WO2011070798A1 - Metal recovery method for recovering metal from wastewater, metal-separating substance for use in recovery of metal from wastewater, and water purification device utilizing the substance - Google Patents

Abstract

Disclosed are: a metal recovery method which can separate and recover a metal from wastewater rapidly and in a large quantity; a substance for use in the separation of a metal; and a water purification device utilizing the substance. Specifically disclosed are: a metal-separating substance which can be used for the recovery of a metal from wastewater, which is characterized by comprising a water-soluble polymer having an acidic group and an anion exchange resin; and a water purification device utilizing the metal-separating substance, which is characterized by comprising a first mixing vessel in which the wastewater is mixed with an aqueous solution of the water-soluble polymer having an acidic group and a second mixing vessel in which a solution produced by mixing the wastewater with the aqueous solution of the water-soluble polymer having an acidic group with an anion exchange resin, wherein a filter is arranged in the inferior part of the second mixing vessel, and the filter has pores so that the anion exchange resin can be held by the pores.

Description

Metal recovery method for recovering metal in sewage, chemical for metal separation for recovering metal in sewage, and water purification apparatus using the same

The present invention relates to a metal recovery method for recovering metals in sewage, a metal recovery agent for recovering metals in sewage, and a water purifier using the same.

When metal-containing wastewater including industrial water contains highly toxic components such as cadmium and copper, the concentration of metal-containing wastewater is reduced to the discharge standard by various methods and discharged to rivers and the ocean. In addition, even in drinking water compatible water purifiers, a method has been proposed in which the inside of the water purifier is filled with an ion exchange resin to trap metals.

In general, metals dissolved in water are present in the form of ions in water. Therefore, a method of trapping with an ion exchange resin (Patent Document 1) and a method of filtering with a reverse osmosis membrane have been proposed. In addition, an agent for metal separation containing iron hydroxide (Patent Document 2) has been proposed. There is also proposed a method of adding a chelating agent to form a water-insoluble aggregate, followed by filtration.

JP 2001-232361 A JP 2006-218359 A

In the method using an ion exchange resin or a reverse osmosis membrane, when the metal concentration in the wastewater is high or the amount of wastewater to be treated is large, the metal trap function is deteriorated in a short time. Therefore, it is not suitable for industrial water and the like, and is used in applications such as drinking water, which have a low metal concentration and a small amount of treatment.

When using iron hydroxide, since the size of the aggregate is small, a metal separation agent is needed to increase the size. Further, there is a problem that the processing time is long because the reaction of aggregation is slow.

In the case of using a chelating agent, there is a problem that it is expensive as compared with the materials of the other methods, and if it is not properly controlled, it remains in the sewage.

Thus, in the prior art, it has been difficult to rapidly separate metals from a large amount of sewage at a practical cost.

An object of the present invention is to provide a metal recovery method for recovering a large amount of metal in sewage at a high speed, a metal separation agent for recovering metal in sewage, and a water purifier using the same.

In order to solve the above-mentioned subject, the feature of the present invention is the medicine for metal separation which recovers the metal in sewage, and the medicine for metal separation contains water-soluble polymer and anion exchange resin which have an acidic group. It is an agent for metal separation characterized by

Further, a feature of the present invention is a metal separation method for recovering metal in sewage, comprising the step of contacting anion exchange resin with the wastewater after the water-soluble polymer having an acidic group is added to the wastewater. Or forming a conjugate of a water-soluble polymer having an acidic group and an anion exchange resin, and then bringing the conjugate into contact with the wastewater.

Further, a feature of the present invention is a water purification apparatus using the above-described chemical for metal separation, which has a first mixing tank for mixing sewage and an aqueous solution of a water-soluble polymer having an acid group, sewage, and an acid group. A second mixing vessel for mixing an aqueous solution of a water-soluble polymer with a liquid mixed with an anion exchange resin, a filter is disposed in the lower part of the second mixing vessel, and the filter has a hole It is a water purifier characterized by the said anion exchange resin being hold | maintained by the hole of a filter.

According to the present invention, it is possible to provide a metal recovery method capable of separating and recovering metal in a large amount at a high speed and in large quantities, a chemical for metal separation and a water purifier using the same. In addition, it is possible to provide a metal recovery method capable of separating and recovering metal at low cost, a chemical for metal separation, and a water purification apparatus using the same. Problems, configurations, and effects other than the above are clarified by the description of the embodiments below.

1 is a scheme of metal separation of one embodiment of the present invention. 1 is a scheme of metal recovery according to an embodiment of the present invention. It is a schematic diagram of the metal separation / collection | recovery apparatus of one Embodiment of this invention. It is a schematic diagram of the metal separation / collection | recovery apparatus of one Embodiment of this invention. It is a schematic diagram of the metal separation / collection | recovery apparatus of one Embodiment of this invention. It is a schematic diagram of the metal separation / collection | recovery apparatus of one Embodiment of this invention. It is a schematic diagram of the metal separation / collection | recovery apparatus of one Embodiment of this invention. It is a schematic diagram of the metal separator of one Embodiment of this invention. It is a schematic diagram of the metal recovery apparatus of one Embodiment of this invention. It is a schematic diagram of the pretreatment apparatus of anion exchange resin used by one Embodiment of this invention. It is a schematic diagram of the metal recovery apparatus of one Embodiment of this invention.

Embodiments of the present invention will be described below using the drawings and the like.

A water-soluble polymer having acid groups is added to the wastewater, and the wastewater is subsequently contacted with a small amount of anion exchange resin. Thereby, metals far exceeding the exchange capacity as ion exchange resin can be separated from sewage. Also, the separated metal can be recovered as a hydroxide.

Furthermore, in the case where a ferromagnetic metal powder such as iron, cobalt or nickel is contained inside the ion exchange resin, it can be recovered by magnetism. Therefore, it is not necessary to hold it in a cylindrical container, and separation from dirty water and washing become easy.

In addition, since the water-soluble polymer and the ion exchange resin having an acidic group are renewable, they can be repeatedly used for metal separation from sewage. Therefore, metal separation can be performed at low cost compared to the prior art. The principle of metal separation from sewage according to the present invention will be described with reference to FIG.

First, the water-soluble polymer 2 having an acidic group is added to the wastewater in which the metal salt 1 is dissolved. Here, the case where it has a carboxyl group as an acidic group is illustrated. Also, although the metal is illustrated as being trivalent, in the case of a metal other than trivalent (a metal such as a monovalent, divalent or tetravalent metal), the maximum valence of one metal ion is obtained. The acidic group is ionically bound. Thereby, an ionic bond 3 composed of a metal ion and the water-soluble polymer 2 having an acidic group is generated. Thus, a water-soluble polymer 4 having a carboxyl group in which metal ions are trapped is formed. Here, metal ions which can not be ionically bonded remain in the sewage if the number of substituents capable of ionic bonding in the metal separation agent is larger than the product of the number of metal ions in the sewage and the valence of the metal ions. Therefore, the metal removal efficiency is not improved. Therefore, it is desirable that the number of carboxyl groups of the water-soluble polymer 4 having a carboxyl group be greater than the product of the number of metal ions in the sewage and the valence of the metal ions. This can reduce metal ions that can not be ionically bound in the sewage.

If metal ions are bound to a cation exchange resin, the rate of binding depends on the surface area of the ion exchange resin. Therefore, to increase the speed of metal separation, it is necessary to reduce the particle diameter of the ion exchange resin or to increase the surface area by providing asperities on the surface of the ion exchange resin. However, since the water-soluble polymer is dissolved in the sewage, the contact area between the water-soluble polymer and the metal ion is nearly infinite. Therefore, when metal ions are bonded to a water-soluble polymer, the separation speed of metal ions is much faster than when metal ions are bonded to a cation exchange resin.

Next, the waste water is brought into contact with the anion exchange resin 5 having an amino group. Then, the water-soluble polymer 4 having a carboxyl group in which metal ions are trapped is ionically bonded to the anion exchange resin 5. It is the water-soluble polymer 4 having a carboxyl group that directly bonds the metal. Since there are a large number of carboxyl groups in the water-soluble polymer 4 having a carboxyl group, a very large number of metal ions are trapped. Next, when the water-soluble polymer 4 having a carboxyl group is bonded to the anion exchange resin 5, the water-soluble polymer 4 having a carboxyl group in which many metal ions are trapped on one amino group is bonded. Therefore, metal ions far exceeding the number of amino groups possessed by the anion exchange resin 5 are bonded to one anion exchange resin 5. Thus, it is possible to efficiently separate metal ions from sewage.

By the way, metal ion separation and recovery are possible even if the order of use of agents used in the present invention is changed. First, an aqueous solution of a water-soluble polymer 2 having an acidic group is added to the anion exchange resin 5, and the amino group on the surface of the anion exchange resin 5 and the acidic group of the water-soluble polymer 2 having an acidic group are ionized. Let me combine. By doing this, the surface of the anion exchange resin 5 can be made to have many acid groups. Thereafter, the anion exchange resin 5 is pulled up from the aqueous solution of the water-soluble polymer 2 having an acidic group. When the anion exchange resin 5 is brought into contact with the sewage in this state, the acidic groups on the surface of the anion exchange resin 5 trap metal ions, and metal separation from the sewage becomes possible. That is, a combination of a water-soluble polymer 2 having an acid group and an anion-exchange resin 5 in advance is used in the order of the water-soluble polymer 2 having an acid group to dirty water and the anion exchange resin 5 in this order. It is a method of adding sewage after forming it. In addition, when making the anion exchange resin 5 which pulled up contact sewage, metal powder which shows ferromagnetism may be added to sewage.

Next, a separation and recovery scheme of metal ions included up to the regeneration of the water-soluble polymer 2 having an acidic group and the anion exchange resin 5 is shown in FIG.

Here, the method of using the water-soluble polymer 6 having an acidic group to the dirty water and the anion exchange resin 5 in this order will be described, but the water-soluble polymer 6 and the anion exchange resin 5 having an acid group in advance It is also possible to add sewage after forming the combined body.

First, the water-soluble polymer 6 having an acidic group is added to the wastewater, and the metal ion 7 and the acidic group 8 are ionically bonded to trap the metal ion 7. Next, the sewage is brought into contact with the anion exchange resin 9. Thereafter, the anion exchange resin 9 is separated from the sewage.

Subsequently, the anion exchange resin 9 is washed with hydrochloric acid. As a result, the water-soluble polymer 6 having an acidic group separates metal ions from the anion exchange resin 9 and dissolves in a cleaning solution containing hydrochloric acid. The metal ions 7 become metal chlorides 10 and dissolve in the cleaning solution containing hydrochloric acid.

In addition, although it demonstrates using hydrochloric acid here, you may use nitric acid, a sulfuric acid, etc., if the metal salt melt | dissolves in a washing | cleaning liquid. For example, among metal species that have a low solubility product of chloride in water, such as silver, etc., the solubility in a cleaning liquid is improved if nitric acid is added instead of hydrochloric acid.

The anion exchange resin 9 is then washed with an aqueous base solution such as sodium hydroxide to convert the surface amino groups in the form of hydrochloride into free amino groups again and then washed with deionized water for regeneration.

On the other hand, when a basic aqueous solution such as sodium hydroxide, which is an aqueous solution of an alkali metal hydroxide, is added to the cleaning solution of hydrochloric acid in which the water-soluble polymer 6 having an acidic group and the metal chloride 10 are dissolved 10 becomes metal hydroxide 11 and precipitates. The metal can be recovered by recovering this by filtration or the like. The recovered metal hydroxide is converted to a metal oxide by roasting or the like and used, or is reduced and converted to a metal and used.

When a sodium hydroxide aqueous solution is used as the base aqueous solution, the water-soluble polymer 6 having an acidic group becomes a group 12 having a sodium salt structure and is dissolved in the washing solution. An appropriate amount of hydrochloric acid is added thereto to acidify the washing solution, and the acid group of the salt structure is converted again to a free acid group. Thus, regeneration of the water-soluble polymer 6 having an acidic group is also possible.

As described above, in the present invention, since a drug for separating and recovering metal ions can also be regenerated, it becomes possible to separate and recover metal ions at low cost.

In addition, it is also possible to use the base aqueous solution used when converting the amino group of anion exchange resin free to metal hydroxide precipitation as it is by devising the process of the metal separation / recovery device mentioned later . By doing so, two steps can be completed in one step, and it is possible to further reduce the cost for recovery.

[1] Agent for metal separation The agent for metal separation contains the following water-soluble polymer having an acidic group, an anion exchange resin, and an additive for metal trap improvement. The composition for metal separation may have no additive.

(1) Water-Soluble Polymer Having Acidic Group A water-soluble polymer having an acid group may be a carboxyl group or a sulfonic acid group as the acid group.

Among these, polyacrylic acid is preferable as the water-soluble polymer having a carboxyl group at a low cost and in terms of easy ionic bond with an amino group. Besides, amino acid-derived polyaspartic acid, polyglutamic acid and the like are also characterized by having low toxicity. Alginic acid is one of the main components of kelp and other seaweeds, and its environmental load is small because the raw material is of biological origin.

Examples of the water-soluble polymer having a sulfonic acid group include polyvinyl sulfonic acid and polystyrene sulfonic acid. These sulfonic acid groups are preferred because they have a higher acidity than carboxyl groups, so the proportion of forming ionic bonds with amino groups is high, and stable bonds can be formed with anion exchange resins.

As described above, as the water-soluble polymer having an acidic group, it is desirable that at least one of polyacrylic acid, polyaspartic acid, polyglutamic acid, alginic acid, polyvinylsulfonic acid and polystyrenesulfonic acid is contained.

In the case where the water solubility of the water-soluble polymer having an acidic group is low, the solubility in water can be improved by forming the acidic group into an ammonium salt structure, a sodium salt structure or a potassium salt structure. An ammonium salt structure, a sodium salt structure or a potassium salt structure is formed, and then a water-soluble polymer having an acid group having a salt structure is added to the wastewater to efficiently form an ionic bond with the amino group of the anion exchange resin. It is possible.

By the way, when the number average molecular weight of the water-soluble polymer having an acidic group is too low, the number of ion binding sites between the water-soluble polymer having an acidic group and the anion exchange resin decreases, and the stability of the conjugate is low. Become. Therefore, the number average molecular weight of the water-soluble polymer having an acidic group is preferably 2,000 or more. The number average molecular weight is measured by gel permeation chromatography (GPC).

In addition, when the number average molecular weight of the water-soluble polymer having an acidic group is too large, one molecule widely covers the surface of the anion exchange resin, and as a result, the binding of another molecule is inhibited. The need to use many anion exchange resins arises. Therefore, the number average molecular weight of the water-soluble polymer having an acidic group is desirably 300,000 or less.

By the way, the metal trapping ability of the water-soluble polymer having an acidic group is affected by the pH of the sewage. When the pH of the sewage becomes too low, specifically, when the pH of the sewage becomes less than 2, the ionic bond between the metal and the water-soluble polymer having an acidic group is dissociated, and the metal can not be trapped. Also, if the pH of the wastewater is too high, specifically if the pH of the wastewater exceeds 5, the stability of the metal ions in the wastewater as ions decreases, and depending on the metal species, it will be in the wastewater as a metal hydroxide. Some things will precipitate out. Therefore, it is desirable to control the pH of the sewage to 2 or more and 5 or less. Specifically, there is a method such as adding a buffer solution to the sewage to control the pH.

(2) Anion exchange resin Anion exchange resin is fine particles of a polymer, and has an amino group on the surface of the anion exchange resin. In addition, those containing ferromagnetic metal powder such as iron, cobalt and nickel inside the anion exchange resin may also be mentioned. Those containing these metal powders can be separated magnetically, etc., and so are suitable for regeneration of anion exchange resins. In addition, you may be the structure in which magnetic metal powder is separately contained as a metal isolation | separation chemical | medical agent.

(3) Additive for metal trap improvement When the basicity of the metal salt in the sewage to be treated is low, the ratio of forming an ionic group with the acidic group of the water-soluble polymer having an acidic group decreases. Therefore, by adding an inorganic salt such as sodium chloride or potassium chloride to the wastewater before adding the water-soluble polymer having an acidic group to the wastewater, the proportion of metal ions which form an ionic bond with the acidic group is increased. This is effective when the counter anion of the metal salt is an organic substance such as acetate ion or benzoate ion. The reason why this effect appears is presumed to be that the allowable percentage of metal ions that can be dissolved in sewage is lowered by the effect similar to salting out that adds salt and precipitates the organic matter dissolved in water. There is.

As an inorganic salt to be added, an alkali metal or alkaline earth metal hydrochloride such as sodium chloride, potassium chloride, magnesium chloride or calcium chloride, an alkali metal or alkaline earth such as sodium sulfate, potassium sulfate, magnesium sulfate or calcium sulfate Examples thereof include metal sulfates, and nitrates of alkali metals or alkaline earth metals such as sodium nitrate, potassium nitrate, magnesium nitrate and calcium nitrate.

[2] Metal separation / recovery method (1) Outline of metal separation method of the present invention The metal separation method of the present invention is as shown in FIG. 1 described above. However, as described above, a water-soluble polymer having an acid group is added to the wastewater, and then the anion exchange resin is added to the water-soluble polymer having an acid group by changing the order of contacting the anion exchange resin. Then, this anion exchange resin, which has been brought into contact with a water-soluble polymer having an acidic group, may be brought into contact with sewage.

(2) Addition ratio of chemicals for metal separation, etc. Here, the product of the number and the valence of metal ions in the sewage is MB, the number of acid groups of the polymer having acid groups to be added is PA, anion exchange resin When the number of amino groups is PB, the addition amount of each is adjusted to be the following inequality. This can increase the rate of metal removal.
PA MB MB (a)
PB ≧ PA-MB (b)

Formula (a) means that in the wastewater, the number of acidic groups of the polymer having acidic groups is greater than or equal to the product of the metal ion and the valence. The reaction to form an ionic bond between the acidic group of the water-soluble polymer and the metal ion in the present invention is originally considered to be an equilibrium reaction. Therefore, if the acid group of the water-soluble polymer is excessive compared to the product of the metal ion and the valence, the trap ratio of the metal ion can be increased.

In the formula (b), the number of amino groups in the anion exchange resin is greater than or equal to the number of acid groups of the polymer having acid groups that do not form ionic bonds with metal ions. Means. As a result, almost all of the polymer having the acidic group having metal ions trapped therein is trapped by the anion exchange resin, so that it is possible to recover most of the polymer having the acidic group from the wastewater. This is preferable in that it does not increase the total carbon compound (TOC) concentration of the waste water.

(3) Measures to improve metal removal As measures to improve metal removal other than the above, when the amount of polymer having an acidic group is considered as the number of acidic groups, the number of acidic groups is the number of metal ions in the sewage and the valence. Add as much as possible to the number of the product of the number.

When an anion exchange resin is brought into contact with sewage, the anion exchange resin is packed in a cylindrical column, then the sewage is passed through or the anion exchange resin is put in a container such as a beaker, the sewage is poured into this, and stirred. And other methods.

When the anion exchange resin is packed in a column and then sewage is passed, fine particles of the anion exchange resin are retained in the column, so that the handling becomes easy also when subsequently washed with hydrochloric acid or purified water.

When the anion exchange resin is placed in a container such as a beaker, the anion exchange resin can be stirred by a stirring mechanism such as a stirring blade, so a water-soluble polymer having an acidic group and an anion exchange resin meet per unit time. The frequency increases. Therefore, the rate at which the anion exchange resin traps the water-soluble polymer having an acidic group is improved. When the anion exchange resin is separated from the dirty water or the hydrochloric acid washing solution, it is recovered by a filter or the like by filtration.

Further, when an anion exchange resin containing ferromagnetic metal powder is used, the anion exchange resin can be adsorbed by a magnet. Therefore, it becomes possible to separate anion exchange resin from dirty water or hydrochloric acid cleaning fluid by using a magnet.

In addition, as a method of enhancing the separation efficiency of metals, a method of adding an inorganic salt to sewage is mentioned. Thereby, it is presumed that the separation efficiency is enhanced by the effect similar to salting out. The inorganic salt to be added is preferably sodium chloride which is abundant in nature. In particular, in the case of sewage treatment of a submarine oil field or the like, the average sodium chloride concentration in seawater is about 3%, and even if it is added up to that level, the influence on the environment is slight and suitable.

[3] Form of Invention of Metal Separation and Recovery Device Next, the metal separation and recovery device of the present invention will be described. Among them, the forms 1 to 7 of the metal separation and recovery device correspond to the method of mixing the water-soluble polymer having an acidic group with the waste water and then bringing it into contact with the anion exchange resin. Further, Form 8 of the metal separation / recovery device corresponds to a method in which an anion exchange resin is added to an aqueous solution of a water-soluble polymer having an acidic group, and then this anion exchange resin is brought into contact with sewage.

(1) Form 1 of metal separation and recovery device
The basic configuration of the metal separation and recovery apparatus of the present invention will be described with reference to FIG.

Sewage is introduced into the first mixing tank 15 through the pipe 14 by the pump 13. The liquid in the first mixing tank 15 is agitated by the overhead stirrer 16. First, a water-soluble polymer aqueous solution having an acidic group is introduced into the first mixing tank 15 from the first tank 17 through the pipe 19 by the pump 18.

Further, the pH of the wastewater and the pH of the mixed liquid of the wastewater and the water-soluble polymer having an acid group are measured by the pH sensor 20, and the pH is controlled as needed as described later.

After the aqueous solution in the first mixing tank 15 is sufficiently mixed, the aqueous solution in the first mixing tank 15 is introduced into the second mixing tank 23 through the pipe 22 using the pump 21. The liquid in the second mixing tank 23 is agitated by the overhead stirrer 24.

By the way, when it is necessary to control the pH of the wastewater, the aqueous solution of the buffer solution is introduced into the first mixing tank 15 from the second tank 25 through the pipe 27 by the pump 26. Thereby, in the first mixing tank 15, the water-soluble polymer having an acidic group is controlled to an appropriate pH to trap metal ions. If there is no need to control the pH of the sewage, it is not necessary to provide the second tank 25, the pump 26 and the pipe 27.

The waste water introduced into the second mixing tank 23 contacts the coexisting anion exchange resin 28, and the water-soluble polymer having an acidic group having metal ions trapped therein is trapped on the surface of the anion exchange resin.

Subsequently, when the shutter 29 is opened, the dirty water is discharged from the second mixing tank 23 through the filter 30 disposed at the lower part of the second mixing tank 23. The filter 30 has a hole, and the anion exchange resin 28 is blocked by the hole of the filter, so it is not discharged from the second mixing tank 23. That is, the anion exchange resin 28 is held by the holes of the filter 30.

Here, when the metal component of the discharged liquid remains considerably, it is returned to the first mixing tank 15 again as dirty water. Also, if the metal component in the discharged liquid is considerably removed, it is sent to a sewage treatment apparatus (not shown in the figure) for removing another substance or discharged to a river. Control of the flow of these liquids is performed by a valve 31. The measurement of the metal concentration in the liquid is carried out by providing a measuring device in the vicinity of the valve or by collecting a small amount of the liquid and separately measuring it.

After the liquid component of the second mixing tank 23 is discharged, the hydrochloric acid aqueous solution is introduced into the second mixing tank 23 from the third tank 32 by the pump 33 through the pipe 34. Then, the water-soluble polymer having an acidic group and the metal ion are separated from the surface of the anion exchange resin 28. Thereafter, the water-soluble polymer having an acidic group and metal ions are sent to a metal recovery tank 35 together with hydrochloric acid. When recovering metal species such as silver that becomes insoluble in water when converted to chloride, nitric acid is used instead of hydrochloric acid.

Subsequently, the sodium hydroxide aqueous solution is introduced into the second mixing tank 23 from the fourth tank 36 through the pipe 37 by the pump 37, and the anion exchange resin 28 is washed. The cleaning solution is also sent to the metal recovery tank 35. Then, since the metal which has been dissolved becomes a hydroxide, it precipitates. The acidic group of the water-soluble polymer having an acidic group has a sodium salt structure. However, the water-soluble polymer having an acidic group is dissolved in water, and when the shutter 39 is opened, it is sent to the water-soluble polymer storage tank 41 having an acidic group via the filter 40. The precipitated metal hydroxide remains on the filter. Although sodium hydroxide is used here for explanation, it is also possible to use hydroxide of an alkali metal or alkaline earth metal such as potassium hydroxide or magnesium hydroxide instead of sodium hydroxide.

Subsequently, purified water is introduced from the fifth tank 42 through the pipe 44 by the pump 43 into the second mixing tank 23, and the anion exchange resin 28 is washed. The cleaning solution is also sent to the metal recovery tank 35, and the metal hydroxide is also cleaned. Thereafter, metal recovery is completed by recovering the metal hydroxide.

The sodium salt of the water-soluble polymer having an acidic group in the water-soluble polymer storage tank 41 is then added to hydrochloric acid to be converted to a water-soluble polymer having an acidic group, and is then sent to the first tank 17 again. Can be used for metal recovery.

(2) Form 2 of metal separation and recovery device
Of the metal separation / recovery apparatus of the present invention, a configuration using a magnetic separation method will be described with reference to FIG. Here, there are two types of methods.

A) In the case of using anion exchange resin particles containing metal powder exhibiting ferromagnetism The particles of the anion exchange resin 28 contain metal powder exhibiting ferromagnetism. The blade portion of the overhead stirrer 24 in the second mixing tank 23 is an electromagnet. In this case, when the inside of the second mixing tank 23 is cleaned, the anion exchange resin 28 is attracted and attached because the magnetic force is applied to the blade portion of the overhead stirrer 24. This makes it possible to recover the metal from the inside of the second mixing tank 23. In addition, also in the case of sending to the metal recovery tank 35, the anion exchange resin is attracted and attached because the magnetic force is applied to the blade portion of the overhead stirrer 24. Thereby, clogging of the filter by the anion exchange resin 28 can also be suppressed.

B) When Adding Metal Powder Showing Ferromagnetism to Sewage Water-soluble polymer having an acidic group and metal powder showing ferromagnetism are added to the sewage. The blade portion of the overhead stirrer 24 in the second mixing tank 23 is an electromagnet. In this case, when the water-soluble polymer having an acidic group traps metal ions, a part of the metal powder exhibiting ferromagnetism is incorporated into the water-soluble polymer having an acidic group. In that state, it is sent to the second mixing tank 23, and when the anion exchange resin 28 and the water-soluble polymer having an acidic group are bonded, metal powder exhibiting ferromagnetism is also taken in the complex.

Subsequently, when the inside of the second mixing tank 23 is washed, etc., a magnetic force is applied to the blade portion of the overhead stirrer 24 to trap metal ions, and the acid group is ionically bonded to the anion exchange resin 28 It is possible to recover the metal from the inside of the second mixing tank 23 by attracting and attaching the water-soluble polymer having the above to the blade. The anion exchange resin 28 and the metal powder exhibiting ferromagnetism are separated by magnetic separation or centrifugation.

(3) Form 3 of metal separation and recovery device
Among the metal separation and recovery devices of the present invention, a configuration in which an anion exchange resin is packed in a column and used will be described with reference to FIG.

The liquid mixed in the first mixing tank 15 is introduced via the funnel 45 into the cylindrical column 46 filled with the anion exchange resin 28. At the lower part of the column 46, a filter 47 is provided to prevent the anion exchange resin 28 from leaking. That is, the anion exchange resin 28 is held by the filter 47.

The liquid that has passed through the anion exchange resin 28 enters the metal recovery tank 35. Thus, the water-soluble polymer having an acidic group having trapped metal ions in the liquid is trapped in the anion exchange resin 28. The interior of the funnel 45 and the interior of the column 46 are positively pressurized by pressurized air or nitrogen gas introduced from the pressurized gas introduction pipe 49 to increase the passing speed of the liquid passing through the interior of the column 46. The processing speed of metal recovery can be improved. Further, the degree of pressurization is controlled by the valve 50.

The liquid that has entered the metal recovery tank 35 is sent to a sewage treatment apparatus (not shown) that removes another substance via the bypass pipe 52 by opening the valve 51 or is discharged to the river. However, these are cases where the metal component in the discharged liquid is considerably removed. If the metal component of the discharged liquid remains considerably, it is returned to the first mixing tank 15 again as dirty water.

Next, the valve 51 is closed, and hydrochloric acid is introduced into the column 46 from the third tank 32. Then, the metal ion and the water-soluble polymer having an acidic group trapped in the anion exchange resin 28 are detached from the anion exchange resin 28 and enter the metal recovery tank 35. Metal ions are converted to metal chlorides. Also, the amino groups on the surface of the anion exchange resin 28 change to the structure of hydrochloride.

Next, an aqueous sodium hydroxide solution is introduced into the column 46 from the fourth tank 36. Then, the amino group of the hydrochloride structure on the surface of the anion exchange resin 28 is converted to a normal amino group. Further, the aqueous sodium hydroxide solution enters the metal recovery tank 35. The dissolved metal chloride is converted to a water-insoluble metal hydroxide and precipitated. In addition, the water-soluble polymer having an acidic group is converted to a sodium salt structure. However, since the water-soluble polymer having an acid group is dissolved, when the shutter 53 is opened, it is sent to the water-soluble polymer storage tank 41 having an acid group via the filter 54. The precipitated metal hydroxide remains on the filter 54.

Subsequently, purified water is introduced from the fifth tank 42 through the funnel 45 into the cylindrical column 46 filled with the anion exchange resin 28, and the anion exchange resin 28 is washed. The cleaning solution is also sent to the metal recovery tank 35, and the metal hydroxide is also cleaned.

Thereafter, metal recovery is completed by recovering the metal hydroxide. Further, the sodium salt of the water-soluble polymer having an acid group in the water-soluble polymer storage tank 41 is then added with hydrochloric acid to be converted to a water-soluble polymer having an acid group, and then the first tank 17 is again obtained. Can be used for metal recovery.

(4) Form 4 of metal separation and recovery device
In the metal separation / recovery apparatus of the present invention, in a configuration in which an anion exchange resin is packed in a column and used, there is provided a mechanism for generating sodium hydroxide by electrolysis instead of adding an aqueous sodium hydroxide solution, as shown in FIG. Explain using.

First, the process is performed with the same configuration and process as in mode 3 of the metal separation / recovery device until hydrochloric acid is added.

In the present embodiment, the sodium chloride aqueous solution is released to the vicinity of the electrode 55 through the pipe 38 from the fourth tank 36 using the pump 37 while the sodium hydroxide aqueous solution is added in the third embodiment of the metal separation / recovery device. . An electrode 55 for performing electrolysis is disposed on the top of the column 46. However, the position of the electrode 55 does not have to be at the top of the column 46. Here, the electrode 55 is used to energize the liquid to electrolyze sodium chloride in the liquid to produce sodium hydroxide. The voltage, current, etc. in the electrolysis are adjusted by the controller 56.

Thereafter, the process proceeds with the same configuration and process as in mode 3 of the metal separation / recovery device. By producing sodium hydroxide by electrolysis, the present apparatus eliminates the need for sodium hydroxide, which is a consumable and harmful substance.

Sodium hydroxide falls under the Poisonous Substances Control Act and is subject to restrictions such as use and storage. However, in the case of this embodiment, since the necessary amount can be generated by electrolysis when necessary, the legal restriction on the operation of the metal separation and recovery device is relaxed.

(5) Form 5 of metal separation and recovery device
Among the metal separation and recovery devices of the present invention, the configuration in which the number of mixing vessels is one will be described with reference to FIG.

A shutter 39 and a filter 40 are disposed below the first mixing tank 15. In addition, piping 34 from the third tank 32, piping 38 from the fourth tank 36, and piping 44 from the fifth tank 42 are provided for the first mixing tank 15. Thereby, the metal separation and recovery apparatus of the present invention can be configured without providing the second mixing tank 23. Here, a filter 40 is disposed below the first mixing tank 15. The filter 40 has a hole. The anion exchange resin 28 is held in the holes of the filter 40. By the above, since one mixing tank can be reduced, the apparatus can be made compact.

In this configuration, the anion exchange resin 28 containing ferromagnetic metal powder is effective. When the waste water and the aqueous solution of the water-soluble polymer having an acidic group are mixed, the anion exchange resin 28 is attached to the blades of the overhead stirrer 16 by applying a magnetic force to the blades of the overhead stirrer 16. Furthermore, by reducing the magnetic force of the overhead stirrer 16 after the sewage and the aqueous solution of the water-soluble polymer having the acid group are mixed, a mixed liquid of anion and the aqueous solution of the water-soluble polymer having the acid group and anions Mix exchange resin 28. This makes it possible to efficiently trap metal ions in the water-soluble polymer having an acidic group.

(6) Form 6 of metal separation and recovery device
Among the metal separation and recovery devices of the present invention, the configuration having a plurality of columns will be described with reference to FIG.

In the case where the column 46 is filled with the anion exchange resin 28 and used, in the metal separation and recovery process of the present invention, the time taken for the gap between the anion exchange resins 28 in the column 46 occupies a considerable part of the whole process. . That is, the time taken for this process can be reduced to a fraction by dividing the columns 46 through which the following four types of liquids A) to D) pass.
A) Liquid in which sewage and aqueous solution of water-soluble polymer having acidic group are mixed B) Hydrochloric acid aqueous solution C) Sodium hydroxide aqueous solution D) Purified water The process is as follows.

The liquid obtained by mixing the waste water and the aqueous solution of the water-soluble polymer having an acidic group is introduced from the first mixing tank 15 into the column 46 at the left end of FIG. Then, the column 46 moves to the right. Next, the aqueous hydrochloric acid solution is introduced into the column 46 from the third tank 32 through the pipe 34. Then, the column 46 moves to the right. Next, an aqueous sodium hydroxide solution is introduced into the column 46 from the fourth tank 36 through the pipe 38. Then, the column 46 moves to the right. Next, purified water is introduced into the column 46 from the fifth tank 42 through the pipe 44.

Since the plurality of columns sequentially go through the separation and recovery steps of the plurality of metals, the time required for the movement of the liquid inside the columns can be shortened in total, and the separation and recovery of metals can be performed at high speed.

(7) Form 7 of metal separation and recovery device
Among the metal separation and recovery devices of the present invention, the configuration for recovering an anion exchange resin by magnetic separation will be described with reference to FIG.

Here, as in FIG. 6, an anion exchange resin 28 is also added to the first mixing tank 15. However, use is made of those in which metal powder exhibiting ferromagnetism is contained inside the particles of the anion exchange resin 28.

Further, the apparatus of this embodiment has an anion exchange resin transport mechanism having a first roller 57, a second roller 58, a third roller 59, a fourth roller 60 and a belt 61. The belt 61 surface from the fourth roller 60 to the second roller 58 through the first roller 57 has a magnetic force. Thereby, the anion exchange resin 28 in the first mixing tank 15 can be attached to the belt surface. Since there is no magnetic force from the second roller 58 to the fourth roller 60, the anion exchange resin 28 separates from the third roller 59 and is collected inside the anion exchange resin recovery tank 62.

As described above, the anion exchange resin 28 in the first mixing tank 15 binds a polymer having an acidic group in which metal ions are trapped.

Thus, the anion exchange resin 28 in which the polymer having an acidic group having metal ions trapped therein is bound is collected in the anion exchange resin recovery tank 62.

Next, FIG. 9 will be used to describe a process of recovering metal from the anion exchange resin 28 to which a polymer having an acidic group having metal ions trapped therein is bound.

First, a hydrochloric acid aqueous solution is introduced into the anion exchange resin recovery tank 62 from the third tank 32 through the pipe 34 by the pump 33. Then, the water-soluble polymer having an acidic group and the metal ion separate from the surface of the anion exchange resin 28. Thereafter, the water-soluble polymer having an acidic group and metal ions are sent to the metal recovery tank 35 together with hydrochloric acid.

Subsequently, the sodium hydroxide aqueous solution is introduced into the anion exchange resin recovery tank 62 from the fourth tank 36 through the pipe 38 by the pump 37, and the anion exchange resin 28 is washed. The cleaning solution is also sent to the metal recovery tank 35. Then, the metal which has been dissolved becomes a hydroxide and is precipitated. The acidic group of the water-soluble polymer having an acidic group has a sodium salt structure. However, the water-soluble polymer having an acidic group is dissolved in water, and when the shutter 39 is opened, it is sent to the water-soluble polymer storage tank 41 having an acidic group via the filter 40. The precipitated metal hydroxide remains on the filter 40.

Thus, metal recovery is possible after the anion exchange resin 28 has been recovered in advance using a magnetic separation system.

(8) Form 8 of metal separation and recovery device
Among the metal separation and recovery devices of the present invention, a configuration in which an anion exchange resin is added to a water-soluble polymer aqueous solution having an acidic group and then recovery of the anion exchange resin by magnetic separation will be described using FIG. .

First, the anion exchange resin 28 containing metal powder exhibiting ferromagnetism is placed in the first mixing tank 15. Next, an aqueous solution of a water-soluble polymer having an acidic group is introduced into the first mixing tank 15 from the first tank 17. Thereafter, it is stirred by an overhead stirrer 16.

Next, the anion exchange resin 28 is an anion exchange resin recovery tank by the anion exchange resin transport mechanism having the first roller 57, the second roller 58, the third roller 59, the fourth roller 60 and the belt 61. 62 collected inside. The collected anion exchange resin 28 is converted to an anion exchange resin 63 in which a water-soluble polymer having an acidic group is attached to the surface. Thus, the pretreatment of the anion exchange resin, that is, the pretreatment of attaching the water-soluble polymer having an acidic group to the surface is completed.

Next, a metal ion recovery scheme using the anion exchange resin 63 in which a water-soluble polymer having an acidic group is attached to the surface will be described with reference to FIG.

First, sewage is poured onto the anion exchange resin 63 on which a water-soluble polymer having an acidic group is attached to the surface. As a result, metal ions in the sewage are trapped by the acidic groups of the water-soluble polymer having acidic groups bound to the surface of the anion exchange resin 63. After the shutter 39 is opened to discharge the dirty water, the shutter 39 is closed.

Next, a hydrochloric acid aqueous solution is introduced into the anion exchange resin recovery tank 62 from the third tank 32 through the pipe 34 by the pump 33. Then, the water-soluble polymer having an acidic group and the metal ion separate from the surface of the anion exchange resin 63 on which the water-soluble polymer having an acidic group is attached to the surface. Thereafter, the water-soluble polymer having an acidic group and metal ions are sent to the metal recovery tank 35 together with hydrochloric acid.

Subsequently, a sodium hydroxide aqueous solution is introduced into the anion exchange resin recovery tank 62 from the fourth tank 36 through the pipe 37 by the pump 37, and an anion having a water-soluble polymer having an acidic group attached to the surface The exchange resin 63 is washed. The cleaning solution is also sent to the metal recovery tank 35. Then, since the metal which has been dissolved becomes a hydroxide, it precipitates. The acidic group of the water-soluble polymer having an acidic group has a sodium salt structure. However, the water-soluble polymer having an acidic group is dissolved in water, and when the shutter 39 is opened, it is sent to the water-soluble polymer storage tank 41 having an acidic group via the filter 40. The precipitated metal hydroxide remains on the filter 40.

As described above, metal recovery is possible even if the order of addition of the wastewater, the water-soluble polymer having an acidic group, and the anion exchange resin is changed. In the case of using the anion exchange resin 28 which does not contain metal powder exhibiting ferromagnetism, ferromagnetism can be obtained by adding metal powder exhibiting ferromagnetism at the time of addition of the water-soluble polymer having an acidic group. The metal powder shown is incorporated into the anion exchange resin 63 in which the water-soluble polymer having an acidic group is attached to the surface. Thereafter, the anion exchange resin 28 can be collected in the anion exchange resin recovery tank 62 by the anion exchange resin transport mechanism.

〔Example〕
Hereinafter, the present invention will be described in more detail by way of specific examples. The following examples show specific examples of the contents of the present invention, and the present invention is not limited to these examples and can be determined by those skilled in the art within the scope of the technical idea disclosed in the present specification. Various changes and modifications are possible.

While stirring 1 liter of a copper sulfate aqueous solution (test water) in which 1595 ppm of copper sulfate is dissolved as a metal salt (test water) (10 mmol as copper sulfate), polyacrylic acid (average molecular weight is 25, 20 g (27.8 mmol as the number of carboxyl groups) of a 10% by weight aqueous solution of 000) were added. The color of the test water changed from pale blue to pale bluish green.

Next, 2 g (exchange capacity corresponds to 2.31 mmol) of anion exchange resin (Mitsubishi Chemical SA10A, exchange capacity: 1.3 meq / ml, apparent density: 0.665 g / ml) was added, and stirring was further continued .

Then, the bluish green color of the test water was considerably reduced. In addition, a pale green substance was adhered to the surface of the anion exchange resin. This is polyacrylic acid in which copper ions are trapped.

Next, after filtering the above mixed solution with filter paper, when the copper sulfate concentration of the filtrate was quantified with an inductively coupled plasma emission spectrophotometer, the copper sulfate concentration in the filtrate decreased to 80 ppm. As mentioned above, the metal ion in sewage was able to be isolate | separated by using polyacrylic acid and anion exchange resin as water-soluble polymer which has an acidic group.

Next, the metal recovery will be described.
After filtration through filter paper, anion exchange resin remained on the filter paper. The filter paper was placed in a beaker, 50 ml of 1N hydrochloric acid was added, and the filter paper was washed well. Then, the ion exchange resin was detached from the filter paper, and the pale green substance adhering to the ion exchange resin was dissolved in hydrochloric acid. In this way, the copper ions become copper chloride and the polyacrylic acid becomes free by releasing the copper ions.

The filter paper was removed from the beaker and 100 ml of 1N aqueous sodium hydroxide solution was added to cause precipitation. This is copper hydroxide. About copper hydroxide was filtered out by filtration and metal recovery was completed by washing with water. The obtained copper hydroxide was about 0.8 g (about 8.2 mmol).

When copper hydroxide is heated to 100 to 120 ° C. for drying, it is easily converted to copper oxide. Therefore, it is recovered in the form of copper hydroxide or copper oxide in consideration of the subsequent use and application method.

By the way, polyacrylic acid is converted to sodium polyacrylate by the addition of sodium hydroxide. Therefore, it is possible to regenerate polyacrylic acid by adding hydrochloric acid again, and this operation can be used again for metal recovery. The regeneration was confirmed by dropping the solution in which the polyacrylic acid was dissolved in methanol, drying the precipitated solid (polyacrylic acid), and then measuring the IR spectrum. Specifically, it was confirmed that the absorption spectra of the polyacrylic acid before being used for metal separation and recovery and the substance after regeneration coincide with each other.

In addition, in the anion exchange resin, the amino groups on the surface are changed to a hydrochloride structure by washing with hydrochloric acid. Therefore, it is possible to regenerate as an anion exchange resin by washing with an aqueous solution of sodium hydroxide to convert the hydrochloride structure back to an amino group and removing excess sodium hydroxide with purified water. This operation can be used again for metal recovery.

From the above, it was confirmed that metals can be recovered using an anion exchange resin that usually traps an acid or the like and a water-soluble polymer having an acidic group. In addition, the amount of anion exchange resin used is only equivalent to 2.31 mmol in terms of exchange capacity, and is smaller than that of recovered copper hydroxide (8.2 mmol) (copper is divalent), When recovering using an ion exchange resin, it is necessary to add at least an exchange volume of at least 16.4 mmol). Therefore, it was also confirmed that metal recovery is possible with a considerably smaller amount than the amount required for ion exchange resin alone.

Furthermore, it was confirmed that polyacrylic acid and anion exchange resin, which are water-soluble polymers having an acidic group used for recovery, can also be regenerated.

The same test as in Example 1 was carried out except that 1 liter of test water in which 1300 ppm of nickel chloride had been dissolved was used instead of 1 liter of test water in which 1595 ppm of copper sulfate had been dissolved. Decreased to 65 ppm. Moreover, it was confirmed that polyacrylic acid and an anion exchange resin which are water-soluble polymers having an acidic group used for recovery as in Example 1 can also be regenerated.

Instead of 20 g of a 10 wt% aqueous solution of polyacrylic acid (average molecular weight 25,000), 27 g of a 10 wt% aqueous solution of sodium polyacrylate (28.7 mmol as the number of structures in which a carboxyl group is converted to a sodium salt) When the same test as in Example 1 was conducted except that it was used, the concentration of copper sulfate in the filtrate dropped to 90 ppm.

Therefore, it has been confirmed that metals dissolved in water can be removed even by using a water-soluble polymer in which a carboxyl group is converted to a salt structure.

The same test as in Example 1 was conducted, except that 24 g of a 10% by weight aqueous solution of polymethacrylic acid (27.9 mmol as the number of carboxyl groups) was used instead of 20 g of a 10% by weight aqueous solution of polyacrylic acid. The copper sulfate concentration in the solution dropped to 90 ppm.

Therefore, it was confirmed that metals dissolved in water can be removed even if polymethacrylic acid is used instead of polyacrylic acid as the water-soluble polymer having a carboxyl group.

Example 1 and Example 1 except using 60 g of a 10 wt% aqueous solution of sodium polystyrene sulfonate (29.1 mmol as the number of structures in which the sulfonic acid group has become a sodium salt) instead of 20 g of a 10 wt% aqueous solution of polyacrylic acid When the same test was conducted, the copper sulfate concentration in the filtrate decreased to 90 ppm.

Therefore, it has been confirmed that even if water solubility having a sulfonic acid group is used as the water-soluble polymer having an acidic group, metals dissolved in water can be removed.

The metal separation / recovery from the copper sulfate aqueous solution (test water) used in Example 1 was performed using the metal separation / recovery apparatus shown in FIG.

Test water is introduced as dirty water into the first mixing tank 15 through the pipe 14 by the pump 13. While stirring by the overhead stirrer 16, the polyacrylic acid aqueous solution was introduced into the first mixing tank 15 from the first tank 17 through the pump 18 and through the pipe 19 by the pump 18. The test water and the aqueous polyacrylic acid solution were stirred by an overhead stirrer 24.

After sufficiently mixing the liquid in the first mixing tank 15, the liquid in the first mixing tank 15 was introduced into the second mixing tank 23 through the pipe 22 by the pump 21. The liquid therein was stirred by an overhead stirrer 24. The liquid introduced into the second mixing tank 23 was in contact with the coexisting anion exchange resin 28, and polyacrylic acid in which copper ions were trapped was trapped on the surface of the anion exchange resin 28.

Subsequently, when the shutter 29 was opened, the test water was discharged from the second mixing tank 23 through the filter 30. After the liquid component of the second mixing tank 23 was discharged, the hydrochloric acid aqueous solution was introduced into the second mixing tank from the third tank 32 by the pump 33 through the pipe 34. In this way, polyacrylic acid and copper ions were removed from the anion exchange resin surface. Thereafter, it was sent to a metal recovery tank 35 together with hydrochloric acid.

Subsequently, the sodium hydroxide aqueous solution was introduced into the second mixing tank 23 from the fourth tank 36 through the pipe 38 by the pump 37, and the anion exchange resin 28 was washed. The cleaning solution was also sent to the metal recovery tank 35. Then, the dissolved copper ions become hydroxides and precipitate. Polyacrylic acid becomes sodium polyacrylate whose carboxyl group has a sodium salt structure. Since sodium polyacrylate is dissolved in water, when the shutter 39 is opened, it is sent to the water-soluble polymer storage tank 41 having an acidic group through the filter 40. The precipitated copper hydroxide remained on the filter 40.

Subsequently, purified water was introduced into the second mixing tank 23 from the fifth tank 42 through the pipe 44 by the pump 43, and the anion exchange resin 28 was washed. The cleaning solution was also sent to the metal recovery tank 35, and the copper hydroxide was also cleaned. The washed copper hydroxide was recovered to obtain about 0.8 g (about 8.2 mmol) of copper hydroxide.

From the above, it was confirmed that metal recovery can be performed by this device.
Further, sodium polyacrylate in the water-soluble polymer storage tank 41 is then added with hydrochloric acid, converted to polyacrylic acid, and then sent again to the first tank 17 and can be used again for metal recovery. I also confirmed that.

The metal separation / recovery from the copper sulfate aqueous solution (test water) used in Example 1 was performed using the metal separation / recovery apparatus shown in FIG.

As in Example 6, the test water and the polyacrylic acid aqueous solution were stirred in the first mixing tank 15, and a mixed liquid of the test water and the polyacrylic acid aqueous solution was formed. The liquid was introduced into the cylindrical column 46 filled with the anion exchange resin 28 by the pump 21.

By pressurizing the inside of the column 46 with pressurized air introduced from the pressure introducing pipe 49, the liquid which has passed through the anion exchange resin 28 quickly is put into the metal recovery tank 35. In this way, polyacrylic acid trapped in copper ions in the liquid was trapped in the anion exchange resin 28. The liquid in the metal recovery tank was discharged through the bypass pipe 52 by opening the valve 51.

Next, the valve 51 was closed, and hydrochloric acid was introduced into the column 46 from the third tank 32. Then, copper ions and polyacrylic acid trapped in the anion exchange resin 28 were removed from the anion exchange resin, and entered the metal recovery tank 35.

Next, an aqueous sodium hydroxide solution was introduced into the column 46 from the fourth tank 36. Then, the amino group of the hydrochloride structure on the surface of the anion exchange resin 28 is converted to a normal amino group. Furthermore, the sodium hydroxide aqueous solution entered into the metal recovery tank 35, and the dissolved copper ions were changed to copper hydroxide insoluble in water and precipitated. Also, polyacrylic acid is converted to sodium polyacrylate. Since sodium polyacrylate is dissolved, when the shutter 53 is opened, it is sent to the water-soluble polymer storage tank 41 having an acidic group through the filter 54. The precipitated copper hydroxide remained on the filter. The copper hydroxide was washed with water to obtain about 0.8 g (about 8.2 mmol) of copper hydroxide.

From the above, it was confirmed that metal recovery can be performed by this device.
Further, sodium polyacrylate in the water-soluble polymer storage tank 41 is then added with hydrochloric acid, converted to polyacrylic acid, and then sent again to the first tank 17 and can be used again for metal recovery. I also confirmed that.

The metal separation / recovery from the copper sulfate aqueous solution (test water) used in Example 1 was performed using the metal separation / recovery apparatus shown in FIG.

As in Example 7, the test water and the polyacrylic acid aqueous solution were stirred in the first mixing tank 15 to form a mixed liquid. The liquid was introduced into the cylindrical column 46 filled with the anion exchange resin 28 by the pump 21, and the liquid having passed through the anion exchange resin 28 was introduced into the metal recovery tank 48.

Next, the liquid in the metal recovery tank 48 was discharged through the bypass pipe 52 by opening the valve 51. Thereafter, the valve 51 is closed and hydrochloric acid is supplied to the column 46 from the third tank 32 to remove copper ions and polyacrylic acid trapped in the anion exchange resin 28 from the anion exchange resin, and the metal recovery tank 48 Was put in

An aqueous sodium chloride solution was introduced into the column 46 from the fourth tank 36. Here, the electrode 55 was used to energize the liquid to produce sodium hydroxide by electrolyzing sodium chloride in the liquid. The potential difference between the two electrodes is about 1.5V. Then, the amino group of the hydrochloride structure on the surface of the anion exchange resin 28 was converted to a normal amino group. Furthermore, the aqueous solution of sodium hydroxide entered into the metal recovery tank 48, and the dissolved copper ion was changed to insoluble copper hydroxide in water and precipitated. Also, polyacrylic acid is converted to sodium polyacrylate. Since the sodium polyacrylate is dissolved, when the shutter 53 is opened, it is sent to the water-soluble polymer storage tank 41 having an acidic group via the filter 54. The precipitated copper hydroxide remained on the filter. The copper hydroxide was washed with water to obtain about 0.8 g (about 8.2 mmol) of copper hydroxide.

From the above, it was confirmed that metal recovery can be performed without the addition of sodium hydroxide which is a harmful substance by utilizing electrolysis. Further, sodium polyacrylate in the water-soluble polymer storage tank 41 is then added with hydrochloric acid, converted to polyacrylic acid, and then sent again to the first tank 17 and can be used again for metal recovery. I also confirmed that.

The metal separation / recovery from the aqueous solution of copper sulfate (test water) used in Example 1 was performed using the metal separation / recovery apparatus shown in FIG. 10 or FIG.

First, 2 g of anion exchange resin 28 (SA10A made by Mitsubishi Chemical, exchange capacity: 1.3 meq / ml, apparent density: 0.665 g / ml) (exchange capacity is equivalent to 2.31 mmol) The mixture was placed in the mixing tank 15 of To this, 2 g of iron powder having an average particle size of 50 μm is added, and as a water-soluble polymer having an acidic group, 20 g of a 10% by weight aqueous solution of polyacrylic acid (average molecular weight 25,000) .8 mmol) was added and stirring was continued further.

Next, the anion exchange resin 28 is recovered by the anion exchange resin 28 by the anion exchange resin transport mechanism having the first roller 57, the second roller 58, the third roller 59, the fourth roller 60 and the belt 61. It was collected inside the tank 62. The collected anion exchange resin 28 is converted to an anion exchange resin 63 in which polyacrylic acid is attached to the surface by ion bonding.

Next, a metal ion recovery scheme using the anion exchange resin 63 in which polyacrylic acid is attached to the surface by ion bonding will be described using FIG.

First of all, test water was poured onto an anion exchange resin 63 in which polyacrylic acid was attached to the surface by ion bonding. As a result, copper ions in the test water were trapped by ionic bonds in the carboxyl groups of the polyacrylic acid bound to the anion exchange resin surface. After the shutter 39 was opened to discharge the dirty water, the shutter 39 was closed.

Next, 50 ml of a 1N aqueous solution of hydrochloric acid was fed from the third tank 32 through the pipe 34 through the pump 33 into the anion exchange resin recovery tank 62 in which polyacrylic acid was attached to the surface by ion bonding. Then, polyacrylic acid and copper ions are separated from the surface of the anion exchange resin 63. Thereafter, polyacrylic acid and copper ions were sent to the metal recovery tank 35 together with hydrochloric acid.

Subsequently, 100 ml of a 1 N aqueous solution of sodium hydroxide was introduced into the anion exchange resin recovery tank 62 from the fourth tank 36 by the pump 37 through the pipe 38, and polyacrylic acid was attached to the surface by ionic bonding. The anion exchange resin 63 was washed. Further, the cleaning liquid was also sent to the metal recovery tank 35. Then, the dissolved copper ions became copper hydroxide and precipitated. In polyacrylic acid, the acid group has a sodium salt structure. The sodium polyacrylate was dissolved in water, and when the shutter 39 was opened, it was sent via the filter 40 to the water-soluble polymer storage tank 41 having an acidic group. The precipitated copper hydroxide remained on the filter. After washing with water, the obtained copper hydroxide was about 0.8 g (about 8.2 mmol).

As described above, it has been confirmed that metal recovery is possible even if the order of addition of dirty water, a water-soluble polymer having an acidic group, and an anion exchange resin is changed.

REFERENCE SIGNS LIST 1 metal salt 2, 6 water-soluble polymer having an acid group 3 ion bonding 4 water-soluble polymer having a carboxyl group 5, 9, 28, 63 anion exchange resin 7 metal ion 8 acid group 10 metal chloride 11 metal Hydroxide 12 Sodium salt structure group 13,18,21,26,33,37,43 Pumps 14,19,22,27,34,38,44 Piping 15 First mixing tank 16,24 Overhead stirrer 17 No. 1 tank 20 pH sensor 23 second mixing tank 25 second tank 29, 39, 53 shutter 30, 40, 47, 54 filter 31, 50, 51 valve 32 third tank 35, 48 metal recovery tank 36 4 tank 41 water-soluble polymer storage tank 42 fifth tank 45 funnel 46 column 49 pressurized gas inlet pipe 52 bypass pipe 55 electricity Pole 56 controller 57 first roller 58 second roller 59 third roller 60 fourth roller 61 belt 62 anion exchange resin recovery tank

Claims (22)

A chemical for metal separation that recovers metals in sewage,
The metal separating agent, wherein the metal separating agent comprises a water-soluble polymer having an acidic group and an anion exchange resin. The metal separation agent according to claim 1, wherein the metal separation agent contains metal powder exhibiting ferromagnetism. The acidic group of the water-soluble polymer having an acidic group is a carboxyl group or a sulfonic acid group,
The metal separation according to claim 1 or 2, wherein the water-soluble polymer having an acidic group comprises at least one of polyacrylic acid, polyaspartic acid, polyglutamic acid, alginic acid, polyvinylsulfonic acid and polystyrenesulfonic acid. Drugs. The medicine for metal separation according to any one of claims 1 to 3, wherein a number average molecular weight of the water-soluble polymer having an acidic group is 2,000 or more and 300,000 or less. The metal according to any one of claims 1 to 4, wherein the acid group of the water-soluble polymer having an acid group is an ammonium salt structure, an alkali metal salt structure, or an alkaline earth metal salt structure. Separation agent. The metal separation agent according to any one of claims 1 to 3, wherein a metal powder is contained inside the anion exchange resin. A metal separation method for recovering metal in sewage, comprising
Contacting an anion exchange resin with the wastewater after the water-soluble polymer having an acidic group is added to the wastewater;
Alternatively, the method comprises the steps of: forming a conjugate of a water-soluble polymer having an acidic group and an anion exchange resin, and then bringing the conjugate into contact with the wastewater. The metal separation | isolation method of Claim 7 including the process by which the metal powder which shows ferromagnetism is added to the said sewage. Separating the ion exchange resin brought into contact with the wastewater from the wastewater;
The step of washing the anion exchange resin;
A step of adding an aqueous solution of an alkali metal hydroxide to the cleaning solution generated by the cleaning;
The metal separation method according to claim 7, comprising the step of filtering out the metal hydroxide deposited in the step of adding the aqueous solution of the alkali metal hydroxide. The anion exchange resin contains metal powder having ferromagnetism,
10. The metal separation method according to claim 7, further comprising the step of separating the anion exchange resin from the waste water by the magnetic force of the metal powder. A step of washing the washed ion exchange resin with a base aqueous solution;
The metal separation method according to claim 9 or 10, further comprising the step of: acidifying the liquid obtained in the step of adding the aqueous solution of the alkali metal hydroxide. The metal separation method according to any one of claims 7 to 11, wherein the conjugate is formed by adding the anion exchange resin to an aqueous solution of a water-soluble polymer having the acidic group. The metal separation method according to claim 8, wherein metal powder exhibiting ferromagnetism is added to the wastewater to be brought into contact with the combined body. The metal separation method according to any one of claims 7 to 13, wherein the pH of the wastewater is 2 or more and 5 or less before the wastewater is brought into contact with the anion exchange resin or the composite. . MB, the product of the number of moles and the number of metals in the sewage
The number of acid groups of the water-soluble polymer having the acid group is PA,
When the number of amino groups possessed by the anion exchange resin is PB,
The sewage purification method according to any one of claims 7 to 14, wherein the metal is recovered by adjusting MB, PA, and PB to be the following inequality.
PA MB MB (a)
PB ≧ PA-MB (b) It is a water purifier using the chemical | medical agent for metal separation as described in any one of Claims 1 thru | or 6, Comprising:
A first mixing tank in which the waste water and an aqueous solution of a water-soluble polymer having an acid group are mixed;
And a second mixing tank in which a mixed liquid of an aqueous solution of a water-soluble polymer having the wastewater and the acidic group and an anion exchange resin are mixed,
A filter is disposed below the second mixing tank,
The filter has a hole and
A water purifier characterized in that the anion exchange resin is held by the holes of the filter. Hydrochloric acid or nitric acid is added to the second mixing tank,
An aqueous solution of an alkali metal or an aqueous solution of an alkaline earth metal is added to the second mixing tank,
The water purifier according to claim 16, wherein water is added to the second mixing tank. Having a column for holding the anion exchange resin instead of the second mixing tank,
The mixed liquid is added to the inside of the column,
At the bottom of the column is a filter,
The water purification device according to claim 16 or 17, wherein the anion exchange resin is held by the filter. Hydrochloric acid or nitric acid is added to the column,
An aqueous solution of an alkali metal or an aqueous solution of an alkaline earth metal is added to the column,
The water purifier according to claim 18, wherein water is added to the column. The column is composed of a plurality of columns,
The plurality of columns are movable,
The column into which the mixed liquid is charged, the column into which the hydrochloric acid or the nitric acid is added, the column into which the aqueous solution of the alkali metal or the aqueous solution of the alkaline earth metal is added, and the column into which the water is added are separately arranged. The water purifier according to claim 19, characterized in that The electrode is placed
21. The water purifier according to claim 17, wherein electrolysis is performed by the electrode instead of adding the aqueous solution of the alkali metal or the aqueous solution of the alkaline earth metal. There is no second mixing tank,
The wastewater and anion exchange resin are mixed in the first mixing tank,
Hydrochloric acid or nitric acid is added to the first mixing tank,
An aqueous solution of an alkali metal or an aqueous solution of an alkaline earth metal is added to the first mixing tank,
A filter is disposed below the first mixing tank,
The filter has a hole and
22. The water purifier according to any one of claims 16, 17 or 21, wherein the anion exchange resin is held in the hole of the filter.

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