JPS631897B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a novel chelating ion exchange resin (hereinafter referred to as chelate resin) having a specific adsorption ability for boron, a method for producing the same, and a method for adsorption treatment thereof. Boron has a Clarke number of 1 x 10 ^-3 and is widely distributed on the earth. Although it does not exist naturally as a simple substance, it exists in soil and brine as boric acid or borate ions, and in seawater. It also exists as metaboric acid at a rate of 4.6 ppm. For this reason, when water is used for agricultural purposes or in industrial fields such as magnesium metal smelting using magnesium chloride collected from seawater as a raw material, boron present in trace amounts can cause harmful effects in various ways. Also,
Boron is used as a structural material in nuclear power plants because of its excellent ability to capture thermal neutrons. The boron content of its structural materials and chemicals needs to be low. Furthermore, strongly basic ion exchange resins are used to remove trace amounts of boric acid from the primary cooling water of pressurized light water reactors. However, with these strongly basic ion exchange resins,
Since there is no selectivity for borate ions, the coexistence of other anions will significantly reduce the boron capture ability, making it impossible to reduce the boron capture ability to below the permissible limit (0.02 ppm). On the other hand, so far, resins that selectively adsorb boron have been commercially available from Rohm and Haas under the trade name Amberlite IRA-743 (for example, Trace Elementus Ishi-743).
The Environment (Trace Elements in the
Environment). 123, pp. 139-143, 1973) This known adsorbent has excellent selectivity for boron, but since it uses styrene as a resin matrix, it compensates for its poor hydrophilicity by forming a large network. However, the resin generally lacks functional strength, has poor organic stain resistance, and cannot withstand long-term use. Furthermore, since the ligand is introduced into the resin matrix through a polymer reaction, more N-methyl-D-glucamine is consumed than necessary, and the process is complicated, which poses a problem in terms of cost. In view of these circumstances, the present inventors have developed a chelate resin that has excellent selective adsorption ability, especially for boron, is hydrophilic, has a high adsorption rate, and has excellent mechanical strength and organic stain resistance. Moreover, as a result of intensive research with the aim of producing it at a low cost, we discovered that all of the above objectives could be achieved by turning a compound in which aminopolyalcohols are introduced into the phenol nucleus into a resin, and we have previously applied for a patent ( (Special Application No. 56-81475). However, although this resin is highly selective for boron and has a high exchange capacity,
They tended to have somewhat poor heat resistance and alkali resistance, and their adsorption properties at low concentrations were not as good as those of commercially available products. In view of this, the present inventor conducted further research and discovered that when aliphatic polyamines are made into a resin as one component, they have excellent heat resistance and alkali resistance, and the adsorption characteristics at low concentrations are improved. , arrived at the present invention. That is, the present invention provides a phenol-based chelating ion exchange resin in which a chelate group is introduced into the phenol nucleus of a phenol, in which the chelate group is an aminopolyalcohol, and the resin matrix constituting the ion exchange resin is a phenol or an aldehyde. A chelating ion exchange resin characterized by being a crosslinked polymer consisting of polyamines and aliphatic polyamines, and aminopolyalcohols introduced into the phenol nucleus by reacting phenols, aldehydes and aminopolyalcohols. An initial product is obtained, and then the obtained initial product is polycondensed with phenols, aldehydes, and aliphatic polyamines in the presence of an alkaline catalyst to form a three-dimensional crosslink. A method for producing a chelating ion exchange resin, which is a polyalcohol and in which the resin matrix constituting the ion exchange resin is a crosslinked polymer consisting of phenols, aldehydes, and aliphatic polyamines, and a method for producing a chelating ion exchange resin in an aqueous solution using such a chelate resin. The present invention relates to an adsorption treatment method characterized by selectively adsorbing heavy metal ions. Examples of the phenols used in the present invention include phenol, o-ethylphenol/m
-Ethylphenol, p-ethylphenol, bisphenol A, o-cresol, m-cresol, p-cresol, 2,3-xylenol,
2,5-xylenol, 3,4-xylenol,
Examples include alkyl-substituted phenols such as 3,5-xylenol, polyhydric phenols such as resorcinol and catechol, and compounds with phenolic hydroxyl groups such as α-naphthol and β-naphthol, and these can be used alone or in combination. However, among them, phenol, bisphenol A, o
-Cresol, m-cresol, p-cresol, 3,5-xylenol, resorcinol, and catechol are preferred, and phenol is particularly preferred. Examples of the aldehydes used in the present invention include formaldehyde, paraformaldehyde, aldehyde derivatives such as hexamethylenetetramine, aliphatic aldehydes such as acetaldehyde and propionaldehyde, aromatic aldehydes such as benzaldehyde, and heterocyclic aldehydes such as furfural. These include aldehydes, which can be used alone or in combination, but among them, formaldehyde, paraformaldehyde,
Hexamethylenetetramine is preferred. The aminopolyalcohols used in the present invention may be of any type as long as they have one amino group and two or more alcoholic hydroxyl groups in the same molecule, but especially N-methyl-D
Glucamine, N-ethyl-D-glucamine, N-
General formula () of methyl-D-mannosamine, N-ethyl-D-mannosamine, etc. (However, _R1 represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and n represents an integer of 1 to 4.) Compounds represented by, tris(hydroxylmethyl)aminomethane, tris(hydroxymethyl)
-N-methyl-aminomethane, tris(hydroxylmethyl)-N-ethylaminomethane, etc. general formula () (However, R ₂ represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms.) Compounds represented by the formula are preferred. Examples of aliphatic polyamines used in the present invention include diethylenetriamine, triethylenetetramine, and the like having the general formula () H ₂ N (CH ₂ CH ₂ NH) _o CH ₂ CH ₂ NH ₂ () (where n is 1 (represents an integer from 2 to 10), a compound represented by the general formula () H ₂ N (CH ₂ ) mNH ₂ () () (where m represents an integer from 2 to 10) such as ethylenediamine, trimethylene diamine, etc. The compounds shown are preferably used. Linear or branched polyethyleneimine can also be used, but its molecular weight is, for example, 300 to 70,000, particularly 300,000 to 70,000.
~1800 is preferred. The chelate resin of the present invention can be produced, for example, by the following method. First, in the first step, phenols, aldehydes, and aminopolyalcohols are reacted in equimolar amounts to synthesize an initial product in which aminopolyalcohols are introduced into phenol nuclei. In general, the temperature conditions for the synthesis reaction of the initial product are
The reaction is carried out at a temperature range of 30 to 100°C, preferably 50 to 90°C, and a reaction time of 1 to 3 hours is generally sufficient, but the reaction may be carried out for a longer time. Next, in the second step, aldehydes, aliphatic polyamines, and phenols are added to the initial product obtained in the first step, and polycondensation is performed in the presence of an alkaline catalyst to effect tertiary crosslinking. At that time,
The aldehyde may be added at a ratio of 3 to 10 mol, preferably 4 to 9 mol, per 1 mol of the aminopolyalcohol. Further, the aliphatic polyamino compound may be added at a ratio of 0.1 to 2.0 mol, preferably 0.3 to 0.8 mol, per 1 mol of the aminopolyalcohol. Furthermore, as phenols, per mole of amino alcohol,
It may be added at a rate of 0.3 to 2.0 mol, preferably 0.7 to 1.2 mol. Next, the temperature and time required for the three-dimensional crosslinking reaction are not necessarily constant depending on the type of raw materials, the type of reaction solvent, and other conditions, but generally 40~
1-10 hours at 150℃, preferably 2-10 hours at 60-130℃
You can choose between 7 hours. In addition, the resin can be molded into any shape such as spherical, powdered, soul-like, membrane-like, or thread-like, but it is usually preferable to form it into small spheres, and conventionally known small sphere-shaped chelate resins can be used. By carrying out pearl polycondensation in an organic solvent that is immiscible with water using exactly the same method as the manufacturing method, granulation and three-dimensional crosslinking can be simultaneously performed to obtain a spherical chelate resin. Examples of organic solvents used in this case include carbon tetrachloride,
Halogenated aliphatic hydrocarbons such as chloroform, trichlorethylene, perchlorethylene, chloral, dichloroethylene, dichloroethane, 1,2-dichloropropane, chlorobenzene, o
- Halogenated aromatic hydrocarbons such as dichlorobenzene, p-dichlorobenzene, and bromobenzene; aromatic hydrocarbons such as benzene, toluene, o-xylene, m-xylene, and p-xylene;
Examples include alicyclic hydrocarbons such as cyclohexane and cyclopropane, and cyclic alcohols such as cyclohexanol and cyclopentanol.
The reaction temperature and reaction time during pearl polycondensation are not necessarily constant depending on the type of reaction product, type of solvent, and other conditions, but are usually 60 to 150°C.
1 to 7 hours at 90 to 130°C, preferably 2 to 5 hours at 90 to 130°C, but in order to obtain a chelate resin with as uniform a composition as possible, the temperature of the polycondensation reaction should be 20 to 90°C. It is desirable to control and then gradually increase the temperature. Finally, the reaction is allowed to proceed under reflux at a temperature of 90 to 130°C, and once the desired condensation stage is reached, dehydration is performed by heating under reduced pressure or normal pressure to obtain the desired resin composition. can. In addition, examples of alkaline polymerization catalysts used in the three-dimensional crosslinking reaction include alkali and alkaline earth metal hydroxides such as sodium hydroxide, potassium hydroxide, lithium hydroxide, and calcium hydroxide, ammonia, Examples include amines such as trimethylamine and triethylamine, and cyclic amines such as pyridine, piperidine, and piperazine. The resin produced as described above is used as a chelate resin as it is or after washing. Since the chelate resin of the present invention exhibits an excellent trapping effect on metal ions, particularly boron, it can selectively adsorb and remove boric acid or boron ions present in trace amounts in all boron-containing solutions, especially concentrated salt water. Can be done. Therefore, it is useful for removing trace amounts of boron present in concentrated magnesium chloride and for removing trace amounts of boron present in dust incinerator smoke washing wastewater. It also has the ability to adsorb arsenic and tellurium, which exist in a solution similar to boron, so they can be used in the same way. The chelate resin of the present invention can be used in various ways depending on its shape; for example, it can be packed in a column or tower and a liquid containing phosmine or other metals is passed therethrough, or the resin of the present invention can be used in a variety of ways. It is used by methods such as immersing the metal in a metal-containing solution. In this case, the temperature of the metal-containing solution is suitably between 5°C and 95°C, preferably between 15°C and 50°C, and the time for contacting the metal ions with the resin is suitably between 1 minute and 50 hours. , preferably between 10 minutes and 2 hours.
In addition, metal ions can be easily recovered from the resin of the present invention that has adsorbed metal ions by bringing them into contact with a mineral acid aqueous solution or an alkaline aqueous solution in the same way as commercially available chelate resins and ion exchange resins, and they can also be regenerated. The resin can be used over and over again. As detailed above, the chelate resin of the present invention can be obtained by a simple manufacturing method, exhibits a special metal trapping effect, particularly an excellent trapping effect for low concentrations of boron, and contains an amino group. It can be used as a weakly basic ion exchange resin. Moreover, it is practical because it can be recycled and reused many times with a simple acid treatment, and it is a new resin that can be used for new applications different from conventional chelate resins. Next, the present invention will be explained in more detail with reference to Examples. In addition, % in an example represents weight %. Example 1 Phenol 29.1g, 37% formalin 25.0g, N
A mixture of 60.0 g of -methyl-D-glucamine and 10 g of water was heated and stirred at 80°C for 2 hours to obtain an initial product. Add 22% caustic soda solution to this initial product.
After adding 56.1 g, 11.2 g of ethylenediamine, and 100 g of 37% formalin and stirring at 30°C for 1 hour,
While cooling to ~20℃, add 33.9g of resorcin to 22%
A solution dissolved in an aqueous solution of caustic soda and 113 g of 37% formalin were added and stirred at 20°C to obtain a viscous reaction liquid. When this reaction solution was subjected to pearl polycondensation using perchlorethylene as a solvent in a conventional manner, a three-dimensional crosslinked resin was obtained in the form of small spheres weighing 180 g. After washing this resin with water, it was neutralized with 4.0% hydrochloric acid, then treated with a 4.0% caustic soda aqueous solution, and then sufficiently washed with water until the phenolphthalein became colorless, resulting in a blackish brown resin with a water content of 50%. It was %. Example 2 Catechol 11.0g, 37% formalin 8.4g, N
A mixed solution of 20.0 g of -methyl-D-glucamine and 5 g of water was heated and stirred at 90°C for 1 hour to obtain an initial product. Add 22% caustic soda solution to this initial product.
18.7g, diethylenetriamine 6.4g and 37%
After adding 33.3 g of formalin and stirring at 40°C for 1 hour, add 11.3 g of resorcin while cooling to 5-20°C.
A solution of g dissolved in a 22% caustic acid aqueous solution,
37.0 g of 37% formalin was added and stirred at 20°C to obtain a viscous reaction liquid. This reaction solution was subjected to pearl polycondensation using a conventional method using chlorobenzene as a solvent, to obtain 60 g of a crosslinked three-dimensional resin in the form of small spheres. When this resin was washed in the same manner as in Example 1, a dark brown resin was obtained, and its water content was 52%. Example 3 A mixed solution of 9.7 g of phenol, 8.4 g of 37% formalin, 12.5 g of tris(hydroxymethyl)aminomethane and 10 g of water was heated and stirred at 70° C. for 3 hours to obtain an initial product. This initial product contains 13.7 g of 30% caustic soda aqueous solution, 3.0 g of polyethyleneimine (Epomin SP-018 manufactured by Nippon Shokubai Kagaku Co., Ltd.) and
After adding 33.3 g of 37% formalin and stirring at 30°C for 1 hour, a solution of 8.8 g of resorcinol dissolved in 10.7 g of a 30% caustic soda aqueous solution and 33.3 g of 37% formalin were added while cooling to 5 to 20°C. 20℃
A viscous reaction solution was obtained by stirring. This reaction solution was subjected to pearl polycondensation using perchloroethylene as a solvent in a conventional manner to obtain 46.5 g of a crosslinked three-dimensional resin in the form of small spheres. When this resin was washed in the same manner as in Example 1, a dark brown resin was obtained, and its water content was 55%. Comparative Example 1 Pearl polycondensation was carried out in the same manner as in Example 1 except that ethylenediamine was not used, and 168g
A three-dimensional crosslinked resin in the form of small spheres was obtained. When this resin was washed in the same manner as in Example 1, a dark brown resin was obtained, and its water content was 54%. Examples 4 to 6 Comparative Examples 2 to 4 1.0 ml of each of the chelate resins produced in Examples 1 to 3 was added in a wet state to 50 ml of a concentrated salt aqueous solution containing 11.8 mg/concentration of boron, and the mixture was shaken. Contact was carried out for 24 hours at 25°C. As a result, the boron concentration in the aqueous solution after treatment is shown in Table 1. In addition, the boron concentration in the aqueous solution is curcumin-
Oxalic acid method (New Experimental Chemistry Course, Volume 9, Maruzen, 1975)
2003, pp. 78-79). The composition of the concentrated salt aqueous solution before treatment was as follows. (B:
11.8mg/, NaCl; 168g/, KCl; 22g/
, CaCl ₂ ; 1.7 g/, ZnCl ₂ ; 0.62 g/, pb
(NO ₃ ) ₂ ; 0.16 g/) Further, as a comparative example, the resin produced in Comparative Example 1, a commercially available strong basic ion exchange resin A, and a commercially available boron selective ion exchange resin B were similarly used for measurement. The results are shown in Table 1.

[Table] From Table 1, the chelate resin of the present invention has better boron adsorption ability at low concentrations than known boron-selective ion exchange resins, and has no removal ability at all with strongly basic ion exchange resins. That is clear. Example 7 Aqueous solution containing 10 mg/concentration of boron (boron-containing aqueous solution adjusted to PH = 7.6 with 0.025 MKH ₂ PO ₄ -K ₂ HPO ₄ (1:4) buffer solution) prepared in Example 1 in 50 ml 1.0 ml of chelate resin was added, and the solution was kept in contact with the solution for 24 hours at 25° C. while shaking. As a result, no boron was detected in the aqueous solution after the treatment.

Claims (1)

[Scope of Claims] 1. A phenolic chelating ion exchange resin in which a chelate group is introduced into the phenol nucleus of a phenol, in which the chelate group is an aminopolyalcohol, and the resin matrix constituting the ion exchange resin is a phenol, A chelating ion exchange resin characterized in that it is a crosslinked polymer comprising aldehydes and aliphatic polyamines. 2 Reacting phenols, adehydes and aminopolyalcohols to obtain an initial product in which aminopolyalcohols are introduced into the phenol nucleus,
Then, the obtained initial product is polycondensed with phenols, aldehydes and aliphatic polyamines in the presence of an alkaline catalyst to form a three-dimensional crosslinked chelate group, which is an aminopolyalcohol. and a method for producing a chelating ion exchange resin, wherein the resin matrix constituting the ion exchange resin is a crosslinked polymer consisting of phenols, aldehydes, and aliphatic polyamines. 3 Metal in an aqueous solution using a chelating ion exchange resin whose chelating group is an aminopolyalcohol and whose resin matrix is a crosslinked polymer consisting of phenols, aldehydes, and aliphatic polyamines. An adsorption treatment method characterized by selectively adsorbing ions.