JPH11165147A - Method for stabilizing heavy metal-containing waste treating agent and heavy metal-containing waste - Google Patents

Abstract

PROBLEM TO BE SOLVED: To highly stabilize the elution of heavy metal ions by controlling the mixing ratio by weight between blast furnace water-crushed slag to a pozzolan active substance in a specified range. SOLUTION: The particle size of blast furnace water-powdered slag, which is an indispensable component, is at the lowest 2,000 cm<2> /g, preferably at the lowest 4,000 cm<2> /g, in Blaine specific surface area, and one or more kinds are used together. The noble metal stabilization effect of the slag increases with the Blaine specific surface area. In addition, by using the slag together with a pozzolan active substance contained as an indispensable substance, the noble metal stabilization effect is increased. The pozzolan active substance is silica dust and others and can be used alone, or one or more kinds can be used together. The mixing ratio by weight of the indispensable component depends not only on the kind of the blade furnace water-crushed slag and the pozzolan active substance but also on the kind and quantity of noble metals in waste and is generally 95/5-5/95, preferably 90/10-10/90, especially preferably 70/30-30/70. The mixture is usually powdered but can be handled as a slurry-shaped liquid composition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waste treatment agent effective for insolubilizing and stabilizing heavy metals contained in general waste and industrial waste, and a method for treating the same. In more detail, incinerators and fly ash generated from incinerators and melting furnaces for municipal garbage, industrial waste, sludge, etc., insolubilize heavy metals contained in wastes, and effectively dispose them for stabilization. The present invention relates to a processing agent for a product and a processing method thereof.

[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, fly ash and industrial waste of city waste containing heavy metals,
Strict regulations are set for the treatment and disposal of specially managed waste.

Conventionally, when disposing of waste containing heavy metals, a method of mixing with cement, adding water as necessary, and kneading the mixture to prevent elution of heavy metals and the like has been adopted. However, the standard value for elution of heavy metals from landfill waste that has been applied since 1995 has been determined to be the most difficult to stabilize in the case of lead. It is required to stabilize it to 0.3 mg / l or less in a dissolution test based on the above-mentioned method, but it is difficult to clear this standard using only cement.

In the case of mixing and hardening waste, which is a typical cement such as ordinary Portland cement, the calcium hydroxide generated in the hydration process promotes hardening of the cement, but excessively hardens the cement. 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. It is considered that the effect is greatly impaired.

Further, attempts have been made to capture and stabilize heavy metal ions by chemical treatment with a sulfur-containing chelating agent or the like. According to this, it is possible to stabilize to below the elution reference value. However, such a drug is not only expensive, but also has insufficient retention of heavy metal ions after the stabilization treatment. There is a problem that the elution amount of heavy metal ions increases.

[0006]

As described above, it is not only difficult to stabilize heavy metal ions below the elution standard with conventional heavy metal-containing waste treating agents and methods, but also to stabilize them. However, at present, there is a problem in the durability and durability of the retention, and there is a concern that secondary pollution may occur over time.

SUMMARY OF THE INVENTION It is an object of the present invention to stabilize heavy metal-containing waste, and to stabilize the elution of heavy metal ions below a reference value, and to maintain the effect of stabilizing heavy metal ions to completely prevent secondary pollution. It is an object of the present invention to provide a treating agent and a treating method capable of preventing the occurrence of

[0008]

Means for Solving the Problems In view of such circumstances, the present inventors have conducted intensive studies on a treating agent and a treating method that can completely stabilize wastes containing heavy metals. As a result, the granulated blast furnace slag and the pozzolanic active substance were found. It has been surprisingly found that heavy metals can be stabilized by the combined use of, and the present invention has been completed. That is, the present invention

(1) A heavy metal-containing waste treating agent characterized by containing granulated blast furnace slag and a pozzolanic active substance; (2) A blending ratio of granulated blast furnace slag and a pozzolanic active substance is 95 by weight. (5) The treating agent according to (1), wherein the silica component in the pozzolanic active substance is 40% by weight or more in terms of SiO _{2 in} terms of SiO _2. The treatment agent according to 1) or (2),
(4) When the alumina component in the pozzolanic active substance is converted into Al ₂ O _{3, the} content of the alumina component is 0.2% by weight or more and 40% or more.
(5) The treating agent according to any one of (1) to (4), wherein the particle size of the pozzolan active substance is 30 μm or less. ,
(6) The specific surface area of the pozzolan active substance is 5,000 to 3,
Treatment agent according to any one of 000,000cm is ² / g (1) to (5), any one of (7) above further containing a dispersing agent and water (1) to (6) , (8) heavy metal-containing waste, the treatment agent according to any one of the above (1) to (7), and water as required, followed by mixing and kneading. (9) Heavy metal-containing waste, (1)-above
(7) A method for treating heavy metal-containing waste, comprising adding the treating agent according to any one of (7) and, if necessary, adding water, mixing and kneading, and then heating the mixture to 40 ° C. or more.
0) The heavy metal-containing waste is incineration ash, fly ash, contaminated soil at a garbage incineration plant, or an industrial waste containing metals that must satisfy the criteria stipulated in Prime Ministerial Ordinance No. 5 (8). Or (9) the method for treating heavy metal-containing waste described in (9), and (11) the heavy metal-containing waste in which the pH of the eluate after the elution test based on the notification of the Environment Agency No. 13 is basic is (1) to (7). The method according to any one of the above (8) to (10), wherein the treatment is carried out by adding the treating agent and the acidic substance according to any one of the above (8) to (12). The treatment agent and the basic substance described in any one of the above (1) to (7) are added to the heavy metal-containing waste having a neutral or acidic pH after the test to perform treatment. To (10), (1)
3) A processed product obtained by the processing method according to any one of the above (8) to (12).

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
The granulated blast furnace slag used as an essential component in the present invention may have a grain size of 2,000 cm ² / g or more in terms of Blaine specific surface area, but is preferably 4,000 cm ² / g.
The above can be used, and one or more can be used in combination. The greater the Blaine specific surface area, the greater the effect of stabilizing heavy metals, but the higher the production cost and the more economically disadvantageous.

Although the mechanism of the stabilizing effect of the heavy metal ions of the granulated blast furnace slag is not always clear, it is considered that the slag itself has the ability to adsorb heavy metal ions. In addition, the hardening reaction of the granulated blast furnace slag proceeds due to the alkali ions contained in the heavy metal-containing waste, and the resulting various hydration products further strengthen the heavy metal ion exchange ability, diffusion suppression ability and adsorption ability. It is also considered to be expressed in a continuous manner.

The heavy metal stabilizing agent of the present invention (hereinafter, referred to as the agent of the present invention) further contains a pozzolan active substance as an essential component. When used in combination with the granulated blast furnace slag, the hydration reaction product has a dense structure, and the above-described heavy metal stabilizing effect is enhanced. Further, it is considered that the mechanical strength of the processed material is also increased. The pozzolanic active substance is a substance that hardens by reacting with water and calcium oxide, calcium hydroxide, aluminum hydroxide, or the like, and is not particularly limited as long as it has the above properties. Specific examples of the pozzolan-activating substance that can be used include silica dust, diatomaceous earth, talc, aerosil, white carbon, kaolin, metakaolin, activated clay, and acid clay. These pozzolanic active substances have a silica content of 40% by weight or more, preferably 50% by weight, when the silica component in the pozzolanic active substance is converted into SiO _2, or the alumina component in the pozzolanic active substance is Al. ₂ O
_It is preferable to use one having an alumina component content of 0.2% by weight or more and less than 40% by weight when converted to ₃ .
These pozzolanic active substances can be used alone or in combination of one or more.

The pozzolanic active material is more reactive when it is amorphous, and has a higher stabilizing effect on heavy metals. Further, the pozzolanic active substance having a finer and larger specific surface area has a higher reactivity and a higher adsorptivity, and thus has a higher stabilizing effect on heavy metals. The particle size is usually 30 μm or less,
Preferably 20 μm or less, particularly preferably 5 nm to 10 μm
m, and its specific surface area is usually 5,000 to 3,000.
10,000 cm ² / g, preferably 10,000 to 3,000
000 cm ² / g, particularly preferably 30,000 to 3,
Million cm ² / g.

When stabilizing heavy metal-containing waste with the treating agent of the present invention, the mixing ratio of granulated blast furnace slag and pozzolanic active substance depends on the type of granulated blast furnace slag used, the type of pozzolanic active substance and the content of heavy metal-containing substance. Although it depends on the type and amount of heavy metals contained in the waste, especially the lead content, the blast furnace granulated slag / pozzolan active substance (weight ratio) is generally 95/5 to 5/5.
The ratio is 5/95, preferably 90/10 to 10/90, particularly preferably 70/30 to 30/70.

The treating agent of the present invention is usually in the form of a powder, but can also be handled as a slurry liquid composition. That is, by adding an aqueous solution containing a dispersant and water to the granulated blast furnace slag and pozzolanic active substance, adding a water-soluble polymer as a thickener as necessary, mixing and kneading, the slurry of the present invention A treating agent can be obtained.

The dispersant used in preparing this liquid composition plays a role in uniformly dispersing the particles. The dispersing agent may be any one that is water-soluble and can uniformly disperse the granulated blast furnace slag and the pozzolanic active substance, such as a formalin condensate of naphthalenesulfonic acid, a melaminesulfonic acid formalin condensate, and a ligninsulfonic acid condensate. Any of those generally known as dispersants for cement and concrete can be used. These dispersants may be used in combination of two or more.

The amount of the dispersant used varies depending on the type, particle size and amount of granulated blast furnace slag used, the type of pozzolan active substance, the particle size and amount of addition, and the like. It is usually 0.1 to 10 parts by weight, preferably 0.3 to 7 parts by weight, particularly preferably 0.5 to 5 parts by weight, based on 100 parts by weight in total. If the amount of the dispersant is less than 0.1 part by weight, the dispersibility is undesirably deteriorated depending on the amount of water to be added. 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, particle size and blending amount of the granulated blast furnace slag to be used, the type, particle size and blended amount of the pozzolan active substance, but the total amount of the granulated blast furnace slag and the pozzolan active substance is 100%. Usually 10 to 60 parts by weight, preferably 15 to 40 parts by weight, more preferably 1 to 10 parts by weight, based on parts by weight.
8 to 30 parts by weight. If the amount is less than 10 parts by weight, it becomes difficult to obtain a liquid state, which is not preferable. When used in an amount of 60 parts by weight or more, dispersibility can be obtained, but long-term stability is deteriorated, which is not preferable. 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, the treating agent of the present invention optionally contains a thickener. The thickener has the effect of improving the viscosity of the liquid composition and suppressing the sedimentation of the dispersed granulated blast furnace slag and the powder particles of the pozzolan active substance (improving storage stability). The thickener is not particularly limited as long as it is a water-soluble one, but poly (meth) acrylate, poly (meth) acrylamide, (meth) acrylic acid / (meth) acrylamide copolymer salt,
Methylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, cellulose derivatives such as hydroxypropylmethylcellulose, polyethylene oxide, polypropylene oxide, polyvinylpyrrolidone, polyvinyl alcohol, specific examples of which may be used relatively high molecular weight such as xanthan gum, However, the present invention is not limited to this. Further, two or more of these thickeners may be used in combination.

The molecular weight of the thickener used depends on the type of the thickener, the type and particle size of the granulated blast furnace slag and the pozzolanic active substance, and cannot be stated uniformly, but the viscosity of the aqueous solution is a guideline for selection. It can be. For example, taking a 0.2% by weight aqueous solution of a thickener as an example, a thickener having a viscosity of 50 cps or more of this aqueous solution is preferable,
More preferably 100 cps or more, 150 cps
Particularly preferable are those having ps or more. The amount of the thickener used depends on the type of the thickener, the granulated blast furnace slag used and the type and particle size of the pozzolanic active substance, and cannot be described uniformly. It is 0.01 to 5 parts by weight, preferably 0.02 to 3 parts by weight.

Since the heavy metal treating agent of the present invention contains granulated blast furnace slag and a pozzolanic active substance as main components, it has a disadvantage that it absorbs and solidifies during use or storage and becomes unusable as when cement is used. This is advantageous from the viewpoint of equipment maintenance because there is no possibility that the solidified material will not adhere to the inner wall of the apparatus and become unusable unless washed with water within several hours after use. In addition, there is an advantage that the powdery composition can be handled as a liquid composition in the form of a slurry as described above when it is possible to handle the powdery work but dislikes the powder work. Other advantages that can be handled as a liquid composition do not require large-scale equipment such as silos because the volume is smaller than that stored as a powder,
It can be mentioned that mixing and kneading with heavy metal-containing waste becomes easy.

When the eluate used in the dissolution test of the heavy metal-containing waste in the No. 13 dissolution test is municipal incineration fly ash or the like, which is highly alkaline, amphoteric heavy metal compounds such as lead compounds are easily dissolved, so that hydrochloric acid and sulfuric acid are used. , Nitric acid, poly aluminum chloride,
Addition of an acidic substance such as an inorganic acidic substance such as ferrous chloride, ferrous sulfate, or aluminum sulfate, or an organic acidic substance such as acetic acid or citric acid to control the pH to a weak alkalinity can stabilize the heavy metal of the treating agent of the present invention. Effect is enhanced. In addition, when the eluate in the dissolution test of Announcement No. 13 is a waste containing heavy metals such as electric furnace ash, melt fly ash, and contaminated soil that is neutral or acidic, the treating agent of the present invention may be treated with sodium hydroxide, hydroxide or the like. Hydroxides of alkali metals such as potassium, carbonates of alkali metals such as sodium carbonate and potassium carbonate, hydroxides of alkaline earth metals such as calcium hydroxide, magnesium hydroxide and barium hydroxide, sodium silicate and potassium silicate ,
Add a basic substance such as alkali metal silicate such as sodium metasilicate and sodium orthosilicate, alkali metal phosphate such as monosodium phosphate and disodium phosphate, cement, cement clinker, etc. to make the pH weakly alkaline. When controlled, the effect of stabilizing heavy metals of the treating agent of the present invention is enhanced.

The amount of the acidic substance or the basic substance used is such that the pH after the dissolution test described in Announcement No. 13 is 8-12.
The amount which can be adjusted to is preferable. The basic substance or the acidic substance may be added in advance to the treating agent of the present invention, but may be used in the stabilizing treatment method of the present invention described later.

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

The treating agent of the present invention can be obtained by uniformly mixing the above components at a predetermined ratio. When the powdery treatment agent of the present invention is obtained, the respective components may be powder-mixed by a known mixing method. The method of mixing when obtaining the liquid treatment agent of the present invention is not particularly limited, but a predetermined amount of a dispersant, water, and, if necessary, a thickener used are mixed to form an aqueous solution. The method of adding to the mixed powder components such as the granulated blast furnace slag and the pozzolanic active substance is preferable because the whole becomes easily uniform.

The method for stabilizing heavy metal-containing wastes of the present invention (hereinafter referred to as the processing method of the present invention) comprises a treating agent of the present invention,
Mix and knead the heavy metal-containing waste and, if necessary, water.
Water is added when the heavy metal-containing waste does not contain water, or when it is contained but insufficient for mixing and kneading. The amount of water used depends on the water content of the heavy metal-containing waste and its particle size.
5 to 80 parts by weight with respect to 0 parts by weight (calculated in a dry state),
Preferably it is 10 to 50 parts by weight. However, this amount differs depending on the shape of the treated body after the stabilization treatment is performed, that is, whether it is pelletized, granulated, or muddy. . The time required for the treatment (mixing, kneading time) is not particularly limited,
It is only necessary that the waste and the treating agent can be uniformly kneaded. 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 heavy metal-containing waste, or each component constituting the treatment agent of the present invention may be mixed with heavy metal-containing waste. The mixing method can be, for example, a kneader-ruder type or an Erich-type mixing kneader equipped with a stirrer when performing a batch process. For example, a mixing method using a kinetic method, a single-shaft or twin-shaft paddle-type kneader, a pan-type mixer, a vibro mixer, or the like can be used.

In the treatment method of the present invention, the treatment agent of the present invention, the heavy metal-containing waste and water as an optional component are mixed, kneaded, or after mixing and kneading, and then the kneaded material is subjected to a heat treatment to suppress heavy metal elution. This is preferable because the effect is significantly improved and the time required for stabilization can be reduced. In the heat treatment, heat generated during kneading may be used, or the kneaded material may be heated as it is or after kneading. Heating temperature is 40 ° C or higher, preferably 50 ° C
That is all. The heating method may be a known method such as a mechanical method or a physicochemical method as described above. The heating time is
It depends on the thermal conductivity, size, heating method, etc. of the kneaded material or the processed material and cannot be said uniquely, but is usually 5 minutes or more, preferably 10 minutes or more, and the uniformity and workability of the processed material Up to 24 hours from the surface is sufficient.

There is no particular limitation on the waste which can stabilize heavy metal ions by the treatment agent and treatment method of the present invention.
Industrial wastes including municipal incineration ash and fly ash, contaminated soil, sludge, or metals that must satisfy the criteria set forth in Prime Ministerial Decree No. 5 can be treated alone or in combination. In addition, when stabilizing municipal incineration fly ash by the treatment method of the present invention, if the treatment agent of the present invention is added to the flue together with slaked lime and activated carbon, the heat of the flue is simultaneously discharged with the exhaust gas such as HCl and dioxin. This is convenient because the used heavy metal can be stabilized. In this case, the treating agent of the present invention may be previously mixed with slaked lime or activated carbon, or the powder or liquid treating agent of the present invention may be sprayed into a flue.

According to the treating agent and the treating method of the present invention, the heavy metals in the heavy metal-containing waste are stabilized, and the heavy metals are hardly eluted from the kneaded material after the treatment.
In the metal elution test by the method for detecting harmful substances contained in industrial waste specified in the above item, the elution amount of heavy metal ions is below the landfill regulation value of Prime Ministerial Ordinance No. 5.

The treated product of the present invention thus obtained may be used as it is or may be pulverized as necessary, to be used as aggregate for cement / concrete or aggregate for road pavement. It can be used as civil engineering and construction materials by molding into a shape.

[0031]

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 5 White carbon (SiO _{2) was} added to 100 parts by weight of granulated blast furnace slag having a specific surface area of 4,000 cm ² / g.
Content 93wt%, Al ₂ O ₃ content of 0.5 wt%, an average particle diameter of 3 [mu] m, a specific surface area 1,500,000cm ² / g) Table 1
Was mixed with powder to obtain a treating agent of the present invention (hereinafter referred to as a treating agent). Incinerated ash from a municipal waste incineration plant (lead content: 1700 mg / kg, lead elution amount: 36.4 ppm based on notification of the Environment Agency Notification No. 13, hereinafter referred to as A fly ash) 100
5 parts by weight of the above agent and 5 parts by weight of the above-mentioned agent were added and mixed.
After adding 0 parts by weight and kneading, the mixture was cured at room temperature for 24 hours and subjected to a dissolution test based on Announcement No. 13, and the results are shown in Table 1.
Table 1 also shows the amount of lead eluted after curing at room temperature for one week or more.

[0033]

Table 1 White Carbon Announcement No. 13 Lead elution amount (ppm) content (parts by weight) 1 day after 1 week after 4 weeks after 8 weeks Example 1 200.29 0.25 0.20 12 Example 2 50 0.25 0.20 0.18 0.09 Example 3 100 0.12 0.05 0.03 N.C. D. Example 4 200 0.15 0.05 0.05 N.P. D. Example 5 300 0.10 0.04 N.P. D. N. D. Note that in Table 1, N.I. D. Means 0.01 ppm or less (the same applies hereinafter).

Examples 6-10 2.5 parts by weight of granulated blast furnace slag having a specific surface area of 8,000 cm ² / g mixed with 100 parts by weight of the heavy metal-containing waste shown in Table 2 in advance were mixed with acid clay ( SiO ₂ content 7
2.3 wt%, an Al ₂ O ₃ content of 13.4 wt%, an average particle size of 3 μm, a specific surface area of 1,100,000 cm ² / g) and 1.5 parts by weight of water were added. After adding and kneading, the mixture was aged for 24 hours and subjected to a lead dissolution test based on Announcement No. 13. The results are shown in Table 2.

[0035]

Table 2 Water addition amount of waste Announcement No. 13 Lead elution amount (parts by weight) Lead elution amount (ppm) (ppm) Example 6 B fly ash 31.9 32 0.22 Example 7 C incineration Ash 0.710 0.06 Example 8 D incineration ash + fly ash 16.18 0.23 Example 9 E Concentrated waste 8.3.0.19 Example 10 F sludge 6.7 330.14

Examples 11 to 16 100 parts by weight of fly ash (lead content: 2800 mg / kg, lead elution amount: 44.2 ppm based on Announcement No. 13) were added to each blast furnace water having the specific surface area of brane shown in Table 3. 10 parts by weight of a processing agent obtained by powder mixing 50 parts by weight of various pozzolanic active substances with 50 parts by weight of crushed slag are added and mixed.
After adding by weight and kneading, the mixture was cured under the processing conditions shown in Table 3 and subjected to a dissolution test based on Announcement No. 13, and the results are also shown in Table 3.

[0037]

Table 3 Table 3 Blaine pozzolanic active substance Treatment conditions Announcement No. 13 Specific surface area type Lead elution amount (cm ² / g) (° C-hour) (ppm) Example 11 2,000 Metakaolin 40-24 0.21 Example 12 4,000 Activated Clay 80-12 0.12 Example 13 6,000 Silica Dust 60-18 0.07 Example 14 8,000 White Carbon 70-8 0.11 Example 15 10,000 Aerosil 40 -18 0.09 Example 16 15,000 talc 90-6 0.24

Examples 17 to 20 50 parts by weight of granulated blast furnace slag having a specific surface area of 4,000 cm ² / g and silica dust (SiO ₂ content: 92 wt.
%, An Al ₂ O ₃ content of 3 wt%, an average particle size of 1 μm, a specific surface area of 1,700,000 cm ² / g) and 50 parts by weight of a formalin condensate of naphthalenesulfonic acid (average molecular weight of 35.0%).
00) 2 parts by weight, 20 parts by weight of water, and an average molecular weight of 1,7
0.2 parts by weight of hydroxypropylcellulose of 00000 was added and mixed to obtain a liquid heavy metal-containing waste treating agent of the present invention. The viscosity of this treatment agent after preparation is 2,000 c
ps (B type viscometer). One week or one month after standing in a container, pseudo-coagulation had occurred, but when it was shaken, it recovered to a liquid state, and when the viscosity was measured, it was 1,
They were 900 cps and 1,800 cps. In addition, after preparation, even if stirring constantly in the state of being put in a container, or for 2 days or more
By stirring intermittently every three days, the liquid state after the preparation was maintained for one month or more. One week after the preparation, this liquid heavy metal-containing waste treating agent of the present invention and water were kneaded with fly ash in the amounts shown in Table 4, respectively, and then cured at room temperature for 24 hours. A lead dissolution test was performed based on the above.
The results are shown in Table 4.

[0039]

Table 4 Addition amount of treatment agent Addition amount of water Annealing No. 13 Lead elution amount (ppm) (parts by weight) (parts by weight) 1 day after 1 week after 13 weeks Example 17 5 32 0.260 .11 N.P. D. Example 18 7 29 0.21 0.10 N.I. D. Example 19 10 26 0.14 0.06 N.I. D. Example 20 15 21 0.07 N.I. D. N. D.

Examples 21 to 23 2 parts by weight of granulated blast furnace slag having a specific surface area of 4,000 cm ² / g based on 100 parts by weight of electric furnace ash generated by H Steel Co., Ltd., and Aerosil (SiO ₂ content: 99.8 wt. %, Al
₂ O ₃ content 0.2 wt%, average particle size 7 μm, specific surface area 3,000,000 cm ² / g) 4 parts by weight of calcium hydroxide in the amount shown in Table 5 and water and water The results obtained by measuring the amount of lead elution 24 hours after the addition and kneading according to the Announcement No. 13 test are also shown in Table 5.

[0041]

Table 5 Table 5 Amount of water added to the treating agent of the present invention Eluate Announcement No. 13 pH of calcium hydroxide (parts by weight) Lead elution amount (ppm) Compounding amount (parts by weight) Untreated ash 0 256 9.9 9.6 Example 21 1 25 8.8 0.08 Example 22 226 10.3 0.04 Example 23 3 27 12.1 0.13

[0042]

The treatment agent for heavy metal-containing wastes of the present invention comprises:
It is suitable for stabilizing heavy metal-containing waste, and can stabilize the elution of heavy metal ions to a high degree, and its effect is continuous. Further, the treatment method of the present invention can easily stabilize a heavy metal-containing compound without using a special apparatus. Furthermore, since the treated product obtained by the treatment method of the present invention can impart strength equal to or higher than the solidification of cement, it can be recycled as civil engineering and building materials such as aggregates and paving materials.

Claims (13)

[Claims] 1. A treatment agent for heavy metal-containing waste, comprising granulated blast furnace slag and a pozzolanic active substance. 2. The treating agent according to claim 1, wherein the mixing ratio of the granulated blast furnace slag and the pozzolanic active substance is 95/5 to 5/95 by weight. 3. The silica component in the pozzolanic active substance is SiO ₂
The treating agent according to claim 1 or 2, wherein the content of the silica component is 40% by weight or more when converted. 4. An alumina component in the pozzolanic active material is Al ₂ O
_3. The treating agent according to claim 1, wherein the content of the alumina component in terms of ₃ is 0.2% by weight or more and less than 40% by weight. 5. The treating agent according to claim 1, wherein the pozzolanic active substance has a particle size of 30 μm or less. 6. The specific surface area of the pozzolanic active substance is 5,000.
The treatment agent according to any one of claims 1 to 5, wherein the amount is from 3 to 3,000,000 cm ² / g. 7. The method according to claim 1, further comprising a dispersant and water.
The treatment agent according to any one of the above. 8. Addition of a heavy metal-containing waste, the treatment agent according to any one of claims 1 to 7, and water as required,
A method for treating heavy metal-containing waste, comprising mixing and kneading. 9. A heavy metal-containing waste, the treating agent according to any one of claims 1 to 7, and, if necessary, water, followed by mixing and kneading, followed by heat treatment at 40 ° C. or higher. Of heavy metal-containing waste. 10. The heavy metal-containing waste is incinerated ash, fly ash, contaminated soil at a garbage incineration plant, or an industrial waste containing metals that must satisfy the criteria set forth in Prime Ministerial Decree No. 5. Item 10. The method for treating heavy metal-containing waste according to item 8 or 9. 11. The treatment agent and the acidic substance according to any one of claims 1 to 7, wherein the pH of the eluate after the dissolution test based on the notification of the Environment Agency No. 13 is basic, and the waste is a heavy metal-containing waste. The treatment method according to any one of claims 8 to 10, wherein the treatment is carried out by adding. 12. The treatment agent and the base according to claim 1, wherein the pH of the eluate after the dissolution test based on the notification of the Environment Agency No. 13 is neutral or acidic, and the waste is a heavy metal-containing waste. 11. The method according to claim 8, wherein the treatment is carried out by adding a toxic substance.
The processing method described in the section. 13. A processed product obtained by the processing method according to any one of claims 8 to 12.