Claims
- 1. A process for recovering rhodium from an aqueous solution containing rhodium complex compounds, said method comprising oxidizing said solution in the presence of an excess, based on said rhodium, of a water-soluble carboxylic acid salt of a carboxylic acid having 7 to 22 carbon atoms, and separating the rhodium as a water-insoluble compound, oxidizing said aqueous solution at 20.degree. to 120.degree. C. with a first oxidant comprising hydrogen peroxide or a substance forming hydrogen peroxide and with a second oxidant comprising oxygen or an oxygen-containing gas.
- 2. The process of claim 1 wherein complex ligands are in said aqueous solution.
- 3. The process of claim 1 wherein said rhodium is in a concentration of 10 to 2000 ppm by weight of said aqueous solution.
- 4. The process of claim 3 wherein said concentration is 30 to 350 ppm by weight of said aqueous solution.
- 5. The process of claim 4 wherein said concentration is 50 to 250 ppm by weight of said aqueous solution.
- 6. The process of claim 2 wherein said ligands are present in an amount of 0.5% to 15% by weight based on said aqueous solution.
- 7. The process of claim 6 wherein said amount is 0.7% to 8.0 by weight based on said aqueous solution.
- 8. The process of claim 7 wherein said amount is 0.8% to 4.0% by weight based on said aqueous solution.
- 9. The process of claim 2 wherein degradation and conversion products of said ligands are in said aqueous solution.
- 10. The process of claim 9 wherein said degradation and conversion products comprise at least one compound selected from the group consisting of phosphine oxides, phosphine sulfides, phosphine sulfides having organic substituents, sulfonic acids, phosphoric acids, and salts thereof.
- 11. The process of claim 9 wherein said product are present in a range of 1% to 15% by weight based on said aqueous solution.
- 12. The process of claim 11 wherein said range is 3% to 12% by weight based on said aqueous solution.
- 13. The process of claim 12 wherein said range is 5% to 10% by weight based on said aqueous solution.
- 14. The process of claim 9 wherein said ligands and products together form a salt residue and there is present 1.5% to 30% by weight of said residue based on said aqueous solution.
- 15. The process of claim 14 wherein there is present 4.0% to 20% by weight of said residue based on said aqueous solution.
- 16. The process of claim 15 wherein there is present 6.0% to 18% by weight of said residue based on said aqueous solution.
- 17. The process of claim 1 wherein there are organic components present which comprise at least one compound selected from the group consisting of olefins, aldehydes, alcohols, aldols, condensation products, and solubilizers.
- 18. The process of claim 17 wherein said organic components comprise 0.15% to 4.0% by weight of said aqueous solution.
- 19. The process of claim 18 wherein said organic components comprise 0.8% to 3.0% by weight of said aqueous solution.
- 20. The process of claim 19 wherein said organic components comprise 1.0% to 1.5% by weight of said aqueous solution.
- 21. The process of claim 1 wherein said carboxylic acid has 8 to 13 carbon atoms.
- 22. The process of claim 21 wherein said carboxylic acid is aliphatic, cycloaliphatic, aromatic, and/or araliphatic.
- 23. The process of claim 21 wherein said carboxylic acid is a monocarboxylic acid.
- 24. The process of claim 23 wherein said monocarboxylic acid is a branched aliphatic acid.
- 25. The process of claim 24 wherein said monocarboxylic acid is taken from the class consisting of 2-ethyl hexanoic acid, isononanoic acid, isotridecanoic acid, and mixtures thereof.
- 26. The process of claim 25 wherein said isononanoic acid is the reaction product of hydroformylation of diisobutylene to form a hydroformylation product followed by oxidation of said hydroformylation product.
- 27. The process of claim 25 wherein said isotridecanoic acid is the reaction product of hydroformylation of tetrapropylene to form a hydroformylation product followed by oxidation of said hydroformylat on product.
- 28. The process of claim 1 wherein said carboxylic acid salt is present at a level of 10 to 500 mols per gram atom of said rhodium.
- 29. The process of claim 28 wherein said level is 30 to 300 mols per gram atom of said rhodium.
- 30. The process of claim 29 wherein said level is 50 to 200 moles per gram atom of said rhodium.
- 31. The process of claim 1 wherein said aqueous solution is treated with said first oxidant and said second oxidant in a single step.
- 32. The process of claim 1 wherein said aqueous solution is treated with said first oxidant in a first step and is treated with said second oxidant in a second step.
- 33. The process of claim 32 wherein said first step is carried out at a first temperature of 20.degree. to 100.degree. C.
- 34. The process of claim 32 wherein said first temperature is 50.degree. to 100.degree. C.
- 35. The process of claim 34 wherein said first temperature is 60.degree. to 100.degree. C.
- 36. The process of claim 32 wherein said second step is carried out at a second temperature of 80.degree. to 120.degree. C.
- 37. The process of claim 36 wherein said second temperature is 85.degree. to 115.degree. C.
- 38. The process of claim 37 wherein said second temperature is 90.degree. to 110.degree. C.
- 39. The process of claim 38 wherein said second temperature is 95.degree. to 105.degree. C.
- 40. The process of claim 1 wherein said hydrogen peroxide is in the form of a water solution.
- 41. The process of claim 40 wherein said water solution contains 3% to 30% hydrogen peroxide.
- 42. The process of claim 32 wherein said rhodium is not removed between said first step and said second step.
- 43. The process of claim 1 wherein said oxidation is carried out under a pressure of 0.1 to 2.0 MPa.
- 44. The process of claim 9 wherein organic components comprising at least one compound selected from the group consisting of olefins, aldehydes, alcohols, aldols, condensation products, and solubilizers are present and said first oxidant is present in an amount in excess of that required to react with said ligands, said degradation and conversion products, and said organic components.
- 45. The process of claim 9 wherein organic components comprising at least one compound selected from the group consisting of olefins, aldehydes, alcohols, aldols, condensation products, and solubilizers are present and said first oxidant is introduced at a rate of 0.5 to 5.0 mols of hydrogen peroxide per mol of oxidizable substance present.
- 46. The process of claim 45 wherein said rate is 0.8 to 3.0.
- 47. The process of claim 46 wherein said rate is 1.2 to 2.6.
- 48. The process of claim 47 wherein said rate is 1.8 to 2.2.
- 49. The process of claim 9 wherein organic components comprising at least one compound selected from the group consisting of olefins, aldehydes, alcohols, aldols, condensation products, and solubilizers is present and said oxygen containing gas is air.
- 50. The process of claim 49 wherein said air is introduced at a velocity of 50 to 2000 liters per hour per mol of oxidizable substance present.
- 51. The process of claim 50 wherein said velocity is 70 to 1500 liters per hour per mol of oxidizable substances present.
- 52. The process of claim 51 wherein said velocity is 100 to 1300 liters per hour per mol of oxidizable substances present.
- 53. The process of claim 1 wherein said aqueous solution has a pH of 4.0 to 8.0.
- 54. The process of claim 53 wherein said pH is 5.0 to 7.5.
- 55. The process of claim 54 wherein said pH is 5.5 to 7.0.
- 56. The process of claim 1 wherein said water-insoluble compound is separated by extraction with a solvent.
- 57. The process of claim 56 wherein said solvent is water insoluble.
- 58. The process of claim 57 wherein said solvent is selected from the group consisting of benzene, toluene, xylene, cyclohexane, aliphatic carboxylic acids, carboxylic acid esters, ketone having 5 to 10 carbon atoms, and mixtures thereof.
- 59. The process of claim 58 wherein said solvent is xylene, toluene, or a mixture thereof.
- 60. The process of claim 59 wherein said solvent is toluene.
- 61. The process of claim 1 wherein said solvent is added after said oxidation is complete.
- 62. The process of claim 32 wherein said solvent is added before said first step.
- 63. The process of claim 32 wherein said solvent is added before said second step.
- 64. The process of claim 63 wherein said solvent is added after said first step.
- 65. The process of claim 56 wherein said extraction is carried out at an extraction temperature of 10.degree. to 100.degree. C.
- 66. The process of claim 65 wherein said extraction temperature is 30.degree. to 70.degree. C.
- 67. The process of claim 66 wherein said extraction temperature is 40.degree. to 60.degree. C.
- 68. The process of claim 61 wherein said rhodium complex compound is ##STR2## wherein Ar.sup.1, Ar.sup.2, and Ar.sup.3 are each a phenyl or naphthyl group; Y.sup.1, Y.sup.2, and Y.sup.3 each denote a straight or branched chain alkyl group with 1 to 4 carbon atoms, an alkoxy group; a halogen atom, an OH, CN, NO.sub.2, or R.sup.1 R.sup.2 N group, in which R.sup.1 and R.sup.2 each stand for a straight or branched chain or alkyl group with 1 to 4 carbon atoms; X.sup.1, X.sup.2 and X.sup.3 are each a carboxylate (COO--) and/or a sulfonate (SO.sub.3 --) group; n.sub.1, n.sub.2, n.sub.3 are the same or different integers from 0 to 5; M is an alkali metal ion, an alkaline earth metal ion, a zinc ion, or an ammonium or quaternary alkylammonium ion of the formula N(R.sup.3 R.sup.4 R.sup.5 R.sup.6).sup.+, in which R.sup.3, R.sup.4, R.sup.5, R.sup.6 each stand for a straight or branched chain alkyl group with 1 to 4 carbon atoms; and m.sub.1, m.sub.2, m.sub.3 are the same or different integers from 0 to 3, at least one of m.sub.1, m.sub.2 or m.sub.3 being equal to or greater than 1.
- 69. The process of claim 32 wherein said first temperature is 30.degree. to 100.degree. C.
Priority Claims (1)
Number |
Date |
Country |
Kind |
3833427 |
Oct 1988 |
DEX |
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Parent Case Info
This application is a continuation of application Ser. No. 07/409,119 filed 9/19/89, now abandoned.
US Referenced Citations (4)
Foreign Referenced Citations (2)
Number |
Date |
Country |
3626536 |
Feb 1988 |
DEX |
1283389 |
Jul 1972 |
GBX |
Continuations (1)
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Number |
Date |
Country |
Parent |
409119 |
Sep 1989 |
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