JPH0765127B2 - Cobalt separation and recovery method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for separating and recovering cobalt. More specifically, the present invention relates to a method for selectively adsorbing and separating and recovering cobalt from an aqueous solution containing cobalt by using a chelate resin having a specific functional group.

[Conventional technology]

Currently, cobalt is used as a catalyst for Fischer-Tropsch synthesis, oxo method, carbonylation reaction, reduction of nitrile, etc., or alloy material such as high speed steel and magnetic material, and superalloy for improving mechanical properties of non-ferrous metal. It is used as a material as well as a plating material.

Cobalt is a valuable metal in addition to refining from ore.
It is necessary to recover from plating wastewater.

However, these raw materials, processing materials, waste water, and the like contain various impurities in addition to cobalt, and it is difficult to recover cobalt. For example, cobalt ore, such as Smaltite, Xcobalt Ore, Cobalt Flower, and Asbolite,
In addition to cobalt, it contains nickel, copper, lead, iron, etc., alloy scrap contains iron, and waste catalyst contains the organic matter used in the reaction. In wastewater, organic matter, coexisting salts, iron and chromium eluted from piping, chromium, Including copper, etc. Among them, when iron coexists, it is difficult to separate from cobalt. For example, when manufacturing from ore, cobalt ore is dissolved in hydrochloric acid, copper, lead, etc. are precipitated with hydrogen sulfide,
Next, iron is oxidized by chlorine, and then precipitated as iron hydroxide with calcium carbonate to separate from cobalt, which is a complicated process.

Usually, a method using a chelate resin has been studied as a method for recovering a metal from an aqueous solution, but when iron is contained together with cobalt, a method for easily separating these is not yet known.

As an example of using a chelate resin for cobalt in water,
(1) Removal of cobalt from wastewater by chelating resin (water treatment technology, Vol.22 P13-18 1981), (2) Japanese Patent Publication Sho 60
-23176 mag has been reported.

[Problems of conventional technology]

However, in the above method, which is the object of the present invention, iron,
Cobalt cannot be easily separated and recovered from an aqueous solution containing a metal such as chromium, an organic substance, or a coexisting salt.
For example, the method (1) is to remove cobalt in wastewater using a chelating resin having an iminodiacetic acid group,
Cobalt can be separated from a mixed solution containing coexisting salt, organic matter and cobalt, but all the metals in water are adsorbed and cobalt and other metals cannot be separated. Especially when the metal concentration is low, as in wastewater, iron has a higher selection rank than cobalt, so iron is preferentially adsorbed and cannot be separated from cobalt.

In the method (2), nickel containing copper as an impurity and / or
Alternatively, a chelate resin having a specific functional group is contacted with a cobalt-containing solution to adsorb copper on the chelate resin to obtain a nickel- and / or cobalt-containing solution from which copper has been removed. For example, excess acid required to dissolve cobalt, or salts, organic substances, etc. formed by neutralizing the excess acid are not adsorbed at all and migrate to the treated water, and these cannot be separated from cobalt.

Usually, the cobalt-containing aqueous solution contains organic substances, coexisting salts, or metals that are difficult to separate from cobalt in addition to cobalt.Therefore, as a method for recovering cobalt from the aqueous solution, these impurities and cobalt can be easily operated. It is desirable to use the method of separation described above.

The present invention has been made in view of the above points, and an object thereof is to selectively separate and recover cobalt from water containing cobalt by using a chelate resin.

[Means for solving problems]

As a result of intensive studies to solve the above problems, the present inventors have found that cobalt can be selectively separated and recovered by contacting a specific chelate resin with cobalt-containing water under certain conditions, and thus the present invention. It came to completion.

That is, the present invention, after adjusting the pH of the aqueous solution containing cobalt 10,000 to 70,000 ppm to pH 7 or less, styrene as a resin matrix-divinylbenzene copolymer, at least one amino acid group selected from the group consisting of epoxy resin and phenol resin, Chelating resin having at least one selected from the group consisting of iminoacetic acid group, iminodiacetic acid group, iminopropionic acid group, iminodipropionic acid group, alkylene phosphoric acid group, phosphoric acid group, or salts thereof as a functional group Is a method for separating and recovering cobalt by selectively adsorbing and separating cobalt by contacting with cobalt.

Examples of the cobalt-containing aqueous solution used in the present invention include cobalt-containing ores, waste catalysts and magnetic materials, acid solutions such as heat-resistant materials, plating waste solutions, mine drainage, and the like, and an aqueous solution containing 10000 to 70000 ppm cobalt. If it is, it is not limited to these.

The chelate resin used in the present invention, glycine group, glutamic acid group, amino acid groups such as lysine group, iminoacetic acid group, iminodiacetic acid group, iminopropionic acid group, iminodipropionic acid group, alkylenephosphoric acid group, phosphoric acid group,
Alternatively, a chelate resin having at least one selected from the group consisting of these alkali metal salts and alkaline earth metal salts as a functional group can be mentioned. Among these, a chelate resin having an iminodiacetic acid group, an alkylene phosphate group, or a salt thereof as a functional group has a large amount of adsorbed cobalt and also has a good elution property of the adsorbed cobalt, which is preferable.

Examples of the resin matrix of the chelate resin having the functional group include divinyl such as styrene-divinylbenzene copolymer, methyl acrylate-divinylbenzene copolymer, methyl methacrylate-divinylbenzene copolymer, acrylonitrile-divinylbenzene copolymer and the like. Examples thereof include a benzene-based copolymer, an epoxy resin, a resorcin resin, a phenol resin, and a vinyl chloride resin, and the resin is preferably of a porous type (MR type) rather than a gel type. When organic matter is present in the treated water, the gel-type chelate resin has a reduced ability to adsorb metals, whereas the MR-type chelate resin does not tend to have a reduced ability to adsorb, and the volume that occurs when the resin is regenerated. This is because the loss of resin crushing due to changes is small.

In the present invention, in order to separate and recover cobalt from the aqueous solution containing cobalt by using the above chelate resin, first, the pH of the aqueous solution containing cobalt is adjusted, and then this aqueous solution is brought into contact with the chelate resin. The pH of the aqueous solution containing cobalt is preferably 7 or less, more preferably pH 3-5. p
When H is 1 or less, the amount of cobalt adsorbed on the chelate resin decreases, and when H is 7 or more, other metals, for example, hydroxides of iron and the like are produced and the adsorption efficiency of the chelate resin decreases. Further, the cobalt concentration in the aqueous solution is preferably 10,000 to 70,000 ppm, and when the cobalt concentration is low, the adsorption amount of iron becomes large, the purity of cobalt in the obtained recovery liquid is lowered, and the cobalt concentration is in the above high concentration range. The adsorption amount of cobalt is larger than that of metals such as iron, so that the separability between these metals and cobalt can be enhanced, and at the same time, coexisting salts, organic substances, etc. can be separated. Aqueous solution of this concentration range is obtained by dissolving ore, alloy scrap, waste catalyst, etc. with acid and further adjusting to a predetermined pH, or when targeting water with low cobalt concentration such as mine drainage and plating wastewater, These waters can be prepared by using the eluate after once treating the water with an ion exchange resin and a chelate resin and concentrating the water.

In the present invention, as a method of bringing water containing cobalt (hereinafter referred to as treated water) into contact with the chelate resin, for example, the chelate resin is immersed in the treated water, or a batch method of immersing and further stirring, a chelate resin is used. Examples of the column system include a column system in which water to be treated is passed through a packed column, and the column system may be either a transient system or a circulation system, but any system may be used.
Any method of downward flow can be adopted. Further, in the column system, the liquid passing rate is SV 0.05 to 50, preferably 0.1 to 3
Can be used for adsorbing cobalt by adsorbing cobalt by circulating water to be treated. Further, in order to enhance the cobalt adsorption capacity, the water to be treated may be heated to 30 to 80 ° C and contacted with the chelate resin at the same temperature.

As described above, organic compounds, inorganic salts or iron, cobalt can be adsorbed and separated from the water to be treated containing a metal other than cobalt, such as chromium, to the chelate resin, and the cobalt adsorbed to the chelate resin is the chelate resin. It can be recovered by eluting with an acid such as hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid or acetic acid of 0.5 to 20 N, preferably 2 to 6 N as an eluent.

As a method for eluting cobalt adsorbed on the chelate resin, a method of contacting and eluting the eluent with the chelate resin in a batch system or a column system can be mentioned, and any system may be used. In the case of the column type, the eluent can be passed through the eluent at a flow rate SV of 0.05 to 10, preferably 0.1 to 3, or can be eluted by circulating the eluent. The cobalt ions eluted from the chelate resin can be recovered as a metal by a method such as electrolysis. Also, the chelate resin after elution of cobalt can be repeatedly used again for adsorbing cobalt in the aqueous solution.

〔Example〕

 Hereinafter, the present invention will be described in more detail with reference to examples.

Example 1 The same chloromethylated resin as in Example 1 was reacted with iminodiacetic acid to obtain a chelating resin having an iminodiacetic acid group. 200m of 10-48 mesh resin of this chelating resin
After packing l into a column (inner diameter 25 mmφ), cobalt catalyst waste liquid (cobalt: 31 g /, iron: 0.62 g /, chromium: 0.57 g /
, Sodium sulfate: 20%, organic substance such as β-hydroxypropionic acid: TOC concentration 25 g /, pH 4.0) 600 ml was passed through at a flow rate of SV 0.5, a temperature of 25 ° C., and a downward flow. A sample of the effluent was taken for each predetermined amount of the effluent (the amount of effluent per resin: the unit is indicated by / -R), and the metal ion concentration and TOC concentration in the effluent were measured. The results are shown in Figure 1.

Next, 500 ml of ion-exchanged water was passed through the metal-adsorbing resin, and the waste liquid remaining in the column was extruded, and then 500 ml of 2N HCl aqueous solution was passed at a flow rate of SV 0.5 at a downward flow to remove metal ions from the resin. Elution was performed. The effluent was sampled for each predetermined flow rate, the metal ion concentration and TOC concentration in the effluent were measured, and the recovered amount was obtained. The results are shown in Tables 1 and 2.

Comparative Example 1 The MR type spherical resin made of the styrene-divinylbenzene copolymer used in Example 1 was reacted with sulfuric acid to obtain a strongly acidic ion exchange resin having a sulfonic acid group. Of this strongly acidic ion exchange resin, 2 g of 10-48 mesh resin was added to 500 ml of the cobalt catalyst waste liquid similar to that in Example 1, and the mixture was mixed at 25 ° C. for 3 hours.
After stirring for an hour, the resin is separated and the residual concentration of cobalt, iron, chromium and TOC in the cobalt catalyst waste liquid is measured,
The amount adsorbed on the resin was determined. The adsorption amount per 1 kg of resin is
Cobalt: 10.3g / kg-R, Iron: 0.8g / kg-R, Chromium: 0.2g
/ kg-R, TOC: 1.3 g / kg-R.

Example 2 Into methyl pentaethylenehexamine tetrapropionate
A cured resin was obtained by reacting 1.3-bis (1.2-epoxypropoxy) benzene. The obtained cured resin was crushed to 20 to 60 mesh and saponified with an aqueous sodium hydroxide solution to obtain a chelating resin having an iminopropionic acid group. 2 g of this chelate resin is used as a cobalt catalyst waste liquid (cobalt: 28 g /
, Iron: 0.60g /, chromium: 0.3g /, sodium sulfate: 18
%, Organic substances such as β-hydroxypropionic acid: TOC concentration
18g /, pH4.5) 500ml, stir at 30 ℃ for 8 hours, separate the resin, and remove the cobalt in the cobalt catalyst waste liquid.
The residual concentrations of iron, chromium and TOC were measured to determine the amount adsorbed on the chelate resin. Adsorption amount per 1 kg of chelate resin is cobalt 28.3 g / kg-R (unit of adsorption amount per 1 kg of resin is g / kg-R), iron: 0.09 g / kg-R, chromium: 0.06
g / kg-R, TOC 0.8 g / kg-R, and cobalt was selectively adsorbed.

Example 3 A porous spherical resin (10 to 60 mesh) made of a styrene-divinylbenzene copolymer obtained by suspension polymerization of 92% by weight of styrene and 8% by weight of divinylbenzene was swollen in ethylene dichloride. Then, chloromethyl ether was reacted in the presence of anhydrous zinc chloride to chloromethylate to obtain a spherical resin (chlorine content: 21.8 / wt%). Then, the obtained chloromethylated resin is reacted with methylphosphoric acid,
A porous chelate resin having a methyl phosphate group as a functional group was obtained. The same cobalt catalyst waste liquid as that used in Example 2 was treated in the same manner as in Example 2. Adsorption amount of metal ions and organic substances to the chelate resin is cobalt: 39.8g
/ kg-R, iron: 0.08g / kg-R, chrome: 0.05g / kg-R, TO
It was C: 1.0 g / kg-R.

〔The invention's effect〕

As described above, the present invention, by bringing an aqueous solution containing cobalt adjusted to a constant concentration and pH into contact with a chelate resin having a specific functional group, cobalt is selectively adsorbed on the chelate resin, and separated and recovered. Is the way to
According to the method of the present invention, it is possible to separate a metal such as iron and chromium, which is difficult to separate from coexisting salts, organic substances or cobalt in an aqueous solution, and cobalt, which is easier than the conventional hydroxide precipitation method, and the ion It has the effect of recovering higher purity cobalt than the exchange resin and chelate resin methods.

[Brief description of drawings]

FIG. 1 shows the relationship between the passing amount and the metal concentration and TOC concentration in the effluent when the cobalt catalyst waste liquid is passed through the chelate resin of Example 3.

Claims (1)

[Claims] 1. An aqueous solution containing 10000 to 70000 ppm of cobalt is adjusted to pH 7 or less, and then, as a resin matrix, at least one selected from the group consisting of a styrene-divinylbenzene copolymer, an epoxy resin and a phenol resin is added,
Having at least one selected from the group consisting of an amino acid group, an iminoacetic acid group, an iminodiacetic acid group, an iminopropionic acid group, an iminodipropionic acid group, an alkylenephosphoric acid group and a phosphoric acid group, or a salt thereof as a functional group. A method for separating and recovering cobalt, which comprises selectively adsorbing and separating cobalt by bringing it into contact with a chelate resin.