JP2796242B2 - Manufacturing method of incinerated ash sintered body - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a chemically stable sintered body by using incinerated ash produced by treating sewage sludge and municipal waste, and more particularly to a method for producing a tile, a floor plate and the like. An object of the present invention is to obtain a sintered body that can be used for various materials such as road pavement materials and building interior and exterior materials requiring high strength.

[0002]

2. Description of the Related Art Sewage sludge and municipal waste, which have been inevitably generated in large quantities in the past, are incinerated in waste incineration plants and the like, and incinerated ash is generated as a residue. Instead of ocean dumping, effective recycling is being pursued.

In general the composition of the ash is a major component weight%, SiO ₂ is 20 to 45, Al ₂ O ₃ is 5 to 17, CaO is 5 to
40, Fe ₂ O ₃ is 5~15, P ₂ O ₅ is 0 to 20, MgO is 0-7
Occurs in the range of The melting temperature of the incinerated ash is 1
It is a high-temperature substance of 300 to 1500 ° C and contains P ₂ O ₅ , so it is highly erodible, easily becomes alkaline in constitution and chemically unstable. The composition of the incinerated ash is not constant due to the difference in the source and the treatment system.

At present, as a method of recycling incinerated ash, incinerated ash is again heated and melted at 1300-1500 ° C. to produce glass / ceramics or crushed stone by casting. Of plastics such as bricks, tiles, etc., by adding plasticizers and shaping them by pressing or the like.

[0005] However, the method of remelting incinerated ash requires a special melting furnace due to the erosion property of the molten material due to the alkali component and P ₂ O ₅ , and the operating conditions due to fluctuations in the composition of the incinerated ash. However, the product characteristics were not uniform, and the product characteristics were inhomogeneous, and in particular, lacked chemical stability.

[0006] In addition, in the method of forming and burning bricks and tiles by adding incineration ash alone or plasticizer, the incineration ash component Ca
High melting point materials such as O, SiO ₂ , and Al ₂ O ₃ increase the firing temperature.When adding a clay-based plasticizer, firing at a high temperature and for a long time is necessary to obtain a homogeneous solid solution sintered body. There are drawbacks that are necessary, and in any case, the fluctuation of the incineration ash composition complicates the management of the firing process, and the product characteristics are not stable. there were. When a plasticizer is added, the moldability is ensured, but there is a drawback that a large amount of waste incineration ash cannot be achieved.

[0007]

SUMMARY OF THE INVENTION Accordingly, the present invention reduces the calcination temperature of incinerated ash containing a large amount of high melting point material, simplifies the control of the calcination process, and maintains the product characteristics, especially chemical stability. It is another object of the present invention to provide a method for producing an incinerated ash sintered body capable of preventing secondary pollution due to elution and achieving large-scale treatment of waste incinerated ash.

[0008]

For this reason, the first invention of the present invention provides a chemical composition containing 100% by weight of incinerated ash with a chemical composition of% by weight.
SiO ₂ is 50 to 75, Al ₂ O ₃ is 1 to 3, CaO is 5 to 10, Mg
Using a glass composition in which O is 0 to 5, Na ₂ O is 5 to 15, and K ₂ O is 0 to 5, 5 to 35 parts by weight of an alkali metal oxide, an alkaline earth metal oxide, Of incinerated ash sintered body which is formed by adding 5 parts by weight or less of a compound or a mixture of a single compound or a compound of these compounds as a medium dissolving aid and sintering at 900 to 1150 ° C.

According to a second aspect of the present invention, the incinerated ash has a chemical composition of 50 to 68% by weight of SiO ₂ , 1 to 6 of Al ₂ O ₃ , and 2
To 10, MgO is 2 to 10, Na ₂ O is 3 to 18, F is 0 to 3,
K ₂ O is 0~15, B ₂ O ₃ is 0 to 5, BaO is 0 to 5, SrO 0
To 5, TiO ₂ is 0 to 3, with the addition of ceramic raw material powder composition or glass powder having the composition ZrO ₂ is 0 to 3 as a sintering promoting material,
This is a method for producing an incinerated ash sintered body in which a composition adjusted so that the CaO / (SiO ₂ + Al ₂ O ₃ ) ratio is 1.0 or less is molded and sintered at 900 to 1150 ° C.

In the first invention, for 100 parts by weight of incinerated ash,
Certain high silicate glass compositions, that is, chemical compositions in weight percent
SiO ₂ is 50 to 75, Al ₂ O ₃ is 1 to 3, CaO is 5 to 10, Mg
O is 0 to 5, Na ₂ O 5-15, the K ₂ O is added to 5-35 parts by weight of glass composition as medium welding material is 0 to 5, incineration ash and fused at low temperature To form a solid solution.
That is, a low-viscosity glass melt is generated between the particles of the incineration ash at a low temperature, and they are mutually dissolved to integrate the particles.
The glass composition in this range has a softening temperature of 600 to 700 ° C and a melting temperature of around 1000 ° C. Therefore,
The glass composition starts to soften from 600 to 700 ° C. and starts to fuse with the incinerated ash, and begins to form a solid solution in the melting temperature range around 1000 ° C. However, since the amount of incinerated ash is large, the melt And the sintering progresses, requiring a higher temperature and time.

Therefore, alkali metal oxides, alkaline earth metal oxides (Na ₂ O, K ₂ O, L ₂ O, BaO, SrO), fluorides (K
F, NaF, CaF ₂ , K ₂ SiF ₆ , Na ₂ SiF ₆ ) and a mixture of a single or a composite of these compounds are added as a solvent for the solvent in an amount of 5 parts by weight or less. These medium-solubilizing agents not only have a medium-solubilizing effect on all the components of the sintered body but also have an effect of significantly lowering the viscosity and increasing the supply and penetration of the melt between the particles. It acts to lower the melting point of each component of the composition by volatilizing at the time of formation. Due to the synergistic action of the medium-soluble material and the medium-soluble auxiliary material of such a glass composition, 900 to 1150 ° C.
By holding for 2 hours, sintering is completed and a dense sintered body can be obtained.

The composition obtained by adding the glass composition and the auxiliary solvent to the incinerated ash is formed by a wet or dry method, and is formed with a binder such as an organic binder or a clay plasticizer as required. However, as a conventional molding binder, a solution of 1% or less of organic CMC, acrylic polymer, PVA, starch, etc., kaolin as an inorganic plasticizer,
Bentonite, water glass and the like are mixed in an amount of 0 to 20 parts by weight based on 100 parts by weight of the incinerated ash.

The reason why the glass composition is added in the range of 5 to 35 parts by weight with respect to 100 parts by weight of the incinerated ash is that when the amount is 5 parts by weight or less, the supply of the melt which can obtain the medium dissolving effect is small. This is because if it is 35 parts by weight or more, the amount of incinerated ash used is small, so that large-scale treatment cannot be achieved. Its chemical composition is 50% to 75% by weight of SiO ₂ and Al
₂ O ₃ is 1-3, CaO is 5-10, MgO is 0-5, Na ₂ O is 5
15, the K ₂ O is 0 to 5 is 600-700 ° C
At about 1000 ° C.

The alkali metal oxides, alkaline earth metal oxides, fluorides, and single or complex mixtures of these compounds are used in an amount of 5 parts by weight or less because of adjusting the viscosity of the incinerated ash composition and mixing the incinerated ash. This is for lowering the melting point of each component of the product. Therefore, these solvent-soluble auxiliary materials need not be added, but are desirably 0.1 to 5 parts by weight.

In the second invention, the chemical composition is 100% by weight of the incinerated ash, the chemical composition is% by weight, and SiO ₂ is 50 to 68 and Al ₂ O ₃ is 1%.
To 6, CaO is 2 to 10, MgO is 2 to 10, Na ₂ O is 3-1
8, F is 0 to 3, K ₂ O is 0 to 15, B ₂ O ₃ is 0 to 5, the BaO
0.5 to 5, SrO is 0.5 to 5, TiO ₂ is 0 to 3, ZrO ₂ 0 to 3
The reason for adding the ceramic raw material powder composition or the glass powder having the following composition is to promote sintering. The material form is
It is a powder mixture in which ceramic raw materials matching the composition are blended, or glass powder matching the composition. The ceramic raw material powder is desirably calcined in advance at 700 ° C. or higher, and volatilization and removal of intervening moisture and water of crystallization, so that the sintering activation is large.

A ceramic raw material composition or glass powder is added as a sintering accelerator, and its CaO / (SiO ₂ + Al ₂ O ₃ ) ratio is 1.
It is adjusted to be 0 or less because the alkali component (Ca
O) and the acidic component (SiO ₂ + Al ₂ O ₃ ) are added to correct the solid solution safely to neutralize the structure of the molded product, improve the chemical stability, and improve the low-temperature sintering. The low-temperature sintering can be performed satisfactorily in the same manner as in the first invention.
The softening started at 0 ° C and started to fuse with the incineration ash, and the melting point of each component of the blend was lowered by adding a sintering accelerator to 1000.
This is because the incineration ash starts to form a solid solution around ゜ C and sintering is completed at about 1100 ゜ C. In addition, the amount of the ceramic raw material composition or glass powder as the sintering accelerator is appropriately 5 to 35 parts by weight in the incinerated ash compound molded article, and the amount of incinerated ash is reduced above that, and the amount of the incinerated ash decreases. It is unsuitable because it cannot be processed in large quantities, and below that, it is difficult to neutralize and unsuitable.

[0017] Incidentally, SiO ₂ in its chemical composition by weight percent ceramic raw material powder composition or glass powder 50~68, Al ₂ O ₃ is 1
6, CaO 2-10, MgO 2-10, Na ₂ O 3-18,
F is 0 to 3, K ₂ O is 0~15, B ₂ O ₃ is 0 to 5, BaO is 0
5, SrO is 0 to 5, TiO ₂ is 0 to 3, the ZrO ₂ was a composition is 0 to 3, softening of the SiO ₂ minutes in many low temperature to neutralize,
This is because the melting becomes good.

The composition obtained by adding the raw material powder composition or glass powder to the incinerated ash is formed by a wet or dry method.
If necessary, it is molded with a binder such as an organic binder or a clay plasticizer. As a conventional molding binder, a solution of 1% or less of organic CMC, acrylic polymer, PVA, starch, etc., inorganic plastic is used. Kaolin as a material,
Bentonite, water glass and the like are mixed in an amount of 0 to 20 parts by weight based on 100 parts by weight of the incinerated ash.

[0019]

According to the first aspect of the invention, the glass composition of the added solvent material begins to soften from 600 to 700 ° C. and starts to fuse with the incineration ash, and is compounded by the addition of a solvent dissolving aid such as an alkali metal oxide. The incineration ash begins to form a solid solution at about 1000 ° C. by lowering the melting point of each component, and sintering is completed up to about 1150 ° C. to obtain a dense sintered body.

In the second invention, a ceramic raw material composition or glass powder was added as a sintering accelerator in such a manner that the CaO / (SiO ₂ + Al ₂ O ₃ ) ratio was 1.0 or less. The composition begins to soften from 600 to 700 ° C and begins to fuse with the incinerated ash, begins to dissolve incinerated ash around 1000 ° C, completes sintering by about 1150 ° C, and neutralizes As a result, a dense sintered molded product with improved chemical stability can be obtained.

The composition of the sintering accelerator is anorthite (CaO.Al ₂ O ₃ .2SiO ₂ ), β-wollastonite (CaO.S
It contains iO ₂ ) which precipitates crystals and contains crystal nucleus components TiO ₂ and ZrO ₂ which promote the precipitation of these crystals. For this reason, since the composition of the incineration ash is SiO ₂ -CaO-Al ₂ O ₃ , the glass phase formed by the composite sintering of this sintering accelerator with SiO ₂ -CaO-MgO-F is a diopside. (CaO ・ MgO ・ 2Si
O ₂ ), wollastonite, calcium silicate fluoride (Ca _{2 to 4} Si _{1 to 2} O _{2 to 7} F ₂ )
Either one of these microcrystals or a needle-like crystal is precipitated in a symbiotic state in the sintered body, and has an effect of reinforcing the strength. Therefore, it can be used not only for road pavement materials but also for building interior and exterior materials and structural materials that require high strength.

[0022]

Embodiments 1 to 4 Hereinafter, embodiments will be described. Example 1 of the first invention is based on 100 parts by weight of incinerated ash A,
35 parts by weight of a high-silicate glass as a solvent, 3 parts by weight of feldspar, 1.5 parts by weight of barium fluoride, and 10 parts by weight of a clay as a binder, and kneading by adding 10 to 20 parts by weight of water. Then, press molding was performed at a molding pressure of 300 kg / cm ² to obtain a green body of 65 × 65 × 10 mm. This is dried sufficiently, put in a heating furnace and heated at a rate of 150 ° C./hour,
After firing at 1100 ° C. for 1 hour, the furnace was naturally cooled.

The composition is shown in Table 1 together with Examples 2 to 4 of the first invention, and Table 2 shows the chemical components of the incinerated ash A, the incinerated ash B and the high silicate glass. Table 3 shows the characteristics of the sintered bodies obtained by changing the heating conditions.

[0024]

[Table 1]

[0025]

[Table 2]

[0026]

[Table 3]

The sintered bodies of Examples 1 to 4 of this example were all high in strength and good in chemical stability.

[0028]

Embodiments 5 to 8 This is an embodiment of the second invention, in which the incineration ashes A and B shown in Table 2 are used and the component ratios shown in Table 4 are used.
A sintering accelerator A is blended. Sintering promoting material A is feldspar (K ₂ O, Al
₂ O ₃ , SiO ₂ ) Serdian (BaO, Al ₂ O ₃ , SiO ₂ ), magnesite (MgO), fluorite (CaO, F), borax (Na ₂ O, B ₂ O ₃ ), sodium fluoride ( Na ₂ O, F), titanium oxide (TiO ₂ ), light ash (Na ₂ O), barium carbonate (BaO), soda-lime glass (SiO ₂ , CaO, Na ₂ O, A
l ₂ O ₃ ), which was calcined at 800 ° C. for 3 hours and then pulverized to a CaO / (SiO ₂ + Al ₂ O ₃ ) ratio of 0.1.
It was prepared to be ０．７0.7. The composition is shown in Table 5 as Examples 5 to 8.

Then, 10 to 20 parts by weight of water was added and kneaded, followed by press molding at a molding pressure of 300 kg / cm ² , and 65 × 6
A green body of 5 × 10 mm was obtained. This was sufficiently dried, placed in a heating furnace, heated at a rate of 150 ° C./hour, and treated with the heating conditions shown in Table 6 together with Examples 5 to 8, and then naturally cooled in the furnace. As shown in Table 6, the obtained sintered body was a good sintered body having a bending strength of 400 kg / cm ² or more.
As a result of analysis by a line diffraction method, precipitation of a composite crystal phase of diopside and calcium silicate fluoride was observed.

[0030]

[Table 4]

[0031]

[Table 5]

[0032]

[Table 6]

[0033]

Embodiments 9 to 12 This is another embodiment of the second invention, in which the incineration ashes A and B shown in Table 2 are used and the component ratios shown in Table 7 are obtained.
A sintering accelerator B is blended. Sintering accelerator B is feldspar (K ₂ O, Al
₂ O ₃ , SiO ₂ ) Silica stone (SiO ₂ ), magnesite (MgO), fluorite
(CaO, F), borax (Na ₂ O, B ₂ O ₃ ), sodium fluoride (Na ₂ O,
F), titanium oxide (TiO ₂ ), light ash (Na ₂ O), barium carbonate (Ba
O), which was melted at 1350 ° C. for 2 hours, and the molten glass was prepared by water granulation. The composition is shown in Table 8 as Examples 9 to 12.

Then, 10 to 20 parts by weight of water was added and kneaded, followed by press molding at a molding pressure of 300 kg / cm ² , and 65 × 6
A green body of 5 × 10 mm was obtained. This was sufficiently dried, placed in a heating furnace, heated at a rate of 150 ° C./hour, and treated with the heating conditions shown in Table 9 together with Examples 9 to 12, and then naturally cooled in the furnace. As shown in Table 9, the obtained sintered body is a good sintered body having a bending strength of 400 kg / cm ² or more.
As a result of analysis by X-ray diffraction, precipitation of a composite crystal phase of diopside and calcium silicate fluoride was recognized.

[0035]

[Table 7]

[0036]

[Table 8]

[0037]

[Table 9]

[0038]

According to the first aspect of the present invention, the glass composition of the added solvent material starts to soften from 600 to 700 ° C. and starts to fuse with the incineration ash, thereby dissolving the alkali metal oxide or the like in the solvent. Lowering the melting point of each component of the formulation by adding
The incineration ash begins to form a solid solution at about 0 ° C., and sintering is completed by about 1150 ° C., so that a dense sintered body can be obtained at low cost. In claim 2, the ceramic raw material composition or glass powder is used as a sintering accelerator in the form of CaO / (SiO ₂
+ Al ₂ O ₃ ) ratio was adjusted to be 1.0 or less, so that the ceramic raw material composition or glass powder was 600 to 70%.
Softening starts at 0 ° C and fusion with incineration ash starts.
The incineration ash began to form a solid solution at around 00 ° C, sintering was completed by about 1150 ° C, and a dense sintered product with neutralization and improved chemical stability could be obtained. It becomes high strength and its use is expanded.

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Tadashi Ozeki 136, Shiogusacho, Seto-shi, Aichi Prefecture Inside Otake Serum Co., Ltd. References JP-A-53-88657 (JP, A) JP-A-55-27041 (JP, A) JP-A-2-12961 (JP, A) JP-A-4-278110 (JP, A) JP-A-5 -58707 (JP, A) JP-A-7-155728 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) B09B 3/00 C04B 35/00

Claims (2)

(57) [Claims] To 1. A ash 100 parts by weight, SiO ₂ Chemical composition in wt% is 50~75, Al ₂ O ₃ is 1 to 3, CaO is 5 to
10, MgO is 0-5, Na ₂ O 5-15, 5-35 parts by weight of the glass composition K ₂ O is 0 to 5 as a medium welding material, alkali metal oxides, alkaline earth metal oxides , A fluoride and a mixture of a single or a complex of these compounds are added as a medium-solubilizing agent in an amount of 5 parts by weight or less, molded and sintered at 900 to 1150 ° C. Production method. 2. The incinerated ash has a chemical composition of 5% by weight and a SiO ₂ of 5% by weight.
0-68, Al ₂ O ₃ is 1-6, CaO is 2-10, MgO is 2
10, Na ₂ O is 3 to 18, F is 0 to 3, K ₂ O is 0 to 15, B ₂
O ₃ is 0-5, BaO is 0-5, SrO is 0-5, TiO ₂ is 0
3. A ceramic raw material composition or glass powder having a composition in which ZrO ₂ is 0 to 3 is added as a sintering accelerator, and the CaO / (SiO ₂
+ Al ₂ O ₃ ) A method for producing an incinerated ash sintered body, comprising molding a composition adjusted to have a ratio of 1.0 or less and sintering at 900 to 1150 ° C.