JPH07116274B2 - Method for producing spherical chelate resin - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing a spherical chelate resin. More specifically, it relates to a method for easily and in high yield producing a spherical chelate resin having a high metal ion exchange capacity from phenols, aldehydes and iminodiacetic acid.

[Prior Art] Conventionally, chelate resins have been widely used for wastewater treatment for separating and removing heavy metals contained in wastewater, or for collecting metals for separating and concentrating valuable metals in water.

In general, the chelate resin includes various chelate resins depending on the type of functional group or the type of material constituting the resin matrix, but the phenolic chelate resin having an iminodiacetic acid group as a functional group has a relatively high metal ion exchange capacity. It is widely used for metal recovery.

The method for producing a phenolic chelate resin having an iminodiacetic acid group as a functional group is as follows: 1) reacting phenols with formaldehyde and a metal salt or ammonium salt of aminocarboxylic acid in the presence of an alkaline catalyst or a divalent metal ion catalyst. A method of obtaining a viscous resin, curing and crushing this to obtain a chelate resin (JP-A-49-51389),
2) A method in which a phenol compound in which an iminodiacetic acid group is introduced into an aromatic ring by a Mannich reaction is used as a starting material, phenols and aldehydes are added to the starting material, and the mixture is heat-cured and crushed to obtain a chelate resin (JP-A-49-99391). Kaisho 50-9299
1, JP-A-50-92993, JP-A-50-103590), 3) Phenol compounds and phenols having iminodiacetic acid groups introduced,
A method of producing a spherical chelate resin by carrying out a polymerization reaction with an aldehyde in a medium (Japanese Patent Publication No. 57-6441) is known.

[Problems to be solved by the invention]

However, in the method 1), since the reaction of phenols, formaldehyde and aminocarboxylic acid is performed in an alkaline manner, the introduction rate of aminocarboxylic acid into the aromatic nucleus is low, and the metal exchange capacity of the obtained chelate resin is low, and Since the shape is powder, there are problems such as large pressure loss when used packed in a column, insufficient flow and insufficient performance, and the method 2) introduces an iminodiacetic acid group into the aromatic nucleus. There are many steps for producing a chelate resin, such as a step for producing a phenol compound, a step for producing a resin by carrying out a condensation reaction with the resulting phenol compound and a phenol or an aldehyde, or a step for further promoting curing. The cost is high, and the resulting chelate resin has the same problem as in 1) when it is used in the powder form in the column method. . In addition, the method of 3) includes a phenol compound manufacturing process, a phenol compound and phenols,
The number of steps such as the step of producing a prepolymer that maintains fluidity by polycondensation reaction with aldehyde, the step of dispersing and curing the prepolymer in a medium is high, and the production cost is high. It is difficult to control the condensation reaction. For example, if the prepolymers have different viscosities, the viscosities vary when dispersed in a medium, and there is a problem that a resin having a certain particle size cannot be obtained in good yield.

The present invention has been made in view of the above problems, and provides a method for producing a spherical chelate resin having a high metal ion exchange capacity from phenols, aldehydes and iminodiacetic acid in a simple process and at a high yield. The purpose is to

[Means for solving problems]

As a result of intensive studies to solve the above-mentioned problems, the present inventors have suspended a mixed aqueous solution of phenols, aldehydes and iminodiacetic acid in a non-water-soluble solvent, and carry out a condensation reaction and a curing reaction in a suspended state. As a result, a chelate resin having a high introduction rate of iminodiacetic acid groups to the aromatic nucleus and a high metal exchange capacity can be produced by a simple process, and the viscosity of the reaction solution is constant, so that the suspension is suspended in a uniform particle size. The inventors have found a method for producing a chelate resin having a uniform particle size in a high yield, and have reached the present invention.

That is, the present invention is a method for producing a phenolic chelate resin using phenols, aldehydes and iminodiacetic acid, after adjusting the pH of the mixed aqueous solution of phenols, aldehydes and iminodiacetic acid to 7 or more, and then using a water-insoluble solvent Is added to the suspension to carry out a suspension polymerization reaction, and then a mineral acid is added to the suspension and cured by heating to produce a spherical chelate resin.

Examples of the phenols used in the present invention include monohydric phenols such as phenol, cresol and xylenol, and polyhydric phenols such as resorcinol, alkylresorcinol, catechol, hydroquinone and pyrogallol.
These may be used alone or in combination of two or more.

Examples of aldehydes used in the present invention include formaldehyde, paraformaldehyde, acetaldehyde, propionaldehyde, trioxane, furfural, benzaldehyde, butyraldehyde and the like, and these may be used alone or in combination of two or more.

To produce the chelating resin of the present invention, first, a predetermined amount of phenols, aldehydes and iminodiacetic acid are contained.
Prepare a mixed solution of pH 7 or above. The reaction molar ratio of phenols, aldehydes and iminodiacetic acid is 1: 2 to 4: 0.5
2 is preferable, and when the amount of aldehydes is 2 mols or less relative to 1 mol of phenols, the introduction rate of iminodiacetic acid is low and the strength of the resin obtained is low, and when it is 4 mols or more, the aldehydes are excessive and do not participate in polycondensation reaction It is not economical because it will be wastefully consumed.

When the amount of iminodiacetic acid used is 0.5 mol or less, the chelate resin has a low metal ion exchange capacity, and when it is 2 mol or more, the rate of introduction of iminodiacetic acid groups in the obtained chelate resin is low. The total concentration of raw materials excluding water in the mixed aqueous solution is 10
It is preferably at least 10% by weight, and if it is less than 10% by weight, the rate of the curing reaction becomes slow. The pH of the mixed aqueous solution is preferably 7 or more. When the pH is 7 or more, iminodiacetic acid has low solubility,
In addition, the system becomes heterogeneous, so the introduction rate of iminodiacetic acid groups becomes low.

The pH can be adjusted with an alkali metal hydroxide, and examples of the alkali metal hydroxide include sodium hydroxide and potassium hydroxide. Further, when a monoalkali metal salt or a dialkali metal salt of iminodiacetic acid is used as a reaction raw material, the pH adjustment of the mixed aqueous solution can be omitted. Prior to suspending this mixed aqueous solution in a water-insoluble solvent, a polycondensation reaction may be performed in advance to a viscosity at which fluidity can be maintained. By suspending in a solvent, it is possible to always suspend to a constant particle size.

Next, the mixed aqueous solution is added to a water-insoluble solvent to suspend it, and then heated at 50 to 150 ° C. for 2 to 20 hours with stirring to carry out a suspension polymerization reaction. The suspension polymerization reaction in this step requires that the reaction of the suspended particles has proceeded to such an extent that the suspended particles do not stick to each other even when the stirring is stopped. Non-water soluble solvents include benzene, toluene, xylene, carbon tetrachloride,
Solvents having low hydrophilicity such as chloroform, trichloroethylene, perchlorethylene, dichloromethane, dichlorobenzene and the like can be mentioned, and these solvents can be used alone or in combination. When adding the mixed aqueous solution to the non-water-soluble solvent, if the surfactant (preferably nonionic surfactant) is dissolved in the non-water-soluble solvent in advance, the mixed aqueous solution will be well dispersed and the particle size will be uniform. Can be

The mixed aqueous solution is suspended in a non-water-soluble solvent, heated to 50 to 150 ° C. to carry out a suspension polymerization reaction, and then a mineral acid is added to the reaction system to cure by heating. The amount of the mineral acid added is such that the resulting chelate resin becomes an acid type, that is, an amount that neutralizes the alkali metal hydroxide required for adjusting the pH of the mixed aqueous solution or more, and a predetermined amount of the mineral acid is 0.5 to Used as a 6N aqueous solution. Examples of the mineral acid include hydrochloric acid, sulfuric acid, nitric acid and the like. After the addition of the mineral acid, the mixture is heated at 50 to 100 ° C. for 1 to 10 hours to cure. By adding a mineral acid and curing by heating, the strength of the resin is repeatedly regenerated and sufficient strength for use can be obtained, and a spherical chelate resin having a high introduction rate of iminodiacetic acid groups can be obtained.

The above-mentioned spherical chelate resin manufacturing process consists of a chelate resin raw material dissolution adjusting process and a spheroidizing process. The spheroidizing process is a simple operation as a series of processes by adding a predetermined amount of mineral acid on the way. Can be done at.

The obtained spherical chelate resin is separated from the solvent and then washed with water to obtain an acid-type chelate resin, or an aqueous solution of a hydroxide of various metals such as alkali metals, alkaline earth metals and iron, or chlorides of these metals. Treated with an aqueous solution as a corresponding metal salt type chelate resin, heavy metals in wastewater, removal,
It can be used to recover valuable metals in water.

〔Example〕

 Hereinafter, the present invention will be described in more detail with reference to examples.

Example 1 Phenol 94 g, 30% formalin aqueous solution, 250 g, and iminodiacetic acid sodium salt 177 g were dissolved in ion-exchanged water 170 g to obtain a mixed aqueous solution of pH 10.5.

Dichlorobenzene (1.3) was charged into a three-necked four-flaco equipped with a thermometer, a reflux condenser and a stirrer, and the above mixed aqueous solution was added to and suspended in the dichlorobenzene under stirring at 60 to 70 ° C. The suspension polymerization reaction was carried out for an hour. Then 50
% Sulfuric acid aqueous solution (196 g) was added to the suspension and the mixture was reacted for 5 hours under reflux of dichlorobenzene to cure. After the reaction was completed, the spherical resin was separated and washed with 10 times the amount of methanol,
Further, it was sufficiently washed with ion-exchanged water to obtain a brown spherical chelate resin (H type) of 5 to 100 mesh.

Batch adsorption test for each metal ion of copper ion, nickel ion, cobalt ion, iron ion using the obtained chelate resin, water flow test to a column using copper ion aqueous solution and metal adsorption by repeated regeneration use A test (hereinafter referred to as "durability test") was performed. The results of the batch-type adsorption test are shown in Table-1, the results of the column water passage test are shown in FIG. 1, and the results of the durability test are shown in FIG.

Each test followed the following method.

○ Batch type adsorption test 600ppm Cu ²⁺ solution (using CuSO ₄ ), 50ppm Ni ²⁺ solution (using NiSO ₄ ), 40ppm Co ²⁺ solution (using CoCl ₂ ), 30p
Fe ³⁺ aqueous solution (using FeCl ₃ ) of pm, each aqueous solution 1
Add 1 ml of 20-28 mesh chelating resin to 25 ℃
After stirring for 3 hours, the resin was filtered off, the metal ion in the filtrate was measured, and the adsorption amount per chelate resin 1 was calculated by converting from the difference from the metal ion concentration in the raw water.

○ Water flow test to column Fill a glass column (inner diameter 12 mmφ) with 10 ml of 20-28 mesh chelate resin and pass a 20 ppm Cu ²⁺ aqueous solution at a flow rate of SV10, downward flow, and The copper ion concentration in the running water solution was measured at the passing amount.

○ Durability test 300 ml of chelating resin (H type) of 20 to 48 mesh is packed in a glass column (inner diameter 25 mmφ), and the regenerating operation shown in Table-1 (-in Table-1 is one cycle) is performed 50 times. During this, 10 ml of resin was sampled each time the regeneration was repeated 10 times.

Next, a non-regenerated resin and each sampled resin were used to perform a batch-type adsorption test to measure the amount of Cu ²⁺ adsorbed and to determine the degree of deterioration of the resin due to repeated regeneration. Degradation degree of resin is 10% Cu ²⁺ adsorption of new resin
It was set to 0%, and the ratio of the adsorption amount to this ratio was shown.

Example 2 Paraformaldehyde (purity 86%) in 480 g of ion-exchanged water
Dissolve 105 g, phenol 37.5 g, resorcin 66 g and iminodiacetic acid 133 g (iminodiacetic acid is not dissolved but dispersed state),
Then, the pH was adjusted to 8.5 with a 20% aqueous sodium hydroxide solution to obtain a uniform mixed aqueous solution.

The mixed aqueous solution obtained above was added to 1400 ml of carbon tetrachloride charged in the same reaction vessel as in Example 1 with stirring, and suspended, and heated at 70 to 80 ° C. for 6 hours to carry out a suspension polymerization reaction. Then, add 250 g of 20% hydrochloric acid aqueous solution to the suspension,
The resin was cured by reacting at ~ 70 ° C under reflux of carbon tetrachloride for 7 hours. After the completion of the reaction, the resin was separated, washed with methanol and washed with water in the same manner as in Example 1 to obtain a dark brown H-type spherical chelate resin having 5 to 150 mesh.

Using the obtained chelate resin, a batch type adsorption test was conducted to measure the adsorption performance of various metal ions, and the results are shown in Table 2.

Example 3 60 g of trioxane, 55 g of resorcin and 150 g of potassium iminodiacetate were dissolved in 600 g of ion-exchanged water to obtain a mixed solution of pH 10.8.

To a reaction vessel similar to that of Example 1, was charged 1500 ml of toluene,
While stirring, the above mixed solution was added, followed by suspension polymerization reaction at 50 to 60 ° C. for 2 hours and then reaction at 60 to 70 ° C. for 5 hours, and 270 g of 30% sulfuric acid aqueous solution was added to the suspension liquid for removal. After 60 ~
The reaction was carried out at 70 ° C for 3 hours. After completion of the reaction, the resin was separated, washed with methanol and washed with water in the same manner as in Example 1 to obtain a dark brown H-type spherical chelate resin of 5 to 150 mesh.

A batch type adsorption test was conducted using the obtained chelate resin, and the adsorption performance of various metal ions was measured. The results are shown in Table 2.

Comparative Example 1 In 170 g of ion-exchanged water, 94 g of phenol, 250 g of 30% formalin aqueous solution, and 177 g of iminodiacetic acid sodium salt were dissolved to obtain pH.
A mixed aqueous solution of 10.6 was obtained.

A reaction vessel similar to that of Example 1 was charged with 1300 ml of dichlorobenzene, and the above mixed aqueous solution was added to the suspension while stirring to suspend it.
A suspension polymerization reaction was carried out at 60 to 70 ° C. for 15 hours without adding a mineral acid, and the resin was separated in the same manner as in Example 1, followed by washing with methanol and water to obtain a Na-type chelate resin.

The obtained resin was added to 2000 g of a 2N aqueous hydrochloric acid solution, and the mixture was stirred at room temperature for 2
After stirring for a while to adjust the chelate-forming group to an acid type, it was thoroughly washed with ion-exchanged water to obtain a dark brown H-type spherical chelate resin of 5 to 100 mesh.

Using the obtained chelate resin, a batch adsorption test and a column liquid passing test were conducted, and the results of the batch adsorption test are shown in Table-2.
Fig. 1 shows the results of the liquid passing test.

Comparative Example 2 Phenol 47 g, 30% formalin aqueous solution 50 g, and iminodiacetic acid 66.5 g were added to ion-exchanged water 10 g and stirred at 70 ° C. for 2 hours,
Then, cool it to 30 ℃ and keep it at the same temperature.
0 g was added, 10 g of ion-exchanged water, 75 g of a 30% formalin aqueous solution and 70 g of phenol were added, and the reaction was carried out at 50 ° C. for 1 hour and cooled to room temperature to carry out precondensation to obtain a mixed solution of pH 4.8.

In a reaction vessel similar to that of Example 1, 1500 ml of dichlorobenzene was charged, and the above mixed solution was added with stirring to suspend the mixture.
The reaction was carried out for 3 hours while dehydrating at 0 ° C. After completion of the reaction, the resin was separated, washed with methanol and washed with water in the same manner as in Example 1 to obtain a dark brown H-type chelate resin of 5 to 100 mesh.

Using the obtained chelate resin, a batch type adsorption test, a column liquid passing test, and a durability test were conducted. The batch type adsorption test result is shown in Table-2, the liquid passing test result is shown in FIG. 1, and the durability test result is shown. Each is shown in FIG.

[Effects of the Invention] As described above, the chelate resin obtained in the present invention is excellent in durability, heat resistance, and chemical resistance, and is a laboratory wastewater containing many substances other than high-temperature wastewater and metal ions. Even when used for treating rubber incinerator wastewater, hospital wastewater, industrial wastewater, etc., the resin is attacked and deteriorates like conventional chelate resins,
There is no risk that the resin will be crushed by repeated reuse and the amount of adsorption will be significantly reduced, and the life of the resin will be greatly extended. Further, the chelate resin of the present invention is superior to the conventional chelate resin in adsorbing metal ions, and has an effect that wastewater treatment can be efficiently performed.

[Brief description of drawings]

FIG. 1 is a graph showing the relationship between the liquid passing amount and the Cu ²⁺ concentration in the effluent of the liquid passing test for Cu ²⁺ of the resins of Example 1 and Comparative Examples 1 and 2, and FIG. 5 is a graph showing the relationship between the number of times of regeneration of the durability test of the resins of Example 1 and Comparative Example 2 and the Cu ²⁺ adsorption rate.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-55-27347 (JP, A) JP-B 53-32391 (JP, B2) JP-B 57-6441 (JP, B2)

Claims (1)

[Claims] 1. A method for producing a phenolic chelate resin using phenols, aldehydes and iminodiacetic acid, wherein the pH of a mixed aqueous solution of phenols, aldehydes and iminodiacetic acid is adjusted to 7 or more, and then it is water-insoluble. A method for producing a spherical chelate resin, which comprises adding to a solvent to carry out a suspension polymerization reaction, then adding a mineral acid to the suspension, and heating to completely cure.