JP2539413B2 - Adsorbent for gallium recovery - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an adsorbent for recovering gallium from a neutral or alkaline solution, and particularly to an absorbent for recovering gallium from an aqueous solution of sodium aluminate in a Bayer process alumina production process. .

[Conventional technology and problems]

In recent years, gallium is expected to be used in large quantities as a material metal in the future with the spread of semiconductors, but since the amount of minerals containing gallium as the main component is extremely small, it is not possible to use gallium in the sodium aluminate aqueous solution used in the Bayer process alumina production process. Gallium contained in is an important gallium raw material.

Bayer method As a method of recovering gallium from an aqueous solution of sodium aluminate, a so-called Bayer solution, in the alumina manufacturing process, conventionally, a carbonation method in which carbon dioxide gas is blown into the Buyer solution to recover gallium as a precipitate, or a buyer by electrolyzing mercury as a cathode is used. A direct electrolysis method for recovering gallium in the liquid as an amalgam is known, but all of them are not practical because of high recovery cost.

Recently, there has been proposed a method for recovering gallium by a liquid-liquid extraction method in which an extraction solvent composed of an extraction reagent that forms a chelate with gallium and an organic solvent is mixed with a Bayer solution and statically separated. However, this method is industrially satisfactory because it has a drawback that the amount of gallium recovered per extraction reagent is not sufficient and the extraction reagent is scattered into the aqueous solution of sodium aluminate, although the extraction reagent is expensive. I can't say.

In order to overcome these drawbacks of the liquid-liquid extraction method, a method of recovering gallium by using a chelate resin having a functional group capable of forming a chelate with gallium immobilized and contacting the resin with a gallium-containing solution has been attempted. ing. For example, a chelate resin having an amidoxime group has a high selective absorption ability for gallium, but has a property of being hydrolyzed by an acid, and therefore has a drawback that the adsorption ability is reduced each time the adsorbed gallium is desorbed with an acid.

8-Hydroxyquinoline compound having high chelate-forming ability with gallium (hereinafter referred to as oxine compound)
Attempts to immobilize resin on resin are found in JP-A-58-6245, JP-A-58-7412 and JP-A-58-96831. Further, JP-A-58-6245 and JP-A-58-6245
JP-A-58-7412 is intended to introduce an oxine compound into a resin base material by reacting aminated polystyrene or aminomethylated polystyrene with halomethylated hydroxylquinoline. In addition, JP-A-58-9683
No. 1 discloses that an oxy compound is condensed with formalin,
Alternatively, a vinyl group is introduced into the same compound and polymerized. In addition, an oxine compound is introduced into a resin by a method essentially equivalent to JP-A-58-6245. As described above, in order to introduce an oxine compound into a resin in the related art, some kind of synthetic reaction is required, so that the resin cost must be high due to a low yield at the time of synthesis and the complexity of the synthetic method.

[Means for solving problems]

As a result of earnest research on an adsorbent for recovering gallium that overcomes these drawbacks, the present inventors found that an adsorbent having an oxine derivative supported on an ion-exchange resin or a porous material having a specific surface area does not contain gallium. They have found that they can be adsorbed efficiently and have completed the present invention. That is, the present invention comprises a resin having an ion exchange capacity or a porous body having a specific surface area of 10 m ² / g or more measured by the BET method and carrying the 8-hydroxyquinoline compound represented by the general formula (I). It is an adsorbent for gallium recovery.

(However, R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , and R ₆ are hydrogen or an alkyl group,
Substituted alkyl group, halogen group, nitro group, nitroso group,
Represents an alkoxy group, which may be the same or different from each other. ) The present invention will be described in more detail below. Examples of the oxine compound used in the present invention include the following.

These are specifically the Chelex 10 made by Chelex.
It is marketed as 0 (trade name). The resin having an ion exchange capacity used in the present invention is not particularly limited, but preferably has a specific surface area of 1 m ² / g or more as measured by the BET method, and has a specific surface area of 10 m ² / g or more. Is particularly preferable. When an ion exchange resin having a specific surface area of less than 1 m ² / g is used, the oxine compound is not effectively supported, resulting in a poor gallium adsorption efficiency. When an ion exchange resin having a specific surface area of 1 m ² / g or more is used, the gallium adsorption efficiency is remarkably improved. As such an ion exchange resin, a styrene type, an acrylic type, a phenol type, etc., as a functional group having an ion exchange ability in a resin matrix,
Examples thereof include those having a sulfonic acid group, a phosphonic acid group, a carboxylic acid group, a quaternary ammonium group, a primary to tertiary amino group, a chelate-forming group and an amphoteric group. The shape of these resins is usually granular or powder, but may be fibrous or any other shape.

Further, as the porous body used in the present invention, BET
Specific surface area measured by the method is 10 m ² / g or more, preferably 30 m ² / g
If it is above, it will not be specifically limited. When a porous body having a specific surface area of less than 10 m ² / g is used, the oxine compound is not effectively supported, and thus the gallium adsorption efficiency is poor and there is a problem in putting it to practical use. If a porous body having a specific surface area of 10 m ² / g or more is used, the gallium adsorption efficiency will be very good. Examples of such a porous body include styrene-based, acrylic-based, phenol-based synthetic adsorbents, silica gel, activated carbon, and zeolite.

The shape of these porous bodies is usually granular or powdery, but other shapes such as fibrous may be used.

In the ion exchange resin or the porous body of the present invention, in order to produce an adsorbent carrying an oxine compound, all that is required is to immerse the ion exchange resin or the porous body in the oxy compound,
It is not particularly necessary to form a covalent bond by a chemical reaction.
At the time of dipping, the oxine compound may be used by dissolving it in a solvent, but a method without using a solvent is also acceptable. As this method, for example, a method in which an ion exchange resin is immersed in an oxine compound for a whole day and night, and then subjected to filtration, washing and drying for practical use is adopted.

The adsorbent of the present invention is preferably used for recovering gallium from a neutral or alkaline gallium-containing solution,
In particular, it is useful for efficiently recovering gallium from a sodium aluminate aqueous solution (so-called Bayer solution) in the Bayer method alumina production process. To recover gallium, first, the gallium adsorbent of the present invention is brought into contact with the gallium-containing solution. The contact method is not particularly limited, and for example, a method of passing a gallium-containing solution through a column packed with an adsorbent, a method of shaking the adsorbent in the gallium-containing solution, or the like is adopted. In the case of using the liquid flow, an upward flow, a downward flow, or the like is appropriately selected as the flow direction of the gallium-containing solution. The adsorbent having adsorbed gallium is then treated with an acid solution to elute gallium. Examples of the acid solution used here include hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid and the like.

As described above, the gallium recovered from the gallium-containing solution into the acid solution can be recovered as metallic gallium by a known method such as an electrolytic method.

[Action, effect]

According to the adsorbent of the present invention, gallium can be extremely efficiently recovered by the interaction between the oxy compound which is the chelating agent and the ion exchange resin or the porous body having a specific surface area. In the case of using an ion exchange resin, the hydrophobic portion of the ion exchange resin acts effectively when adsorbing and supporting an oxine compound, which is also hydrophobic, and the ion exchange resin is more effective for gallium-containing solutions. This is because the hydrophilic portion acts effectively, facilitates the adsorption of gallium, and fully exerts the gallium adsorption ability of the oxine compound. When using a porous body, the oxine compound is adsorbed and supported in a molecular form on the surface of the innumerable pores forming the porous body, and when this is brought into contact with a gallium-containing solution, each oxine compound is This is because the molecule sufficiently exhibits the gallium adsorption ability. The ability to adsorb gallium due to these interactions is completely unthinkable in a liquid-liquid extraction method using the same oxine compound.

Furthermore, since the adsorbent of the present invention does not require the use of an organic solvent in the recovery of gallium, the gallium-containing mother liquor and the eluent are not contaminated by the organic solvent, and therefore do not adversely affect the electrolysis step in the subsequent step. It has the advantage of

In addition, the adsorbent of the present invention has an advantage that it can be repeatedly subjected to adsorption and desorption operations without deteriorating the adsorption effect when desorbing adsorbed gallium.

[Examples] Hereinafter, the present invention will be specifically described with reference to Examples.

Example 1 1 part by weight of Levatit SP120 (manufactured by Bayer), which is a sulfonic acid type strong ion exchange resin having a specific surface area of 26.3 m ² / g measured by the BET method using a polystyrene resin as a base material, was mixed with Kerex 100 It was immersed in 5 parts by weight (made by Rex Co., Ltd.) for a whole day and night, and then filtered, washed and dried to obtain an adsorbent. 1 g of the obtained adsorbent, an aqueous solution of sodium aluminate from the buyer cycle of the alumina manufacturing process containing Ga 103 ppm
After adding to 250 ml and shaking for 15 hours, the Ga concentration was measured and it was found that 3.6 g of Ga was adsorbed per 1 kg of the resin.

Examples 2 to 5 Instead of the ion exchange resin used in Example 1, various ion exchange resins shown in Table 1 were used to impregnate Kerex 100 in accordance with Example 1 to prepare an adsorbent. The same Ga adsorption test as in Example 1 was conducted using these adsorbents. The results are shown in Table 1.

Example 6 10 ml of the adsorbent obtained in Example 2 was packed in a column having an inner diameter of 12 mmφ, and 100 ml of an aqueous solution of sodium aluminate from a Bayer cycle containing Ga 103 ppm was passed from the top of the column. After water extrusion, 20 ml of 1N HCl was passed through the top of the tower to remove the adsorbed Ga. Further, the same operation of adsorption and desorption was repeated. Table 2 shows the Ga adsorption capacity for each time.

Example 7 The results of measuring the oxine content in the adsorbent obtained in Example 2 are shown in Table 3. At the same time, the amount of adsorbed gallium measured in Example 2 was converted and shown per unit weight of oxine.

Comparative Example 1 A gallium extractant consisting of 1 g of Kerex 100, 1 g of n-decanol and 8 g of kerosene was added to 25 ml of the same aqueous solution of sodium aluminate used in Example 1 and shaken for 4 hours, and then the Ga concentration was measured. The results are shown in Table 3.

Example 8 As a porous body, a specific surface area measured by the BET method of 403 m ² /
1 part by weight of a polystyrene-based synthetic adsorbent A having g was immersed in 5 parts by weight of Kelex 100 (manufactured by Chelex Co., Ltd.) for one day and then dried, washed and dried to obtain an adsorbent. 1 g of the obtained adsorbent was added to 250 ml of an aqueous solution of sodium aluminate from the buyer cycle of the alumina manufacturing process containing Ga 103 ppm, and 1
After shaking for 5 hours, the Ga concentration was measured and the porous body was 1 kg.
It was confirmed that it adsorbed 5.9 g of Ga per unit.

Examples 9 to 12 The porous adsorbents shown in Table 4 were used in place of the synthetic adsorbent used in Example 8, and according to Example 8, kerex was used.
100 was impregnated to prepare an adsorbent. Using these adsorbents, the same Ga adsorption test as in Example 8 was conducted. The results are shown in Table 4.

Example 13 10 ml of the adsorbent obtained in Example 8 was packed in a column having an inner diameter of 12 mmφ, and 100 ml of an aqueous sodium aluminate solution from a Bayer cycle containing Ga 103 ppm was passed from the top of the column. After water extrusion, 20 ml of 1N HCl was passed through the top of the tower to remove the adsorbed Ga. Further, the same operation of adsorption and desorption was repeated. Table 6 shows the Ga adsorption capacity for each time.

Example 14 The results of measuring the oxine content in the adsorbent obtained in Example 8 are shown in Table 7. At the same time, the amount of adsorbed gallium measured in Example 8 was converted and shown per unit weight of oxine.

Claims (1)

(57) [Claims] 1. An adsorbent for recovering gallium, which comprises an 8-hydroxyquinoline compound represented by the general formula (I) supported on a resin having an ion exchange capacity. (However, R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , and R ₆ are hydrogen or an alkyl group,
Substituted alkyl group, halogen group, nitro group, nitroso group,
Represents an alkoxy group, which may be the same or different from each other. )