JPH0334799B2 - - Google Patents

Description

[Detailed description of the invention]

<Industrial Application Field> The present invention effectively utilizes naturally occurring volcanic glass such as whitebait glass, which is considered to be a type of unused resource.
This invention relates to a method for producing fine type A zeolite with good whiteness, which is currently used as a builder for detergents. <Prior Art> It is already known that a water glass solution with few impurities can be synthesized by boiling volcanic glass in an alkaline aqueous solution (Japanese Patent Laid-Open No. 50-91597). However, water glass that can be synthesized from volcanic glass contains iron in a weight ratio of 0.001 to 0.004 to silica, and when A-type zeolite, which is used as a builder for detergents, is synthesized using water glass containing iron as a raw material, the whiteness decreases. This results in undesirable A-type zeolite crystals. Also,
In the method disclosed in JP-A-59-26917, an extremely highly concentrated aluminosilicate slurry is produced by using a highly concentrated sodium aluminate solution, but this method uses commercially available water glass. It does not mention anything about the behavior of iron, which is inevitably mixed in when natural minerals are used as starting materials. Currently, the method for synthesizing A-type zeolite for builders using natural minerals as a starting material is a method using residual silica obtained by acid treatment of smectite clay (Japanese Patent Publication No. 26-1119, Japanese Patent Publication No. 52-62314,
JP 52-62315) has been disclosed, and natural type A zeolite for builders has actually been manufactured and sold, but the synthesis of type A zeolite for builders using volcanic glass has not yet been put into practical use. This is the reality. <Problems to be Solved by the Invention> In the present invention, even if the A-type zeolite that is the final product contains iron, it is not concentrated on the crystal surface and is transferred to the grain boundaries or inside the crystal grains. By making it possible to synthesize A-type zeolite with good whiteness by keeping it at
The aim is to effectively utilize volcanic glass as an unused resource. <Means for Solving the Problems> In the present invention, in order to achieve the above object, 0.45 to 0.8 mol (preferably 0.6
3 to 6N (preferably 4 mol) of _Na2O
The volcanic glass is heated between 95 and 105° C. for 2 to 6 hours (preferably 3 to 5 N) in a sodium hydroxide solution.
4 hours) to extract the water glass with an iron contamination rate of 0.001 to 0.002 in Fe ₂ O ₃ /SiO ₂ weight ratio, and then convert the solid hydroxide into industrial sodium hydroxide solution or industrial sodium hydroxide. Sodium hydroxide solution obtained by dissolving sodium (the content of NaOH is
40-60%, preferably NaOH content 48-52%)
Sodium aluminate solution (Na ₂ O/Al ₂ O ₃
molar ratio of 1.12 to 1.70), mix the water glass solution and the sodium aluminate solution at room temperature,
Further at room temperature for 30 minutes to 4 hours (preferably 1 hour to 2 hours)
The amorphous gel thus obtained is aged for 80 h).
A fine A-type zeolite with good whiteness and high ion exchange rate, which is crystallized by heating at ~110℃ (preferably 90-100℃) for 20 minutes to 2 hours (preferably 40 to 1 hour). This is the manufacturing method. The crystal content of the A-type zeolite produced is 25%.
-100%, and the product other than type A zeolite crystals is amorphous alkali metal-containing aluminum silicate with ion exchange ability. <Function> If the concentration of the sodium hydroxide solution when extracting water glass is less than 3N, even if a highly concentrated sodium aluminate solution prepared from industrial sodium hydroxide and industrial aluminum hydroxide is used, Of the batch composition during zeolite synthesis
The H ₂ O/Na ₂ O molar ratio increases, the alkali concentration of the slurry decreases, and only coarse crystals are produced. In addition, when the sodium hydroxide concentration when extracting water glass is over 6N, the amount of iron contained in the extracted water glass becomes 0.002 or more in weight ratio to silica, and A-type zeolite with good whiteness is synthesized. become unable. Also, the concentration of sodium hydroxide solution when preparing sodium aluminate solution is
If NaOH is used to reduce the concentration to 40% or less, H ₂ O/Na ₂ O will be reduced in the batch composition during zeolite synthesis as described above.
As the molar ratio increases, the alkali concentration in the slurry decreases, and not only coarse crystals are obtained, but also type A zeolite with poor whiteness is synthesized. H ₂ O / Na ₂ O molar ratio during A-type zeolite synthesis is 15 to 30.
(1) Rapid crystallization causes impurities to contaminate and remain inside crystal grains or at grain boundaries. (2) The amount of iron precipitated per unit surface area decreases due to the increase in specific surface area. (3) As the alkali concentration of the mother liquor increases, iron becomes more likely to separate into the mother liquor. For these reasons, type A zeolite with good apparent whiteness can be synthesized. When the Na ₂ O / Al ₂ O ₃ molar ratio of the sodium aluminate solution exceeds 1.7, when the A-type zeolite synthesis waste liquid (sodium hydroxide solution containing low concentrations of silica and alumina) is recycled and reused. To,
It requires a concentration step and has the disadvantage that excess sodium hydroxide must be recycled. Synthesis waste liquid of A-type zeolite has a lower alkali concentration than the one during synthesis because the A-type zeolite product is extracted from the system containing approximately 1 mol of Na ₂ O per 1 mol of silica and alumina. It's getting lower. Therefore, although this synthetic waste liquid can be used as is as a sodium hydroxide solution for redissolving volcanic glass, it is not suitable for dissolving aluminum hydroxide to produce a highly concentrated sodium aluminate solution. In order to synthesize a sodium aluminate solution using this waste liquid, it is necessary to concentrate it to a sodium hydroxide concentration equal to or higher than industrial sodium hydroxide solution (48% NaOH or higher). Therefore, it is preferable that the Na ₂ O / Al ₂ O ₃ molar ratio of the sodium aluminate solution be as low as possible, but if it is produced from an industrial sodium hydroxide solution and aluminum hydroxide under normal pressure near the boiling point, Na ₂ O in aqueous sodium aluminate solution/
The Al ₂ O ₃ molar ratio is approximately 1.12, and anything lower than that cannot be obtained under normal pressure. The method of the present invention uses iron-containing volcanic glass.
Using water glass containing a small amount of iron extracted at a relatively low alkali concentration and a high concentration sodium aluminate solution, A-type zeolite with good whiteness suitable for detergent builders can be industrially advantageously produced. This is an excellent way to provide <Example> Next, the present invention will be explained in more detail with reference to Examples. Note that each performance in the Examples was measured by the following method. 1 Crystallization rate Calculated using the following formula as the ratio of the intensity of the same diffraction line of the sample to the powder X-ray diffraction intensity of the standard. The standard product is A-4 (powder form) from Toyo Soda Co., Ltd.
was used. Crystallization rate = ΣI (height of the diffraction line of the sample) / ΣI ₀ (height of the diffraction line of the standard) x 100 (%) The test diffraction lines included in ΣI and ΣI ₀ are (100) , (110), (221, 300), (311), (321),
There are a total of seven diffraction lines: (410, 322) and (332). 2 Whiteness The whiteness of the A-type zeolite was measured using an electronic color difference meter manufactured by Tokyo Denshoku Co., Ltd., model TC-55D. Hunter whiteness L, a and b are used as standard white plates respectively.
White porcelain plates of 92.1, +0.2 and 3.3 were used. The color difference was expressed by the ΔE value of the following formula. △E=√(100−) ² + ² + ² Here, L, a, and b are the lightness (L), hue (a), and saturation (b) of the UCS color system devised by Hunter. show. Note that the L, a, and b values have the following relationships with the three stimulus values X, Y, and Z received by photoreceptor cells that are sensitive to red, green, and blue-violet, respectively. L=100√ a=175(1.025×−Y)/√ b=70(Y−0.847Z)/√ Note that the smaller the ΔE value, the better the whiteness, and it becomes 0 for complete white. The ΔE value of commercially available natural type A zeolite is 2.07 to 2.18. 3. Ion exchange rate: Place 250ml of 1mM calcium chloride solution in a temperature-controlled container equipped with a stirrer, add 0.1g of zeolite dispersed in 10ml of distilled water using ultrasonic waves, and stir for 0.5 minutes, then 3 minutes. 10 minutes,
Each sample sampled after 30 minutes and 60 minutes was filtered using a membrane filter, and the concentration of remaining calcium ions was measured by atomic absorption spectrometry to obtain a calcium ion concentration decrease curve. *Example 1 215 g of ball-milled volcanic glass (94% glass) from Ebino, 197 ml of industrial sodium hydroxide (48% NaOH) and 503 ml of distilled water were added to a reaction vessel equipped with a stirrer, and the mixture was heated at 100°C. After heat treatment at the same temperature for 4 hours, the mixture was filtered under pressure to separate insoluble matter. The resulting water glass solution had the following composition.

[Table] Industrial sodium hydroxide solution (NaOH 48
%) 600ml, 95% solids sodium hydroxide 77.3
g and 604.8 g of industrial aluminum hydroxide were placed in a reaction vessel equipped with a stirrer and heated and dissolved at 100° C. for 1 hour. When the solution was suction-filtered using a Buchner funnel equipped with 5C filter paper, a very small amount of red precipitate was separated. The sodium aluminate solution thus obtained was further passed through a decolorizing tank filled with activated carbon under pressure to remove trace amounts of colored substances. This sodium aluminate solution has the following composition.

[Table] 350 ml of the above water glass and 78.8 ml of the above sodium aluminate solution were mixed and stirred for 1 minute using a homogenizer. The gel thus obtained has the following composition in terms of oxide molar ratio. R ₂ O / SiO ₂ = 1.944 SiO ₂ / Al ₂ O ₃ = 2.0 H ₂ O / R ₂ O = 18.3 (R ₂ O = Na ₂ O + K ₂ O) This gel was placed in 8 stainless steel beakers. Aliquots of 68 g were taken out, and the top of the beaker was sealed with a silicone rubber stopper with a two-way stopper. This took 20 minutes. After aging at 25°C for 40 minutes, it was crystallized at 90°C. The crystallization rate of the A-type zeolite produced after a crystallization time of 48 minutes was 80.8%, and the color difference (ΔE value) determined from Hunter's L, a, and b values was 2.04. Further, the ion exchange rate was as shown in FIG. *Example 2 Industrial sodium hydroxide solution (48
%) and 604.8 g of industrial aluminum hydroxide were placed in a reaction vessel equipped with a stirrer and heated and dissolved at 100°C for 1 hour. The solution was filtered using a stainless steel pressure filtration device equipped with 5C filter paper. This sodium aluminate solution has the following composition.

[Table] 260 ml of water glass extracted from volcanic glass in Example 1 was added to 62.4 ml of this sodium aluminate solution, mixed, and stirred for 1 minute using a homogenizer. The gel thus obtained has the following composition in terms of oxide molar ratio. R ₂ O/SiO ₂ = 1.984 SiO ₂ /Al ₂ O ₃ = 2.0 H ₂ O/R ₂ O = 18.2 (R ₂ O = Na ₂ O + K ₂ O) This gel was poured into 8 stainless steel beakers. Take 50g each and place the upper part of the beaker into 2 pieces.
It was sealed with a silicone rubber stopper. This took 20 minutes. After further aging at 25℃ for 40 minutes,
It crystallized at ℃. The crystallization rate of the product A-type zeolite with a crystallization time of 48 minutes was 76.8%, and the color difference (△E value) calculated from Hunter's L, a, and b values was 1.70.
It was hot. Further, the ion exchange rate was as shown in FIG. *Example 3 129 g of ball-milled volcanic glass (94% glass) from Ebino was charged with 118.2 ml of industrial sodium hydroxide solution (48% NaOH) and 581.8 ml of distilled water into a reaction vessel equipped with a stirrer. 4 at temperature at 100℃
After heat treatment for a period of time, insoluble matter was separated by pressure filtration. The resulting water glass solution had the following composition.

[Table] Industrial sodium hydroxide solution (NaOH 48
%) 600ml, 95% solids sodium hydroxide 77.3
g, 604.8 g of industrial aluminum hydroxide and 1.0 g of activated carbon were placed in a reaction vessel equipped with a stirrer,
The mixture was heated and dissolved at ℃ for 1 hour. The sodium aluminate solution thus obtained was suction filtered using a Buchner funnel using 5C filter paper. The sodium aluminate solution after filtration had the following composition.

[Table] 350 ml of the above water glass and 43.3 ml of the above sodium aluminate solution were mixed and stirred for 1 minute using a homogenizer. The composition of the gel thus obtained was as follows in terms of oxide molar ratio. R ₂ O/SiO ₂ = 2.09 SiO ₂ /Al ₂ O ₃ = 2.00 H ₂ O/R ₂ O = 28.21 (R ₂ O = Na ₂ O + K ₂ O) This gel was placed in 8 stainless steel beakers. Aliquots of 57 g were taken out, and the top of the beaker was sealed with a silicone rubber stopper with a two-way stopper. This took 20 minutes. It was aged at 25°C for 40 minutes and crystallized at 90°C. The crystallization rate of the product with a crystallization time of 60 minutes is
The color difference (ΔE value) calculated from Hunter's L, a, and b values was 1.87. Further, the ion exchange rate was as shown in FIG. *Example 4 172 g of ball-milled volcanic glass (94% glass) from Ebino, 157.6 ml of industrial sodium hydroxide solution (48% NaOH) and 542.4 ml of distilled water.
The mixture was placed in a reaction vessel equipped with a stirrer and heated at 100°C for 4 hours, followed by pressure filtration to separate insoluble matter. The resulting water glass solution had the following composition.

[Table] 60.6 ml of the sodium aluminate solution whose preparation method was shown in Example 3 was added to 350 ml of this water glass, mixed, and stirred for 1 minute using a homogenizer.
The composition of the gel thus obtained was as follows in terms of oxide molar ratio. R ₂ O/SiO ₂ = 1.989 SiO ₂ /Al ₂ O ₃ = 2.00 H ₂ O/R ₂ O = 21.97 (R ₂ O = Na ₂ O + K ₂ O) This gel was placed in 8 stainless steel beakers. Aliquots of 63 g were taken out, and the top of the beaker was sealed with a silicone rubber stopper with a two-way stopper. This took 20 minutes. It was aged at 25°C for 40 minutes and crystallized at 90°C. The crystallization rate of the product with a crystallization time of 60 minutes is
At 86.6%, the color difference (ΔE value) determined from Hunter's L, a, and b values was 1.86. Moreover, the ion exchange rate was as shown in FIG. *Example 5 193.5 g of ball-milled volcanic glass (94% glass) from Ebino, 177.3 ml of industrial sodium hydroxide solution (48% NaOH) and 522.7 ml of distilled water.
The mixture was placed in a reaction vessel equipped with a stirrer and heated at 100°C for 4 hours, followed by pressure filtration to separate insoluble matter. The resulting water glass solution had the following composition.

[Table] 71.9 ml of the sodium aluminate solution shown in the preparation method in Example 3 and 2.3 ml of distilled water were added to 350 ml of this water glass, mixed, and stirred for 1 minute using a homogenizer. The composition of the gel thus obtained was as follows in terms of oxide molar ratio. R ₂ O/SiO ₂ = 1.993 SiO ₂ /Al ₂ O ₃ = 2.00 H ₂ O/R ₂ O = 19.06 (R ₂ O = Na ₂ O + K ₂ O) This gel was placed in 8 stainless steel beakers. Aliquots of 65 g were taken out, and the top of the beaker was sealed with a silicone rubber stopper with a two-way stopper. This took 20 minutes. It was aged at 25°C for 40 minutes and crystallized at 90°C. The crystallization rate of the product with a crystallization time of 60 minutes is
The color difference (ΔE value) determined from Hunter's L, a, and b values was 2.00. Moreover, the ion exchange rate was as shown in FIG. *Example 6 150.5 g of ball-milled volcanic glass (94% glass) from Ebino, 137.9 ml of industrial sodium hydroxide solution (48% NaOH) and 562.1 g of distilled water
ml was placed in a reaction vessel equipped with a stirrer, heated at 100°C for 4 hours, and filtered under pressure to separate insoluble matter. The resulting water glass solution had the following composition.

[Table] Add 56.5 ml of the sodium aluminate solution prepared in Example 3 to 350 ml of the above water glass, and distilled water.
Add 1.8ml and mix, then use a homogenizer to
Stir for a minute. The composition of the gel thus obtained was as follows in terms of oxide molar ratio. R ₂ O/SiO ₂ = 1.986 SiO ₂ /Al ₂ O ₃ = 2.00 H ₂ O/R ₂ O = 23.71 (R ₂ O = Na ₂ O + K ₂ O) This gel was placed in 8 stainless steel beakers. Aliquots of 61 g were taken, and the top of the beaker was sealed with a silicone rubber stopper with a two-way stopper. This took 20 minutes. It was aged at 25°C for 40 minutes and crystallized at 90°C. The product with a crystallization time of 60 minutes has a crystallinity of 90
%, and the color difference (ΔE value) determined from Hunter's L, a, and b values was 1.75. Moreover, the ion exchange rate was as shown in FIG. <Effects of the Invention> As described above, according to the present invention, the glass extracted in the range described above is used as a silica source, the sodium aluminate solution prepared by the method described above is used as an alumina source, and both are mixed and aged. , By performing a simple operation of heat treatment, the whiteness can be improved.
In addition, a high-quality detergent builder with a high ion exchange rate can be synthesized from volcanic glass.

[Brief explanation of drawings]

Figures 1 and 2 are graphs showing the change over time in the calcium ion concentration in the solution when 10 ml of zeolite-water slurry containing 0.1 g of zeolite was added to 250 ml of 1 mM calcium chloride solution.

Claims (1)

[Claims] 1. Water glass obtained by treating volcanic glass with a 3-6N sodium hydroxide solution is used as a silica source, and industrial aluminum hydroxide is converted into an industrial sodium hydroxide solution or an industrial sodium hydroxide solution. A sodium aluminate solution obtained by dissolving solid sodium hydroxide is used as an alumina source, and the silica source and alumina source are mixed at room temperature,
It is further aged at room temperature for 30 minutes to 4 hours, and the resulting amorphous gel is crystallized by heating at 80 to 110°C for 20 minutes to 2 hours. A method for synthesizing a builder for detergents with a good whiteness value of less than 2.2. 2 The composition of the mixture of water glass synthesized from volcanic glass and the sodium aluminate solution is Na ₂ O / SiO ₂ = 1.5 to 2.2 SiO ₂ /Al ₂ O ₃ = 1.8 to 2.2 H ₂ O / Na in terms of oxide molar ratio. The method for synthesizing a detergent builder according to claim 1, wherein ₂ O = 15 to 30.