane, toluene, the xylenes, chlorohexane, chloroheptane, chlorodecane, and mixtures thereof.
Claim 15
Dependent Claim
15 words
The method defined in claim 11 wherein, in step a), said liquid hydrocarbon is kerosene.
Claim 16
Dependent Claim
29 words
The method defined in claim 11 wherein, in step a), the volume ratio of liquid hydrocarbon to phosphoric acid is in the range of from about 0.2 to 2.
Claim 17
Dependent Claim
36 words
The method defined in claim 11 wherein, in step d), said aqueous base is selected from the group consisting of NH 4 OH, NaOH, KOH, Na 2 CO 3 , and K 2 CO 3 .
Claim 18
Dependent Claim
48 words
The method defined in claim 11 wherein, in step d), the volume ratio of aqueous base to liquid hydrocarbon, containing crud-forming agents, is at least about 0.3 and wherein the strength of the aqueous base is in the range of from about 0.3 to 30 percent by weight.
Claim 19
Dependent Claim
54 words
The method defined in claim 11 wherein, in the step d), the volume ratio of aqueous base to liquid hydrocarbon, containing crud-forming agents, is in the range of from about 0.5 to 2 and wherein the strength of the aqueous base is in the range of from about 1 to 10 percent by weight.
Claim 20
Dependent Claim
40 words
The method defined in claim 11 further comprising the step of clarifying the phosphoric acid to a solids content of less than about 0.5 percent by volume prior to mixing the phosphoric acid with the liquid hydrocarbon in step a).
Claim 21
Dependent Claim
40 words
The method defined in claim 11 further comprising the step of clarifying the phosphoric acid to a solids content of less than about 0.3 percent by volume prior to mixing the phosphoric acid with the liquid hydrocarbon in step a).
Claim 22
Dependent Claim
17 words
The method defined in claim 11 wherein said washing agent is aqueous H 2 SO 4 .
Claim 23
Dependent Claim
34 words
The method defined in claim 11 wherein the wet-process phosphoric acid is treated with an organic extraction solvent comprising di(2-ethylhexyl)phosphoric acid and trioctylphosphine oxide after being separated from the liquid hydrocarbon in step b).
References Cited (Backward Citations)
US3619161A
Cited
US3867511A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-06-10 | 1983-12-10 | 1984-06-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-06-10 | 1987-12-10 | 1988-06-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-06-10 | 1991-12-10 | 1992-06-10 | $7700.00 | Window Closed / Lapsed |