JPH09314099A - Treating agent for heavy metal-containing waste and stabilizing method of heavy metal-containing waste - Google Patents

Abstract

PROBLEM TO BE SOLVED: To completely stabilize a heavy metal-containing waste such as a general or industrial waste or a contaminated soil to prevent secondary pollution by preparing a treating agent for the heavy metal-containing waste, in which a latent hydraulic material is incorporated. SOLUTION: At the time of stabilizing the incineration ash of a municipal waste or the industrial waste, containing the heavy metals, the treating agent for the heavy metal-containing waste, in which the latent hydraulic material is incorporated, is used. As the latent hydraulic material, at least one kind selected from a blast furnace water granulated slag, a converter slag, lime stone and silica fume is mentioned. And a dispersing agent and water are incorporated in the treating agent and as the dispersing agent, a high polymer having a carboxylic group or the salt in the molecule is used. Further, a water soluble high polymer or a water soluble sulfide is incorporated in the treating agent as a thickener and as the water soluble sulfide, one or more kinds selected from CaSx (in the formula, (x) expresses 1-5) is used and calcium superphosphate is incorporated as a water soluble phosphate.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to insolubilizing heavy metals contained in general or industrial waste, contaminated soil and sludge,
The present invention relates to a waste treatment agent effective for stabilizing treatment and a treatment method thereof. More specifically, municipal waste, industrial waste,
A treatment agent for waste that is effective for insolubilizing and stabilizing heavy metals contained in incinerator ash and waste generated from sludge incinerators and melting furnaces, and heavy metals contained in contaminated soil, and it Related to the treatment method.

[0002]

2. Description of the Related Art In recent years, as wastes generated from cities and factories have increased, wastes containing heavy metals have been required to be sufficiently detoxified for environmental measures. In particular, incineration ash and industrial waste of municipal solid waste containing heavy metals are subject to strict regulations on their treatment and disposal as specially controlled waste.

[0003] Conventionally, when disposing of waste containing heavy metals, a method has been adopted in which the waste is mixed with cement and, if necessary, water is added and kneaded to prevent the elution of heavy metals and the like and stabilize the landfill. . However, the elution standard value of heavy metals from waste that undergoes landfill treatment applied from 1995 is 0.3 mg in the elution test based on the Environmental Agency Notification No. 13 in the case of lead, which is the most difficult to stabilize. /
1 or less, and cadmium and hexavalent chromium are each 0.
Although it is obliged to stabilize at 3 mg / l and 1.5 mg / l or less, it is difficult to clear this standard with cement alone.

[0004] In the case of mixing and hardening waste, which is a typical cement, that is, ordinary portland cement, calcium hydroxide produced in the hydration process accelerates hardening of the cement, but is excessive. The generated calcium hydroxide raises the pH of the mixture of waste and cement and increases the solubility of heavy metal ions such as lead, which is an amphoteric element, so that the heavy metal stabilizing effect originally thought to be possessed by cement is large. It is thought that this is because it is damaged.

Further, when cement is used, it is good if it is used continuously, but when the treatment is interrupted, the treated products which remain unless the facilities such as a mixer and a kneader are washed. There is a problem that it solidifies on the vessel wall.

Further, it has been attempted to treat heavy metal ions by a chemical treatment with a sulfur-containing chelating agent or the like to stabilize them, and according to this, it is possible to stabilize below the elution standard value. However, such a drug is not only expensive, but also because the retention of heavy metal ions after the stabilization treatment is insufficient, even if a sufficient heavy metal stabilization effect is exhibited immediately after the treatment, There is a problem that the elution amount of heavy metal ions increases.

[0007]

As described above, it is not only difficult to stabilize heavy metal ions below the elution standard by the conventional treatment agent and treatment method for heavy metal-containing waste, but also stable stabilization is not possible. However, there is a problem in the sustainability and durability of the retention, and there is a concern about secondary pollution over time. An object of the present invention is to prevent heavy metal-containing waste from being stabilized by stabilizing the elution of heavy metal ions below a standard value, and further maintaining the effect of stabilizing the heavy metal ions to completely prevent secondary pollution. It is to provide a treating agent and a treating method capable of

[0008]

In view of these circumstances, the inventors of the present invention have earnestly studied for a treating agent and a treating method capable of completely stabilizing a heavy metal-containing waste, and as a result, have completed the present invention. .

That is, the present invention provides (1) a treatment agent for heavy metal-containing waste, which contains a latent hydraulic substance,
(2) Potential hydraulic material is granulated blast furnace slag, converter slag,
The heavy metal-containing waste treatment agent according to (1) above, which is at least one selected from coal ash and silica fume.
(3) The treatment agent for heavy metal-containing waste according to (1) above, wherein at least one of the latent hydraulic substances is granulated blast furnace slag.
(4) The above (1) -containing a dispersant and water.
The heavy metal-containing waste treatment agent according to any one of (3), (5) the heavy metal-containing waste according to (4) above, wherein the dispersant is a polymer having a carboxylic acid group or a salt thereof in the molecule. Treatment agent, (6) a treatment agent for heavy metal-containing waste according to the above (4) or (5), further comprising a water-soluble polymer as a thickener, and (7) a treatment agent further containing a water-soluble sulfide The heavy metal-containing waste treatment agent according to any one of (1) to (6), and (8) the water-soluble sulfide has the formula (1): CaS _x (1) (where x in the formula (1) is 1). The number of the heavy metal-containing waste treatment agent according to (7) above is one or more selected from the compounds represented by

(9) The treatment agent for heavy metal-containing waste according to any one of (1) to (8) above, which further comprises at least one water-soluble phosphate, and (10) the water-soluble phosphate. The treatment agent for heavy metal-containing waste according to the above (9), which is lime superphosphate,
(11) Heavy metal-containing waste, wherein the treatment agent according to any one of the above (1) to (10), and optionally water is added and mixed and kneaded. Treatment method, (12) Heavy metal-containing waste is selected from incineration ash of refuse incinerator, industrial waste, contaminated soil, or sludge 1
The present invention relates to the method for treating heavy metal-containing waste described in (11) above, which is more than one kind.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below.

The latent hydraulic substance used as an essential component in the present invention is a substance that is not cured only by mixing with water or an aqueous solution containing an acid and an acid salt, but is cured by addition of a stimulant such as an alkali. Say. Specific examples of the latent hydraulic material that can be used include granulated blast furnace slag, converter slag,
Examples thereof include coal ash, silica fume, volcanic ash, and chaff ash. Of these latent hydraulic substances, granulated blast furnace slag, converter slag, coal ash and silica fume are preferable, and granulated blast furnace slag is particularly preferable. These latent hydraulic substances can be used alone or in combination of one or more.

When granulated blast furnace slag is used as the latent hydraulic material, granulated blast furnace slag having a Blaine specific surface area of 2,000 cm ² / g or more can be used, but preferably 4,000 cm ² / g. Or more, more preferably 8,000 cm ² / g or more, particularly preferably 10,000
To use those of 0cm ² / g~13,000cm ² / g.

Although the mechanism of the stabilizing effect of the heavy metal ion of the latent hydraulic substance is not always clear, it is considered that the latent hydraulic substance itself has a heavy metal ion adsorbing ability and the like. In addition, the alkali ion contained in the heavy metal-containing waste causes the hardening reaction of the latent hydraulic substance to proceed, and various hydration products resulting from the solid metal have a stronger and continuous exchange ability and adsorption ability for the heavy metal ion. It is also considered to be expressed in.

When stabilizing the heavy metal-containing waste with a latent hydraulic substance, the blending amount of the latent hydraulic substance is the kind of the latent hydraulic substance to be used and the kind and amount of the heavy metal contained in the heavy metal-containing waste. 0.1 to 60 per 100 parts by weight of heavy metal-containing waste, depending on the lead content.
Parts by weight, preferably 1 to 40 parts by weight, more preferably 1.5 to 20 parts by weight.

The heavy metal-containing waste treating agent of the present invention is usually in a powder state, but it can be handled as a slurry-like liquid composition. That is, by adding a dispersant and water or an aqueous solution containing an acid and an acid salt to a latent hydraulic substance, and optionally adding a water-soluble polymer as a thickener, and mixing and kneading the slurry-like present invention. Can be obtained.

The dispersant used in preparing the liquid composition serves to uniformly disperse the particles. As the dispersant, those which are water-soluble and can uniformly disperse the latent hydraulic substance, for example, formalin condensate of naphthalene sulfonic acid, melamine sulfonic acid formalin condensate, cement such as lignin sulfonic acid condensate, dispersant for concrete. However, a polymer having a carboxylic acid group or a salt thereof in the molecule is preferable. Specific examples that can be used include poly (meth) acrylic acid, (meth) acrylic acid / maleic acid copolymers, (meth) acrylic acid / maleic acid / vinyl ether copolymers, (meth)
Acrylic acid itaconic acid, styrene copolymers, acrylic acid-itaconic acid-methacrylate-styrene copolymer, & C ₅ -C ₈ olefin copolymers of maleic anhydride acid, and alkali metal salts thereof and, (meth) Acrylic acid, maleic acid, itaconic acid, styrene, copolymers of monomers copolymerizable with vinyl ether, and water-soluble alkali metal salts thereof may be mentioned. It is not limited to coalescence. Further, two or more kinds of these dispersants may be used in combination. Here, (meth) acrylic acid means acrylic acid or methacrylic acid.

The above-mentioned copolymerizable monomers include hydroxyethyl (meth) acrylate, N-vinylpyrrolidone, styrenesulfonic acid and its alkali metal salts, allylsulfonic acid and its alkali metal salts, methallylsulfonic acid and Its alkali metal salts, vinyl acetate,
Methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, acrylonitrile,
Examples thereof include (meth) acrylic amide, ethylene, propylene, and isobutylene, but are not limited to the monomers listed here.

The molecular weight of the dispersant is preferably 1,000.
To 200,000, more preferably 3,000 to 10
It is 0000. Molecular weight is 1,000 or less and 20
If it is more than 10,000, the dispersibility is deteriorated, which is not preferable.

The amount of these dispersants used varies depending on the type and particle size of the latent hydraulic substance used, but is usually 0.1 to 10 parts by weight, preferably 100 parts by weight, based on 100 parts by weight of the total latent hydraulic substance. 0.3 to 7 parts by weight, particularly preferably 0.
5 to 5 parts by weight. When the amount of the dispersant used is less than 0.1 part by weight, the dispersibility is deteriorated depending on the amount of water added, which is not preferable. Even if it is used in an amount of 10 parts by weight or more, the effect corresponding to the added amount cannot be obtained, which is economically disadvantageous.

The amount of water used varies depending on the type and particle size of the latent hydraulic substance used, but the total amount of latent hydraulic substance is 1
It is usually 10 to 60 parts by weight, preferably 15 to 40 parts by weight, and more preferably 18 to 30 parts by weight with respect to 00 parts by weight. If it is less than 10 parts by weight, it is difficult to make it liquid, which is not preferable. If it is used in an amount of 60 parts by weight or more, dispersibility can be obtained, but undesirably, storage stability deteriorates.
Generally, when the amount of the dispersant added is increased, the amount of water required for dispersion tends to be small.

When the treating agent of the present invention has a liquid composition,
If necessary, it contains a thickener. The thickener has the effects of improving the viscosity of the liquid composition and suppressing the settling of powder particles of the latent hydraulic substance dispersed therein (improvement of storage stability). The thickener is not particularly limited as long as it is water-soluble, polyacrylic acid salt, polyacrylamide, acrylic acid-acrylamide copolymer salt, methyl cellulose,
Specific examples of hydroxyethyl cellulose, hydroxypropyl cellulose, cellulose derivatives such as hydroxypropyl methyl cellulose, polyethylene oxide, polypropylene oxide, polyvinylpyrrolidone, polyvinyl alcohol, xanthan gum and the like having relatively high molecular weight can be used, but are not limited thereto. Not something. Further, two or more kinds of these thickeners may be used in combination.

The molecular weight of the thickener used depends on the type of thickener and cannot be uniformly stated, but the viscosity of the aqueous solution thereof can be used as a guide for selection. For example, taking a 0.2 wt% aqueous solution of a thickener as an example, a thickener having a viscosity of the aqueous solution of 50 cps or more is preferable.
Those having cps or more are more preferable, and those having 150 cps or more are particularly preferable. The amount of the thickener used is usually 0.01 to 3 with respect to 100 parts by weight of water to be added.
Parts by weight, preferably 0.02 to 1 part by weight.

Since the treatment agent for waste containing heavy metals of the present invention contains a latent hydraulic substance as a main component, it has a drawback that it cannot be used because it solidifies by absorbing moisture during use or during storage as in the case of using cement. This is advantageous in facility maintenance because the solidified substance does not adhere to the inner wall of the device and become unusable unless it is washed with water within several hours after use. Furthermore, the treatment agent for heavy metal-containing waste of the present invention can be handled as a powder, but when powder work is disliked, it can be handled as a slurry liquid composition as described above. ing. Besides, it can be handled as this liquid composition,
Since it has a smaller volume than that of the powder, it does not require a large facility such as a silo, and has the advantage of facilitating mixing and kneading with heavy metal-containing waste.

In one embodiment of the present invention, it is preferable to use a water-soluble sulfide and / or a water-soluble phosphate in addition to the latent hydraulic substance. It is said that water-soluble sulfides stabilize the heavy metals by reacting the sulfide ions generated in the presence of water with the heavy metal ions in the waste containing heavy metals to form sulfide heavy metal salts that are sparingly soluble in water. By using it together with a hydraulic substance, a stabilizing effect on heavy metals, which has hitherto not been obtained, can be obtained.

Specific examples of the water-soluble sulfide that can be used include:
Examples thereof include sodium sulfide, potassium sulfide, calcium sulfide, sodium hydrosulfide, urea hydrosulfide, and a sulfur-containing organic chelating agent. The following formula (1): CaS _x (1) (where x is 1 to 5) It is preferable to use one kind or a mixture of two or more kinds selected from the compounds represented by

These water-soluble sulfides may be used as a mixture of two or more kinds, and it is preferable to use polysulfide having a large amount of sulfur because the stabilizing effect of the heavy metal becomes large. The water-soluble sulfide can be used as a powder as it is, but it is preferably used as an aqueous solution or an aqueous dispersion so as to be uniformly mixed with the heavy metal-containing waste. The concentration of the water-soluble sulfide used in the aqueous solution or the aqueous dispersion is not particularly limited, but is usually 1 to 50% by weight, preferably 10 to 40% by weight. The amount of these water-soluble sulfides to be used must be appropriately determined depending on the type and particle size of the latent hydraulic substance, or the type of heavy metal-containing waste, especially the elution amount of heavy metal ions, but generally 100 parts by weight of the latent hydraulic substance is used. On the other hand, it is 1 to 100 parts by weight, preferably 2 to 50 parts by weight, particularly preferably 2.5 to 25 parts by weight.

Further, in the water-soluble phosphate, the phosphate ion produced in the presence of water reacts with the heavy metal ion in the heavy metal-containing waste to become a water-insoluble heavy metal phosphate, which elutes the heavy metal in the heavy metal-containing waste. Known to suppress,
When used in combination with a latent hydraulic substance, heavy metals can be stabilized more strongly and permanently.

Specific examples of the water-soluble phosphate that can be used in the present invention include ammonium salts such as diammonium hydrogen phosphate, ammonium dihydrogen phosphate and triammonium phosphate, monopotassium phosphate, potassium dihydrogen phosphate, dipotassium hydrogen phosphate.
Alkali metal salts such as disodium hydrogen phosphate and sodium dihydrogen phosphate, alkaline earth metal salts such as monobasic calcium phosphate and dibasic calcium phosphate, potassium metaphosphate, sodium metaphosphate, sodium tripolyphosphate, sodium polyphosphate, lime superphosphate However, the present invention is not limited to these. The water-soluble phosphate may be used as a powder,
It may be used as an aqueous solution or an aqueous dispersion in order to uniformly mix it with the heavy metal-containing waste. Moreover, you may use these, mixing 2 or more types. Among these water-soluble phosphates, lime superphosphate is particularly preferable because it is not only excellent in stabilizing heavy metals but also inexpensive. The amount of water-soluble phosphate to be used must be appropriately determined depending on the type and particle size of the latent hydraulic substance, or the type of waste containing heavy metals, especially the elution amount of heavy metal ions.
1 to 100 parts by weight, preferably 2 to 100 parts by weight
It is 50 parts by weight, particularly preferably 2.5 to 25 parts by weight.

Further, in the treatment agent of the present invention, various admixtures may be used if necessary for the purpose of improving the moldability of the treated heavy metal-containing waste. Specific examples of admixtures that can be used include pulverized slow-cooled slag, ferrochrome slag, silica, alumina, talc, silica sand, silica powder, clay, kaolin, calcium carbonate, porcelain crushed product, titania, zirconia, river sand, etc. Filler, glass fiber,
Examples thereof include carbon fibers, vinylon fibers, nylon fibers, aramid fibers, polypropylene fibers, acrylic fibers, polyester fibers and the like, cellulose fibers, steel fibers, alumina fibers and the like. Further, a setting retarder such as sugar or glucose, a surface treating agent such as a silane coupling agent, a pigment or the like may be used if necessary.

The treatment agent of the present invention containing components other than the latent hydraulic substance can be obtained by uniformly mixing the above components in a predetermined ratio.

In order to obtain the treatment agent of the present invention in powder form, each component may be powder-mixed by a known mixing method. In addition, the method of mixing when obtaining the liquid treatment agent of the present invention is not particularly limited, but after a predetermined amount of a dispersant, water, and a thickener to be used are mixed to prepare an aqueous solution, The method of adding to the powder component such as the latent hydraulic substance that has been mixed is preferable because the whole can be easily made uniform.

The treatment method of the heavy metal-containing waste of the present invention is performed by mixing and kneading the treatment agent of the present invention, the heavy metal-containing waste, and water (arbitrary component) described later. The equipment for mixing and kneading them and the order of adding them are not particularly limited. The treatment agent of the present invention mixed in advance may be mixed with the heavy metal-containing waste, or each component constituting the treatment agent of the present invention may be mixed with the heavy metal-containing waste. As a mixing method, for example, in the case of performing a batch-type treatment, a kneader-ruder type or an Erich type mixing and kneading machine equipped with a stirrer can be used. Moreover, when performing a continuous process, a uniaxial or biaxial paddle type kneader can be used.

Water is added when the heavy metal-containing waste does not contain water, or when it does contain water but is insufficient for mixing and kneading. The amount of water used varies depending on the water content of the heavy metal-containing waste and the particle size thereof, but is generally 5 to 100 parts by weight of the heavy metal-containing waste (converted in a dry state).
It is 80 parts by weight, preferably 10 to 50 parts by weight. However, this amount also differs depending on how the shape of the treated body after the stabilization treatment is made, that is, whether it is pelletized or granular. The time required for the treatment (mixing and kneading time) is not particularly limited as long as the waste and the treating agent can be uniformly kneaded.

There are no particular restrictions on the wastes that can be used for stabilizing heavy metal ions with the treatment agent of the present invention, such as municipal wastes,
For example, granular industrial waste, contaminated soil, sludge, etc. as they are, or incinerated ash obtained by incinerating them (incinerated fly ash)
Etc. can be treated alone or in combination.

According to the treating agent and the treating method of the present invention, the heavy metal in the heavy metal-containing waste is stabilized, and the heavy metal hardly elutes from the kneaded product after the treatment. In the metal elution test by the method of toxic substances contained in industrial waste, the elution amount of heavy metal ions is below the regulation value.

[0037]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.

Examples 1 to 6 Incinerated fly ash (lead content 2780 pp obtained from an incinerator in a city
m) 100 parts by weight of granulated blast furnace slag (Blaine specific surface area of 10000 cm ² / g) and water were added and mixed in the following amounts and kneaded, and then a lead elution test based on Notification No. 13 of the Environmental Agency was conducted. The results are shown in Table 1. The amount of lead eluted from untreated incineration fly ash was 10.1 mg / l.

[0039]

[Table 1] Table 1 Granulated blast furnace Lead elution amount Slag addition amount Water addition amount 1 day after treatment 1 week after treatment (parts by weight) (parts by weight) (mg / l) (mg / l) Example 1 3 40 0.05 0.02 Example 2 5 20 0.08 0.03 Example 3 10 20 0.16 0.01 or less Example 4 20 20 0.15 0.01 or less Example 5 30 30 0.16 0.01 or less Example 6 40 30 0.10 0.02.

Examples 7 to 12 To 100 parts by weight of incinerated fly ash used in Examples 1 to 6, 5 parts by weight of granulated blast furnace slag having a different Blaine specific surface area and 40 parts by weight of water were added, respectively. After stabilizing the heavy metals in the fly ash in the same manner as in Examples 1 to 6, a lead elution test was performed. Table 2 shows the results.

[0041]

[Table 2] Table 2 Brane specific surface area of granulated blast furnace slag lead elution amount 1 day after treatment 1 week after treatment (cm ² / g) (mg / l) (mg / l) Example 7 2,000 0.05 0.03 Example 8 3,000 0.08 0.02 Example 9 4,000 0.06 0.02 Example 10 6,000 0.06 0.03 Example 11 8,000 0.04 0.01 or less Example 12 13,000 0.06 0.01 or less.

Examples 13 to 15 Examples 1 to 1 except that the granulated blast furnace slag was replaced with silica fume or coal ash and the addition amounts were shown in Table 3, respectively.
After the same operation as in 2, a lead elution test was performed. The results are shown in Table 3.

[0043]

[Table 3] Table 3 Silica fume Coal ash Addition amount of lead elution amount 1 day after treatment 1 week after treatment (parts by weight) (parts by weight) (mg / l) (mg / l) Example 13 5 0.06 0.03 Implementation Example 14 10 0.05 0.03 Example 15 10 0.07 0.04.

Examples 16 to 18 Using incinerated fly ash (lead content 930 ppm, elution amount of lead from untreated fly ash 70 mg / l), granulated blast furnace slag (Brane ratio as a treatment agent for waste containing heavy metals) Surface area 10,
000 cm ² / g) and sodium dihydrogen phosphate (Example 16), sodium polyphosphate (Example 17) and lime superphosphate (Example 18) as the phosphoric acid compounds, respectively, in the amounts shown in Table 4, respectively. After operating in the same manner as in Examples 1 to 6, a lead elution test was conducted. The results are shown in Table 4.

[0045]

Table 4 Table 4 Granulated blast furnace slag Phosphoric acid compound Addition amount of lead elution amount Addition amount 1 day after treatment 1 week after treatment (parts by weight) (parts by weight) (mg / l) (mg / l) Example 165 2 0.28 0.01 or less Example 17 10 3 0.22 0.01 or less Example 18 5 3 0.20 0.01 or less.

Examples 19 to 22 Incinerated ash obtained by incineration of industrial waste (lead content 780
ppm, the amount of lead elution from untreated ash is 30 mg / l), and as a treatment agent for incinerated ash containing heavy metals, granulated blast furnace slag (Brane specific surface area 8,000 cm ² / g) and sodium sulfide (implemented Example 19), sodium hydrosulfide (Example 20), calcium sulfide (CaS2.3, Example 2)
1) or calcium sulfide (CaS3.7, Example 2)
Examples 1 to 6 except that 2) was used in the amounts shown in Table 5, respectively.
After the same operation as above, a lead elution test was conducted. Table 5 shows the results.

[0047]

[Table 5] Table 5 Granulated blast furnace slag Water-soluble sulfide Addition amount of lead elution amount Addition amount 1 day after treatment 1 week after treatment (parts by weight) (parts by weight) (mg / l) (mg / l) Example 19 5 2 0.21 0.01 or less Example 20 10 3 0.30 0.01 Example 21 5 3 0.18 0.01 or less Example 22 5 2 0.23 0.01 or less.

Examples 23 to 26 Granulated blast furnace slag (Blaine specific surface area 4,000 cm ² /
g) 2.5 parts by weight of a sodium salt (average molecular weight of 45,000) of a copolymer of acrylic acid and maleic anhydride, 20 parts by weight of water, and an average of 90 parts by weight of a powder mixture containing 90 parts by weight of silica fume. 0.1 parts by weight of sodium polyacrylate having a molecular weight of 3,000,000 was added and mixed to obtain a liquid treatment agent for heavy metal-containing waste of the present invention. The viscosity of this treating agent after preparation is 3,600 cps (B type viscometer)
Met. One week or one month after being placed in a container and still standing, pseudo-condensation had occurred, but it recovered to a liquid state when vibration was applied, and the viscosity was measured to be 3,500 cps and 3, 3, respectively.
It was 550 cps. Further, even after the preparation, the liquid state after the preparation was maintained for one month or more by continuously stirring the mixture in a container or by intermittently stirring the mixture every 2 to 3 days.

One week after preparation, the liquid treatment agent for heavy metal-containing waste of the present invention and water were used in the amounts shown in Table 6, respectively, and kneaded with the incinerated fly ash of municipal waste used in Examples 1 to 6. Then, after stabilizing treatment, a lead elution test was performed. The results are shown in Table 6.

[0050]

[Table 6] Table 6 Treatment agent Lead elution amount Added amount Water added 1 day after treatment 1 week after treatment (parts by weight) (parts by weight) (mg / l) (mg / l) Example 23 5 20 0.06 0.02 Example 24 10 18 0.05 0.03 Example 25 20 16 0.05 0.03 Example 26 30 14 0.03 0.02.

Examples 27 and 28 Contaminated soil containing heavy metals (elution amount of hexavalent chromium and cadmium from untreated soil was 1320 mg /
1 and 1.3 mg / l), respectively, except that Example 1 was used.
The same treatment as Example 9 (Example 27) and the same treatment as Example 22 (Example 28) were performed. Table 7 shows the results.

[0052]

[Table 7] Table 7 Chromium elution amount (mg / l) Cadmium elution amount (mg / l) 1 day after treatment 1 week after treatment 1 day after treatment 1 week after treatment Example 27 0.25 0.01 or less 0.05 0 0.01 or less Example 28 0.11 0.01 or less 0.02 0.01 or less.

[0053]

The treatment agent for heavy metal-containing wastes of the present invention comprises:
It is suitable for stabilizing heavy metal-containing waste, can highly stabilize heavy metal ions, and can significantly reduce elution, and the effect is long-lasting. In addition, since it can be stored in a liquid composition, it is an unprecedented heavy metal treating agent which has the advantages of compensating for the drawbacks of conventional cement solidification and chemical treatment. Further, the treatment method of the present invention can easily stabilize the heavy metal-containing waste without using a special device.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location B09C 1/08 C04B 22/16 Z C02F 11/00 B09B 3/00 ZAB C04B 22/14 304H 22 / 16 304K // C04B 103: 60 (72) Inventor Koichi Ikeda 143-1 Namienomachi, Takasaki-shi Gunma Prefecture (72) Inventor Masayuki Kiyomoto 1476-5 Sachigawa, Omiya City Saitama Prefecture (72) Osamu Matsumoto Gunma Prefecture 352-3 Shibamachi, Isesaki City

Claims (12)

[Claims] 1. A treatment agent for heavy metal-containing waste, which contains a latent hydraulic substance. 2. The treating agent according to claim 1, wherein the latent hydraulic substance is at least one selected from granulated blast furnace slag, converter slag, coal ash, and silica fume. 3. The treating agent according to claim 1, wherein at least one of the latent hydraulic substances is granulated blast furnace slag. 4. The method according to claim 1, further comprising a dispersant and water.
The treatment agent according to any one of claims 1 to 3. 5. The treating agent according to claim 4, wherein the dispersant is a polymer having a carboxylic acid group or a salt thereof in the molecule. 6. The treating agent according to claim 4, further comprising a water-soluble polymer as a thickening agent. 7. The method according to claim 1, further comprising a water-soluble sulfide.
The treatment agent according to any one of 6 above. 8. The water-soluble sulfide is one or more selected from compounds represented by the formula (1): CaS _x (1) (where x represents a number of 1 to 5 in the formula (1)). The treatment agent according to claim 7. 9. The treatment agent according to claim 1, further containing one or more water-soluble phosphates. 10. The treating agent according to claim 9, wherein the water-soluble phosphate is lime superphosphate. 11. Treatment of heavy metal-containing waste, characterized in that heavy metal-containing waste, the treatment agent according to any one of claims 1 to 10 and, if necessary, water are added and mixed and kneaded. Law. 12. The heavy metal-containing waste is selected from incineration ash of a refuse incinerator, industrial waste, contaminated soil, or sludge.
The treatment method according to claim 11, wherein the treatment method is at least one kind.