JPS6233590A - Method for collecting metal - Google Patents

Abstract

PURPOSE:To efficiently collect and remove metallic ions in waste water by adding a polyamine derivative and at least one kind among Na monosulfide, Na polysulfide and Na hydrosulfide to the waste water. CONSTITUTION:A polyamine derivative having at least one beta-hydroxyalkyl group and at least one dithiocarboxyl group or its salt in one molecule as the N-substituted group and at least one kind among Na monosulfide, Na polysulfide and Na hydrosulfide are added to waste water to collect and remove the ions of metals (e.g., mercury, Cd, zinc, lead, copper, Cr, gold, silver and platinum) in the waste water. The ratio of the polyamine derivative to Na sulfides to be used is preferably regulated to 20/80-98/2. The total amt. of both materials is preferably controlled to 0.9-1.5 molar equivalents of the amt. of the metallic ions. The waste water, in this case, is preferably adjusted at 4-9pH.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a method for collecting metals.

[Conventional technology]

In recent years, as the pollution of rivers, oceans, etc. by wastewater from factories has become a problem, regulations to prevent pollution by wastewater have been strengthened, and it is now mandatory to keep metals contained in wastewater below a specified concentration. In particular, strict regulations are in place for heavy metals that are harmful to the human body, such as mercury, cadmium, zinc, copper, and chromium. For this reason, various methods have been proposed to remove metals from wastewater, including ion flotation, ion exchange, electrolytic flotation, electrodialysis, reverse osmosis, slaked lime, A known method is a neutralization coagulation-sedimentation method in which metals are turned into hydroxides by adding an alkali neutralizing agent such as caustic soda, and then removed by coagulation and precipitation using a polymer flocculant.

[Problem that the invention seeks to solve]

However, the ion flotation method, ion exchange method, electrolytic flotation method, electrodialysis method, and reverse osmosis method have problems such as heavy metal removal rate, operability, and running cost, and are only suitable for some special wastewater treatments. Currently, it is only used.

In addition, in the neutralization coagulation precipitation method, a large amount of metal hydroxide sludge is generated, and these hydroxide sludges have poor dewatering properties.
Since the sludge volume is large, it is difficult to transport, and it is also very difficult to remove heavy metals to below the wastewater standard value. Moreover, depending on how these sludges are disposed of, they may be redissolved and cause secondary pollution.

[Means for solving problems]

As a result of intensive research in view of the above points, the present inventors have found that at least one β-hydroxyalkyl group and at least one dithiocarboxy group or a salt thereof in one molecule are N
- It was discovered that polyamine derivatives having as a substituent have excellent performance as metal scavengers, but as a result of further intensive research, the above polyamine derivatives and at least one of sodium monosulfide, sodium polysulfide, and sodium hydrogen sulfide were discovered. The present inventors have discovered that metal ions in waste water can be most efficiently collected and removed by using the above methods in combination, and have completed the present invention.

The metal collection method of the present invention uses a polyamine derivative having at least one β-hydroxyalkyl group and at least one dithiocarboxy group or a salt thereof as an N-substituent in one molecule, and sodium monosulfide. In this method, at least one of sodium polysulfide and sodium hydrogen sulfide is added to wastewater containing metal ions to collect and remove metal ions in the wastewater.

The polyamine derivative used in the present invention has at least one β-hydroxyalkyl group as an N-substituent substituted with an active hydrogen bonded to a nitrogen atom in a polyamine molecule having a primary amino group and/or a secondary amino group. ,
It is a compound having at least one dithiocarboxy group (C35H) or its salts, such as alkali metal salts such as sodium salts and potassium salts, alkaline earth metal salts such as calcium salts, ammonium salts, and the like. This polyamine derivative has, for example, at least one β-hydroxyalkyl group obtained by ring-opening addition of an epoxy alkane to a polyamine as an N-substituent, and has at least one active hydrogen group bonded to a nitrogen atom. a compound having
That is, at least one dithiocarboxy group obtained by reacting poly(or mono)-N-(β-hydroxyalkyl)polyamine with carbon disulfide, or by reacting polyamines with carbon disulfide, is substituted with an N-substituent. and has at least one active hydrogen bonded to the nitrogen atom, i.e. poly(or mono)-N-
It can be obtained by ring-opening addition of an epoxy alkane to (dithiocarboxy)polyamine, but after the reaction is completed, it can be treated with an alkali such as sodium hydroxide, potassium hydroxide, ammonium hydroxide, etc., or the reaction can be carried out in the presence of an alkali. The active hydrogen of the dithiocarboxy group can be replaced with an alkali metal, an alkaline earth metal, ammonium, etc. by performing the following steps. The reaction between poly(or mono)-N-(β-hydroxyalkyl)polyamine and carbon disulfide is carried out in a solvent, preferably water or alcohol, at 30-100°C for 1-10 hours, especially at 40-70°C for 2 hours.
It is preferable to carry out the treatment for 5 hours. In addition, the reaction between poly(or mono)-N-(dithiocarboxy)polyamine and epoxyalkane can be carried out using a solvent, preferably water, alcohol,
in a single or mixed solvent such as acetone, dioxane, methyl ethyl ketone, etc. at 40 to 100°C for 1 to 19 hours,
Especially at 60-80°C in a 1:l mixed solvent of water-acetone.
It is preferable to carry out the treatment for 2 to 3 hours.

Examples of the above polyamines include ethylenediamine,
Propylene diamine, butylene diamine, hexamethylene diamine, diethylene triamine, dipropylene triamine, diethylene triamine, triethylene tetramine, tripropylene tetramine, tributylene tetramine, tetraethylene pentamine, tetrapropylene pentamine, tetrabutylene pentamine, pentaethylene hexazine, etc. Polyalkylene polyamine; aniline, phenylene diamine, xylene diamine, metaxylene diamine, iminobispropylamine, monomethylaminopropylamine, methyliminobispropylamine, 1
, 3-bis(aminomethyl)cyclohexane, 1.3-
Diaminopropane, 1゜4-diaminobutane, 3,5-
Diaminochlorobenzene, melamine, 1-aminoethylpiperazine, piperazine, 3,3'-dichlorobenzidine, diaminophenyl ether, tolidine base, m-
Toluylene diamine, etc., polyethylene polyimine (average molecular weight 300 or more), etc. are used. Furthermore, N-alkyl polyamine, N-hydroxyalkyl polyamine, N-
N-substituted polyamines having an alkyl group, hydroxyalkyl group, acyl group, etc. as a substituent such as acyl polyamine can also be used. These N-substituted polyamines can be obtained by reacting the polyamines with alkyl halides, epoxyalkanes, fatty acids, etc.

Examples of N-alkylpolyamines include N-alkylethylenediamine, N-alkylpropylenediamine,
N-alkylhexamethylenediamine, N-alkylphenylenediamine, N-alkylxylenediamine, N
Examples include -alkyldiethylenetriamine, N-alkyltriethylenetetramine, N-alkyltetraethylenepentamine, and N-alkylpentaethylenehexamine, and the N-substituted alkyl group preferably has 2 to 18 carbon atoms.

The N-hydroxyalkylpolyamine preferably has a hydroxyalkyl group having 4 to 35 carbon atoms, such as N-hydroxyethylpolyamine, N-hydroxypropylpolyamine, N-hydroxybutylpolyamine,
N-(β-hydroxydodecyl)polyamine, N-(β-hydroxydodecyl)
-hydroxytetradecyl) polyamine, N-(β-hexadecyl) polyamine, N-(β-hydroxyoctadecyl) polyamine, N-(β-hydroxyoctacosyl) polyamine, and the like. The N-acylpolyamines preferably have acyl groups having 3 to 30 carbon atoms, such as N-acetylpolyamines, N-propionylpolyamines, N-butyrylpolyamines, N-caproylpolyamines, N-lauroylpolyamines, N- Examples include oleoyl polyamine, N-myristyroyl polyamine, N-stearoyl polyamine, N-beheroyl polyamine, and the like. The above polyamines and N-substituted polyamines can be used alone or in combination of two or more.

Epoxy alkanes preferably have 2 to 28 carbon atoms, such as ethylene oxide, propylene oxide,
Examples include butylene oxide and α-olefin oxide (having 6 to 28 carbon atoms).

In the method of the present invention, at least one β-hydroxyalkyl group and at least one dithiocarboxy group are
A polyamine derivative having a substituent group and at least one of sodium monosulfide, sodium polysulfide, and sodium hydrogen sulfide are added to wastewater to collect and remove metal ions in the wastewater.

As the sodium polysulfide, sodium disulfide, sodium trisulfide, sodium tetrasulfide, and sodium trisulfide are used. The purpose of the present invention can be achieved if the weight ratio of the polyamine derivative and the above-mentioned sodium sulfides is 1:99 to 99:1, but especially 20:80 to 98:1.
It is preferable that it is 2.

The polyamine derivative and the sodium sulfides may be mixed in advance and added to the wastewater, or they may be added to the wastewater separately, but it is preferable to mix them in advance and add them to the wastewater. Incidentally, when adding them separately, the effect of removing metal ions is almost the same whether the polyamine derivative is added first and then the sodium sulfides are added, or the metal ion removal effect is added in the reverse order.

The polyamine derivative used in the present invention can be used alone as a metal scavenger, but when used in combination with sodium sulfide, the generated flocs are even larger, the time required for floc sedimentation can be shortened, and metal ions in wastewater can be used. can be collected and removed extremely efficiently. Sodium sulfides also have the ability to form complexes with metal ions, but when used alone, the flocs produced are extremely small, making it difficult to precipitate and remove the flocs. Metal ions in wastewater can be efficiently collected and removed.

This is thought to be due to the synergistic effect of the ability of polyamine derivatives to form a complex with metal ions and the ability of sodium sulfides to form a complex with metal ions. Therefore, the amount of polyamine derivatives and sodium sulfides added to wastewater should be 0.7 to 0.7 to the amount of metal ions in wastewater, as the total amount of both.
An amount of 4 molar equivalents, particularly 0.9 to 1.5 molar equivalents, is preferred.

In the present invention, when collecting and removing metal ions in wastewater by adding polyamine derivatives and sodium sulfides to wastewater, it is preferable to adjust the pH of the wastewater to 3 to 10, particularly 4 to 9. The acid or alkali used to adjust the pH may be anything as long as it does not inhibit the formation of flocs.Usually, the acid used is hydrochloric acid, sulfuric acid, nitric acid, etc., and the alkali is sodium hydroxide, hydroxide, etc. Potassium, calcium hydroxide, etc. are used.・According to the method of the present invention, mercury, cadmium, zinc, lead, copper,
Chromium, arsenic, gold, silver, platinum, vanadium, thallium, etc. can be efficiently collected and removed.

〔Example〕

Hereinafter, the present invention will be explained in more detail with reference to Examples.

Example 1 In a four-way flask equipped with a stirrer, temperature needle, dropping funnel, and reflux condenser, 106 g of N-(β-hydroxylauryl)ethylenediamine and 20% sodium hydroxide solution were added. V
? 90 g of fi was charged, and 33 g of carbon disulfide was added dropwise from the dropping funnel while stirring vigorously at 40 tl', and after the dropwise addition was completed, aging was carried out at the same temperature for 4 hours. Next, the reaction solution was poured into a large amount of acetone to form a precipitate, and the precipitate was purified by reprecipitation three times in a water-acetone system, and then dried under reduced pressure to obtain a polyamine with a sulfur content of 17.5%. 125 g of derivative powder was obtained.

30 g of sodium monosulfide to 100 g of this polyamine derivative
0.3 g of the mixture containing 5 g of copper ion-containing aqueous solution (5
aqueous solution containing cadmium ions (containing 50 ppm Cd2”, p
H=5.0), water 1m ion-containing aqueous solution (50
p pm of Hg2°, pH=5.0), lead ion-containing aqueous solution (containing 50 p pm of PB", pH=5.0)
(7) The four types of aqueous solutions were added to 10oll of a pot, stirred for 5 minutes, and then allowed to stand to measure the time until the generated flocs precipitated. The results are shown in Table 1. Next, after the generated flocs were filtered, the residual metal ion concentration in the filtrate was measured by atomic absorption spectrometry. The results and the volume of the generated flocs are also shown in Table 1.

Example 2 Into the same apparatus as in Example 1, 118 g of N-(β-hydroxyoctyl)triethylenetetramine and 180 g of a 20% aqueous sodium hydroxide solution were charged, and 66 g of carbon disulfide was reacted in the same manner as in Example 1. Purified and dried pale yellow polyamine derivative powder with sulfur content of 26.8% 19
5g was obtained.

To 100g of this polyamine derivative, 30g of ternarized sodium
0.3 g of a mixture containing 0.3 g was added to 1000 d of the same four metal ion-containing aqueous solutions as in Example 1, and the floc precipitation time, floc production amount, and residual metal ion concentration in the filtrate were measured in the same manner as in Example 1. was measured. The results are shown in Table 1.

Example 3 Into the same apparatus as in Example 1, 173 g of N,N″-bis(β-hydroxyoctyl)triethylenetetramine and 2
360 g of 0% sodium hydroxide water RWf was charged, and then 66 g of carbon disulfide was reacted in the same manner as in Example 1. After purification and drying, 286 g of pale yellow-white polyamine derivative powder with a sulfur content of 19.1 wt% was obtained. Obtained.

2 sodium hydrogen sulfide to 100g of this polyamine derivative
0g of the mixture was mixed with 0.4g of the same mixture as in Example 1.
Each of the seeds was added to the metal ion-containing aqueous solution 10001, and the floc precipitation time, floc production amount, and residual metal ion concentration in the filtrate were measured in the same manner as in Example 1. Results first
Shown in the table.

Example 4 167 g of N-(β-hydroxyhexadecyl)diethylenetriamine and 290 g of water were charged into the same apparatus as in Example 1, heated to 60"C, and 44 g of carbon disulfide was dropped from the dropping funnel. After the dropping was completed, Aging was performed at the same temperature for 4 hours.Then, the reaction solution was heated to 70-75°C, and 20%
120 g of sodium hydroxide was added and the reaction was carried out for 1.5 hours. Thereafter, purification and drying was performed in the same manner as in Example 1 to obtain 207 g of a light reddish brown polyamine derivative powder with a sulfur content of 15.7 wt%.

20 g of sodium monosulfide to 100 g of this polyamine derivative
0.3 g of a mixture of g and 15 g of sodium trisulfide
10 of the same four metal ion-containing aqueous solution as in Example 1.
The floc precipitation time, floc production amount, and residual metal ion concentration in the filtrate were measured in the same manner as in Example 1. The results are shown in Table 1.

Example 5 429 g of water was charged into the same apparatus as in Example 1, and then N
- (β-hydroxyoctacosyl)hexamethylenediamine (299 g) was finely ground and dispersed in water, and then
4'1 g of carbon disulfide was dropped at 0°C, and after the dropping was completed,
It was aged at the same temperature. Next, 74 g of a 30% aqueous sodium hydroxide solution was added, and the temperature was raised to 50° C. to carry out a reaction for 1.5 hours. After completion of the reaction, insoluble components were filtered off, washed with water, and further washed with acetone, then ground and dried under reduced pressure to obtain 306 g of a yellow ground polyamine derivative having a sulfur content of 12.5 wt%.

0.4 g of a mixture of 100 g of these 8 polyamine RMs and 20 g of sodium monosulfide was added to 1000 ml of the same four metal ion-containing aqueous solutions as in Example 1, and floc precipitation was carried out in the same manner as in Example 1. The time, floc production amount, and residual metal ion concentration in the filtrate were measured. The results are shown in Table 1.

Example 6 99 g of commercially available polyethylene polyimine (manufactured by Nippon Shokubai Kagaku Kogyo 1, Epomin SP-300) was mixed with 1 part of ethyl alcohol.
46 g, and 212 g of epoxy alkane (carbon number 12) was added dropwise under reflux while stirring at 75°C.
After the dropwise addition was completed, the mixture was maintained at the same temperature for 2 hours and then concentrated to obtain 231 g of a yellow crystalline solid. This crystalline solid 200
g was finely pulverized and dispersed in 200 g of water, 20 g of sodium hydroxide was added thereto, and 32 g of carbon disulfide was added dropwise at 40° C. After completion of the dropwise addition, the reaction was continued at the same temperature for 2 hours. After completion of the reaction, insoluble components were filtered out and washed with water, further washed with acetone, and dried under reduced pressure to obtain sulfur-containing i10. 241 g of a yellow polyamine derivative pulverized product of xwt% was obtained.

0.3 g of a mixture of 4 long polyamine 'tFr' and 30 g of sodium trisulfide was added to each of the four metal ion-containing aqueous solutions 100014 as in Example 1, and floc precipitation was carried out in the same manner as in Example 1. The time, floc production amount, and residual metal ion concentration in the filtrate were measured. The results are shown in Table 1.

Example 7 200 g of the same crystalline solid as in Example 6, in which polyethyleneimine was reacted with an epoxy alkane, was dissolved in 58 g of concentrated ammonia water, then dispersed in 300 g of water, and heated at 40°C.
32 g of carbon disulfide was added dropwise, and after the addition was completed, the reaction was continued at the same salinity for 2 hours.

After the reaction was completed, insoluble components were filtered off, washed with water, further washed with acetone, and dried under reduced pressure to obtain 239 g of a yellow pulverized polyamine derivative having a sulfur content of 10.86%.

Sodium monosulfide 15g per 100g of this polyamine derivative
0.3 g of a mixture of g and 15 g of sodium trisulfide
10 of the same four metal ion-containing aqueous solution as in Example 1.
00 xi, and the floc precipitation time, floc production amount, and residual metal ion concentration in the filtrate were measured in the same manner as in Example 1. The results are shown in Table 1.

Example 8 100g of the polyamine derivative obtained in Example 6 was added to 200g of water.
and further add 248 ammonium chloride to make 5
The reaction was carried out at 0°C for 4 hours, and after the completion of the reaction, insoluble components were filtered out and washed with water, further washed with acetone, and dried under reduced pressure to replace the active hydrogen of the dithiocarboxy group with ammonium, resulting in a sulfur content of 11. 95 g of a 5 wt % yellow polyamine derivative was obtained.

3 sodium hydrogen sulfide to 100g of this polyamine derivative
0.3 g of the mixture mixed with 0.0 g of
Each of the seeds was added to 1000 d of a metal ion-containing aqueous solution, and the floc precipitation time, floc production amount, and residual metal ion concentration in the filtrate were measured in the same manner as in Example 1. Results first
Shown in the table.

Example 9 100 g of sodium salt of N-(dithiocarboxy)ethylenediamine and 116 epoxy alkane (12 carbon atoms)
．． 5 g of water and acetone <1:1) for 3 hours at 80°C. After the reaction, the reaction solution was poured into a large amount of acetone to form a precipitate, and the filtered precipitate was poured into water. - It was purified by reprecipitation three times in an acetone system and dried under reduced pressure to obtain 165 g of a light brown polyamine derivative powder with a sulfur content of 17.6%.

30 g of sodium monosulfide to 100 g of this polyamine derivative
Add 0.3 g of the mixture of g to 1000 ml of the same four metal ion-containing aqueous solutions as in Example 1,
In the same manner as in Example 1, floc settling time, floc production amount, and residual metal ion concentration in the filtrate were measured. The results are shown in Table 1.

Example 10 In an apparatus similar to Example 1, 120% of the sodium salt of N,N,N'-)lis(dithiocarboxy)phenylenediamine was added.
．． 6g, epoxy alkane (12 carbon atoms) 5.5.2g
and 500 g of water-acetone (1:1), and
After carrying out the reaction at °C for 4 hours, the reaction solution was poured into a large amount of acetone to form a precipitate, and the filtered precipitate was purified in the same manner as in Example 9 and dried under reduced pressure to obtain a sulfur content of 32.
．． 76wt% light brown polyamine derivative powder 170
．． 5g was obtained.

20 g of sodium trisulfide to 100 g of this polyamine derivative
0.3 g of the mixture containing 0.3 g of the mixture was added to 10,100 O of the same four metal ion-containing aqueous solutions as in Example 1, and the floc precipitation time, floc production amount, and residual metal ions in the filtrate were determined in the same manner as in Example 1. The concentration was measured. Results first
Shown in the table.

Example 11 In the same device as in Example 1, N', N'', N#, ・N''-
Tetrakis(dithiocarboxy)triethylenetetramine 159.0g, epoxyalkane (12 carbon atoms) 73
．． After charging 6 g and 500 g of water-acetone (1:1) and carrying out the reaction in the same manner as in Example 10, purification and drying were carried out in the same manner to obtain a brown polyamine derivative powder with a sulfur content of 32.8 wt%. 230g was obtained.

100g of this polyamine derivative and 10g of sodium monosulfide
0.3 g of a mixture of 5 g of sodium trisulfide and 5 g of sodium trisulfide were added to 100 g of the same four metal ion-containing aqueous solution as in Example 1.
0 d, and the floc precipitation time, floc production amount, and residual metal ion concentration in the filtrate were measured in the same manner as in Example 1. The results are shown in Table 1.

Example 12 99 g of commercially available polyethylene polyimine (manufactured by Nippon Shokubai Kagaku Kogyo ■, Epomin 5POO3, molecular weight approximately 300) was dissolved in 146 g of ethyl alcohol, heated to 75° C. with stirring, and refluxed to dissolve an epoxy alkane (carbon number 12> 212g
was added dropwise, and after the dropwise addition was completed, the reaction was further continued at the same temperature for 2 hours. After the reaction was completed, the reaction solution was concentrated to obtain 2Log of yellow crystalline solid. 200 g of the obtained crystalline solid was finely ground and dispersed in 200 g of water, 20 g of sodium hydroxide was added, and 32 g of carbon disulfide was added dropwise at 40°C. After the dropwise addition was completed, the mixture was allowed to react at 40°C for 2 hours. Ta. After completion of the reaction, insoluble components were filtered off, washed with water, further washed with acetone, and dried under reduced pressure to obtain 235 g of yellow pulverized polyamine M4 with a sulfur content of 10.6 wt%.

100g of this polyamine derivative and 1% sodium hydrogen sulfide
0.5 g of the mixture mixed with 0 g of
Each was added to 1,000 samples of a metal ion-containing aqueous solution of the seeds, and the floc precipitation time, floc production amount, and residual metal ion concentration in the filtrate were measured in the same manner as in Example 1. The results are shown in Table 1.

Comparative Example 1 0.3 g of the same polyamine derivative as in Example 1 was added to 10.00 g of the same four metal ion-containing aqueous solution as in Example 1.
tZ, and the floc precipitation time, floc production amount, and residual metal ion concentration in the filtrate were measured in the same manner as in Example 1. The results are shown in Table 1.

〔Effect of the invention〕

As explained above, in the metal collection method of the present invention, at least one β-hydroxyalkyl group and at least one dithiocarboxy group or its salt are N
Collecting and removing metal ions in wastewater by adding a polyamine derivative as a substituent and at least one of sodium monosulfide, sodium polysulfide, and sodium hydrogen sulfide to wastewater containing metal ions as a metal collector. Since this method is adopted, metal ions in wastewater can be efficiently collected and removed even with a smaller amount of metal collector than in conventional metal collection methods. Moreover, the polyamine derivative used in the present invention can sufficiently collect and remove metal ions even when used alone, but when used in combination with at least one of sodium monosulfide, sodium polysulfide, and sodium hydrogen sulfide, the two can synergize. It works effectively, and the floc sedimentation rate is faster than when a polyamine derivative is used alone, and it has the effect of highly efficiently collecting and removing metal ions in wastewater.

Commissioner of the Japan Patent Office Michibu Uga Metal collection method 3, relationship with the case of the person making the amendment Patent applicant address 4-66-1 Horikiri, Izuka-ku, Tokyo Name Miyoshi Oil Co., Ltd. Representative Takeyuki Miki 4, agent Person 101 Address 2-75 Kanda Sakuma-cho, Chiyoda-ku, Tokyo, Date of amendment order Voluntary amendment 6, Detailed description of the invention in the specification subject to amendment 7, Contents of amendment as attached (11 Specification No. 1) In line 13, "20. Detailed description of the invention" is corrected to "3. Detailed description of the invention."

(2) "Reverse osmosis method" on page 2, line 13 of the same page is corrected to "reverse osmosis pressure method."

(3) On page 3, line 10 of the same page, change ``The heading is...'' to ``
...I found something," he corrected himself.

(4) Insert the following sentence next to "...can be replaced." on page 5, line 11.

"Furthermore, some active hydrogens in the dithiocarboxy group can be substituted with an alkali metal, an alkaline earth metal, ammonium, etc. to produce a polyamine derivative having a dithiocarboxy group and a salt of a dithiocarboxy group as a substituent."
(5) Delete "Aniline," on page 6, line 12.

(6) Delete "1,3-diaminopropane, 1,4-diaminobutane," from lines 17 to 18 of the same page.

(7) "Tolidine base" on page 7, line 1 is corrected to "tolidine."

(8) Delete "N-hydroxyalkylpolyamine" from lines 4 to 5 on the same page.

(9) Delete "hydroxyalkyl group" in line 6 of the same page.

(10) "Epoxyalkane," lines 9-10 on the same page.
Delete.

αυ Delete "N-hydroxyalkyl polyamines, etc." from lines 1 to - on page 8 of the same document.

α2 Correct “3 to 30 carbon atoms” in lines 11 to 12 of the same page to “2 to 30 carbon atoms”.

0■ "Epoxyalkane...for example, ethylene oxide" on page 9, lines 1-2 is corrected as follows.

"The β-hydroxyalkyl group in the polyamine derivative used in the present invention having at least one β-hydroxyalkyl group and at least one dithiocarboxy group or a salt thereof as a substituent has 2 to 28 carbon atoms.
Preferred boxyalkanes for introducing a β-hydroxyalkyl group are those having 2 to 28 carbon atoms. Examples of the epoxyalkane include ethylene oxide, etc." α Xun "Polyamine derivative and sodium monosulfide" in lines 8 and 9 of the same page is corrected to "polyamine taH! and sodium monosulfide."

July 8, 1985 Patent Application No. 172128 of 1985 2 Name of the invention Metal collection method 3 Relationship with the person making the amendment Case Patent applicant address Tokyo 4-66-1 Horikiri, Katsushika-ku Name: Miyoshi Oil Co., Ltd. Representative: Takeyuki Miki 4, Agent: 101 Address: 2-75 Kanda Sakuma-cho, Chiyoda-ku, Tokyo Date of amendment order

Claims (1)

[Claims] A polyamine derivative having at least one β-hydroxyalkyl group and at least one dithiocarboxy group or a salt thereof as an N-substituent in one molecule, and at least one of sodium monosulfide, sodium polysulfide, and sodium hydrogen sulfide. 1. A method for collecting metals, which comprises adding seeds to wastewater containing metal ions to collect and remove metal ions in the wastewater.