JPH0349615B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a phenol-aldehyde-based chelating ion exchange resin. Various research reports have been made on chelating ion exchange resins in which ligands capable of forming complexes with heavy metal ions are introduced into polymer compounds. , for example, Dowex A-1 (Dowex A-1).
(manufactured by Chemical Co., Ltd.), Diaion CR-10, 20 (manufactured by Mitsubishi Chemical Corporation), and Uniselect UR-10, 20, 30
(manufactured by Unitika) etc. have been commercialized. but,
These resins have extremely poor selectivity for heavy metal ions to be adsorbed, and in particular have a problem in selective trapping performance for uranium. In addition, many studies have been conducted on chelating ion exchange resins having phosphonic acid groups, and their selective adsorption ability for certain metals, such as uranium, has been reported, but the manufacturing process is complicated and the cost is high. Due to reasons such as poor adhesion, expensive raw materials, and low resin strength, chelating ion exchange resins that only have phosphonic acid groups have not been commercialized because of their limited ability to selectively adsorb uranium. This method was insufficient in its ability to be applied to the separation and recovery of uranium from seawater, crude phosphoric acid for fertilizer, etc. For example, Zh, Anal, Khin Volume 29, Item 1284, 1974 describes a method for producing iminodiethylenephosphonic acid type styrene resin. However, this method requires long and complicated steps for producing iminodiethylene phosphonic acid, and the cost of raw materials is high, so that it cannot be used industrially. In view of these circumstances, the present inventors conducted extensive research with the aim of easily and inexpensively producing a chelating ion exchange resin that exhibits excellent selective adsorption ability, especially for uranium. By converting into a resin a compound in which phosphonic acid is introduced into the amino group of a compound having a hydroxyl group,
Found that all the above objectives are achieved,
The invention has been completed. That is, the present invention provides a phenol-aldehyde resin having a crosslinked structure, in which some of the phenols constituting the resin have primary and/or secondary alkylamino groups introduced into the benzene nucleus, and It is a phenol in which part or all of the hydrogen atoms directly connected to the nitrogen atom of the alkylamino group are substituted with a methylene phosphonic acid group, and the adsorption amount for uranyl ions is per gram of resin.
A phenol-aldehyde-based chelating ion exchange resin characterized in that the amount thereof is at least 0.8 mmol. In the present invention, as a part of the phenols constituting the phenol-aldehyde resin, for example, approximately 16 to 91 mol% is calculated from the charge amount shown below.
It is preferable that The compound used in the present invention that has a phenolic hydroxyl group and a primary and/or secondary alkylamino group in the same molecule (hereinafter referred to as a phenolic compound having an amino group) has a phenolic hydroxyl group and a primary and/or secondary alkylamino group in the same molecule. Alternatively, any compound having a secondary alkylamino group may be used. Preferred examples of such compounds include salicylamine, tyramine, p-hydroxybenzylamine, etc. (n represents an integer from 1 to 20) Compounds having a phenolic hydroxyl group and a primary alkylamino group in the same molecule, general compounds such as tyrosine, o-hydroxyphenylglycine, p-hydroxyphenylglycine, etc. formula() (n represents an integer from 1 to 20) A compound having a phenolic hydroxyl group and a primary alkylamino group in the same molecule, 2,4-
General formula () of dihydroxybenzylamine, 4,4'-dihydroxybenzylamine, etc. (n and m represent integers from 1 to 20.) Compounds having a phenolic hydroxyl group and a secondary alkylamino group in the same molecule, ammonia obtained by reacting ammonia with phenols and aldehydes. Compounds having a phenolic hydroxyl group and primary and secondary alkylamino groups in the same molecule, such as resols, and polyethyleneimine-phenol-formalin condensates obtained by reacting polyethyleneimine with phenols and aldehydes. Examples include compounds having a phenolic hydroxyl group and primary and secondary alkylamino groups. In addition, the following general formula () (nm represents an integer of 1 to 20.) A compound in which two hydrogen atoms in the benzene nucleus are substituted with alkylamino groups may also be used. Examples of the phenols used in the present invention include phenol, o-cresol, m
-cresol, p-cresol, 2,3-xylenol, 2,5-xylenol, 3,5-xylenol, α-naphthol, β-naphthol, o-
Ethylphenol, m-ethylphenol, p-
Examples include alkyl-substituted monovalent phenols such as ethylphenol, divalent phenols such as catechol, resorcinol, and bisphenol A, and trivalent phenols such as pyrogallol and chloroglucin. These can be used alone or in combination. Examples of the aldehydes used in the present invention include aliphatic saturated aldehydes such as formaldehyde, acetaldehyde and propionaldehyde, aromatic aldehydes such as benzaldehyde and salicylaldehyde, heterocyclic aldehydes such as furfural, paraformaldehyde, and hexamethylene. Examples include formaldehyde derivatives such as tetramine. These can be used alone or in combination. The chelating ion exchange resin of the present invention can be produced, for example, by the following method.
First, in the first step, a phenol compound having an amino group is treated with 80 to
Phosphous acid and aldehydes are reacted at 120°C to replace some or all of the hydrogen atoms of the alkylamino groups with methylenephosphonic acid groups. Next, in the second step, the reaction product obtained in the first step (this reaction product is referred to as an iminomethylenephosphonic acid derivative), phenols, and aldehydes are mixed with a mineral acid, sodium hydroxide, potassium hydroxide, 30 in the presence of alkaline compounds such as ammonia
The condensation reaction is carried out at ~200°C, preferably 50-130°C. In this case, the iminomethylenephosphonic acid derivative obtained in the first step may be isolated and the condensation reaction may be carried out, or the condensation reaction may be carried out directly without isolation. In addition, bead-shaped resin can be obtained by performing the condensation reaction in the second stage by adding a substantially insoluble solvent to form a suspension system. As for the amount to be charged, the molar ratio of the phenol compound having an amino group, phosphorous acid, and aldehydes in the first stage is 1:0.9n to 1.5n:0.9n to 2n, preferably 1:1:
1n to 1.3n: 1.1 to 1.5n (n represents an alkylamino group and the number of hydrogen atoms), and the aldehydes in the second stage are phenol compounds having an amino group.
0.5 to 10 times the mole, preferably 5 to 8 times the mole, the phenol is a phenol compound having an amino group.
The amount is 0.1 to 5 times the mole, preferably 1 to 2.5 times the mole. As the phosphorous acid used in the first step, a compound that generates phosphorous acid by reaction (for example, triethyl phosphorite, dibutyl phosphorite) may be used. In addition, examples of the substantially water-insoluble solvent used in the above-mentioned condensation reaction include saturated or unsaturated aliphatic hydrocarbons such as hexane, octane, and octyne; alicyclic hydrocarbons such as cyclohexane and decalin; Examples include aromatic hydrocarbons such as benzene and toluene, and halogenated hydrocarbons such as dichloroethane and dichlorobenzene in which some or all of the hydrogen atoms of these hydrocarbons are replaced with chlorine, fluorine, or bromine. may be used alone or in combination. The chelating ion exchange resin of the present invention may be used alone, or may be supported on a porous carrier such as activated carbon or zeolite, or may be used in combination with these porous carriers. Of course, it may also be used in combination with other ion exchange resins or chelating ion exchange resins. The chelating ion exchange resin of the present invention can be used in any form such as beads, powder, lumps, plates, membranes, rings, threads, etc., but bead-like resins are usually used. Since the chelating ion exchange resins of the invention exhibit a remarkable adsorption capacity for heavy metal ions, especially uranium, they can be used in all uranium-containing solutions, particularly preferably in low-concentration uranium solutions, such as seawater, crude phosphoric acid for fertilizers, uranium-containing solutions, etc. It can be used to separate and recover uranium from mine water, uranium smelting wastewater, impression leaching solutions, etc. When the chelating ion exchange resin of the present invention is brought into contact with a uranium-containing solution, the iminodi(methylenephosphonic acid) group or the iminomethylenephosphonic acid group forms a very stable chelate with uranium, and the stability constant of the chelate is large. Therefore, uranium is considered to be adsorbed at a high adsorption rate and a fast adsorption rate. The chelating ion exchange resin of the present invention can also be applied to the selective separation and recovery of useful heavy metal ions other than uranium, such as copper, nickel, zinc, cobalt, and the like. The chelating ion exchange resin of the present invention can be used in various ways depending on its shape. For example, it may be packed in a column or tower and a liquid containing uranium or other heavy metals may be passed therethrough, or It is used by immersing a chelating ion exchange resin in a heavy metal-containing solution. In this case, the temperature of the heavy metal-containing solution is suitably between 5°C and 95°C, preferably between 15°C and 50°C, and the time for contacting the heavy metal ions with the resin is suitably between 1 minute and 50 hours. , preferably between 10 minutes and 2 hours. In addition, heavy metal ions can be recovered from the chelating ion exchange resin of the present invention that has adsorbed heavy metal ions by contacting it with a mineral acid aqueous solution or an alkaline aqueous solution in the same way as with commercially available chelating ion exchange resins and ion exchange resins. The regenerated resin can be used over and over again. The chelating ion exchange resin of the present invention is obtained by a simple manufacturing method as described in detail above, and exhibits a special heavy metal trapping effect, particularly an excellent trapping effect for uranium. Moreover, it is a new resin that can be recycled and used many times with a simple acid treatment, making it practical and usable for new applications different from conventional phenol-aldehyde-based chelating ion exchange resins. . Next, the present invention will be explained in more detail with reference to Examples. In addition, % in an example represents weight %. Example 1 1 mole of tyrosine, 2 moles of phosphorus and 20% hydrochloric acid,
It was dissolved in an aqueous solution and heated to reflux while stirring. In this state, 6 mol of a 37% formalin aqueous solution was added dropwise over an hour or so, and stirring was continued while refluxing for another hour. Then, after cooling to room temperature, 2 moles of phenol and 4 moles of 37% formalin were added and reacted at 90 to 95°C for 3 hours. After the reaction is completed, the reactant is taken out, crushed, and washed with water.
The mixture was heated in an air bath at 110 to 120°C for 5 hours to obtain a powdery chelating ion exchange resin. Example 2 After reacting 1 mole of tyrosine, 2 moles of phosphorous acid, and 6 moles of 37% formalin in the same manner as in Example 1, a 40% NaOH aqueous solution was added to this solution to make it strongly alkaline. When 1.5 mol of phenol and 5 mol of formalin were added to this solution and heated at 90°C for 1 hour, the contents gelled. Take this out and
After pulverizing and washing the formalin with water, the mixture was heated in an air bath at 110 to 120°C for 5 hours to obtain a powdery chelating ion exchange resin. Example 3 1 mole of phenol, 1 mole of 37% formalin, 30
% ammonia was heated at 40° C. for 1 hour to form an ammonia aresol. To this liquid, 2 moles of phosphorous acid and concentrated hydrochloric acid were added to make it strongly acidic, and then 6 moles of formalin were added in the same manner as in Example 1. Thereafter, in the same manner as in Example 1, it was crosslinked with 2 moles of phenol and 4 moles of formalin to obtain a powdery chelating ion exchange resin. Example 4 The chelating ion exchange resins obtained in Examples 1, 2, and 3 were each added to a 1000 ppm uranyl nitrate aqueous solution prepared in advance and shaken for 24 hours. Thereafter, the amount of uranyl ions adsorbed on the resin was determined by measuring the concentration of uranyl ions remaining in the liquid. The results are shown in Table 1.

[Table] Example 5 In the same manner as in Example 2, 1 mole of tyrosine, 2 moles of phosphorous acid, and 6 moles of 37% formalin were reacted, and then heated soda was added to make the mixture alkaline. To this liquid were added 1.5 mol of resorcin and 5 mol of 37% formalin, and further, with stirring, n-paraffin was added.
Then, with continuous stirring, it was heated at 60°C for 1 hour and at 20°C for 1 hour.
After heating at 90°C for 1 hour, the contents began to solidify into granules. Thereafter, the contents were transferred to an autoclave and reacted at 120°C for 5 hours to complete gelation. The resulting granular resin was isolated by filtration, air-dried, washed with water, and then immersed in a 1NH ₂ SO ₄ solution to convert the resin from Na type to H type. Thereafter, this resin was filtered to obtain bead-shaped chelating ion exchange resin. The amount of uranyl ions adsorbed on this ion exchange resin was determined in the same manner as in Example 4, and it was found to be 1.2 mmol/g resin. Reference Example 1 Chelating ion exchange resin 15c.c. obtained in Example 5
was packed in a column and adjusted to pH 1 with phosphoric acid.
Liquid 20 containing 100 ppm UO ₂ ²⁺ was
The solution was passed at a rate of 51/hr. Next, after washing with water, 150 c.c. of an 8M aqueous sulfuric acid solution was passed through at a space velocity of 11/hr to elute the adsorbed uranium. The amount of uranium recovered was 85% of the uranium in the phosphoric acid that was passed through. Reference example 2 Chelating ion exchange resin 100 obtained in Example 5
1 mg of seawater (uranium content: 3 μg) was added and shaken at room temperature for 24 hours. Analysis of the amount of uranium adsorbed on this resin revealed that 2.5 μg of uranium had been adsorbed, giving an adsorption rate of 83%.

Claims (1)

[Claims] 1. In a phenol-aldehyde resin having a crosslinked structure, some of the phenols constituting the resin have primary and/or secondary alkylamino groups introduced into the benzene nucleus, and the nature of the alkylamino group A phenol/aldehyde type which is a phenol in which some or all of the hydrogen atoms directly bonded to elementary atoms are substituted with methylene phosphonic acid groups, and has an adsorption amount of uranyl ions of at least 0.8 mmol per 1 g of resin. Chelating ion exchange resin.