JP2007112960A - Ion scavenger and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ion scavenger excellent in both cation- and anion-scavenging properties. <P>SOLUTION: The ion scavenger contains Mg, Al, Fe and an alkali metal (R) in respective amounts meeting the requirements mentioned below on a 110°C-dried basis and on an oxide basis. The requirements are as follows: 100 pts.wt. MgO, 100-500 pts.wt. Al<SB>2</SB>O<SB>3</SB>, 15-100 pts.wt. Fe<SB>2</SB>O<SB>3</SB>, and ≤15 pts.wt. R<SB>2</SB>O calculated in terms of Na<SB>2</SB>O. Its Ca content calculated in terms of CaO is controlled to ≤2 wt.% per the total weight of Mg, Al and Fe on an oxide basis. The X-ray diffraction pattern of its 110°C-dried matter has diffraction peaks at 2θ values of from 20.5 to 22.5°, from 36.0 to 37.0° and from 61.0 to 62.0°. These peaks substantially disappear in the X-ray diffraction pattern of its 550°C-fired matter. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an ion scavenger, and more particularly to an ion scavenger having both a cation scavenging property and an anion scavenging property.

For various factory effluents, heavy metal ions such as Pb ²⁺ and Cd ²⁺ and cation components such as NH ₄ ⁺ ions, CrO ₄ ²⁻ , AsO ₄ ³⁻ , PO ₄ ³⁻ , BO ₃ ³⁻ halogen ions, etc. In many cases, it contains an anionic component, and it is required to remove these harmful ionic components during drainage. In general, such ionic components are removed as precipitates, flocs, and the like. For this purpose, the drainage must be kept in a sedimentation tank or the like for a long time. Accordingly, there is a need for a water treatment agent that quickly captures various ion components by filtration.
Moreover, harmful heavy metals are also contained in fly ash generated in refuse incinerators, etc., which are solidified with cement and disposed of by landfill. However, harmful heavy metals are eluted from the solidified cement and new environmental pollution is a problem.

In order to solve such a problem, a cation adsorbent composed of aluminum, magnesium and silicon (Patent Document 1) and an anion adsorbent mainly composed of titanium, zirconium and zinc (Patent Document 2) have been proposed. . In addition, it has been proposed to use a solid acid powder such as Al ₂ (SO ₄ ) ₃ , aluminum silicate, and aluminum phosphate as a heavy metal scavenger as a fly ash treatment agent (Patent Document 3).

  According to the heavy metal scavenger disclosed in Patent Document 3, various heavy metals are captured in the form of stable compounds such as salts, and environmental pollution due to elution can be effectively avoided. There is a need for a scavenger that has not yet been able to satisfy the scavenging effect and has further improved the scavenging action on heavy metals. From such a viewpoint, the present inventor has previously proposed a heavy metal scavenger excellent in heavy metal scavenging properties (Patent Document 4).

The heavy metal scavenger proposed in Patent Document 4 is produced from an acidic waste liquid produced in the acid treatment step of clay, and Na, Mg, Al and Si are converted to 110 ° C. dry standard and converted to oxides. The following conditions:
Na ₂ O: 0.2 to 6% by weight
MgO: 10 to 20% by weight
Al ₂ O ₃ : 20 to 45% by weight
SiO ₂ : 8 to 40% by weight
The amount of loss on ignition (1050 ° C.) is in the range of 20 to 40% by weight, and a part of the elements is at least the following formula:
Mg _2.85 Al _5.7 Si _10.3 O ₃₂ · 14H ₂ O
Na [Al ₂ Si ₆ O ₁₆ ] · 6H ₂ O
(Na, Ca) Al ₃ (SO ₄ ) ₂ (OH) ₆
In particular, the Fe ₂ O ₃ content is suppressed to 8 wt% or less.
JP-A-5-31358 JP-A-9-187646 JP-A-7-204605 JP 2005-48063 A

However, although the heavy metal scavenger of Patent Document 4 has high scavenging ability for cations such as Pb ²⁺ and Cd ^2+, there is a problem that scavenging ability for anions such as CrO ₄ ²⁻ and AsO ₄ ³⁻ is low. Further, in general, various scavengers other than the above-mentioned Patent Documents 1 to 4 have been proposed as scavengers excellent in scavenging properties for various ions, and many of them are put to practical use. Only one of the ions has a good trapping property, and no trapping agent having a good trapping property for either a cation or an anion is known. For example, a calcined product of hydrotalcite (i.e., from which carbonate radicals have been removed) shows scavenging ability for both cations and anions, but the scavenging ability does not last and the scavenging ability disappears over time. Therefore, practical application is difficult. For this reason, when using for the treatment of the drainage containing both a cation and an anion, there existed a problem that the agent excellent in cation capture | acquisition property and the agent excellent in anion capture | acquisition had to be used together.

  Accordingly, an object of the present invention is to provide an ion scavenger excellent in both cation scavenging ability and anion scavenging ability.

According to the present invention, Mg, Al, Fe, and alkali metal (R) are in the following conditions:
MgO: per 100 parts by weight Al ₂ O ₃ : 100 to 500 parts by weight Fe ₂ O ₃ : 15 to 100 parts by weight R ₂ O: contained in an amount satisfying 15 parts by weight or less in terms of Na ₂ O, and in terms of CaO In the X-ray diffraction pattern of the dried product at 110 ° C., 2θ = 20.5 to 22.5, in which the Ca content is suppressed to 2% by weight or less per the total weight of Mg, Al and Fe in terms of oxide. , 36.0 to 37.0 degrees, and 61.0 to 62.0 degrees, and the peak disappears substantially in the X-ray diffraction pattern of the fired product at 550 ° C. An ion scavenger having an anion scavenging property and cation scavenging property is provided.

  In the ion scavenger of the present invention, Si may be contained in an amount of 500 parts by weight or less per 100 parts by weight of MgO on a dry basis at 110 ° C. and in terms of oxide.

  According to the present invention, an aqueous slurry containing aluminum sulfate, magnesium sulfate and iron sulfate is prepared, and an alkaline aqueous solution is poured into the aqueous slurry at a temperature of 10 to 80 ° C. to adjust the pH to 8.5 to 10. A method for producing an ion scavenger having an anion scavenging property and a cation scavenging property, characterized by adjusting to 5, then aging, filtering, washing with water and drying is provided.

  In the production method of the present invention, it is preferable to use an alkali silicate solution or an alkali aluminate solution as the alkali solution.

The ion scavenger of the present invention has good scavenging ability not only for cations such as Pb ²⁺ and Cd ²⁺ but also for anions such as CrO ₃ ³⁻ , AsO ₄ ³⁻ , or BO ₃ ³⁻ , F ^−. As shown in Examples described later, it has an excellent characteristic that it can simultaneously capture cations and anions.

  Moreover, although the ion-trapping agent of this invention can be used with forms, such as a powder and a granular molding, according to a use, it has the unexpected characteristic that particle strength is high. That is, when an anion and a cation are captured by adding to a drainage liquid containing various harmful ions, it is usually used in the form of a granular molded product having a relatively large particle size. This is because the agent that has trapped ions can be easily separated by filtration. In such a usage pattern, if the particle strength is low, the particles may collapse when dropped in water to form powdery fine particles, which may make filtration difficult. Since the ion scavenger of the present invention has the property of high particle strength, it does not cause particle collapse even when dropped in water, and the above disadvantages can be effectively avoided. .

The ion scavenger of the present invention is obtained by alkali treatment of an aqueous slurry containing sulfates of Mg, Al and Fe at a certain ratio, as will be described later. As elemental elements, Mg, Al, Fe and The alkali metal (R) is dried under the condition of 110 ° C. and converted to oxide, and the following conditions:
MgO: 100 parts by weight Al ₂ O ₃ : 100 to 500 parts by weight, particularly 120 to 300 parts by weight Fe ₂ O ₃ : 15 to 100 parts by weight, especially 20 to 100 parts by weight R ₂ O: 15 in terms of Na ₂ O It is contained in an amount satisfying not more than 1 part by weight, particularly 1 to 10 parts by weight, and at the same time containing Mg, Al and Fe in such an amount balance, it is dried at 110 ° C. in X-ray diffraction measurement. The X-ray diffraction pattern of the product has diffraction peaks in the region of 2θ = 20.5 to 22.5 degrees, 36.0 to 37.0 degrees, and 61.0 to 62.0 degrees, and is fired at 550 ° C. In the X-ray diffraction pattern, it is important that the diffraction peak substantially disappears. These three X-ray diffraction peaks coincide with the three strong lines of goethite (HFeO ₂ ). Therefore, in the ion scavenger of the present invention, at least a part of Fe forms a goethite-like structure. In addition, it is considered that a part of Al is substituted with Fe and incorporated into a goethite-like structure to form a pseudo goethite crystal.

That is, in the present invention, while the basic sulfate containing Mg, Al and Fe is distributed in an amorphous state, crystals (goethite or pseudo-goethite) showing the above X-ray diffraction pattern are generated. It is believed that the presence of such crystals exhibits excellent anion scavenging properties. For example, as will be apparent from Examples and Comparative Examples described later, when the 110 ° C. dried product exhibits the diffraction pattern as described above by X-ray diffraction measurement, Cr ₂ O ₇ ²⁻ , AsO ₃ ³⁻ , BO ^{3 -} shows a high retention against anions such as F ^{chromatography} (example 1, Figure 1), when not exhibit such diffraction patterns, Al, as a content or the like of Mg and Fe are the same However, it does not show a trapping property for anions (Comparative Examples 1 and 2).

In the present invention, except for those that contribute to the formation of crystals exhibiting the X-ray diffraction pattern as described above, each element of Mg, Al, and Fe is present in an amorphous basic sulfate. However, alkali metals (R) such as Na exist in a form that compensates for the charge balance of Mg, Al, and Fe, and such alkali metals (R) substitute for cations such as Pb ²⁺ and Cd ^2+. As a result, it seems to have a high cation scavenging property. As the alkali metal (R), Na is most common, but Li or K may be used. Further, since the sulfate is obtained as a starting material, the ion scavenger of the present invention usually has a sulfate radical (SO ₃ ) content in the range of about 0.2 to 15% by weight.

  Furthermore, in the present invention, it is extremely important that the Ca content is suppressed to 2% by weight or less, particularly 1% by weight or less, based on the total weight of Mg, Al and Fe in terms of oxides. That is, as is clear from Comparative Example 2 described later, when the Ca content is more than the above range, the cation trapping property is remarkably lowered. Although the reason for such a decrease in cation scavenging by Ca is not exactly elucidated, it is likely that chemically stable gypsum is formed and the proportion of alkali metal (R) is relatively reduced. For this reason, it seems that the anion scavenging ability by ion exchange with the alkali metal (R) as described above is greatly reduced.

  Such an ion scavenger of the present invention is required to contain each element of Mg, Al, and Fe in the above-mentioned proportions in order to express the cation scavenging property and the anion scavenging property in a balanced manner. When the Fe content is within the above-described range, it has an unexpected advantage of having a high particle strength while maintaining such ion trapping properties. That is, those having an Fe content less than the above-mentioned range have low particle strength. For example, when dropped in water and used, the particles collapse and become powdery. As a result, clogging or the like is likely to occur, and thus it may be difficult to remove the used agent by filtration. However, since the ion scavenger of the present invention containing a predetermined amount of Fe has a high particle strength, for example, when it is molded into an appropriately sized granular material, it is introduced into water to trap anions and cations. Also when performed, the particles do not disintegrate, thus exhibiting excellent filterability, and the used agent can be easily separated by filtration.

In addition to the above-described elemental components, the ion scavenger of the present invention contains, for example, Si in an amount of 500 parts by weight or less, particularly 2 to 300 parts by weight per 100 parts by weight of MgO on a dry basis at 110 ° C. and in terms of oxide. It may contain. That is, Si exists as amorphous SiO ₂ , and even when such Si component is contained, the cation scavenging property and the anion scavenging property are not impaired, but rather the anion scavenging property tends to increase slightly. There is. However, when the Si content exceeds the above range, the content of crystals showing the X-ray diffraction pattern, which is considered to contribute particularly to the anion scavenging property, is relatively reduced, so that the anion scavenging property tends to be lowered.

As is clear from FIG. 2 showing the X-ray diffraction pattern of the scavenger of Example 4 described later, the ion scavenger of the present invention containing no SiO ₂ component has the above-mentioned three X-ray diffraction peaks, A clear peak is shown in the region of 2θ = 8.5 to 10 degrees. That is, the peak in this region also indicates the stacking in the c-axis direction, and it is considered that the layer has a structure in which the layer also extends in the ab plane direction, and it is easy to incorporate cations and anions between the layers. Therefore, it is believed that even if the content of active ingredients such as goethite-like crystals showing the three strong lines is relatively lowered, it is possible to maintain a certain cation scavenging ability and anion scavenging ability.

  In addition, the ion scavenger of the present invention may contain components other than the above-described element components on the condition that the Ca content is suppressed within the above range, such as various metal oxides. Such other components may be contained in an amount of 7% by weight or less based on the total weight of Mg, Al, and Fe in terms of oxides. That is, when the content of other components is increased, the content of active ingredients such as crystals showing the three strong lines is relatively decreased, so that the cation trapping property and the anion trapping property are decreased.

  The ion scavenger of the present invention having the composition and structure described above is produced by preparing an aqueous slurry containing magnesium sulfate, aluminum sulfate and iron sulfate and subjecting it to an alkali treatment.

The solid content concentration of the aqueous slurry is usually about 0.5 to 10% by weight, and the ratio of magnesium, aluminum and iron in the aqueous slurry is the weight ratio in terms of oxides of Mg, Al and Fe. Is set to be in the above-described range. Further, as the amount of Si in terms of oxide falls within the range described above, silica components may contain (SiO _2). However, it is necessary that the Ca content and the amount of components other than the above metals be suppressed to the above-described ranges. The amount ratio of each component is summarized as follows.

MgO: 100 parts by weight Al ₂ O ₃ : 100 to 500 parts by weight, particularly 120 to 300 parts by weight Fe ₂ O ₃ : 15 to 100 parts by weight, especially 20 to 100 parts by weight R ₂ O: 15 in terms of Na ₂ O Parts by weight or less, especially 1 to 10 parts by weight CaO: 2% by weight or less, particularly 1 part by weight or less Other metal components (oxide conversion): 7% by weight or less The CaO content and other metal component contents are MgO, It is a value when the total amount of Al ₂ O ₃ and Fe ₂ O ₃ is 100% by weight.

  In addition, aluminum sulfate, magnesium sulfate, iron sulfate and silica are all components contained in the solution generated by the acid treatment of clay, and the amount of other components is suppressed to a predetermined amount or less. If Mg, Al, Fe and Si components are contained, this solution can be used as a raw material.

  Alkaline treatment is performed by pouring an alkaline aqueous solution into the above slurry at a temperature of 10 to 80 ° C., and adjusting the pH to a range of 8.5 to 10.5. Then, the crystal showing the three strong lines described above can be deposited.

  In the above alkali treatment, when the temperature is out of the above range, the crystals showing the three strong lines described above are not formed, and particularly when the temperature is higher than the above range, it is described in Patent Document 4. As a result, even if the cation trapping property can be secured, the anion trapping property cannot be obtained. Similarly, when the pH is out of the above range, the crystals showing the three strong lines described above are not generated, or the anion scavenging ability cannot be expressed due to precipitation of other crystals.

  The aqueous alkali solution used for the alkali treatment is not limited to this, but caustic soda and caustic potash are preferably used, and sodium silicate can also be used. In particular, it is preferable to use sodium silicate to produce an ion-trapping agent containing a Si component. Furthermore, sodium aluminate can be used in combination if necessary. When using sodium silicate or sodium aluminate, it is necessary to adjust the amount ratio of sulfate to be used so that the Al content and the Si content satisfy the above-mentioned conditions in the final composition. It is.

  After the alkali treatment, the ion scavenger of the present invention can be obtained by aging, and then filtering, washing with water and drying. The ripening is for precipitating an effective amount of the crystals showing the above-mentioned three strong lines. Usually, the treated slurry may be at a temperature of 10 to 80 ° C. for about 2 to 50 hours or longer. Is carried out by leaving it stationary.

  The ion scavenger of the present invention thus obtained is excellent in cation scavenging and anion scavenging, so it can be used for removing harmful heavy metal ion components from fly ash, soil, groundwater, rivers, hot springs, industrial wastewater, etc. It can be suitably used for removing contained harmful ion components.

  The form of use can be used as a predetermined granular product after crushing and sieving after drying, or as a fine powder by pulverization, classification or the like. Generally, after pulverizing to an appropriate size, it is molded into granules, rods, pellets, spheres, barrels, plates, honeycombs, cylinders, fibers, etc. It can also be used. In particular, the ion scavenger of the present invention is excellent in particle strength and has a property that the particles do not disintegrate into a powder form even when thrown into water, so that the filterability is good, and therefore 0.3 to 10 mm. Most preferably, it is dropped into water as a granular material having a particle size of about a degree and used for capturing various ions.

  Further, since the ion scavenger of the present invention has excellent scavenging properties for both cations and anions, it can be used alone without being used in combination with other agents. Is a great advantage of the present invention, but if necessary further synthetic zeolite, natural zeolite, activated carbon, smectite clay, amorphous aluminum silicate, magnesium silicate, calcium silicate, hydrotalcite and the like It is also possible to mix iron- and iron-zinc-based ion adsorbents, ion exchange resins and the like and mold them, or mix and use granular products.

  Furthermore, the ion scavenger of the present invention can also support an organic acid, for example, to enhance the cation trapping ability. Examples of such organic acids include monocarboxylic acids, dicarboxylic acids, and tricarboxylic acids. Examples of aminosulfonic acid include sulfanilic acid, and examples of monocarboxylic acid typically include formic acid, acetic acid, benzoic acid and the like. Examples of the dicarboxylic acid include aliphatic unsaturated dicarboxylic acid, aliphatic saturated dicarboxylic acid, aromatic dicarboxylic acid, and alicyclic dicarboxylic acid. The aliphatic unsaturated dicarboxylic acid preferably has 4 to 6 carbon atoms, such as fumaric acid, maleic acid, itaconic acid, citraconic acid and the like. The aliphatic saturated dicarboxylic acid preferably has 2 to 6 carbon atoms, and examples thereof include succinic acid, malonic acid, tartaric acid, malic acid, glutaric acid, and adipic acid. The aromatic dicarboxylic acid preferably has a benzene ring, and examples thereof include phthalic acid, isophthalic acid, and terephthalic acid. The alicyclic dicarboxylic acid is preferably an acid having a cyclohexyl ring, and examples thereof include cyclohexane dicarboxylic acid. A typical example of the tricarboxylic acid is citric acid. The organic acid to be used is preferably substantially odorless and solid at room temperature, and tartaric acid, malic acid, citric acid, and fumaric acid are preferable.

  Such an organic acid may be used, for example, in an amount of 1 to 30 parts by weight per 100 parts by weight of the ion scavenger of the present invention and attached to the surface or pores of the scavenger. As such an attaching means, an impregnation method, a co-grinding method, or the like is used. Of these, attachment by mechanochemical treatment is particularly preferred.

  In the impregnation method, an organic acid is added to water or an organic polar solvent, for example, alcohols such as methanol and ethanol, ketones such as acetone and methyl ethyl ketone, ethers such as methyl ether and tetrahydrofuran, cellosolve solvent, diethylene glycol ether solvent and the like. The dissolved solution is impregnated with the ion scavenger of the present invention and dried to obtain a product. As the organic acid solution, it is generally preferable to use a solution having an organic acid concentration of 5 to 20% by weight.

  On the other hand, in the co-grinding method, the solid organic acid and the ion scavenger of the present invention are co-ground in a pulverizer. As the pulverizer, a ball mill, a jet mill, a vibration mill, a colloid mill or the like is used, and a jet mill is particularly preferably used. When a small amount of water, generally 5 to 25% by weight of water per composition, is added to the pulverization, the organic acid is effectively taken into the pores.

The excellent effects of the present invention will be described in the following experimental examples.
In addition, this invention is not limited to the following examples.
Each test method was performed according to the following method.

(1) Chemical composition Measured with a fluorescent X-ray diffractometer RIF-3000 manufactured by Rigaku Corporation. In addition, the ignition loss was calculated | required from the weight loss value in 600 degreeC.

(2) Preparation of powder sample for X-ray diffraction measurement:
The granular or coarse sample is pulverized in a mortar by a conventional method, dried at 110 ° C. (normal drying treatment) or baked at 550 ° C. to obtain a powdery measurement sample, and an X-ray diffractometer (manufactured by Rigaku Corporation) (MultiFlex, Cu-Kα) was measured under the following conditions.
Tube voltage: 40 kV, tube current: 30 mA, divergence slit: 0.15 mm, scattering slit: 1 °, light receiving slit: 0.3 mm.
View results:
The determination as to whether or not the X diffraction pattern falls under the characteristics of the present invention and the display symbols in Tables 1 and 2 were determined as follows.
X-ray diffraction pattern of dried product at 110 ° C. Diffraction angle 2θ = 20.5 to 22.5 degrees, 36.0 to 37.0 degrees and 61.
All three regions from 0 to 62.0 degrees have diffraction peaks.
× ·· All three regions do not have diffraction peaks, or all three regions
Does not have a diffraction peak and has a diffraction peak in a region different from the above three regions
Yes.
X-ray diffraction pattern of the fired product at 550 ° C. The diffraction peaks in all of the above three regions have substantially disappeared.
× ·· The diffraction peaks in all the above three regions are not substantially lost, or the above three regions
Diffraction peaks in all the regions are not substantially lost and are different from the above three regions
It has a diffraction peak in the region.

(3) Ion adsorption test Lead (Pb: Pb ²⁺ ) and cadmium (Cd: Cd ²⁺ ) for cation adsorption measurement, arsenic (As: AsO ₃ ^3- ), chromium (for anion adsorption measurement) Standard solution for atomic absorption measurement of Cr: Cr ₂ O ₇ ²⁻ ), boron (B: BO ₃ ³⁻ ), fluoride ion (F: F ⁻ ) (1,000 ppm, manufactured by Wako Pure Chemical Industries, Ltd.) And each is diluted 200 times with pure water (→ 5 ppm).
Weigh 1,000 ml of the above diluted solution in a 1 L beaker, put 0.33 g, 0.50 g or 1.00 g sample in terms of dried product at 110 ° C. into a small cage made of stainless steel mesh and put it in the upper liquid. Fix to (position of about 2 to 5 cm from the liquid surface), rotate the magnetic stirrer at the bottom of the beaker, stir for 24 hours, let stand for 30 minutes, and sample the upper supernatant to make the test solution.
When the sample is a powder, the sample is directly placed in the above diluent and dispersed, stirred and adsorbed under the same conditions, filtered using a microfilter (KGS-47, manufactured by Advantech), and the filtrate is sampled. Use the test solution.
Next, these test solutions were diluted as necessary, the concentration of each atom was measured by ICP emission spectrometry, and the ion adsorption amount in terms of each atomic weight was determined from the concentration difference between the stock solution (the diluted solution) and the test solution. .
The analysis of fluorine (F) was performed by ion chromatography.

(4) Disintegration After visually observing the disintegration of the granular material when dropped in water, place the granular material on the glass plate after 48 hours of immersion, and place the convex surface of the watch glass on the granular material from above. The disintegration property when pressed with a finger from the concave surface was determined as follows.
◎ It does not collapse at all in water, and it is hard to collapse even if it is pressed against a watch glass.
○ Although it does not collapse underwater, it tends to collapse when pressed against a watch glass.
ΔSlightly disintegrates in water.
× Almost all disintegrates in water.

(5) Specific surface area measurement It measured by BET method by nitrogen adsorption.

Example 1
Preparation of solution A;
2 L of water is placed in a 5 L stainless steel container, and under stirring, 206 g of commercially available aluminum sulfate powder (Al ₂ O ₃ min: 17%) and 123 g of magnesium sulfate heptahydrate (manufactured by Wako Pure Chemical Industries) are added and dissolved. (= A ₁ liquid). Separately, 25 grams of ferric sulfate heptahydrate (manufactured by Wako Pure Chemical Industries, Ltd.) is weighed into a 300 ml beaker, 250 ml of water is added, and the mixture is stirred to dissolve (= A ₂ solution). Then added to A ₂ solution A ₁ solution, to obtain a solution A by adjusting the liquid temperature to 35 ° C..
Preparation of solution B;
In a 3 L stainless steel container, weigh 125 g of industrial No. 3 sodium silicate (SiO ₂ : 28%, Na ₂ O: 8.8%) and 100 g of industrial 49% caustic soda solution and add 2 L of water to make it uniform. Solution B was prepared, and the solution temperature was adjusted to 35 ° C. to obtain solution B.
Next, A liquid is stirred and B liquid is poured over about 1 minute. After the addition, add 49% sodium hydroxide solution with a dropper until the pH is stable at about 9.5. When the pH was stable at 9.5 to 9.6, the mixture was aged at room temperature for 20 hours.
After completion of aging, the reaction solution is filtered by suction and washed with the same amount of water as the mother liquor. After washing with water, the filter cake is placed in a constant temperature dryer at 110 ° C. for about 15 hours and dried. After completion of drying, the powder was crushed to an appropriate size in a mortar and sieved to about 1-2 mm using a sieve to obtain the ion scavenger of the present invention.
Table 1 shows the chemical composition, X-ray diffraction pattern, ion adsorption amount, disintegration property, and other measurement results for the obtained granular material sample. Moreover, the X-ray-diffraction pattern of 110 degreeC dried material (normally dried material) and the X-ray-diffraction pattern of 550 degreeC baked material were shown in FIG.

Example 2
In Example 1, the powder was pulverized with a small sample mill without being crushed and granulated with a mortar to obtain a fine powder.
Table 1 shows the chemical composition, X-ray diffraction pattern, ion adsorption amount, disintegration, and other measurement results for the obtained fine powder sample.

Example 3
In Example 1, except that the liquid temperature of A liquid and B liquid was adjusted to 55 degreeC, it prepared similarly and obtained the ion-trapping agent of this invention sieved to about 1-2 mm.
Table 1 shows the chemical composition, X-ray diffraction pattern, ion adsorption amount, disintegration property, and other measurement results for the obtained granular material sample.

Example 4
In Example 1, the same preparation was performed except that 49% caustic soda solution was added to the A solution without adjusting the B solution, and the pH was adjusted to 9.5 to 9.6, and sieved to about 1-2 mm. An ion scavenger of the present invention was obtained.
Table 1 shows the chemical composition, X-ray diffraction pattern, ion adsorption amount, disintegration, and other measurement results of the obtained granular material sample, and FIG. 2 shows the X-ray diffraction pattern of the normally dried product.

Example 5
In Example 1, the ion scavenger of the present invention was prepared in the same manner except that the amount of ferric sulfate was changed to 11.5 g which is a half amount, and sieved to about 1-2 mm.
About the obtained granular material sample, it showed in Table 1 about the chemical composition, the X-ray-diffraction pattern, the amount of ion adsorption, disintegration, and other measurement results.

Example 6
Preparation of solution C;
Tension of water 2L stainless steel vessel 5L, stirring, dissolved by adding magnesium sulfate heptahydrate (manufactured by Wako Pure Chemical) 123 g (= _{C 1} solution). Ferric sulfate heptahydrate separately (manufactured by Wako Pure Chemical Industries, Ltd.) weighed 25 grams beaker 300 ml, water 250ml added and dissolved by stirring (= _{C 2} solution). Then added to C ₂ solution in C ₁ solution, to obtain a C solution by adjusting the liquid temperature to 35 ° C..
Preparation of solution D In a 3 L stainless steel container, weigh 154 g of industrial sodium aluminate (Al ₂ O ₃ 22.7%, Na ₂ O 18.2%) and 30 g of caustic soda (NaOH), and add 2 L of water. A uniform solution was obtained, and the solution temperature was adjusted to 35 ° C. to obtain solution D.
Next, C liquid is stirred and D liquid is poured over about 1 minute. After the addition, add 49% sodium hydroxide solution with a dropper until the pH is stable at about 9.5. When the pH was stable at 9.5 to 9.6, the mixture was aged at room temperature for 20 hours.
Thereafter, a granular material of about 1-2 mm was obtained in the same manner as in Example 1.
About the obtained granular material sample, it showed in Table 1 about the chemical composition, the X-ray-diffraction pattern, the amount of ion adsorption, disintegration, and other measurement results.

Example 7 and Example 8
A granular material of about 1-2 mm obtained in Example 1 was absorbed in a desiccator of 90% RH for 2 weeks (Example 7), and further immersed in pure water for 1 month to absorb water (Implementation) The results of the ion adsorption test of Example 8) are shown in Table 1.

Comparative Example 1
125 g of industrial No. 3 sodium silicate (SiO ₂ 28%, Na ₂ O 8.8%) 125 g and industrial 49% caustic soda solution 65 g are weighed in a 5 L stainless steel container, and ₂ L of water is added to form a uniform solution. The liquid temperature is adjusted to 35 ° C. (= E liquid).
Separately, industrial sodium aluminate _{(Al 2 O 3 22.7%,} Na 2 O18.2%) of 154g was dissolved in water of 1L, adjusting the liquid temperature to 35 ° C. (= F liquid).
A solution in which 123 g of magnesium sulfate heptahydrate (manufactured by Wako Pure Chemical Industries, Ltd.) is dissolved in 1 L of water and 25 grams of ferric sulfate heptahydrate (manufactured by Wako Pure Chemical Industries, Ltd.) is dissolved in 300 ml of water. In addition, a uniform solution is formed, and the liquid temperature is adjusted to 35 ° C. (= G liquid).
F liquid and G liquid are simultaneously added to E liquid under stirring over about 1 minute and mixed. The pH of the slurry after mixing was 12.9.
This slurry was formed at room temperature for 20 hours, and thereafter filtered, washed with water, dried and crushed in the same manner as in Example 1 to obtain a granular material sieved to about 1-2 mm.
Table 2 shows the chemical composition, X-ray diffraction pattern, ion adsorption amount, disintegration property, and other measurement results for the obtained granular material sample. Moreover, the X-ray diffraction pattern of the normally dried product is shown in FIG.

Comparative Example 2
In a 20 L polypropylene container, 10 L of a solution adjusted to pH 2.0 by adding magnesium hydroxide slurry (35%) to the cleaning solution at the time of producing activated clay was added, and the stirring solution at the time of producing the synthetic faujasite type zeolite (with stirring) ( Add pH 13.2) until the pH is around 7.0. When the pH was stabilized at 7.0 ± 0.5, the stirring was stopped, and after standing overnight, the supernatant liquid was cut off, and under stirring, the diluted sodium aluminate solution (F solution) used in Comparative Example 1 had a pH of about 9.5. Added until.
The slurry was aged at room temperature for 20 hours, and thereafter prepared in the same manner as in Comparative Example 1 to obtain a granular material sieved to about 1-2 mm.
Table 2 shows the chemical composition, X-ray diffraction pattern, ion adsorption amount, disintegration, and other measurement results of the obtained granular material sample, and FIG. 3 shows the X-ray diffraction pattern of the normally dried product.

Comparative Examples 3-7
Granules obtained by roughly crushing natural zeolite (clinoptilolite) and sieving to about 1-2 mm (Comparative Example 3); Granules obtained by crushing synthetic A-type zeolite molded product and sieving to about 1-2 mm (Comparative Example 4), a hydrotalcite powder (manufactured by Wako Pure Chemical Industries) (Comparative Example 5), a powder obtained by firing the powder at 600 ° C. for 1 hour (Comparative Example 6), and the 600 ° C. fired powder as a watch Table 2 shows the results of an ion adsorption test conducted on a dish (Comparative Example 7) which was spread on a plate and left in a desiccator of 90% RH for 2 weeks.

Example of adsorption test in mixed ion solution:
For the samples of Examples 1, 4, and 5 and Comparative Examples 1, 2, and 5, the amount of each ion adsorbed from the six-type ion mixed solution was measured by the following method, and the results are summarized in Table 3.
In a 1 L volumetric flask, each ion of a cation (Pb ²⁺ , Cd ²⁺ ) and an anion (AsO ₃ ³⁻ , Cr ₂ O ₇ ²⁻ , BO ₃ ³⁻ , F ⁻ ) is added to each core atom (Pb, Cd, Each atomic absorption measurement standard solution is added and mixed so as to be 5 ppm each in terms of atomic weight of As, Cr, B, F), and water is added to make a total volume of 1 L to prepare a mixed ion solution.
Next, 1.00 g of a sample was put in the mixed ion solution and measured by a method based on the ion adsorption test.
The powder product was also adsorbed in the same manner as the ion adsorption test, filtered, and the filtrate was used as a test solution.

2 is an X-ray diffraction pattern of a 110 ° C. dried product (normally dried product) and a 550 ° C. calcined product of the ion scavenger of the present invention according to Example 1. FIG. 4 is an X-ray diffraction pattern of an ion scavenger of the present invention (usually a dried product) according to Example 4. It is an X-ray diffraction pattern of the thing (normally dry matter) obtained by the comparative example 1 and the comparative example 2. FIG.

Claims (4)

Mg, Al, Fe and alkali metal (R) are dried at 110 ° C. and converted to oxides under the following conditions:
MgO: per 100 parts by weight Al ₂ O ₃ : 100 to 500 parts by weight Fe ₂ O ₃ : 15 to 100 parts by weight R ₂ O: contained in an amount satisfying 15 parts by weight or less in terms of Na ₂ O, and in terms of CaO In the X-ray diffraction pattern of the dried product at 110 ° C., 2θ = 20.5 to 22.5, in which the Ca content is suppressed to 2% by weight or less per the total weight of Mg, Al and Fe in terms of oxide. , 36.0 to 37.0 degrees, and 61.0 to 62.0 degrees, and the peak disappears substantially in the X-ray diffraction pattern of the fired product at 550 ° C. An ion scavenger having an anion scavenging property and a cation scavenging property.   The ion-trapping agent according to claim 1, which contains Si in an amount of 500 parts by weight or less per 100 parts by weight of MgO on a dry basis at 110 ° C and in terms of oxide.   An aqueous slurry containing aluminum sulfate, magnesium sulfate and iron sulfate is prepared, and an aqueous alkaline solution is poured into the aqueous slurry at a temperature of 10 to 80 ° C. to adjust the pH to 8.5 to 10.5, followed by aging. , Filtration, washing and drying, a method for producing an ion scavenger having anion scavenging and cation scavenging.   The method for producing an ion scavenger according to claim 3, wherein an alkali silicate solution or an alkali aluminate solution is used as the alkali solution.

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