JP2862813B2 - Heavy metal fixing agent and method for treating heavy metal-containing material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heavy metal immobilizing agent capable of immobilizing heavy metals present in solid powder such as incinerated fly ash, slag, soil, sludge or slurry-like substances to prevent elution of heavy metals. And a method for immobilizing heavy metals.

[0002]

2. Description of the Related Art Conventionally, agents added to fix 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 include polyamines and polyamines. Water-soluble polymer chelating agents obtained by adding carbon disulfide to polyethyleneimine (for example, JP-A-3-231921, JP-A-6-15280)
No. 1).

[0003]

However, since it is difficult to prepare a high-concentration aqueous solution of a water-soluble polymer chelating agent in terms of solubility or solution viscosity, a relatively dilute aqueous solution is used. There is a problem in workability, such as the need to handle the drug solution and the increase in weight and volume after addition due to the addition of excess water. In addition, expensive compounds such as polyethyleneamine are used, which causes a problem in cost.

[0004]

Means for Solving the Problems The present inventors fixed heavy metals present in solid powder or slurry-like substances such as incinerated fly ash, slag, soil, sludge and the like to prevent heavy metals from being eluted. As a result of extensive studies to obtain a heavy metal immobilizing agent that can be used as a high-concentration aqueous solution and quickly immobilizes heavy metal ions, the present invention has been achieved.

That is, the present invention relates to a compound (1) having a molecular weight of 100 to 500 having one of the following functional groups in a molecule containing a sulfur atom and having a salt-forming or complex-forming property, a salt-forming or a complex containing a sulfur atom: Having a molecular weight of 200 to 5, having at least two of the following functional groups that are formable in the molecule:
000 (2) and, if necessary, a water-soluble polymer compound (3) having a number average molecular weight of 5,000 to 10,000,000, and the compounding amount of (3) is (1)
(2) a heavy metal fixing agent that is not more than 30% by weight based on the total amount of (3); and adding the heavy metal fixing agent and water as needed to a solid powder or slurry (4) containing a heavy metal. This is a method for treating heavy metal-containing materials to be kneaded. Functional group containing a sulfur atom and capable of forming a salt or complex: dithiocarbamic acid group, thiocarbamic acid group, thioamide group, thioureido group, xanthogenic acid group, thiol group, thiophenol group and alkali metal, ammonium or amine thereof Functional group selected from the group consisting of salts

In the present invention, examples of the functional group which contains a sulfur atom and has a salt-forming property or a complex-forming property in compounds (1) and (2) include, for example, a dithiocarbamic acid group, a thiocarbamic acid group and a thioamide group. Thioureido, xanthate, thiol and thiophenol groups. Of these, xanthate groups,
The thiocarbamic acid group, dithiocarbamic acid group and thiophenol group may be in the form of a salt of an alkali metal, ammonium, amine or the like. Of these, preferred are dithiocarbamic acid groups and their alkali metal salts and amine salts.

The compounds (1) having a molecular weight of 100 to 500 having one functional group in the molecule as exemplified above include, for example, (a) a linear or cycloalkylxanthogenic acid having 1 to 8 carbon atoms; Phenylxanthic acid in which up to 5 hydrogen atoms may be substituted with a hydroxyl group or an alkyl ether group, (c) a linear or cycloalkylthiocarbamic acid having 1 to 8 carbon atoms, (d) 1 to 5 hydrogen atoms Is a phenylthiocarbamic acid which may be substituted with a hydroxyl group or an alkyl ether group, (e) a linear or cycloalkyldithiocarbamic acid having 1 to 8 carbon atoms, and (f) a hydroxyl group or an alkyl ether having 1 to 5 hydrogen atoms. Phenyldithiocarbamic acid which may be substituted with a group, (g) an alkylthiol having 1 to 8 carbon atoms, (h) 1 to 5 hydrogen atoms Is a thiophenol which may be substituted with a hydroxyl group or an alkyl ether group, (k) a linear or cycloalkylthioureido having 1 to 8 carbon atoms, and (co) 1 to 5 hydrogen atoms are substituted with a hydroxyl group or an alkyl ether group. (H) a chain or cycloalkylthioamide having 1 to 8 carbon atoms; and (h) phenyl in which 1 to 5 hydrogen atoms may be substituted with a hydroxyl group or an alkyl ether group. Thioamide. Among these, xanthogenic acid, thiocarbamic acid, dithiocarbamic acid and thiophenol are lithium salts, sodium salts, potassium salts, ammonium salts, monoalkylamine salts having 1 to 8 carbon atoms, and dialkylamine salts 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. Preferable examples of (1) are (e) a linear or cycloalkyldithiocarbamic acid alkali metal salt or dialkylamine salt having 1 to 8 carbon atoms, and specific examples of the alkali metal salt of (e) include dimethyl. Examples include sodium dithiocarbamate, potassium dimethyldithiocarbamate, potassium methylethyldithiocarbamate, sodium diethyldithiocarbamate, potassium methyl-t-butyldithiocarbamate, sodium ethylhexyldithiocarbamate, potassium methylcyclohexyldithiocarbamate, potassium di-n-butyldithiocarbamate, and the like. Can be Specific examples of the dialkylamine salt of (E) include dimethyldithiocarbamic acid dimethylamine salt, diethyldithiocarbamic acid diethylamine salt, and di-n-butyldithiocarbamic acid dibutylamine salt. Most preferred is potassium di-n-butyldithiocarbamate.

Examples of the compound (2) having two or more functional groups in the molecule and having a molecular weight of 200 to 5,000 include, for example, (S) a linear or cycloalkyldixanthogenic acid having 1 to 8 carbon atoms. (C) a linear or cycloalkyltrixanthogenic acid having 1 to 16 carbon atoms; (so) phenyldixanthic acid in which 1 to 4 hydrogen atoms may be substituted with a hydroxyl group or an alkyl ether group; A chain or cycloalkylbisthiocarbamic acid having 1 to 32 carbon atoms, (h) a chain or cycloalkyltristhiocarbamic acid having 1 to 32 carbon atoms, (z) a hydroxyl group or an alkyl ether having 1 to 4 hydrogen atoms. Phenylbisthiocarbamic acid which may be substituted with a group, (te) a linear or cycloalkylbisdithiocarbamic acid having 1 to 32 carbon atoms, A) linear or cycloalkyltrisdithiocarbamic acid having 1 to 32 carbon atoms; (n) a linear or cycloalkyltetrakisdithiocarbamic acid having 1 to 32 carbon atoms; (d) a hydroxyl or alkyl ether group having 1 to 4 hydrogen atoms. Phenylbisdithiocarbamic acid which may be substituted with (nu) phenyltrisdithiocarbamic acid wherein 1 to 4 hydrogen atoms may be substituted with a hydroxyl group or an alkyl ether group, (d) alkyl having 1 to 16 carbon atoms Dithiol, (no) alkyltrithiol having 1 to 16 carbon atoms, (c) dithiophenol in which 1 to 5 hydrogen atoms may be substituted with a hydroxyl group or an alkyl ether group, A chain or cycloalkyldithioureido; Ureido, (f) phenyldithioureide in which 1 to 5 hydrogen atoms may be substituted with a hydroxyl group or an alkyl ether group, (e) a reactant of polyamines (5) with carbon disulfide, (f) molecular weight 4000 The following reaction products of polyethyleneimine and carbon disulfide; (M) polycondensation products of polyamines (5) and epihalohydrin having a molecular weight of 4500 or less; reaction products of polyamines having a molecular weight of 4500 or less; and (M) molecular weight of 4000 The following reaction products of polyvinylamine and carbon disulfide are exemplified. Among these, compounds containing a xanthate group, a thiocarbamate group, a dithiocarbamate group, and a thiophenol include lithium salts, sodium salts, potassium salts, ammonium salts, monoalkylamine salts having 1 to 8 carbon atoms, and 1-carbon atoms. To 8 dialkylamine salts, carbon number 1
Or a quaternary ammonium salt having 1 to 8 carbon atoms.

Preferred examples of (2) include (T)
(G) alkali metal salts and dialkylamine salts of (na), (e) and (ma).

The polyamines (5) in the above (e) and (mi) include an imino group or an amino group in which one or two active hydrogen atoms are bonded to a nitrogen atom.
Compounds having at least one compound, for example, ethylenediamine, propylenediamine, butylenediamine, hexamethylenediamine, diethylenetriamine, dipropylenetriamine, dibutylenetriamine, triethylenetetramine, tripropylenetetramine, tributylenetetramine, tetraethylenepentamine, tetrapropylene Polyalkylenepolyamines such as pentamine, tetrabutylenepentamine and pentaethylenehexamine; phenylenediamine, xylenediamine, iminobispropylamine, monomethylaminopropylamine, methyliminobispropylamine, 1,3-bis (aminomethyl) cyclohexane, Examples include melamine, piperazine, 1-aminoethylpiperazine, diaminophenyl ether and the like. Of these, preferred are piperazine, ethylenediamine, alkali metal salts and amine salts of a reaction product of N, N'dimethylethylenediamine and carbon disulfide.
Specific examples of particularly preferred compounds 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), and ethylenediamine. Potassium salt of reactant with carbon disulfide, sodium salt of reactant of N, N 'dimethylethylenediamine with carbon disulfide, potassium salt of reactant of diethylenetriamine with carbon disulfide, reaction of piperazine with carbon disulfide Salts of diamines, di-n-butylamine salts of reactants of piperazine and carbon disulfide, dimethylamine salts of reactants of ethylenediamine and carbon disulfide, and reactants 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 salts of the reaction product of piperazine and carbon disulfide, and the di-n-butylamine salt of the reaction product of piperazine and carbon disulfide. The reactant of (e) a polyamine and carbon disulfide and the (m) of a reactant of polyethyleneimine having a molecular weight of 4000 or less and carbon disulfide are disclosed in JP-A-3-2319.
It can be obtained by the method described in JP-A-21 or the like.

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, preferably (1) is 30 to 70% by weight, (2) is 30 to 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 from 5,000 to 10,000,000.
0, preferably 5,000 to 5,000,000. Examples of such a water-soluble polymer (3) include acrylamide polymer, acrylamide / acrylic acid (salt) copolymer, acrylamide / acrylic acid (salt) /
2-acrylamide-2-methylpropanesulfonic acid (salt) copolymer, acrylamide / (meth) acryloyloxyethyltrimethylammonium chloride copolymer acrylamide / (meth) acryloyloxyethyltrimethylammonium chloride copolymer and (meth) acryloyl Nonionic, anionic, and weakly cationic polymers such as oxyethyltrimethylammonium chloride polymer. 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 5000 or more may be used.
A polyisocyanate having a molecular weight of 4500 or more and a polycondensate of polyamines and epihalohydrin having a molecular weight of 4500 or more and a polyamine having a molecular weight of 4000 or more and a polyamine having a molecular weight of 4000 or more and disulfide having a molecular weight of 4000 or more Reactants with carbon. Two or more of the water-soluble polymers exemplified as (3) above may be used in combination.

The heavy metal fixing agent of the present invention is effective for fixing heavy metals in heavy metal-containing materials having various properties such as block-like solids, powders, liquids, slurries, and pastes. It is effective for immobilizing heavy metals in solid powder or slurry-like heavy metal-containing substances such as soil and sludge, and is particularly suitable for immobilizing heavy metal-containing incinerated 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. In addition, when adding separately, either may be added first. When the heavy metal-containing material is in a slurry form, only the fixing agent may be added alone,
Usually, (1), (2) and (3) are used by mixing them in advance, but they may be added separately.

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

In the method of the present invention, the above metal fixing agent and, if necessary, water may be merely sprayed on the surface of the solid powder or slurry material, but it is preferable to knead the solid powder or slurry material by adding it. . If necessary, a common coagulant or neutralizing agent may be used in combination.

[0017]

EXAMPLES The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples. In addition, the molecular weight in an Example represents a number average molecular weight, and% represents weight%. Production Example 1 Water 3 was added to a reaction vessel capable of cooling and stirring and capable of purging with nitrogen.
70 parts, potassium hydroxide 180 parts, piperazine 67 parts,
Charge 140 parts of a 50% aqueous solution of dimethylamine,
Stirred at 0 rpm. After confirming that the solid matter 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, the mixture was aged 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 added to a reaction vessel capable of cooling / stirring and capable of purging with nitrogen.
00 parts, 120 parts of potassium hydroxide and 70 parts of piperazine were charged and stirred at 200 rpm. After confirming that the solid matter 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, the mixture was aged at the same temperature for 3 hours to obtain a piperazine derivative. A 40% aqueous solution was obtained.

Comparative Production Example 2 Water 7 was added to a reaction vessel capable of cooling and stirring and capable of purging with nitrogen.
0 parts, 60 parts of potassium hydroxide, and 140 parts of a 50% by weight aqueous solution of dimethylamine were charged and stirred at 200 rpm. After confirming that the solids in the reaction vessel were dissolved,
80 parts of carbon disulfide was added dropwise at 35 ° C. under a nitrogen atmosphere.
After completion of the dropwise addition, the mixture was aged at the same temperature for 3 hours to obtain a 60% aqueous solution of a dimethylamine derivative.

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

Production Example 3 Water 3 was added to a reaction vessel capable of cooling and stirring and capable of purging with nitrogen.
70 parts, sodium hydroxide 180 parts, N, N 'dimethylethylenediamine 70 parts, 50% by weight of dimethylamine
An aqueous solution (140 parts) was charged and stirred at 200 rpm. After confirming that the solid matter 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, the mixture was aged 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 being cooled and stirred and replaced with nitrogen.
Forty parts, 130 parts of piperazine and 190 parts of diethylamine were charged and stirred at 200 rpm. After confirming that the solid matter in the reaction vessel was dissolved, 35 ° C under a nitrogen atmosphere.
Then, 240 parts of carbon disulfide was added dropwise, and after completion of the addition, the mixture was aged 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 added to a reaction vessel capable of cooling and stirring and capable of purging with nitrogen.
40 parts, sodium hydroxide 100 parts, piperazine 90
Parts, 130 parts of di-n-butylamine, and 200 rpm
m. After confirming that the solid matter in the reaction vessel was dissolved, carbon disulfide 240
Then, the mixture was aged 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 and 2 To 50 parts of fly ash produced by incineration of garbage, 0.17 parts of a heavy metal fixing agent synthesized in Production Examples 1 to 5 and Comparative Production Examples 1 and 2 was added.
10 parts of water was added and kneaded at 80 ° C. for 10 minutes. Dissolution test for treated and untreated ash after kneading (Environment Agency Announcement 13
), And the concentration of the eluted lead ions was measured. The results were as shown in Table 1 below.

Comparative Example 3 Fly ash 50 generated by incineration of garbage used in Examples 1 to 5
0.17 part of a commercially available chelating agent (heavy metal fixing agent manufactured by Miyoshi Oil & Fat Co., Ltd., trade name "Epofloc L-1") and 10 parts of water were added to the mixture, and kneaded at 80 ° C for 10 minutes. The treated ash after kneading and the untreated ash were subjected to an elution test (No. 13 published by the Environment Agency) and the concentration of eluted lead ions was measured. The results were as shown in Table 1 below.

[0026]

[Table 1]

[0027]

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

──────────────────────────────────────────────────の Continuation of the front page (51) Int.Cl. ⁶ Identification symbol FI B09C 1/08 B09B 3/00 304J C02F 11/00 101 304K (72) Inventor Kuniyoshi Yoshio 11-Hitohashi Nohonmachi, Higashiyama-ku, Kyoto-shi 1. Inside Sanyo Chemical Industries Co., Ltd. (72) Inventor Hideki Omori 1 at 11-11 Hitotsubashi Honcho, Higashiyama-ku, Kyoto City Inside Sanyo Chemical Industries Ltd. (72) Hiroshi Yoshimochi 1 at 11-11 Hitotsubashi Nohonmachi, Higashiyama-ku, Kyoto City (72) Inventor Yoshihiro Hori 3-4-7 Nishi-Shinjuku, Shinjuku-ku, Tokyo Kurita Industries, Ltd. (72) Inventor Ichiro Ito 3-4-7, Nishi-Shinjuku, Shinjuku-ku, Tokyo Examiner in Industrial Co., Ltd. Emiko Sakazaki (56) References JP-A-57-107298 (JP, A) JP-A-1-164492 (JP, A) JP-A-5-50055 (JP, A) JP-A-8-41017 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) C09K 3/00 108 B09B 3/00 B09C 1/02 B09C 1/08 C02F 11/00 101

Claims (6)

(57) [Claims] 1. A molecular weight 10 having one of the following functional groups in the molecule is a salt-forming or complex-forming include sulfur
Compounds of 0-500 (1), compounds having a molecular weight 200 to 5,000 having two or more in one or more molecules of the following functional groups which are salt-forming or complex-forming include sulfur atom (2), and Number average molecular weight 5,000-1 if necessary
Water-soluble polymer compound of 0,000,000 (3) from the <br/> Ri name blending amount of (3) (1), the total of (2), (3)
Der Ru heavy metal immobilizing agent 30% by weight or less based on the amount. Sulfuric acid
Functionality that contains a yellow atom and is salt-forming or complex-forming
Group: dithiocarbamic acid group, thiocarbamic acid group, thioamido
Group, thioureido group, xanthate group, thiol
Groups, thiophenol groups and their alkali metals,
Functionality selected from the group consisting of ammonium or amine salts
Base 2. The compounding ratio of (1), (2) and (3) is as follows:
(1): (2): (3) = 10 to 90% by weight: 10 to 7
The heavy metal fixing agent according to claim 1, wherein 0% by weight: 0 to 30% by weight . 3. The method according to claim 1, wherein (1) is an alkali metal salt and / or an 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 a molecule. 4. (1) is potassium dimethyldithiocarbamate and / or a dialkylamine salt,
The heavy metal fixing 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, comprising adding the heavy metal fixing agent according to claim 1 and optionally water to a solid powder or slurry (4) containing the heavy metal and kneading the mixture. 6. The method according to claim 5, wherein (4) is incinerated fly ash containing a heavy metal.