JP2000167529A - Separation of water soluble component from exhaust gas dust or incineration ash - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for separating water soluble components such as salts efficiently and simply from exhaust gas dust or incineration ash. SOLUTION: In the separation of water soluble components from exhaust gas dust or incineration ash, granules obtained from the dust or the ash are contacted with an aqueous solvent to extract the water soluble components and separated into the extraction residue and an extraction liquid. Cement dust, urban refuse incineration ash molten fly ash, sewage sludge incineration fly ash, sewage sludge incineration ash molten fly ash, and the like can be used as the exhaust gas dust or the incineration ash. The amount of the aqueous solvent to be used is, for example, 40-500 pts.wt. for 100 pts.wt. of the granules. The obtained extraction liquid can be used as a fertilizer, a road antifreeze, and the like, and the extraction residue can be used as a cement raw material and the like.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for separating water-soluble components from exhaust gas dust or incinerated ash, a method for producing a high-concentration aqueous solution of a water-soluble component contained in exhaust gas dust or incinerated ash, exhaust gas dust or incineration. The present invention relates to a method of using an aqueous solvent extract of ash and an aqueous solvent extract residue, and a method of growing a plant using an aqueous solvent extract of exhaust gas dust or incinerated ash.

[0002]

2. Description of the Related Art Dust (exhaust gas dust) accompanying exhaust gas from a cement burning furnace, a municipal refuse incinerator, a municipal refuse incinerator, a sewage sludge incinerator, a sewage sludge melting furnace, or the like is generally used as a bag filter or an electric dust collector. , And some are effectively used, but most are disposed of. For example, a cement firing furnace generates a large amount of dust mainly composed of calcareous material, potassium chloride, and the like. Fly ash from flue gas from incineration of municipal garbage, and even fly ash from molten municipal ash, contain water-soluble alkali metal chlorides, alkaline earth metal chlorides, and heavy metals, and are environmentally friendly. How to deal with these is an important issue. In addition, incineration ash such as incineration ash of city garbage and sewage sludge has the same problem.

On the other hand, in recent years, industrial waste has been used as a cement raw material, and cement dust has been remixed and used in cement. However, when industrial waste is used as a raw material for cement, salt is contained in the cement dust. Therefore, cracks and cracks are likely to occur in concrete structures using cement in which such cement dust is directly mixed. Dust generated from incineration of municipal garbage and sewage sludge is mixed with a solidifying agent such as cement and solidified, and a part of it is melted to prevent leaching of heavy metals and used as roadbed material. However, most have been disposed of by landfill. But,
Leakage of water-soluble components due to rainwater etc. at the final disposal site requires management of leachate. These methods have limited effectiveness unless they recycle waste and have to go around sooner or later.

[0004] In order to solve such a problem, there has been proposed a method of performing an appropriate treatment in advance when reusing cement dust as cement raw material. For example, Japanese Patent Application Laid-Open No. 62-252351 discloses a method in which fine dust obtained by treating a part of an exhaust gas from a cement kiln is washed with water, dewatered, and then reused as a cement raw material. Japanese Patent Application Laid-Open No. 4-77337 discloses a method for producing a low alkali cement, which comprises adding water to cement dust to form a slurry, and filtering the slurry. JP-A-6-15
No. 7089 discloses that the first p
Adding a H adjuster to form a primary slurry having a pH optimum for precipitation of the first obstacle substance in the dust; removing the first obstacle substance precipitated in the primary slurry; Adding a second pH adjuster to the secondary slurry to form a secondary slurry having a pH optimum for precipitation of the second obstacle substance.
Japanese Patent Application Laid-Open No. Hei 7-277786 discloses that, in the production of cement and a cement-based solidifying agent for burning chlorine-containing raw materials such as municipal garbage incinerators, dust in kiln exhaust gas is collected, washed, and washed. There is disclosed a method of treating kiln exhaust gas dust, which is characterized in that it is reused as a raw material and uses a washing liquid as raw material forming water.

As a method for treating incinerated fly ash, Japanese Patent Application Laid-Open No. 7-123857 discloses a method in which baked pellets of incinerated fly ash from urban garbage are washed with a salt-soluble solution to elute salts, and then the liquid fertilizer is used. There is disclosed a method for producing a horticultural culture soil in which a liquid fertilizer is mixed into the pores of the pellet by contact with the substance. JP-A-8-309309 discloses that incinerated fly ash is washed with water to remove water-soluble salts in the incinerated fly ash, and a heavy metal insolubilizing agent is added to the incinerated fly ash to add heavy metal in the incinerated fly ash. There is disclosed a method for treating incinerated fly ash, which comprises insolubilizing incinerated fly ash and heating and compressing the incinerated fly ash containing the insolubilized heavy metals to cause a hydrothermal reaction to be solidified.

However, in the method of directly washing the dust such as cement dust and incinerated fly ash with water, the separation between the liquid and the solid is poor and the extraction rate of the water-soluble component is low. Further, when it is intended to effectively use not only the washed dust but also the water-soluble components contained in the cleaning liquid, the cost becomes extremely high and the practicality is poor. That is, since water-soluble components such as salts contained in dust are abundant in fine particles of 10 μm or less, they are usually washed in a slurry state, but a large amount of water is required to obtain a stirrable slurry. And Therefore, the concentration of the water-soluble component in the obtained washing solution is very low, and it takes a lot of cost to recover and effectively use the water-soluble component. In addition, when separating dust and liquid, it is necessary to perform an operation such as taking the supernatant liquid by allowing it to stand, or centrifuging or pressing, but it takes a long time to separate the liquid by standing. Since the amount of water contained in the solid is extremely large and the amount of the supernatant is small, the separation efficiency and the recovery of the water-soluble component are very low. Also, in order to increase the salt concentration in the supernatant, even if the supernatant is repeatedly used, the specific gravity of the washing liquid gradually increases, and it takes a longer time for sedimentation and separation by standing of dust, and the supernatant liquid that can be separated The ratio becomes extremely small. In addition, even in the method of separation by centrifugation, squeezing, or the like, the water content in the obtained cake-like solid content is large, the efficiency of separating water-soluble components is low, and the size of the apparatus is also increased. Further, when the washing liquid is repeatedly reused as an extract in order to increase the concentration of the water-soluble component, there is a drawback that complicated mechanical separation must be repeated each time.

In the method of washing the fired pellets of the dust with water, the water-soluble components such as salts are sealed in the melt by firing, so that the recovery rate of the water-soluble components is low and the water-soluble components can be effectively used. Not suitable for use.

[0008] Exhaust gas dust generated by incineration of municipal waste is characterized in that it has a large content of alkaline earth metals and heavy metals, and exhaust gas dust generated when sewage sludge is incinerated is impure. In addition, they have features such as the inclusion of phosphates, and all have problems such as difficulty in water washing treatment and reuse after treatment.

[0009]

Accordingly, an object of the present invention is to provide a method for efficiently and easily separating water-soluble components such as salts from exhaust gas dust and incinerated ash.
Another object of the present invention is to provide a method capable of efficiently recovering water-soluble components from exhaust gas dust and incinerated ash without eluting heavy metals and the like. Still another object of the present invention is to provide a method for obtaining an aqueous solution of a water-soluble component having a low content of heavy metals from exhaust gas dust and incinerated ash. Another object of the present invention is to provide a method for obtaining an aqueous solution containing a high concentration of water-soluble components such as salts from exhaust gas dust and incinerated ash. Still another object of the present invention is to provide an economical and effective use of exhaust gas dust and incinerated ash.

[0010]

Means for Solving the Problems To achieve the above object, the present inventors have intensively studied a method for increasing the concentration of dust in water and reducing the moisture content of dust when the dust is brought into contact with an aqueous solvent. As a result, when the dust is granulated in advance and the obtained granules are brought into contact with an appropriate amount of water without firing, a simple operation allows an aqueous solution having a high water-soluble component concentration and a dust having a low water-soluble component content to be easily treated. It was found that a residue was obtained, and the present invention was completed.

That is, the present invention relates to a method for separating water-soluble components from exhaust gas dust or incinerated ash, wherein the granulated product obtained by granulating the exhaust gas dust or incinerated ash is brought into contact with an aqueous solvent to obtain a water-soluble component. A method for separating a water-soluble component from exhaust gas dust or incinerated ash, comprising extracting a water-soluble component and then separating an extraction residue and an extract.

[0012] The present invention also relates to a method for producing a mixture of 100 parts by weight of a granulated material obtained by granulating exhaust gas dust or incinerated ash.
A method for producing a high-concentration aqueous solution of a water-soluble component in exhaust gas dust or incinerated ash, characterized by extracting a water-soluble component by contacting with a part by weight of an aqueous solvent. The present invention further provides:
A method of using an aqueous solvent extract of exhaust gas dust or incinerated ash, wherein the extract obtained by the above separation method or a treated liquid thereof is used as a fertilizer or a road deicing agent or a raw material thereof. The present invention further provides a method for growing a plant using the extract obtained by the above separation method as a fertilizer or a raw material thereof. The present invention also provides a method for using an aqueous solvent extraction residue of exhaust gas dust or incinerated ash using the extraction residue obtained by the above separation method as a cement raw material.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The dust used in the present invention includes:
Exhaust gas dust and incinerated ash (hereinafter sometimes collectively referred to as “dust”) are included. Exhaust gas dust includes cement dust, municipal garbage incineration fly ash (exhaust gas dust generated during municipal garbage incineration), municipal waste incineration ash melting fly ash (exhaust gas dust generated when municipal garbage incineration ash is melted), sewage sludge incineration Fly ash (exhaust gas dust generated during sewage sludge incineration), sewage sludge incineration ash melting fly ash (exhaust gas dust generated when melting sewage sludge incineration ash), and the like. Further, as exhaust gas dust, steelmaking dust, non-ferrous steelmaking dust, crude oil combustion dust (crude ash) and the like can be used.
On the other hand, as incineration ash, municipal garbage incineration ash, sewage sludge incineration ash, marine oil spill incineration ash and the like can be exemplified. Exhaust gas dust and incinerated ash can be used alone or in combination of two or more.

Preferred dusts include cement dusts (chlorine-containing dusts and the like contained in exhaust gas from cement kilns).
Is included. In particular, dust in the exhaust gas is classified, and dust containing fine chlorine-rich fine particles having a particle size of several 10 μm or less is suitable. Further, municipal waste incineration fly ash, municipal waste incineration ash melting fly ash, sewage sludge incineration fly ash, and sewage sludge incineration ash melting fly ash are also preferable. These exhaust gas dusts are usually composed of fine particles having a particle size of 10 μm or less, and are collected by a bag filter or an electric dust collector.

The above-mentioned dust often contains chlorine (Cl). The form of chlorine (Cl) varies depending on the type of dust. For example, cement dust combines with potassium derived from clay and is emitted mainly in the form of potassium chloride, while municipal waste gas exhaust dust mainly emits sodium chloride and potassium chloride, as well as acidic components contained in the exhaust gas. It exists in the form of calcium chloride formed by reaction with calcium hydroxide or the like added for the purpose of neutralization.

In the dust, water-soluble components include alkali metal chlorides such as potassium chloride and sodium chloride, alkaline earth metal chlorides such as calcium chloride, and sulfuric acid such as alkali metals and alkaline earth metals. Salts, carbonates, and oxides of alkali metals are also included.

On the other hand, cement-based exhaust gas dust contains Al ₂ O ₃ , Fe as a water-insoluble component or a water-insoluble component.
0, SiO ₂ , CaO, etc., and the municipal garbage incineration fly ash often contains a poorly water-soluble metal compound such as a Pb, Zn, or Cu compound.

Preferred dusts used in the present invention include:
Dust, chlorine (C) having a content of alkali metals such as K and Na of 3% by weight or more (for example, about 3 to 50% by weight, preferably 5 to 45% by weight, particularly preferably about 7 to 40% by weight);
l) The content is 3% by weight or more (for example, 3 to 45% by weight, preferably 5 to 40% by weight, particularly preferably 7 to 40% by weight).
Dust), and the total content of the alkali metals and alkaline earth metals such as Ca is 10% by weight or more (for example, 10 to 7%).
(About 0% by weight) dust. Particularly preferred dusts have a K content of 1% by weight or more (e.g.
50% by weight, preferably 3 to 50% by weight, and more preferably about 5 to 50% by weight) of dust.

The method for granulating the exhaust gas dust or incinerated ash is not particularly limited, and a conventional granulation method such as a rolling method, a vibration method, a compression molding method, an extrusion molding method, and a spraying method is used. . Granulation is usually performed by adding a small amount of water to dust. The amount of water may be in a range that does not impair the granulation properties and the hardness of the granulated material, and is, for example, 5 to 100 parts by weight, preferably about 10 to 50 parts by weight, based on 100 parts by weight of dust. .

In general, dusts fired at a high temperature of 800 ° C. or more often contain hydraulic components (calcium oxide, calcium silicate, calcium aluminate, etc.). By granulating and curing as needed, a granulated product having sufficient strength can be obtained. Curing may be performed in the air, but may be performed in a closed container or in humid air. The curing time is, for example, about 1 day or more (about 1 to 90 days).

In the case of using dust having insufficient hydraulic components such as dust left in the air for a long period of time, granulation is performed so that the granules do not collapse when contacted with an aqueous solvent. Granulation can also be performed by adding an appropriate amount of the hydraulic component or binder. As the binder, for example, inorganic or organic binders such as cement, water glass, bentonite, calcium hydroxide, magnesium hydroxide, starch, sodium ligninsulfonate, and CMC can be used. After granulation, to suppress disintegration at the time of contact with the aqueous solvent, and to increase mechanical strength, drying,
Heating and solidification may be performed.

During granulation, heavy metal insolubilizing agent (sequestering agent)
Or an adsorbent can be added. As the heavy metal insolubilizing agent, for example, a compound capable of forming a sulfide of a heavy metal, for example, ammonium sulfide, sodium sulfide, potassium sulfide,
Ammonium bisulfide, sodium bisulfide, potassium bisulfide,
Hydrogen sulfide and the like; compounds capable of forming a dithiocarbamate of a heavy metal, such as sodium dithiocarbamate and potassium dithiocarbamate, are exemplified, but not limited thereto. Examples of the adsorbent include activated carbon. The addition amount of the heavy metal insolubilizing agent (sequestering agent) and the adsorbent is, for example, about 0.001 to 5 parts by weight, preferably about 0.005 to 0.5 parts by weight, based on 100 parts by weight of the dust. is there.

By adding a heavy metal insolubilizing agent to the granulated product, elution of heavy metals contained in the dust into the aqueous solvent can be suppressed, and a high-purity aqueous solution containing no heavy metals (for example, potassium chloride aqueous solution, etc.) ) Can be obtained. Such an aqueous solution can be suitably used for applications such as fertilizer. In addition, by allowing the granulated material to contain an adsorbent, transfer to an aqueous solvent such as colloid particles can be prevented.

The size of the granulated product can be appropriately selected in consideration of the transfer rate of the water-soluble component to the aqueous solvent, the amount of the aqueous solvent to be used, and the like, but usually the average particle size is about 0.5 to 50 mm. , Preferably about 1 to 30 mm, more preferably 2 to 30 mm.
It is about 10 to 10 mm. In the case of granules having a shape other than a spherical shape, such as a disk shape, a column shape, a donut shape, a cubic shape, and a rectangular parallelepiped shape, the size may be set in consideration of the contact area with water. It is preferable that the length and diameter of one side are within the above ranges. Particle size of granulated material is 0.5m
If it is less than m, when it is immersed in an aqueous solvent, wetting is partially delayed, and the separability at the time of separating an extract and an extraction residue tends to be poor. On the other hand, if the particle size exceeds 50 mm, it takes a long time to extract the water-soluble component, and the component tends to be damaged during handling after extraction and separation.

In the present invention, as a method of bringing the granulated material into contact with the aqueous solvent, a method of immersing the granulated material in the aqueous solvent (immersion method), circulating or flowing the extract using a pump or the like is used. Or a method in which a water-soluble component is washed out from the surface of the granule while spraying a small amount of an aqueous solvent on the granule. The contact between the granulated material and the aqueous solvent can be carried out by any method such as a fluidized bed system, a fixed bed system, a batch system, and a continuous system.

As the aqueous solvent, water is usually used, but depending on the type of the extraction component, a mixed solvent of water and a water-soluble organic solvent (alcohols, ketones, ethers, aprotic polar solvents, etc.) Can also be used. When a mixed solvent of water and a water-soluble organic solvent is used, the proportion of water is at least 50% by weight, preferably at least 80% by weight, more preferably at least 90% by weight.

As described above, the granulated material usually contains a hydraulic component, and thus solidifies firmly with the passage of time in the presence of moisture. Therefore, even if a large amount of water-soluble components such as salts are removed, the voids in the particles are replaced with water, and are hardly disintegrated, and the size of the granulated material is hardly changed.

The temperature (extraction temperature) at which the granulated material is brought into contact with the aqueous solvent (extraction temperature) can be appropriately selected within a range that does not impair operability and extraction efficiency, but is generally from 5 ° C. to the boiling point of the aqueous solvent (water Alone, at 100 ° C at normal pressure), preferably 1
It is about 5 to 90 ° C. The contact time between the aqueous solvent and the granulated material depends on the composition of the aqueous solvent, the composition and particle size of the granulated material, the ratio of the amount of the aqueous solvent to the granulated material, the extraction temperature, and the desired concentration of the water-soluble component in the extract. Usually, it is about 0.5 hour to 7 days at room temperature, preferably about 1 hour to 2 days at room temperature. To shorten the contact time, reduce the particle size, increase the difference between the concentration of the water-soluble component in the liquid (aqueous solvent or extract) and the concentration in the granulated product, or use a heated liquid. Such a method is particularly effective.

Although the liquidity of the aqueous solvent may be acidic,
The pH is preferably about 6 to 14, and for example, when it is desired to suppress elution of heavy metals, the pH is preferably adjusted to about 8 to 12. In addition, in order to remove hydrogen chloride and the like contained in cement dust and municipal garbage incineration fly ash, an alkali component may be sprayed into the gas.In such a case, the dust itself shows alkalinity. It is sufficient to use a neutral aqueous solvent.

The amount of the aqueous solvent used may be within a range that does not impair the extraction efficiency. However, in order to increase the concentration of the water-soluble component in the extract, the amount of water required for the saturated concentration of the water-soluble component is required. Is, for example, about 40 to 500 parts by weight, preferably 50 to 2 parts by weight, based on 100 parts by weight of the granulated product (dry basis).
About 00 parts by weight, more preferably about 60 to 130 parts by weight is desirable. By setting the use amount of the aqueous solvent within the above range, a high-concentration solution of the water-soluble component (for example, a saturated solution or a solution close to the saturation concentration) can be obtained, and the recovered water-soluble component can be used for various purposes. In this case, the cost required for removing the aqueous solvent can be significantly reduced.

In the immersion method, the strongest extract is obtained when the minimum amount of aqueous solvent that fills the gap between the fluids is used.
Therefore, in the case of a true spherical granule, particles having different diameters can be mixed at an appropriate ratio to lower the porosity and increase the concentration of the water-soluble component in the extract. When columnar or disc-shaped granules are used, it is preferable to make the packing dense by aligning the directions. Furthermore, the concentration of water-soluble components and the extraction efficiency can be increased by multistage extraction, countercurrent multistage extraction, and the like.

After extraction, the extract and the extraction residue (granulated material)
Separation can be easily performed at a high recovery rate by simple operations such as decantation and filtration, and each can be effectively used for various purposes.

According to the method of the present invention, the concentration of the water-soluble component in the extract can be significantly increased as compared with the case where the exhaust gas dust is extracted as a slurry. Further, usually, a substance such as a hardly soluble heavy metal or the like migrates into an aqueous solvent in the form of a colloid or a solution.In the present invention, the migration to the aqueous solvent is suppressed because the colloid particles are aggregated by granulation. Since the amount of the substance such as the heavy metal dissolved in the aqueous solvent is related to the solubility product, if the amount of the used liquid is small, the amount transferred to the aqueous phase decreases. Therefore, the purity of the water-soluble component is higher than that of the slurry extraction method, and the treatment at the time of purification is easy.
In addition, in the method of the present invention, since the granulated material is brought into contact with the aqueous solvent, the extraction liquid and the extraction residue can be rapidly separated as compared with the conventional slurry extraction method, and moreover, in one separation operation. Since a high recovery rate can be obtained, work efficiency and separation efficiency can be greatly improved. Furthermore, in the present invention, since the granulated material is subjected to the extraction operation without firing, the extraction efficiency of the water-soluble component from the granulated material is extremely high as compared with the conventional method of washing burned pellets of dust with water.

The extract may be subjected to a heavy metal insolubilization treatment, an adsorbent treatment, a neutralization treatment, or the like, if necessary. By performing the heavy metal insolubilization treatment, a trace amount of heavy metals present in the extract can be removed. In the adsorbent treatment, colloid particles and the like in the extract can be removed. Further, by performing the neutralization treatment, the usability of the extract can be increased.

The heavy metal insolubilizing treatment or the adsorbent treatment can be carried out by bringing the extract into contact with the heavy metal insolubilizing agent (sequestering agent) or the adsorbent and separating them by filtration or the like. The amount of the heavy metal insolubilizing agent and the adsorbent can be appropriately set depending on the amount of the heavy metals and the like contained in the extract, the amount of the heavy metal insolubilizing agent and the like.
It is about 0.001 to 1.0 parts by weight with respect to parts by weight.

The neutralization treatment can be performed by adding an alkali or an acid to the extract. Examples of the alkali include sodium hydroxide, potassium hydroxide, and aqueous ammonia, and examples of the acid include hydrochloric acid, sulfuric acid, nitric acid, and phosphoric acid.

The extract obtained by the method of the present invention or its treated liquid can be used as a potash fertilizer to be used for growing plants (for example, vegetables, flowers, grains, trees, etc.), or to use a small amount of sodium chloride, It can be used as a road deicing agent, which can be in the presence of calcium chloride, or as a hypochlorite ion by oxidizing and electrolyzing chloride ions in the form of an aqueous solution to be used as a disinfectant (disinfectant) when discharged into sewers. it can.

For example, since most of the cations extracted from cement dust are potassium and the remaining small amount is sodium and calcium, the extract can be used as potassium fertilizer. The extract is desirably subjected to a heavy metal insolubilization treatment to prevent soil contamination by heavy metals, or a neutralization treatment to prevent occurrence of vegetation damage. When used as potash fertilizer, it is preferable to adjust the pH within the range of 6-8.

Fly ash derived from municipal waste (fly ash from incineration of municipal waste,
Municipal incineration ash (melt fly ash) contains a large amount of water-soluble components such as potassium chloride, calcium chloride, and sodium chloride, and an aqueous solution of these mixtures can be obtained as an extract. This aqueous solution can be used as it is for the above purposes, and if necessary, the components are separated and purified by a conventional method such as partial crystallization by concentration or crystallization using the difference in solubility depending on the temperature. You can also.

The extraction residue obtained by the method of the present invention can be used as a cement raw material or a non-ferrous metal material. For example,
Extraction residue from cement dust can be used as a raw material for cement or as a non-ferrous metal raw material depending on the content of heavy metals. In addition, the extraction residue of fly ash from incineration of municipal waste generally has a high content of heavy metals, and thus can be used as a raw material for non-ferrous metals.

In addition to the above-mentioned dust, municipal ash such as a stalker furnace, steelmaking dust such as a blast furnace, a converter, and an electric furnace,
Extraction liquids and extraction residues obtained by extracting non-ferrous steel dust, sewage sludge incineration ash, and the like can also be effectively used for the above-mentioned applications depending on the type of the contained components.

[0042]

According to the present invention, water-soluble components are extracted by contacting the exhaust gas dust or granulated incineration ash with an aqueous solvent, so that water-soluble components such as salts can be efficiently and easily removed from exhaust gas dust and the like. Can be separated. Further, an aqueous solution containing a high concentration of water-soluble components such as salts can be obtained from exhaust gas dust and the like. When a heavy metal insolubilizing agent or the like is added to the granulated product, water-soluble components can be efficiently recovered without eluting heavy metals and the like from exhaust gas dust and the like. When the extract is subjected to a heavy metal insolubilization treatment or the like, an aqueous solution of a water-soluble component having a low content of heavy metals can be obtained from exhaust gas dust and the like. Further, according to the present invention, exhaust gas dust and incinerated ash can be used economically and effectively.

[0043]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples. Unless otherwise specified, “parts”
"%" And "ppm" indicating the concentration and content indicate values on a weight basis.

Example 1 In a cement manufacturing process, a high-temperature combustion gas extracted from a kiln was rapidly cooled, and 100 parts of cement dust and 20.8 parts of water collected by a dust collector were placed in a dish having a diameter of 1 m and a rim 20c.
The granulation was performed at 16 rpm and an angle of 55 ° using a tumbling granulator of m. Table 1 shows the composition of the cement dust used.

[Table 1] The obtained granules have an average particle size of 10 mm and a water content of 17.
2%. This was left to cure in a sealed container for 7 days. To 100 parts of the cured granules, 49.4 parts of water was added so that the whole of the granules was immersed in water.
The mixture was left at 24 ° C. for 24 hours to extract water-soluble components in the granules. The granules did not collapse during standing. The separation of the granulated material and the liquid is good, and the extract is separated from the granulated material (extraction residue) by decantation, and filtered using a filter cloth to remove turbidity in the obtained extract. 49.9 parts of a clear yellow alkaline liquid (pH = 12.5) were obtained. The wet cake on the filter cloth is 0.18 parts (water content: 45.0).
%), And the powdering ratio was 0.10%. The concentration of chlorine (Cl) in the filtrate was 8.71%. A part of the filtrate is taken (100 parts), and the water is evaporated to form a solid.
0 parts were obtained. Table 2 shows the composition analysis value of this solid.

[Table 2] The chlorine (Cl) recovery rate with respect to the charged chlorine (chlorine Cl in cement dust) was 52.2%, and the potassium chloride content of the recovered solid was 89%. The extraction residue has a chlorine (Cl) concentration of 5.51% (Dry) and can be used as a cement raw material. Also, a part of the filtrate is taken (100 parts), and a 0.1N aqueous sodium sulfide solution is added until no precipitate is formed (about 1.1 parts). After allowing to stand overnight, the precipitate is filtered. Different. The sulfide filtered off at this time was 3.6 parts (Wet). About 1N hydrochloric acid was added to the filtrate.
Seven parts were added to make it neutral. The water was evaporated using 100 parts of the neutralized solution to give 19.1 parts of a solid. Table 3 shows the composition analysis value of this solid.

[Table 3] The potassium chloride content of the recovered solid was 89%.

Examples 2 and 3 The amount of water added to 100 parts of the granulated product was 90.4 parts.
Each operation of extraction, decantation, filtration, and evaporation of the filtrate to dryness was performed in the same manner as in Example 1 except that the extraction time was 4 hours (Example 2) or 24 hours (Example 3). Table 4 shows the results. The results of Example 1 are also shown.

[Table 4]

Example 4 An extraction operation was performed in the same manner as in Example 1 except that the extraction temperature was 25 ° C., 50 ° C. or 83 ° C., and the extraction time was 4 hours. As a result, the concentrations of chlorine (Cl) in the extract were 3.76%, 6.03%, and 7.71%, respectively, and the extraction rate increased as the temperature increased.

Example 5 [0047] 100 parts of the granulated material (extraction residue) extracted in Example 1 was left standing at room temperature (25 ° C) for 24 hours using 49 parts of water to remain in the granulated material. Water soluble components were extracted. The granules did not collapse during standing. The separation between the granulated material and the liquid was good, and when the extract was separated from the granulated material (extraction residue) by decantation, almost no turbidity was found in the extract. 53 parts of a slightly yellow transparent alkaline liquid (pH 12.5) was obtained as an extract. This solution had a chlorine (Cl) concentration of 3.66% and a specific gravity of 1.047. The total chlorine (Cl) recovery rate of the first (Example 1) and the second (Example 5) is the chlorine (Cl) in the cement dust.
Was 74.3%.

Example 6 (Counterflow extraction experiment) 75 parts of the extract obtained in Example 5 was added to 100 parts of the granulated substance (cured granulated substance) obtained in the same manner as in Example 1. The mixture was added and left at 25 ° C. for 24 hours to extract water-soluble components in the granulated product. The granules did not collapse during standing. The separation of the granulated material and the liquid was good, and the extract and the granulated material (extraction residue) were separated by decantation. The extract was filtered using a filter cloth to remove turbidity, and 73 parts of a yellow transparent alkaline liquid (pH 12.9) was obtained. 0.19 parts of the wet cake on the filter cloth (water content: 45.0)
%), And the powdering rate was 0.11%. The concentration of chlorine (Cl) in the filtrate was 9.33%.

Examples 7 to 10 100 parts of the same cement dust and 17.0 parts of water as in Example 1 were mixed with a disk pelletizer (Fuji Powder Co., Ltd., F5 / 1).
It was extruded using 1-175) to obtain a columnar granule having a diameter of 5 mm and a length of 5 to 20 mm. The water content immediately after molding was 14.5%. The granules were air dried for 6 days. The water content after drying was 7.33%. Using the dried granules, an extraction operation was performed under the conditions shown in Table 5. The extract and the granulated product (extraction residue) were separated by decantation, and the extract was filtered. The separation of the extract from the granulated product (extraction residue) was extremely easy, and the granulated product did not collapse during the extraction. The composition of the solid obtained by evaporating the extract to dryness was analyzed to determine the chlorine (Cl) recovery rate. Table 5 shows the results.

[Table 5]

Examples 11 to 14 The extruded product obtained in Example 7 was used as a mulmerizer (Showa Engineering KK, type: SK-450-4540).
And sized. The obtained granules were spheres (ellipsoids) having a particle size of 5 to 7 mm, and the water content immediately after granulation was 14.5%. The granules were air dried for 6 days. The water content after drying is 9.3
2%. Using the dried granules, an extraction operation was performed under the conditions shown in Table 6. Extracts and granules (extraction residues)
And were separated by decantation. The separation of the extract from the granulated product (extraction residue) was extremely easy, and the granulated product did not collapse during the extraction. The composition of the solid obtained by evaporating the extract to dryness was analyzed to determine the chlorine (Cl) recovery rate. Table 6 shows the results.

[Table 6]

Examples 15 and 16 73.5 parts of dust having the composition shown in Table 7 below and 26.5 parts of water
And granulation by a method similar to that of Example 1, using 0.03 part of sodium sulfide and 0.03 part of sodium sulfide (Example 15 only). The average particle size of the granulated product was 15 mm, and the water content was 26.5%.

[Table 7] The granules were left in humid air for 17 hours and then 32.3.
Then, the mixture was left standing for 24 hours to extract the water-soluble components in the granules. The extraction temperature was gradually lowered from 90 ° C to 40 ° C. Thereafter, the extract and the granulated product (extraction residue) were separated by decantation, the extract was evaporated to dryness, and the solids obtained were analyzed for the content of KCl and Pb, and the chlorine (Cl) in the dust was analyzed. The chlorine (Cl) recovery rate, the KCl recovery amount, and the KCl purity were determined. Table 8 shows the results.

[Table 8]

Example 17 Granulation was performed in the same manner as in Example 1 except that dust having the composition shown in Table 9 below was used. The average particle size of the obtained granules is 0.5 to
4 mm, the water content was 17.0%.

[Table 9] This was left to cure in a sealed container for 50 days. To 100 parts of the hardened granules, 47.5 parts of water was added so that the whole of the granules was immersed in water, and left at 25 ° C. for 16 hours to extract water-soluble components in the granules. During this time, the granules did not collapse. The separation of the granulated material and the liquid is good, and the granulated material (extraction residue) and the extract are separated by decantation, and filtered using a filter cloth to remove turbidity in the obtained extract. 44.6 parts of a yellow transparent alkaline liquid (pH 13.3) were obtained. The wet cake on the filter cloth was 0.21 part (water content: 46.2%), and the powdering rate was 0.11%. The concentration of chlorine (Cl) in the filtrate is 1
1.15%.

Example 18 100 parts of fly ash [chlorine (Cl) content 9.86%] generated when incinerating urban garbage using a stoker furnace;
Granulation was performed according to Example 1, using 2.5 parts of slaked lime and 27 parts of water. The average particle size of the granulated product was 10 mm, and the water content was 20.8%. The granules were cured in humid air for one week. 79 parts of water was added to 100 parts of the cured granules, and the mixture was allowed to stand at room temperature for 23 hours to extract a water-soluble component in the granules. Then, a liquid and a solid were separated. At that time, the granulated product did not collapse and there was almost no powdered product. By the above operation, 69.8 parts of the extract and the wet granules 9
9.8 parts were obtained. The extract has a pH of 11.8 and a specific gravity of 1.
08, the chlorine (Cl) concentration was 5.42%, and the chlorine extraction rate (recovery rate) was 55.3%. In the extract,
Na ⁺ , K ⁺ , Ca ^{2+ and the} like were observed.

Comparative Examples 1 to 3 100 parts of the same cement dust as in Example 1 were mixed with water (25 ° C.) in an amount shown in Table 10 below to prepare a slurry liquid.

[Table 10] The obtained slurry liquids were each stirred at 25 ° C. for 1 hour, and then allowed to stand for 24 hours to extract water-soluble components in dust. In the case of Comparative Example 1, the subsequent experiment could not be performed because stirring was not possible. After standing, the liquid and the wet dust were separated. After separating the supernatant by decantation, the lower wet dust was subjected to suction filtration, and the supernatant and the filtrate obtained by suction filtration were combined to obtain an extract. Table 10 shows the time required for suction filtration (separation time). The extract was a yellow transparent alkaline liquid. Table 11 shows the amount of the extract, the chlorine (Cl) concentration in the extract, the chlorine (Cl) recovery rate, the pH of the extract, the weight of the wet cake (extraction residue) on the filter paper, and the moisture content of the wet cake (extraction residue) in Table 11. Show.

[Table 11] A part (100 parts) of the extract of Comparative Example 2 was taken and the water was evaporated to obtain 6.6 parts of a solid. Table 12 shows the composition analysis value of this solid. The potassium chloride content in the solid was 85%.

[Table 12] As a result, in the extraction by the slurry method, the amount of the extract obtained by decantation was small, and suction filtration was necessary in order to increase the recovery amount of the extract. However, the water content in the extraction residue after suction filtration is large, on the order of 40%, and it is difficult to increase the chlorine concentration in the extract, and the obtained recovered solid has a high content of lead as a heavy metal. . In each of the above examples, the time required for separating the granulated material (extraction residue) from the extract is extremely short.
In the case of the slurry method (comparative example), it took a long time. For example, when the separation operation was performed using the same apparatus on the same scale, in the case of the slurry method, suction filtration required 80 to 100 times as long as that in the example.

Example 19 In Example 1, the effectiveness of a solid (recovered potassium chloride) obtained by concentrating an aqueous solution obtained by subjecting an extract to sodium sulfide treatment and neutralization treatment as a fertilizer is confirmed. Therefore, based on the seedling test method, germination and growth and yield investigation tests were performed using komatsuna. Table 13 shows the results.
An example using a reagent grade potassium chloride was used as a control.

[Table 13] As shown in the table, when the recovered potassium chloride obtained in Example 1 was used, the germination rate on day 3 after sowing was 9 in each group.
It showed a value of 5% to 98%, and no planting symptoms such as suppression of germination were observed. The growth after germination was almost the same as in the control group.

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[Procedure amendment]

[Submission date] October 4, 1999 (1999.10.
4)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claims

[Correction method] Change

[Correction contents]

[Claims]

8. A heavy metal insolubilization process the extract, the method of separation according to any one of claims 1 to 7 for performing at least one processing selected from the adsorbent treatment and neutralizing treatment.

9. Aqueous solvent 40 of the exhaust gas dust or granules 100 parts by weight of resulting ash and granulated pH6~14
A method for producing a high-concentration aqueous solution of a water-soluble component in exhaust gas dust or incinerated ash, wherein the water-soluble component is extracted by contacting the water-soluble component with a water-soluble component.

10. An aqueous solution of waste gas dust or incinerated ash, wherein the extract obtained by the method according to any one of claims 1 to 8 or the treated liquid is used as a fertilizer, a road deicing agent or a raw material thereof. How to use the solvent extract.

11. The method of claim 1 growing method of a plant using either extract obtained by the method according to claim or the processing liquid 8 as a fertilizer or feed.

12. A method for using an aqueous solvent extraction residue of exhaust gas dust or incineration ash, wherein the extraction residue obtained by the method according to any one of claims 1 to 8 is used as a cement raw material.

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0004

[Correction method] Change

[Correction contents]

In order to solve such a problem, conventionally, when cement dust is reused as a cement raw material,
A method of performing an appropriate process in advance has been proposed. For example,
Japanese Patent Application Laid-Open No. 62-252351 discloses a method in which fine dust obtained by treating a part of an exhaust gas from a cement kiln is washed with water, dehydrated, and reused as a cement raw material. Japanese Patent Application Laid-Open No. 4-77337 discloses a method for producing a low alkali cement, which comprises adding water to cement dust to form a slurry, and filtering the slurry. Japanese Patent Application Laid-Open No. 6-157089 discloses a process in which a first pH adjuster is added to dust of a kiln combustion gas to form a primary slurry having a pH optimal for precipitation of a first obstacle substance in the dust. A step of removing a first obstacle substance precipitated in the slurry; and a step of adding a second pH adjuster to the primary slurry to form a secondary slurry having a pH optimum for precipitation of the second obstacle substance. A kiln dust processing system is disclosed. Also, Japanese Patent Application Laid-Open
Japanese Patent Publication No. -277786 discloses that dust in kiln exhaust gas is collected and washed with water, and the washed dust is reused as a raw material in the production of cement and cement-based solidifying agents for burning chlorine-containing raw materials such as municipal waste incinerators. In addition, there is disclosed a method for treating kiln exhaust gas dust, wherein a washing liquid is used as raw material forming water.

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0010

[Correction method] Change

[Correction contents]

[0010]

Means for Solving the Problems To achieve the above object, the present inventors have intensively studied a method for increasing the concentration of dust in water and reducing the moisture content of dust when the dust is brought into contact with an aqueous solvent. As a result, the dust was granulated in advance, and the obtained granulated material was burned at a specific pH without firing.
It has been found that an aqueous solution having a high concentration of a water-soluble component and a dust residue having a low content of a water-soluble component can be obtained by a simple operation when brought into contact with an appropriate amount of water having a specific value.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0011

[Correction method] Change

[Correction contents]

That is, the present invention relates to a method for separating water-soluble components from exhaust gas dust or incinerated ash, wherein the granulated material obtained by granulating exhaust gas dust or incinerated ash has a pH of 6 or more.
To 14 and 40 to 50 with respect to 100 parts by weight of the granulated product.
Contacting with 0 parts by weight of an aqueous solvent to extract water-soluble components,
Next, there is provided a method for separating water-soluble components from exhaust gas dust or incinerated ash, which comprises separating an extraction residue and an extract.

[Procedure amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0012

[Correction method] Change

[Correction contents]

According to the present invention, 100 parts by weight of a granulated product obtained by granulating exhaust gas dust or incinerated ash is adjusted to pH 6 to 14.
A method for producing a high-concentration aqueous solution of a water-soluble component in exhaust gas dust or incinerated ash, comprising contacting the aqueous solution with 40 to 500 parts by weight of a water-soluble component to extract a water-soluble component. The present invention further provides a method for using an aqueous solvent extract of exhaust gas dust or incinerated ash using the extract obtained by the above separation method or the treated liquid as a fertilizer or a road deicing agent or a raw material thereof. . The present invention further provides
There is provided a method for growing a plant using the extract obtained by the above separation method as a fertilizer or a raw material thereof. The present invention
Further, the present invention provides a method for using an aqueous solvent extraction residue of exhaust gas dust or incineration ash using the extraction residue obtained by the above separation method as a cement raw material.

[Procedure amendment 6]

[Document name to be amended] Statement

[Correction target item name] 0029

[Correction method] Change

[Correction contents]

The liquid property of the aqueous solvent is pH 6 to 14,
For example, when it is desired to suppress elution of heavy metals, pH 8 to
It is preferable to adjust to about 12. In addition, in order to remove hydrogen chloride and the like contained in cement dust and municipal garbage incineration fly ash, an alkali component may be sprayed into the gas.In such a case, the dust itself shows alkalinity. It is sufficient to use a neutral aqueous solvent.

[Procedure amendment 7]

[Document name to be amended] Statement

[Correction target item name] 0030

[Correction method] Change

[Correction contents]

The amount of the aqueous solvent used may be within a range that does not impair the extraction efficiency. However, in order to increase the concentration of the water-soluble component in the extract, the amount of water required for the saturated concentration of the water-soluble component is required. . The amount of the aqueous solvent used in the present invention is as follows.
The amount is 40 to 500 parts by weight, preferably about 50 to 200 parts by weight, more preferably about 60 to 130 parts by weight, based on 00 parts by weight (dry basis). By setting the use amount of the aqueous solvent within the above range, a high-concentration solution of the water-soluble component (for example, a saturated solution or a solution close to the saturation concentration) can be obtained, and the recovered water-soluble component can be used for various purposes. In this case, the cost required for removing the aqueous solvent can be significantly reduced.

[Procedure amendment 8]

[Document name to be amended] Statement

[Correction target item name] 0042

[Correction method] Change

[Correction contents]

[0042]

According to the present invention, a water-soluble component is extracted by contacting an exhaust gas dust or a granulated substance of incinerated ash with a specific amount of an aqueous solvent having a specific pH value. Water-soluble components can be efficiently and easily separated. Further, an aqueous solution containing a high concentration of water-soluble components such as salts can be obtained from exhaust gas dust and the like. When a heavy metal insolubilizing agent or the like is added to the granulated product, water-soluble components can be efficiently recovered without eluting heavy metals and the like from exhaust gas dust and the like. When the extract is subjected to a heavy metal insolubilization treatment or the like, an aqueous solution of a water-soluble component having a low content of heavy metals can be obtained from exhaust gas dust and the like. Further, according to the present invention, exhaust gas dust and incinerated ash can be used economically and effectively.

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Claims (11)

[Claims] 1. A method for separating a water-soluble component from exhaust gas dust or incinerated ash, wherein a granulated product obtained by granulating exhaust gas dust or incinerated ash is brought into contact with an aqueous solvent to extract a water-soluble component. And then separating an extraction residue and an extraction liquid, wherein the water-soluble component is separated from exhaust gas dust or incinerated ash. 2. The exhaust gas dust or incineration ash, at least one selected from the group consisting of cement dust, municipal waste incineration fly ash, municipal waste incineration ash melting fly ash, sewage sludge incineration fly ash, and sewage sludge incineration ash melting fly ash. The separation method according to claim 1, wherein one kind of dust is used. 3. The method according to claim 1, wherein exhaust gas dust or incinerated ash having an alkali metal content of 3% by weight or more is used. 4. The method according to claim 1, wherein exhaust gas dust or incinerated ash having a chlorine (Cl) content of 3% by weight or more is used. 5. When granulating exhaust gas dust or incinerated ash,
The separation method according to any one of claims 1 to 4, wherein a heavy metal insolubilizing agent or an adsorbent is added. 6. The separation method according to claim 1, wherein the amount of the aqueous solvent used is 40 to 500 parts by weight based on 100 parts by weight of the granulated product. 7. The separation method according to claim 1, wherein the extract is subjected to at least one treatment selected from a heavy metal insolubilization treatment, an adsorbent treatment, and a neutralization treatment. 8. Exhaust gas dust, characterized in that 100 parts by weight of granulated material obtained by granulating exhaust gas dust or incinerated ash are brought into contact with 40 to 500 parts by weight of an aqueous solvent to extract water-soluble components. Alternatively, a method for producing a high-concentration aqueous solution of a water-soluble component in incinerated ash. 9. An aqueous solution of exhaust gas dust or incinerated ash, wherein the extract obtained by the method according to any one of claims 1 to 7 or the treated liquid is used as a fertilizer or a road deicing agent or a raw material thereof. How to use the solvent extract. 10. A method for growing a plant, comprising using an extract obtained by the method according to any one of claims 1 to 7 or a treated liquid thereof as a fertilizer or a raw material thereof. 11. A method for using an aqueous solvent extraction residue of exhaust gas dust or incinerated ash, wherein the extraction residue obtained by the method according to claim 1 is used as a cement raw material.