SULFONATED AMINOMETHYLATED CHELATE RESINS

Abstract

The invention relates to sulfonated aminomethylated chelate resins, to a method for producing same, to the use thereof for obtaining and purifying metals, in particular rare earth metals, from aqueous solutions and organic liquids, and for producing highly pure silicon.

Claims

1. A chelating resin comprising functional groups of structural element (I) ##STR00004## in which: represents a polymer skeleton; R.sub.1 and R.sub.2, independently of one another, represent —CH.sub.2COOX, —CH.sub.2PO(OX.sup.1).sub.2, —CH.sub.2PO(OH)OX.sup.2, —(CS)NH.sub.2, —CH.sub.2-pyridyl or hydrogen, wherein R.sub.1 and R.sub.2 cannot both simultaneously be hydrogen; and X, X.sup.1, X.sup.2 and Y independently of one another represent hydrogen, sodium or potassium.

2. The chelating resin as claimed in claim 1, wherein: R.sub.1 and R.sub.2 independently of one another, are —CH.sub.2PO(OX.sup.1).sub.2, —CH.sub.2PO(OH)OX.sup.2 or hydrogen; and X.sup.1 and X.sup.2, independently of one another, represent hydrogen, sodium or potassium.

3. A process for preparing the chelating resin as claimed in claim 1, the process comprising: a) converting monomer droplets composed of: at least one monovinylaromatic compound and at least one polyvinylaromatic compound, and at least one initiator or an Initiator combination  into a bead polymer, b) phthalimidomethylating and sulfonating the bead polymer with phthalimide in the presence of oleum to produce phthalimidomethylated, sulfonated bead polymer, wherein the amount of free SO.sub.3 is at least 0.69 mol based on 1 mol of phthalimide, c) converting the phthalimidomethylated, sulfonated bead polymer into aminomethylated, sulfonated bead polymer, and d) reacting the aminomethylated, sulfonated bead polymer to afford chelating resins comprising functional groups of structural element (I).

4. The process for preparing the chelating resin as claimed in claim 3, wherein the bead polymers in step a) are prepared in monodisperse form and thus monodisperse chelating resins are prepared.

5. The process for preparing the chelating resin as claimed in claim 3, wherein the amount of free SO.sub.3 in step b) is between 0.69 and 1.5 mol based on 1 mol of phthalimide.

6. The process for preparing the chelating resin as claimed in claim 3, wherein the amount of free SO.sub.3 in step b) is between 0.69 and 1.2 mol based on 1 mol of phthalimide.

7. A chelating resin comprising functional groups of structural element (I) prepared as claimed in claim 3.

8. A method for adsorption of metals from fluids, the method comprising contacting a fluid containing metals with the chelating resin of claim 1 and adsorbing the metals from the fluid onto the chelating resin.

9. The method as claimed in claim 8, wherein the fluid comprising aqueous solutions or organic liquids.

10. The method as claimed in claim 8, wherein the metals are selected from the group mercury, gallium, iron, cobalt, nickel, copper, zinc, lead, indium, cadmium, manganese, uranium, vanadium, elements of the platinum group, gold, silver, or the rare earths.

11. The method as claimed in claim 8, wherein the metals are rare earths.

12. The method as claimed in claim 11, wherein the rare earths are scandium, lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, yttrium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, scandium, yttrium and lanthanum.

13. The method as claimed in claim 8, wherein the metals are selected from the group indium, scandium, neodymium, lanthanum and praseodymium.

14. A method for preparing and purifying silicon with the chelating resin according to claim 1, the method comprising: reacting a silicate with an acidifying agent in the presence of the chelating resin according to claim 1 to produce high-purity silicon dioxide, and reducing the high-purity silicon dioxide to produce silicon having a purity of greater than 99.99%.

15. The method as claimed in claim 14, wherein the chelating resin comprises functional groups of structural element (I), wherein R.sub.1 and R.sub.2, independently of one another, are —CH.sub.2PO(OX.sup.1).sub.2 or —CH.sub.2PO(OH)OX.sup.2, and X.sup.1 and X.sup.2, independently of one another, represent hydrogen, sodium or potassium.

16. The chelating agent as claimed in claim 1, wherein: R.sub.1 is hydrogen, —CH.sub.2PO(OX.sup.1).sub.2 or —CH.sub.2PO(OH)OX.sup.2; and R.sub.2 is —CH.sub.2PO(OX.sup.2).sub.2 or —CH.sub.2PO(OH)OX.sup.2.

17. The chelating agent as claimed in claim 1, wherein: R.sub.1 is hydrogen; R.sub.2 is —CH.sub.2PO(OX.sup.2).sub.2 or —CH.sub.2PO(OH)OX.sup.2; and X, X.sup.1, X.sup.2 and Y represent hydrogen.

18. The chelating agent as claimed in claim 17, wherein the —SO.sub.3H radical is located in an ortho position in relation to the —CH.sub.2— group.

Description

EXAMPLE 1

Preparation of the Monodisperse Macroporous Bead Polymer Based on Styrene, Divinylbenzene and Ethylstyrene

[0102] A 10 l glass reactor is initially charged with 3000 g of demineralized water and a solution of 10 g of gelatin, 16 g of disodium hydrogenphosphate dodecahydrate and 0.73 g of resorcinol in 320 g of deionized water are added and commixed. The mixture is equilibrated to 25° C. Subsequently, while stirring, a mixture of 3200 g of microencapsulated monomer droplets having a narrow particle size distribution, composed of 5% by weight of divinylbenzene and 1% by weight of ethylstyrene (used in the form of a commercial isomer mixture of divinylbenzene and ethylstyrene with 80% divinylbenzene), 0.4% by weight of dibenzoyl peroxide, 56.3% by weight of styrene and 37.5% by weight of isododecane (technical isomer mixture having a high proportion of pentamethylheptane) is added, the microcapsule consisting of a formaldehyde-hardened complex coacervate composed of gelatin and a copolymer of acrylamide and acrylic acid, and 3200 g of aqueous phase having a pH of 12 are added.

[0103] The mixture is stirred and polymerized to completion by increasing the temperature in accordance with a temperature program beginning at 25° C. and ending at 95° C. The mixture is cooled, washed over a 32 μm sieve and then dried at 80° C. under reduced pressure.

[0104] This affords 1893 g of a monodisperse bead polymer with a smooth surface.

[0105] The monodisperse bead polymer has a chalky white appearance and a bulk density of about 390 g/l.

Preparation of a Phthalimidomethylated Resin Further Comprising SO.sub.3H Groups—Molar Ratio of Free SO.sub.3 to Phthalimide is 0.7 to 1 During Phthalimidomethylation

[0106] 419.3 g of phthalimide, 1410 g of 1,2-dichloroethane (DCE) and 242.5 g of 30% by weight formaldehyde solution are initially charged into a four-neck flask at RT and healed to boiling point.

[0107] At commencement of reflux (about 70° C.) the pH is adjusted to pH 5.5-6.0 with aqueous sodium hydroxide solution, ω (NaOH)=50%. The mixture is boiled at boiling point for 30 min. The water is then removed. 30.7 g of monohydrate are then added at about 70′C.

[0108] Water is then again removed until the ether is obtained. The mixture is then stirred at RT for up to 12 h and 245.7 g of oleum, ω (free SO3) 65%, are then metered in at 25-30° C.

[0109] 317.1 g of monodisperse bead polymer from example 1 in 1000 ml of DCE are then added at 30-40° C. The mixture is stirred at 65° C. for 6.5 h.

[0110] The DCE liquor is suctioned off via a filter suction pipe, the filtrate is re-slurried with preheated DM water (max. 70° C.) and the remaining DCE is distilled off.

[0111] The resin is then rinsed out with DM water. [0112] Volume yield=1900 ml of resin [0113] Dry weight=0.3932 g/ml

Elemental Analysis:

[0114] Nitrogen content 5.0% by weight [0115] Sulfur content 3.1% by weight

Preparation of an Aminomethyl-Containing Resin Further Comprising SO.SUB.3.H Groups

[0116] 2100 ml of resin from example 2a), 2520 ml of aqueous sodium hydroxide solution prepared from 767 g of 50% by weight aqueous sodium hydroxide solution and 2140 ml of water are charged at RT into a 61 VA autoclave.

[0117] The autoclave is then heated up to 180° C. at 200 rpm over 2 h.

[0118] The autoclave is held at this temperature for 8 h.

[0119] After cooling the test product is washed with DM water until neutral.

[0120] Volume yield=1571 ml

HCI number supplied form CI form OH form
1.29 mol/l 30 ml 38 ml 31 ml
Washing water=>0.5 l/30 ml

Substitution=0.63

[0121] Dry weight=0.2696 g/ml

Preparation of a Resin Comprising Aminomethylphosphonic Acid Groups and Further Comprising SO.SUB.3.H Groups

[0122] 1520 ml of resin from example 2b) is initially charged into a round flask together with 759 ml of DM water at room temperature. 701.6 g of dimethyl phosphite are then added dropwise over 15 min and the mixture is stirred for a further 15 min. 1962 g of 98% by weight sulfuric acid are then metered in over 2 h. The mixture is then heated to 95° C. 716 g of 30% by weight formaldehyde solution are then added dropwise at 95° C. The mixture is stirred at 95° C. for a further 4 h. After cooling the resin is washed with DM water until neutral.

Volume yield=1870 ml

[0123] The resin is converted into the free base form with aqueous sodium hydroxide solution, ω (NaOH)=4%.

Volume yield=2680 ml
NaOH number: 2.78 mol/l

[0124] The presence of chelating aminomethylphosphonic acid groups is reflected by the NaOH number. 2.78 mol of aminomethylphosphonic acid groups are present per liter of end product.

NaCl number: 0.79

[0125] The presence of strongly acidic suffonic acid groups is reflected by the NaCl number and by the sulfur content of 5.0% by weight.

[0126] 0.79 mol of sulfonic acid groups are present per liter of end product.

End Product Composition by Elemental Analysis

[0127] ω (N)=4.6% by weight ω (P)=8.3% by weight ω (O)=27.0% by weight ω (S)=5.0% by weight

TABLE-US-00001 TABLE 1 Mol of free Amount of SO.sub.3 per End product End product End product End product chelating groups Amount of strongly Structural mole of % by weight % by weight % by weight % by weight in mol/liter of acidic groups in Test elements phthalimide of sulfur of oxygen of nitrogen of phosphorus resin mol/liter of resin Example 1 Sulfonic acid 0.7 to 1 5.0 27.0 4.6 8.3 2.78 0.79 groups and aminomethyl- phosphonic acid groups Summary of results from example 1