JP3179693B2 - Method for producing crystalline inorganic builder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing an inorganic builder useful as an ion exchanger and an alkali agent, and more particularly to a method for producing an inorganic builder having excellent ion exchange properties and moisture absorption resistance.

[0002]

2. Description of the Related Art Sodium silicate has ion exchange properties higher than that of zeolite, but its use is limited because it is soluble in water. As a means for solving the problem, a crystalline calcium silicate alkali hydrate obtained by hydrothermal synthesis is disclosed in Japanese Patent Publication No. 61-59245, but has sufficient water resistance but low ion exchange capacity and substantially. Not suitable as a builder for detergents.

The calcium and magnesium components include chlorides of calcium and magnesium,
Sulfates, carbonates, phosphates and the like are used. These are dissolved in water and have high dispersibility. However, when they are added in a large amount, chlorine, nitric acid, phosphoric acid and the like generated in the calcination decomposition process can be used. Depending on the product, corrosion in the furnace, exhaust gas treatment equipment, etc., need to be considered.

[0004]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a novel method for producing an inorganic builder having excellent moisture absorption resistance and high ion exchange ability.

[0005]

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, calcium and / or Mg components having an average particle size of 0.01 to 60 μm, It has been found that the above object can be achieved by a method using magnesium hydroxide powder or a slurry thereof, and the present invention has been completed.

That is, the gist of the present invention is as follows: (1) The general formula x
During _{1 K 2 O · x 2 Na} 2 O · ySiO 2 · zMeO ( _{wherein, y / (x 1 + x} 2) = 1.0~2.1, z / y =
_{0.005~1.0, x 1 / x 2 =} 0.01~2.0,
Me = Ca and / or Mg. In the method for producing a crystalline inorganic builder having the composition represented by the formula (1), an alkali metal compound and an average particle are added to a soda water glass having a composition having a molar ratio of SiO ₂ / Na ₂ O of 2.1 to 4.2. A method for producing an inorganic builder, comprising calcining or drying and then calcining a composition obtained by mixing calcium hydroxide and / or magnesium hydroxide powder or a slurry thereof having a diameter of 0.01 to 60 μm, (2) The method according to the above (1), wherein the purity of the calcium hydroxide and / or magnesium hydroxide is 85% or more, (3)
The method according to the above (1) or (2), wherein the solid concentration of the slurry of calcium hydroxide and / or magnesium hydroxide is 50% by weight or less.

[0007]

Method of producing an inorganic builder of the embodiment of the present invention have the general formula _{x 1 K 2 O · x 2} Na 2 O · ySiO 2 · z
MeO (where y / (x ₁ + x ₂ ) = 1.0 to 2.1;
_{z / y = 0.005~1.0, x 1} / x 2 = 0.01~
2.0, Me = Ca and / or Mg. In the method for producing a crystalline inorganic builder having the composition represented by the formula (1), an alkali metal compound and an average particle are added to a soda water glass having a composition having a molar ratio of SiO ₂ / Na ₂ O of 2.1 to 4.2. It is characterized by firing or drying and then firing a composition obtained by mixing calcium hydroxide and / or magnesium hydroxide powder or slurry having a diameter of 0.01 to 60 μm.

The soda water glass used has a molar ratio of SiO ₂ / Na ₂ O of 2.1 to 4.2, preferably 2.3 to 3.7. If the ratio of SiO ₂ is smaller than this range, the viscosity tends to be high, and it is difficult to obtain a suitable mixed state. If the ratio is larger than this range, it is difficult to obtain soda water glass, and more alkali components are added. Therefore, the raw material cost tends to be high.

Examples of the alkali metal compound used as the alkali component include hydroxides, silicates, sulfates, nitrates and the like, with sodium hydroxide, potassium hydroxide, sodium metasilicate, potassium silicate and the like being preferred.

The amount of alkali metal compound to be added is determined by the type and amount of soda water glass and the desired end product composition. Examples of the form of the alkali metal compound include a powder, a granule, and an aqueous solution. From the viewpoint of solubility and operability, the alkali metal compound is preferably added as an aqueous hydroxide solution.

The calcium component and the magnesium component used are both hydroxides. Methods for producing each component include precipitation synthesis from a water-soluble salt, calcination and slaking of carbonate, slaking of quick lime, and the like. However, the present invention is not particularly limited to these. The form may be either powder or slurry. The slurry in the narrow sense refers to a suspension having fluidity, but in the present invention, a cake having no fluidity is also included in the slurry of the present invention, and this can also be used in the present invention.

The purity of calcium hydroxide and magnesium hydroxide is preferably at least 85%, particularly preferably at least 90%. When both are used together, it is preferred that both are at least 85%, particularly preferably both are at least 90%. Examples of the impurities include oxides such as silicon, aluminum, iron, magnesium, sodium, and potassium, and metal compounds such as hydroxides, carbonates, phosphates, and sulfates. The total of these impurities is less than 10% by weight. Should be fine. If it exceeds 10% by weight, the crystallization of the builder tends to be inhibited.

The average particle size of calcium hydroxide and magnesium hydroxide is 0.01 to 60 μm, preferably 0.01 to 50 μm, and more preferably 0.0 to 50 μm.
2 to 40 μm. If the average particle size exceeds 60 μm, unreacted substances tend to remain due to a decrease in reactivity, so that the reaction time in mixing becomes longer, which is not preferable in terms of productivity. On the other hand, when the particle diameter is less than 0.01 μm, although the reactivity is increased due to the increase of the surface area, it becomes difficult to industrially pulverize. Further, the finer the particles, the more easily they react with the carbon dioxide gas in the air, and thus there is a problem in stability.

The maximum particle size of calcium hydroxide and magnesium hydroxide is 100 μm or less, preferably 75 μm or less. If the maximum particle size exceeds 100 μm, unreacted substances tend to remain due to a decrease in reactivity.
The reaction time in mixing becomes long, which is not preferable in terms of productivity.

The above particle size is measured by a laser diffraction type particle size distribution analyzer, LA-700, manufactured by Horiba, Ltd. Further, the above-mentioned average particle size means a volume-based average particle size obtained from the distribution.

The method for controlling the average particle size and the maximum particle size is not particularly limited. In general, when the particle size is adjusted by pulverization, calcium hydroxide and magnesium hydroxide before mixing can be dried or wet. Pulverization may be performed, and in some cases, pulverization may be performed simultaneously with mixing with water glass and an alkali component. Alternatively, it may be prepared by a precipitation reaction of a water-soluble calcium salt. Further, oxides and silicates may be used together as calcium and magnesium raw materials as long as the present invention is not impaired.

At this time, the slurry concentration of the calcium hydroxide and magnesium hydroxide is preferably 50% by weight or less, more preferably 5 to 30% by weight. If the slurry concentration exceeds 50% by weight, the viscosity of the slurry increases, which is not preferable in terms of poor operability and dispersibility.
The medium of the slurry may be any medium having low reactivity with the powder, and water, alcohols and the like are preferably used.

The order of addition when mixing calcium hydroxide and / or magnesium hydroxide is not particularly limited, but after adding calcium hydroxide and / or magnesium hydroxide to soda water glass and mixing, an alkali component is added. In this case, dispersion of calcium hydroxide and magnesium hydroxide tends to occur, so that it is necessary to lower the slurry concentration or to design a mixture in consideration of dispersibility.

When adding calcium hydroxide and / or magnesium hydroxide, the liquid temperature is preferably 0 to 100 ° C, preferably 10 to 80 ° C, and more preferably 20 to 60 ° C.
If the temperature is lower than 0 ° C., the viscosity of the water glass increases, so that the power required for stirring increases, and the energy consumption tends to increase. If the temperature is higher than 100 ° C., the liquid in the tank becomes thick and gelled.

The method for adding the calcium hydroxide and / or magnesium hydroxide and the alkali component may be dropping on the liquid or pouring into the liquid.

In the production method of the present invention, the raw materials are mixed as described above. The container used at this time is not particularly limited as long as it can perform appropriate mixing. A tubular or loop reactor can be used.

In the present invention, the raw materials are mixed at a predetermined ratio so as to have a desired composition, and the final mixture is fired or dried and then fired. Drying is usually 100 to 40
Perform at 0 ° C. There the drying temperature is likely to require low when longer drying times than this temperature, with H ₂ higher than this range
There is a tendency that the O content becomes small and it is difficult to obtain good crystals. The drying is performed until the H ₂ O content after drying becomes 5 to 40% by weight, preferably 10 to 30% by weight. The drying method is not particularly limited as long as it can be dried to the above-mentioned water content, and a device such as a spray dryer or a tunnel dryer can be used.

The firing is usually carried out in the range of 500 to 100.
It is crystallized by firing at 0 ° C., preferably 550-750 ° C. If the heating temperature is lower than this range, the decomposition reaction of calcium hydroxide and / or magnesium hydroxide is not sufficient, so that crystallization tends to be insufficient. If it is higher than this range, the particles become coarse and the ion exchange capacity tends to decrease. The firing time is usually 0.1 to 24 hours. Such firing can be usually performed in a heating furnace such as an electric furnace or a gas furnace.

According to the production method of the present invention, the general formula x
During _{1 K 2 O · x 2 Na} 2 O · ySiO 2 · zMeO ( _{wherein, y / (x 1 + x} 2) = 1.0~2.1, z / y =
_{0.005~1.0, x 1 / x 2 =} 0.01~2.0,
Me = Ca and / or Mg. ) Can be produced, the crystalline inorganic builder having the composition represented by
The preferable one in terms of the performance is y / (x ₁ +
x ₂ ) = 1.5-2.0, z / y = 0.01-1.0,
It is those of x ₁ / x ₂ = 0.007~1.2.

[0025]

The present invention will be described in more detail with reference to the following Examples and Comparative Examples, but the present invention is not limited to these Examples and the like. In addition, the measured value in this example was measured by the following method.

The cation exchange characteristics and moisture absorption resistance in Examples and the like were 200 mesh (average particle size 30 ± 3 μm).
m: Laser diffraction particle size distribution analyzer, manufactured by Horiba, LA-
The sample ground as follows was used.

The cation exchange capacity (CEC) was determined by accurately weighing 0.04 g of the above sample, and adding an aqueous calcium chloride solution (concentration: C
100 ppm as aCO ₃ )
After stirring at 0 ° C. for 10 minutes, filtration was carried out using a membrane filter having a pore size of 0.2 μm (manufactured by Advantech, nitrocellulose), and the amount of Ca contained in 10 mL of the filtrate was measured by EDTA titration. From the value, the calcium ion exchange capacity of the sample (cation exchange capacity C
aCO ₃ mg / g). 0.5g sample for moisture absorption
Is precisely weighed in a plastic container having a diameter of 30 mm and a depth of 5 mm, and stored in a constant temperature and humidity room at 30 ° C. and a relative humidity of 90%. The amount of weight increase after storage for 24 hours was precisely weighed to determine the weight increase rate (%) of the stored powder, and evaluated according to the following criteria (ΔW). ◎: 0 to 30%, ：: 30 to 50%, Δ: 50 to 70
%, ×: 70 to 100%

Example 1 No. 3 water glass (manufactured by Osaka Keiso, SiO ₂ content 29.45)
%, Na ₂ O content 9.88%, SiO ₂ / Na ₂ O =
2.98) 15.00 kg was charged into a 20-liter container, purged with N _{2 at} room temperature, and rotated at 3 rpm with a homomixer.
While stirring at 000 rpm, 48% sodium hydroxide (manufactured by Tosoh Corporation) 6818 was weighed precisely to obtain the composition shown in Table 1.
g, 48% potassium hydroxide (manufactured by Toa Gosei) 517 g, 2
0% by weight lime milk (manufactured by Hibino Industries, maximum particle diameter 35 μm,
Average particle diameter 18.5 μm, purity 95.0% CaO conversion, 30% by weight magnesium hydroxide slurry (Ube Industries, maximum particle diameter 25 μm, average particle diameter 11.3 μm)
Was dropped at a rate of 1 liter per minute by a tube pump, and mixed for 20 minutes after the completion of the dropping. The mixture was placed in a 300 mm × 300 mm × 80 mm Ni container.
000 g, filled with hot air circulation electric furnace (Motoyama) 60
Baking was performed at 0 ° C. × 5 hours. After firing, the powder was pulverized to 200 mesh or less and powdered to obtain an inorganic builder. Table 3 shows the ion exchange characteristics of the obtained inorganic builder. This inorganic builder exhibited crystallinity, and was excellent in both ion exchange properties and moisture absorption resistance.

Examples 2 to 20 In Example 1, except that the raw materials as shown in Tables 1 and 2 were used and calcined so as to become the builder shown in Table 3,
In the same manner as in Example 1, inorganic builders 2 to 20 were obtained.
Table 3 shows the ion exchange characteristics and moisture absorption resistance of the obtained inorganic builder powder. In each case, it exhibited crystallinity, and was excellent in both ion exchange properties and moisture absorption resistance. In addition, the No. 4 water glass used was made of Osaka silicate, SiO ₂ content 23.6%, N ₂
a ₂ O content _{6.28%, SiO 2 / Na 2} O = 3.89
Met.

Comparative Example 1 No. 3 water glass (manufactured by Osaka Keiso, SiO ₂ content 29.45)
%, Na ₂ O content 9.88%, SiO ₂ / Na ₂ O =
2.98) 15.00 kg was charged into a 20-liter container, purged with N _{2 at} room temperature, and rotated at 3 rpm with a homomixer.
While stirring at 000 rpm, 48% sodium hydroxide (manufactured by Tosoh Corporation) 1614 was weighed precisely to obtain the composition shown in Table 2.
g, 48% potassium hydroxide (manufactured by Toa Gosei) 1723 g,
30% by weight lime milk (maximum particle diameter 30 μm, average particle diameter 2
1.3 μm) and a 20% by weight magnesium hydroxide slurry (maximum particle diameter 35 μm, average particle diameter 13.7 μm) were respectively dropped at a rate of 1 liter per minute by a tube pump, and mixed for 20 minutes after the completion of the dropping. 3
100mm x 300mm x 80mm Ni container
0g filling, 600 ℃ in hot air circulation electric furnace (Motoyama)
Baking for 5 hours. After firing, the powder was pulverized to 200 mesh or less and powdered to obtain an inorganic builder. Table 3 shows the ion exchange characteristics of the obtained inorganic builder. This inorganic builder had low crystallinity, and was inferior in ion exchange properties and moisture absorption resistance.

Comparative Example 2 No. 3 water glass (manufactured by Osaka Keiso, SiO ₂ content 29.45)
%, Na ₂ O content 9.88%) in a 20 liter container, purged with N _{2 at} room temperature, and stirred with a homomixer at 3000 rpm.
2474 g of 48% sodium hydroxide (manufactured by Tosoh), 517 g of 48% potassium hydroxide (manufactured by Toa Gosei), 20% by weight lime milk (maximum particle diameter 140 μm)
m, average particle diameter 80.9 μm), 35 wt% magnesium hydroxide (maximum particle diameter 120 μm, average particle diameter 71.2)
μm) was added dropwise at a rate of 1 liter per minute using a tube pump, and mixed for 20 minutes after the addition was completed. 1000 g of the mixture is charged into a 300 mm × 300 mm × 80 mm Ni container, and a hot air circulation electric furnace (manufactured by Motoyama)
At 600 ° C. for 5 hours. After firing, the powder was pulverized to 200 mesh or less and powdered to obtain an inorganic builder. Table 3 shows the ion exchange characteristics of the obtained inorganic builder. This inorganic builder had low crystallinity, and was inferior in ion exchange properties and moisture absorption resistance.

Comparative Example 3 An inorganic builder was obtained in the same manner as in Example 1 except that the raw materials as shown in Table 2 were used and calcined so as to obtain the builders shown in Table 3. Table 3 shows the ion exchange characteristics and moisture absorption resistance of the obtained inorganic builder powder.
This inorganic builder has low crystallinity, ion exchange properties,
The moisture resistance was also poor.

[0033]

[Table 1]

[0034]

[Table 2]

[0035]

[Table 3]

As shown by the above results, Examples 1 to 20
The inorganic builder obtained in is excellent in moisture absorption resistance and has high ion exchange capacity. On the other hand, Comparative Example 1 in which the purity of calcium hydroxide and magnesium hydroxide was low, Comparative Example 2 in which the average and maximum particle diameters of calcium hydroxide and magnesium hydroxide were large, and Comparative Example in which the particle diameter of calcium hydroxide was large All of the inorganic builders obtained in 3 had low crystallinity, and therefore had insufficient moisture absorption resistance and low ion exchange ability.

[0037]

According to the production method of the present invention, an inorganic builder excellent in moisture absorption resistance and having high ion exchange ability can be suitably produced.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-7-89712 (JP, A) JP-A-6-200291 (JP, A) JP-A-6-157026 (JP, A) 59245 (JP, B2) (58) Field surveyed (Int. Cl. ⁷ , DB name) C11D 3/12 C01B 33/20-33/46

Claims (4)

(57) [Claims] 1. The general formula x ₁ K ₂ O.x ₂ Na ₂ O.yS
iO ₂ · zMeO (where y / (x ₁ + x ₂ ) = 1.0
~2.1, z / y = 0.005~1.0, x 1 / x 2 =
0.01 to 2.0, Me = Ca and / or Mg. In the method for producing a crystalline inorganic builder having the composition represented by the formula (1), the molar ratio SiO ₂ / Na ₂ O is set to 2.
Soda water glass having a composition of 1 to 4.2, an alkali metal compound and an average particle diameter of 0.01 to 60 μm are both used.
A method for producing an inorganic builder, comprising calcining or drying and then calcining a composition obtained by mixing calcium hydroxide and / or magnesium hydroxide powder or a slurry thereof. 2. The method according to claim 1, wherein the purity of calcium hydroxide and / or magnesium hydroxide is 85% or more. 3. The method according to claim 1, wherein the solid content of the slurry of calcium hydroxide and / or magnesium hydroxide is 50% by weight or less. 4. The method according to claim 1, wherein the alkali metal compound is added as an aqueous hydroxide solution.