JPH08269434A - Heavy metal fixing agent and method for treating heavy metal containing substance - Google Patents

Abstract

PURPOSE: To obtain a heavy metal fixing agent which can be used as a high- concn. aq. soln. when added to a heavy metal contg. substance such as incineration fly ash, slag, soil, or sludge and quickly fixes the heavy metal contained in the substance to prevent the dissolution of the metal. CONSTITUTION: The heavy metal fixing agent comprises a compd. contg. a sulfer molecule and having a salt- or complex- forming functional group in the molecular and a mol.wt. of 100-500, a compd. having at least two similar functional groups and a mol.wt. of 200-5,000, and if necessary a water-sol. polymer compd. having a number-average mol.wt. of 5,000-10,000,000.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a heavy metal immobilizing agent capable of immobilizing heavy metals present in solid powder or slurry-like substances such as incinerated fly ash, slag, soil and sludge to prevent elution of heavy metals. And a heavy metal immobilization treatment method.

[0002]

2. Description of the Related Art Conventionally, as a chemical agent added to immobilize heavy metals present in solid powder or slurry-like substances such as incinerated fly ash, slag, soil, sludge and the like to prevent elution of heavy metals, polyamine and Water-soluble polymer chelating agent obtained by adding carbon disulfide to polyethyleneimine (for example, JP-A-3-231921 and JP-A-6-15280).
No. publication) is known.

[0003]

However, since it is difficult to make a highly concentrated aqueous solution from the viewpoint of solubility or solution viscosity, a water-soluble high molecular weight chelating agent is used in a relatively dilute aqueous solution. There is a problem in workability such that the drug solution has to be handled and extra water is added, resulting in an increase in weight and volume after addition. In addition, since expensive compounds such as polyethyleneamine are used, there is a cost problem.

[0004]

The present inventors have added heavy metals present in solid powder or slurry-like substances such as incinerated fly ash, slag, soil and sludge to immobilize and prevent the elution of heavy metals. The present invention has been accomplished as a result of intensive studies to obtain a heavy metal immobilizing agent that can be used as a high-concentration aqueous solution and promptly immobilizes heavy metal ions.

That is, the present invention relates to a compound (1) having a molecular weight of 100 to 500 and having one functional group containing a sulfur atom and having a salt-forming property or a complex-forming property in the molecule, a salt-forming compound having a sulfur atom or a complex-forming property. (2) having a molecular weight of 200 to 5,000 having two or more functional groups in the molecule and, if necessary, a number average molecular weight of 5,000 to 1
A heavy metal-immobilizing agent consisting of 0,000,000 water-soluble polymer compounds (3); and a heavy metal-containing solid powder or slurry (4) to which the heavy metal-immobilizing agent and optionally water are added and kneaded It is a method for treating heavy metal-containing substances.

In the present invention, the functional group which contains a sulfur atom and has a salt-forming property or a complex-forming property, which each of the compounds (1) and (2) has, is, for example, a dithiocarbamic acid group, a thiocarbamic acid group or a thioamide group. , Thioureido group, xanthogenic acid group, thiol group, thiophenol group, thioether group, thioester group, dithioester group, sulfonic acid group and sulfuric acid group. Of these, the sulfonic acid group, the sulfuric acid group, the xanthogenic acid group, the thiocarbamic acid group, the dithiocarbamic acid group and the thiophenol group may be salts of alkali metals, ammonium, amines and the like. Among these, preferred are dithiocarbamic acid group, thiocarbamic acid group, thioamide group, thioureido group, xanthogenic acid group, thiol group, thiophenol group and alkali metals thereof,
Salts such as ammonium and amine are more preferable, and dithiocarbamic acid group and its alkali metal salts and amine salts are more preferable.

Examples of the compound (1) having one functional group in the molecule and having a molecular weight of 100 to 500 include (a) chain-like or cycloalkylsulfonic acid having 1 to 16 carbon atoms, and (a) 1 To benzene sulfonic acid in which 5 hydrogen atoms may be substituted with a hydroxyl group or an alkyl ether group, (c) a chain having 1 to 16 carbon atoms or a cycloalkyl sulfuric acid, (d) a chain having 1 to 8 carbon atoms Or cycloalkylxanthogenic acid, (e) phenylxanthogenic acid in which 1 to 5 hydrogen atoms may be substituted with a hydroxyl group or an alkyl ether group, (f) a chain or cycloalkylthiocarbamic acid having 1 to 8 carbon atoms, (G) Phenylthiocarbamic acid in which 1 to 5 hydrogen atoms may be substituted with a hydroxyl group or an alkyl ether group, (h) a chain having 1 to 8 carbon atoms, or Cycloalkyl dithiocarbamate, (Ke) 1-5 phenyl dithiocarbamate substituted hydrogen atom is a hydroxyl group or an alkyl ether group, (co) alkylthiol having 1 to 8 carbon atoms,
(Sa) Thiophenol in which 1 to 5 hydrogen atoms may be substituted with a hydroxyl group or an alkyl ether group, (shi)
C1-C8 chain or cycloalkyl thioether, (S) C1-C8 chain or cycloalkyl thioester, (SE) C1-C8 chain or cycloalkyl dithioester, (SO) carbon Number 1 to 8 chain or cycloalkyl thioureido, (ta) 1 to 5 hydrogen atoms may be substituted with a hydroxyl group or an alkyl ether group, phenyl thioureido, (chi) Number 1 to 8 carbon chain Or cycloalkylthioamide, and (tsu) 1
Phenylthioamides in which ~ 5 hydrogen atoms may be substituted with hydroxyl groups or alkyl ether groups are mentioned. Among these, sulfonic acid, sulfuric acid, xanthogenic acid, thiocarbamic acid, dithiocarbamic acid and thiophenol include lithium salt, sodium salt, potassium salt, ammonium salt, monoalkylamine salt having 1 to 8 carbon atoms, and 1 to 8 carbon atoms. 8 dialkylamine salt, 1 to 1 carbon atoms
It may be a trialkylamine salt of 8 or a quaternary ammonium salt of 1 to 8 carbon atoms. Preferable examples of (1) include (E), (O), (F), (K), (K),
(Ke), (ko), (sa), (so), (ta), (chi),
(Tu) and their lithium salts, sodium salts, potassium salts, ammonium salts, monoalkylamine salts having 1 to 8 carbon atoms, dialkylamine salts having 1 to 8 carbon atoms, trialkylamine salts having 1 to 8 carbon atoms, Examples thereof include quaternary ammonium salts having 1 to 8 carbon atoms. More preferable is
(K) an alkali metal salt or a dialkylamine salt of a chain or cycloalkyldithiocarbamic acid having 1 to 8 carbon atoms, and specific examples of the alkali metal salt of (K) include sodium dimethyldithiocarbamate and potassium dimethyldithiocarbamate. Examples thereof include potassium methylethyldithiocarbamate, sodium diethyldithiocarbamate, potassium methyl-t-butyldithiocarbamate, sodium ethylhexyldithiocarbamate, potassium methylcyclohexyldithiocarbamate, potassium di-n-butyldithiocarbamate, and the like. Specific examples of the (k) dialkylamine salt include dimethyldithiocarbamic acid dimethylamine salt, diethyldithiocarbamic acid diethylamine salt, and di-n-butyldithiocarbamic acid dibutylamine salt. Most preferred is potassium di-n-butyldithiocarbamate.

The compound (2) having two or more functional groups exemplified above and having a molecular weight of 200 to 5,000 includes, for example, (te) chain-like or cycloalkyldisulfonic acid having 1 to 16 carbon atoms, (G) benzenedisulfonic acid in which 1 to 4 hydrogen atoms may be substituted with a hydroxyl group or an alkyl ether group, (na) a chain or cycloalkyl sulfuric acid having 1 to 16 carbon atoms, (d) 1 to carbon atoms 8 chain or cycloalkyl dixanthogenic acid, (nu) carbon number 1
To 16 chain-like or cycloalkyltrixanthogenic acid, (n) phenyldixanthogenic acid in which 1 to 4 hydrogen atoms may be substituted with a hydroxyl group or an alkyl ether group, (no) chain having 1 to 32 carbon atoms Or cycloalkylbisthiocarbamic acid, (C) a chain or cycloalkyltristhiocarbamic acid having 1 to 32 carbon atoms,
(H) Phenylbisthiocarbamic acid in which 1 to 4 hydrogen atoms may be substituted with a hydroxyl group or an alkyl ether group, (F) a chain or cycloalkylbisdithiocarbamic acid having 1 to 32 carbon atoms, (F) A chain or cycloalkyl tris dithiocarbamic acid having 1 to 32 carbon atoms,
(E) a chain or cycloalkyltetrakisdithiocarbamic acid having 1 to 32 carbon atoms, (m) phenylbisdithiocarbamic acid in which 1 to 4 hydrogen atoms may be substituted with a hydroxyl group or an alkyl ether group, (mi) 1 ~ Phenyltrisdithiocarbamic acid in which 4 hydrogen atoms may be substituted with a hydroxyl group or an alkyl ether group,
(M) alkyldithiol having 1 to 16 carbon atoms, (m) alkyltrithiol having 1 to 16 carbon atoms, (mo) dithiophenol in which 1 to 5 hydrogen atoms may be substituted with a hydroxyl group or an alkyl ether group. , (F) carbon number 1 to 1
6 alkyldithioether, (Y) C1-16 alkyldithioester, (Yo) C1-16 chain or cycloalkyldithioester, (L) C1
~ 16 linear or cycloalkyldithioureido,
(I) a chain or cycloalkyltrithioureido having 1 to 16 carbon atoms, (l) phenyldithioureido in which 1 to 5 hydrogen atoms may be substituted with a hydroxyl group or an alkyl ether group, (le) polyamines (5) Reaction product of carbon disulfide, (b) Reaction product of polyethyleneimine having a molecular weight of 4000 or less and carbon disulfide, (wa) Polyamines (5) and molecular weight 450 obtained by polycondensation of epihalohydrin
A reaction product of 0 or less polycondensate polyamine and carbon disulfide,
(2) A reaction product of polyvinylamine having a molecular weight of 4000 or less and carbon disulfide can be mentioned. Of these, compounds containing a sulfonic acid group, a sulfuric acid group, a xanthogenic acid group, a thiocarbamic acid group, a dithiocarbamic acid group, and thiophenol include lithium salts, sodium salts, potassium salts, ammonium salts, and monohydric groups having 1 to 8 carbon atoms. It may be an alkylamine salt, a dialkylamine salt having 1 to 8 carbon atoms, a trialkylamine salt having 1 to 8 carbon atoms, or a quaternary ammonium salt having 1 to 8 carbon atoms.

As a preferable example of (2), (d),
(Nu), (ne), (no), (ha), (hi), (hu),
(F), (e), (ma), (mi), (m), (me),
(Mo), (la), (ri), (ru), (re), (b),
(Wa), (wo) and their lithium salts, sodium salts, potassium salts, ammonium salts, monoalkylamine salts having 1 to 8 carbon atoms, dialkylamine salts having 1 to 8 carbon atoms, and trialkyl groups having 1 to 8 carbon atoms. Alkyl amine salt, carbon number 1
And the quaternary ammonium salt of 8. Particularly preferred are alkali metal salts and dialkylamine salts of (F), (F), (V), (R) and (B).

As the polyamines (5) in the above (i) and (ii), an imino group or an amino group in which one or two active hydrogen atoms are bonded to a nitrogen atom is used.
Examples thereof include compounds having more than one, such as ethylenediamine, propylenediamine, butylenediamine, hexamethylenediamine, diethylenetriamine, dipropylenetriamine, dibutylenetriamine, triethylenetetramine, tripropylenetetramine, tributylenetetramine, tetraethylenepentamine, tetrapropylene. Polyalkylene polyamines such as pentamine, tetrabutylene pentamine, pentaethylene hexamine; phenylenediamine, xylenediamine, iminobispropylamine, monomethylaminopropylamine, methyliminobispropylamine, 1,3-bis (aminomethyl) cyclohexane, Melamine, piperazine, 1-aminoethylpiperazine, diaminophenyl ether and the like can be mentioned. Among these, preferred are an alkali metal salt and an amine salt of a reaction product of piperazine, ethylenediamine, N, N ′ dimethylethylenediamine and carbon disulfide.
Specific examples of particularly preferable ones include sodium salt of a reaction product of piperazine and carbon disulfide (sodium piperazine bisdithiocarbamate), potassium salt of a reaction product of piperazine and carbon disulfide (potassium piperazine bisdithiocarbamate), ethylenediamine and Reaction of potassium disulfide with potassium salt, reaction product of N, N ′ dimethylethylenediamine with carbon disulfide, sodium salt of reaction product of diethylenetriamine with carbon disulfide, reaction of piperazine with carbon disulfide Diethylamine salt, di-n-butylamine salt of the reaction product of piperazine and carbon disulfide, dimethylamine salt of the reaction product of ethylenediamine and carbon disulfide, reaction product of N, N ′ dimethylethylenediamine and carbon disulfide Diisopropylamine salt, diethylenetriamine and disulfide And di n- propylamine salt of the reaction product of carbon and the like. Most preferred are the diethylamine salt of the reaction product of piperazine and carbon disulfide and the di-n-butylamine salt of the reaction product of piperazine and carbon disulfide. Further, the reaction product of polyamines and carbon disulfide of (ii) and the reaction product of polyethyleneimine having a molecular weight of 4000 or less and carbon disulfide of (ii) are disclosed in JP-A-3-2319.
It is obtained by the method described in Japanese Patent No. 21.

In the present invention, (1), (2), (3)
The compounding ratio of (1) is usually 10 to 90% by weight, (2) is 10 to 70% by weight, (3) is 0 to 30% by weight, and preferably (1) is 30 to 70% by weight, (2) is 30-6
0% by weight, and (3) is 0 to 20% by weight.

In the present invention, the number average molecular weight of the water-soluble polymer (3) is usually 5,000 to 10,000,000.
It is 0, preferably 5,000 to 5,000,000. Examples of such water-soluble polymer (3) include acrylamide polymer, acrylamide / acrylic acid (salt) copolymer, acrylamide / acrylic acid (salt) /
2-Acrylamido-2-methylpropanesulfonic acid (salt) copolymer, acrylamide / (meth) acryloyloxyethyltrimethylammonium chloride copolymer acrylamide / (meth) acryloyloxyethyltrimethylammonium chloride copolymer or (meth) acryloyl Nonionic, anionic, and weakly cationic polymers such as oxyethyltrimethylammonium chloride polymers are mentioned. Further, as the water-soluble polymer (3), a water-soluble polymer compound having a salt-forming or complex-forming functional group containing a sulfur atom and having a molecular weight of 5,000 or more may be used.
Reaction product of polyethylenimine of not less than 00 and carbon disulfide, polycondensation product of polyamines and epihalohydrin having a molecular weight of 4500 or more, reaction product of polyamine and carbon disulfide, polyvinylamine having molecular weight of 4000 or more and disulfide An example is a reaction product with carbon. Two or more kinds of the water-soluble polymers exemplified as the above (3) may be used in combination.

The heavy metal immobilizing agent of the present invention is effective for immobilizing heavy metals in heavy metal-containing materials having various properties such as block-like solids, powders, liquids, slurries and pastes, but incinerator fly ash, slag, It is effective in immobilizing heavy metals in solid powdery or slurry-like heavy metal-containing materials such as soil and sludge, and is particularly suitable for immobilizing heavy metal-containing incineration fly ash.

The heavy metal fixing agent of the present invention is usually 30 to 7
Although it is added as a 0% by weight aqueous solution, the heavy metal fixing agent and water may be added separately. When they are added separately, either one may be added first. When the heavy metal-containing material is in the form of a slurry, only the immobilizing agent may be added alone,
Moreover, although (1), (2) and (3) are usually mixed in advance and used, they may be added separately.

The amount of the heavy metal fixing agent of the present invention added is preferably 0.5 to 5 molar equivalents of the heavy metal content, and particularly 0.8.
~ 2 molar equivalents are preferred.

In the method of the present invention, the above-mentioned metal immobilizing agent and, if necessary, water may be sprinkled on the surface of the solid powder or slurry-like substance, but it is preferable to add to the solid powder or slurry-like substance and knead. . If necessary, an ordinary flocculant or neutralizing agent may be used in combination.

[0017]

The present invention will be described in detail below with reference to examples, but the present invention is not limited thereto. In addition, the molecular weight in an Example represents a number average molecular weight, and% represents weight%. Production Example 1 Water 3 in a reaction vessel that can be cooled and stirred and that can be replaced with nitrogen
70 parts, potassium hydroxide 180 parts, piperazine 67 parts,
Charge 140 parts of 50% aqueous solution of dimethylamine,
Stirred at 0 rpm. After confirming that the solid substance in the reaction vessel was dissolved, 240 parts of carbon disulfide was added dropwise at 35 ° C. in a nitrogen atmosphere, and after completion of the addition, aging was carried out at the same temperature for 3 hours to immobilize heavy metals. A 50% aqueous solution of Agent 1 was obtained.

Comparative Production Example 1 Water 3 was placed in a reaction vessel capable of cooling and stirring and capable of nitrogen substitution.
00 parts, potassium hydroxide 120 parts, and piperazine 70 parts were charged and stirred at 200 rpm. After confirming that the solid substance in the reaction vessel was dissolved, 160 parts of carbon disulfide was added dropwise at 35 ° C. under a nitrogen atmosphere, and after completion of the addition, aging was carried out at the same temperature for 3 hours to give a piperazine derivative. A 40% aqueous solution was obtained.

Comparative Production Example 2 Water 7 was placed in a reaction vessel which can be cooled and stirred and which can be replaced with nitrogen.
0 parts, 60 parts of potassium hydroxide and 140 parts of a 50 wt% aqueous solution of dimethylamine were charged and stirred at 200 rpm. After confirming that the solids in the reaction vessel have dissolved,
80 parts of carbon disulfide was added dropwise at 35 ° C. in a nitrogen atmosphere,
After completion of the dropping, aging was carried out at the same temperature for 3 hours to obtain a 60% aqueous solution of the dimethylamine derivative.

Production Example 2 A 40% aqueous solution of the piperazine derivative of Comparative Production Example 1 was added to 50%.
Parts and 50 parts of a 60% aqueous solution of the dimethylamine derivative of Comparative Production Example 2 were mixed to obtain a 50% aqueous solution of the heavy metal fixing agent 2.

Production Example 3 Water 3 was added to a reaction vessel capable of cooling / stirring and nitrogen substitution.
70 parts, sodium hydroxide 180 parts, N, N 'dimethylethylenediamine 70 parts, 50% by weight of dimethylamine
140 parts of an aqueous solution was charged and stirred at 200 rpm. After confirming that the solid substance in the reaction vessel was dissolved, 240 parts of carbon disulfide was added dropwise at 35 ° C. in a nitrogen atmosphere, and after completion of the addition, aging was carried out at the same temperature for 3 hours to immobilize heavy metals. A 50% aqueous solution of Agent 3 was obtained.

Production Example 4 Water 4 was added to a reaction vessel capable of cooling and stirring and capable of nitrogen substitution.
40 parts, piperazine 130 parts, and diethylamine 190 parts were charged and stirred at 200 rpm. After confirming that the solid matter in the reaction vessel was dissolved, in a nitrogen atmosphere, at 35 ° C
Then, 240 parts of carbon disulfide was added dropwise, and after completion of the addition, aging was carried out at the same temperature for 3 hours to obtain a 56% aqueous solution of the heavy metal fixing agent 4.

Production Example 5 Water 4 was placed in a reaction vessel which can be cooled and stirred and which can be replaced with nitrogen.
40 parts, sodium hydroxide 100 parts, piperazine 90
Part, di-n-butylamine 130 parts were charged, and 200 rp
It was stirred at m. After confirming that the solid matter in the reaction vessel was dissolved, carbon disulfide 240 was added at 35 ° C. under a nitrogen atmosphere.
Then, after completion of the dropping, aging was carried out at the same temperature for 3 hours to obtain a 53% aqueous solution of the heavy metal fixing agent 5.

Examples 1 to 5, Comparative Examples 1 to 2 To 50 parts of fly ash produced by incineration of dust, 0.17 parts of the heavy metal fixing agent synthesized in Production Examples 1 to 5 and Comparative Production Examples 1 and 2,
10 parts of water was added, and the mixture was kneaded at 80 ° C. for 10 minutes. Dissolution test of treated and untreated ash after kneading (Environment Agency Public Notice 13
No.) and the concentration of eluted lead ions was measured, and the results shown in Table 1 below were obtained.

Comparative Example 3 Fly ash 50 produced by incineration of waste used in Examples 1 to 5
To the part, 0.17 part of a commercially available chelating treatment agent (heavy metal fixing agent manufactured by Miyoshi Yushi Co., Ltd., trade name "Epofloc L-1") and 10 parts of water were added, and the mixture was kneaded at 80 ° C for 10 minutes. The treated ash after kneading and the untreated ash were subjected to an elution test (Environmental Agency Bulletin No. 13) to measure the eluted lead ion concentration. The results shown in Table 1 below were obtained.

[0026]

[Table 1]

[0027]

The heavy metal fixing agent of the present invention is incinerated fly ash,
It can be used as a high-concentration aqueous solution when added to solid powder or slurry-like substances such as slag, soil, and sludge, and has excellent workability, and it quickly fixes heavy metals present in the solid powder or slurry-like substances. It is also excellent in the function to prevent the elution of heavy metals by converting into heavy metal.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location B09C 1/08 B09B 3/00 304J C02F 11/00 101 304K (72) Inventor Katsura Goda Higashiyama-ku, Kyoto Sanyo Kasei Kogyo Co., Ltd. 1-11, Hitotsubashi Honcho (72) Inventor Kuniyoshi Yoshio 1-11, Hitotsubino-honcho, Higashiyama-ku, Kyoto City 1 Sanyo Kasei Kogyo Co., Ltd. (72) Inventor Hideki Omori Hitotsubashi-honcho, Higashiyama-ku, Kyoto No. 11 No. 1 Sanyo Chemical Industry Co., Ltd. (72) Inventor Hiroshi Yoshimochi No. 11 Hitotino-honcho, Higashiyama-ku, Kyoto No. 11 No. 1 Sanyo Chemical Industry Co., Ltd. -7 Kurita Industry Co., Ltd. (72) Inventor Ichiro Ito 3-4-7 Nishishinjuku, Shinjuku-ku, Tokyo Kurita Industry Co., Ltd.

Claims (6)

[Claims] 1. A molecular weight of 100 to 100 having one salt-forming or complex-forming functional group containing a sulfur atom in the molecule.
Compound (1) having a molecular weight of 500, compound (2) having a molecular weight of 200 to 5,000 having two or more salt-forming or complex-forming functional groups containing a sulfur atom in the molecule and, if necessary, a number-average molecular weight of 5,000. A heavy metal fixing agent comprising a water-soluble polymer compound (3) of 10,000,000. 2. The salt-forming or complex-forming functional groups in (1) and (2) are dithiocarbamic acid groups, thiocarbamic acid groups, thioamide groups, thioureido groups, xanthogenic acid groups, thiol groups and these. The heavy metal fixing agent according to claim 1, which is one or more functional groups selected from the group consisting of alkali metal, ammonium or amine salts. 3. (1) is an alkali metal salt and / or amine salt of dialkyldithiocarbamic acid,
The heavy metal fixing agent according to claim 2, wherein (2) is an alkali metal salt and / or an amine salt of a compound having two or more dithiocarbamic acid groups in the molecule. 4. (1) is dimethyldithiocarbamic acid potassium salt and / or dialkylamine salt,
The heavy metal immobilizing agent according to claim 3, wherein (2) is a piperazine bisdithiocarbamic acid potassium salt and / or a dialkylamine salt. 5. A method for treating a heavy metal-containing material, which comprises adding a heavy metal-immobilizing agent according to any one of claims 1 to 4 and water if necessary to a solid powder or slurry (4) containing a heavy metal and kneading the mixture. 6. The treatment method according to claim 5, wherein (4) is incineration fly ash containing a heavy metal.