JP2684163B2 - Sintered material made of calcium phosphite and zeolite powder and its manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a sintered material using a waste component containing calcium phosphite as a main component and a zeolite powder such as Otani stone produced from a treatment process of a plating waste liquid, which is mainly used for paving. The present invention relates to a sintered material used for a fired building material such as a tile, an exterior, and an interior tile, and a method for producing the same.

[0002]

2. Description of the Related Art Today, electroless nickel plating is widely used in the industrial world, but the amount of waste liquid reaches 100,000 tons per year, 90% of which is dumped into the ocean, which is a serious problem as a cause of environmental pollution. Has been done. Therefore, the present inventor
Previously, a method of regenerating this electroless nickel plating waste solution has been proposed (Japanese Patent Application No. 5-294053), and its outline is a salt in which hypophosphite is oxidized by electroless nickel plating film formation. To the electroless nickel plating waste liquid containing, ammonium hydroxide is added at a ratio of 0.2 to 4 mol, more preferably 1.8 to 2.2 mol, relative to 1 mol of nickel ions present in the waste liquid, Then, a phosphite treating agent containing at least one of the group consisting of hydroxides of calcium, barium or strontium is added,
The present invention is characterized by selectively removing a phosphite compound without precipitating nickel ions, and in short, provides a method of recycling a waste solution of electroless nickel plating and recycling it.

[0003]

However, regarding the regeneration treatment of this waste liquid, when removing the plating-inhibiting component with calcium hydroxide mainly used as a phosphorous acid treatment agent, about 120 g of calcium phosphite per liter of waste liquid is removed. Inevitable by-product. Then, this time, the method of reusing this calcium phosphite was examined, and various means were tried in order to complete the processing method with respect to the said electroless nickel plating waste liquid.

As a part of this, the use as a sintered body was examined paying attention to the binding property of calcium phosphite. First, the calcium phosphite was mixed with a clay component containing feldspar, porcelain stone, etc. used in ceramics. I tried firing. However, when it is heated to a high temperature and the sintering reaction proceeds, it is accompanied by a large shrinkage, leaving a large latent strain inside including cracks and bubbles, and as a result, a large dimensional change and deformation occur after cooling. Exposed. Also in terms of physical strength, the bending strength and impact resistance are low, and it cannot be used for building materials.

Therefore, as a result of intensive studies, when zeolite powder such as Otani stone was mixed with the calcium phosphite and sintered, the physical strength was excellent, dimensional change and deformation were minimal, and water retention was maintained. It was found that the characteristics of excellent properties and water permeability can be obtained, and the present invention has been completed here.

[0006]

The sintered material of the present invention is generally
5 to 50% by weight of calcium phosphite, 5 to 50% by weight of zeolite powder, and a third component such as a sintering aid are mixed and fired.

First, calcium phosphite is as described above.
In carrying out the method of recycling the waste solution of the electroless nickel plating and recycling it, the by-product can be used. The waste liquid of electroless nickel plating consists of sodium hypophosphite 23 g / l sodium phosphite 120 g / l nickel ion 5 g / l organic acid (succinic acid, citric acid, etc.) 30 g / l When sodium acid salt is removed with calcium hydroxide Ca (OH) ₂ , about 120 g of calcium phosphite is produced per liter of waste liquid, and in addition, about 1% of nickel ions and some organic acids coprecipitate. Calcium phosphite containing some coprecipitated components is collected from the liquid, dried with hot air, and pulverized with a pulverizer such as a ball mill to a powder having a particle size of about 0.2 to 0.5 mm.

The mixing ratio of the calcium phosphite is 5 to 50% as a whole weight ratio in order to maintain strength. 5%
In the following, the strength is insufficient and the merit of blending is lost.
This is because water permeability and water retention are lost in the above.

Next, as the zeolite powder, natural zeolite or synthetic zeolite can be used, but economically, natural zeolite such as Otaniishi is preferable. The Otani stone is
(Na ₂ · K ₂ ) O. Al ₂ O ₃ . SiO ₂ ⁸ . It is represented by the chemical formula of H ₂ O, has the most thermally stable clinoptilolite structure of natural zeolite, contains fine pores of 1 μm or less, and contains a large amount of crystal water. The pores containing water of crystallization cause sintering shrinkage while adsorbing the surrounding gas molecules as the water of crystallization is lost by heating, and the temperature is 1000 ° C.
As a result, even if the original lattice structure of zeolite is collapsed and the original zeolite lattice structure is collapsed, a sintered body is obtained in which ultrafine pores are still left.

The particle size of the zeolite powder is 0.5 m.
Those having a particle diameter of 0.5 mm or less are desirable, and those having a particle diameter of 0.5 mm or more are coarse and cannot withstand the strength required for a sintered material. In addition, the mixing ratio is 5 to 50% in terms of the total weight ratio in order to have both bending strength and water permeation / water retention functions. This is because if it is 5% or less, there is no water permeability / water retention function, and if it is 50% or more, the quality such as dimensional accuracy of the sintered material is not stable and the bending strength is also reduced.

Clay, glass powder, slag, etc. are mixed as the third component, but the clay and glass powder supplement the calcium phosphite and zeolite because they lack plasticity, and the slag is a sintered material. This is because the shrinkage error is suppressed in controlling the dimensional accuracy of.

After mixing and adjusting the above-mentioned components, they are molded under pressure while applying high-frequency vibration to have a predetermined size and shape,
This is heated and baked in an environment of about 1000 ° C to 1200 ° C and sintered to obtain the sintered material of the present invention. At this time, the firing temperature may be about 100 ° C. lower than the sintering temperature of ceramics or the like, but this is because the pores of the zeolite structure allow hot air to pass through, so that heat easily reaches the inside. Because.

[0013]

The sintered material of the present invention obtained by the above-mentioned manufacturing method is
It was confirmed that they completely melt each other and form a new structure. That is, first, when the cross section was observed with a scanning electron microscope according to the procedure of Example 2 described later, as shown in FIG. 1, in the sintered body (A) containing calcium phosphite and clay as main components, No clear melting was observed,
Grain boundaries of relatively large particles were observed. On the other hand, in (B) which is an example of the sintered material of the present invention, the blended raw materials were mutually melted, and no grain boundary was observed at all. As a result, it was confirmed that the sintered materials of the present invention were completely melted with each other.

Regarding the structure thereof, the one prepared according to the procedure of Example 3 was subjected to an X-ray analyzer while comparing with Otaniishi powder and calcium phosphite as raw materials for compounding,
The X-ray diffraction pattern is as shown in FIG. 2, which shows a completely different diffraction pattern from the powder of Otani stone and calcium phosphite. Was found to have a different new material structure.

Next, with respect to the physical strength of the sintered material of the present invention, the bending strength required for building materials and the like was measured based on the procedure of Example 1. As a result, the sintered material of the present invention,
Whereas porcelain ceramics are 100 N / cm or more and ceramic ceramics are 60 N / cm or more, 250
It was confirmed to have an excellent bending strength of N / cm or more. This is because, as shown in the above complete melting, the particles are fused enough to lose the grain boundary and the particles are connected to each other.In addition, calcium phosphite has a strong bonding strength due to the calcium and phosphorus components, and a strong structural force after melting. Is one factor, and the other is that the tissue having voids of pores shows a kind of flexible structure, exhibits elasticity to bending action, and obtains resistance. It is considered that the harmony between the mutual bondability and the soft structure of the tissue brings about excellent bending strength.

Further, paying attention to the large number of pores in the sintered material,
The water permeability and water retention were measured, and it was found that the sintered material of the present invention had excellent water permeability equivalent to that of sandy ground and good water retention. That is, according to the procedure of Example 4, a saturated water permeability test, a pF test, and an unsaturated water permeability test were performed on the physical properties relating to water permeability and water retention, and the results shown in Table 2, FIG. 3 and FIG. 4 were obtained. .
As a result, the saturated hydraulic conductivity was 1.25 × 10 ⁻⁴ cm / s.
ec shows a very small value, which is a value corresponding to sandy soil with relatively good water permeability, water absorption has a good saturation level of 93% at capillary saturation, and water retention is pF. From the test results, a constant value was maintained up to pF2.2, and when it exceeded this range, the water content ratio tended to decrease rapidly. This is because the sintered material of the present invention has good water retention up to a certain value of pF and retains water in the pores of the sintered material, but when it exceeds a certain value, water cannot be retained and water is discharged. It shows that the water permeability is improved, and the property of having both water permeability and water retention is obtained. From this characteristic, it is possible to derive the effect of preventing the formation of heat islands in the city as a pavement tile described later.

Finally, the sintered material of the present invention is less likely to be deformed or cracked due to less latent strain, and is excellent in stability of size and shape at the time of molding. As a result, even a relatively large building material can be obtained. Molding is possible in one step. Although about 1% of nickel ions are contained in the by-product of calcium phosphite, the metal ions function as a coloring agent when heated during firing, and give a light coloring effect to the product.

[0018]

Example 1 A mixture was prepared based on the following formulation. Otaniishi 40wt% Calcium phosphite 25wt% Clay 15wt% Glass powder 10wt% Slag 10wt% While vibrating this with a high frequency vibration device, 10 with a hydraulic molding machine
Pressurized to 0 kg / cm ² , molded into a plate of 300 × 300 × 25 mm, heated to 1160 ° C. in a firing furnace, and fired and sintered for 3 hours in total firing.

The bending strength is shown in Table 1 in comparison with that of porcelain ceramics and the like.

[0020]

[Table 1]

[0021]

[Example 2] A comparative example (A), which is a mixture of clay and calcium phosphite having the following composition, and the sintered material (B) of the present invention obtained in Example 1 were compared, and their cross sections were observed with a scanning electron microscope. I took a picture. Comparative Example (A) Formulation: Clay-50 wt%, calcium phosphite-50 wt% The results were as shown in FIG.

[0022]

[Example 3] The sintered material of the present invention obtained in Example 1, calcium phosphite produced as a raw material during the regeneration treatment of the plating waste liquid, and Oyaishi powder were subjected to an X-ray analyzer, and the X-ray diffraction pattern was obtained. I asked. The results are shown in FIG.

[0023]

Example 4 The sintered material of the present invention obtained in Example 1 was subjected to a saturated water permeation test, a pF test and an unsaturated water permeation test using a cylindrical body having a diameter of 50 mm and a thickness of 24 mm as a test sample. Saturation in the saturated water permeability test shows that the inside of the specimen is about 0.9 kgf / c.
It was carried out by reducing the pressure to m ² and passing deaerated water. The water permeation test was carried out based on JIS A1202, deaerated water was used as the test water, and the water permeation pressure was controlled at a constant water level. p
The F test was carried out based on JSFT151 of the Japan Society of Geotechnical Engineering, and the pressure applied to the specimen was a pressure method in all the steps of the test. The unsaturated water permeability test is conducted by Richard.
s method. The results are shown in Table 2.

[0024]

[Table 2]

[0025]

From the above constitution and operation, the present invention has the following excellent effects. (A) Good physical properties such as bending strength and suitable for structural use such as building materials. (B) Since it has excellent dimensional stability during molding, it can be applied to relatively large molded products. Conventionally, since the sintered material is severely deformed, it is not possible to mold a large size or a thick one, and a cutting step for size matching is required, but the product of the present invention can omit it, and Thick sintered products can be obtained in one step. (C) Since it has both water permeability and water retention, if it is applied to paving stone tiles, etc., it is easy to guide rainwater to the underground due to water permeability, and when it receives solar heat because it has water retention. , Induces a cooling action due to latent heat absorption accompanying evaporation,
The heat island phenomenon in the city can be suppressed. (D) Due to the porosity of the zeolite, the heat can reach the inside efficiently, and the sintering can be performed at a lower temperature than that of the conventional sintered material, and the operating cost can be reduced. (E) Since calcium phosphite, which is a by-product of the regeneration treatment of the electroless nickel plating waste liquid, can be effectively used, the problem of environmental pollution can be solved and the cost of the regeneration treatment of the plating waste liquid can be suppressed. .

[Brief description of the drawings]

FIG. 1 is an electron micrograph of a comparative example (A) shown in Example 2 and a sintered material of the present invention (B).

FIG. 2 is an X-ray diffraction diagram comparing the sintered material of the present invention shown in Example 3 with a raw material.

FIG. 3 is a graph showing a pF test result of the sintered material of the present invention shown in Example 4.

FIG. 4 is a graph showing an unsaturated water permeability test result of the sintered material of the present invention shown in Example 4.

Claims (8)

(57) [Claims] 1. Calcium phosphite in a weight ratio of 5 to 50%
And a zeolite powder in a weight ratio of 5 to 50% and a third component of a sintering aid. 2. Calcium phosphite in a weight ratio of 5 to 50%
And 5 to 50% by weight of zeolite powder, a sintering aid
The third component mixture was adjusted, pressure molding of, 1000 ° C. to 1
A method for producing a sintered material, which comprises sintering in a temperature range of 200 ° C. 3. A sintered material, wherein the calcium phosphite according to claim 1 or 2 is a component that is a by-product when regenerating the electroless nickel plating waste liquid. 4. A method for producing a sintered material, wherein the calcium phosphite according to claim 1 or 2 is a component that is a by-product when regenerating the electroless nickel plating waste liquid. 5. A sintered material in which the zeolite according to claim 1 or 2 is Oyaishi. 6. A method for producing a sintered material, wherein the zeolite according to claim 1 or 2 is Oyaishi. 7. A sintered material containing at least clay and glass powder in the third component according to claim 1 or 2. 8. A method for producing a sintered material, which comprises at least clay and glass powder in the third component according to claim 1 or 2.