JPS6221711A - Selective separation and recovery of gallium - Google Patents

Abstract

PURPOSE:To enable the separation and recovery of Ga from a Ga-containing solution in high selectivity and efficiency, by using a membrane containing a specific hydrophobic compound having N-nitrosohydroxyamine group. CONSTITUTION:A membrance containing a hydrophobic compound of formula (R1 is 3-30C straight, branched or alicyclic alkyl or alkenyl; R2 is phenylene, naphthylene, hydrophenylene or hydronaphthylene; X is H, inorganic or organic ammonium ion or alkali metal; n is 0, 1 or 2) having N-nitrosohydroxy amino group is prepared beforehand. Gallium is separated and recovered selectively from a gallium-containing solution by using the above membrane. The compound of formula is e.g. N-nitrophenylhydroxylamine ammonium salt, N- nitrosonaphthylhydroxylamine ammonium salt, etc., having hydrophobic substituent group such as octyl, dodecyl, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for selectively separating and recovering gallium.

More specifically, the present invention relates to a method for selectively separating and recovering gallium in a solution using a membrane containing a specific compound having chelate-forming ability.

[Conventional technology]

Demand for gallium has been increasing significantly in recent years due to developments in the semiconductor field and the like. Unlike iron and copper, gallium does not have a single ore. Gallium is widely contained in small amounts in bauxite, which is raw aluminum ore, coal smoke, zinc sulfide ore, Germanic ore, etc., so various methods have been used to separate and recover it, requiring a lot of effort and expense. . In other words, it is a simple process and has few harmful effects.

The development of a technology that can economically and efficiently separate and recover gallium is expected to have great commercial value. Now, in the production of gallium that is currently carried out on an industrial scale, most of the raw materials are a gallium-aluminum mixed solution containing a large amount of aluminum, called Bayer liquid, which is used when producing alumina from bauxite by the Bayer process. It is.

To process bauxite using the Bayer method, first the raw ore is heated and decomposed with an aqueous sodium hydroxide solution to prepare a sodium aluminate solution. At this time.

The gallium mostly migrates into the sodium aluminate solution. The sodium aluminate is then cooled.

Aluminum hydroxide is added as seeds to accelerate the hydrolysis reaction. Since most of the aluminum is precipitated as aluminum hydroxide, it is separated into r.

At this time, most of the gallium remains in the P liquid. The f liquid is evaporated and concentrated and reused for bauxite treatment.

This F liquid is called Bayer's liquid and is essentially a raw material for gallium production.

For separation and recovery of gallium using Bayer's solution.

Various methods have been implemented or proposed. In addition to the current method using mercury amalgam and the method of blowing carbon dioxide gas, recently, a method of solvent extraction using a chelate extractant made of an oxine derivative with increased hydrophobicity (Japanese Patent Application Laid-Open No.
Publication No. 1-32411.

No. 53-52289, No. 54-99726, etc.), a method of adsorption separation using a chelate resin having an iminodiacetic acid group as a functional group (Japanese Patent Application Laid-open No. 58-42737, etc.), amidoxime as one functional group.

Adsorption separation method using chelate resin containing oxine
Publication No. 31, etc.) have been proposed.

However, each of these methods has various drawbacks. Disadvantages of the current method include mercury dissolution loss, mercury contamination, complicated operations, and low gallium recovery efficiency. Even recently proposed methods have many problems in actual use. In the method using hydrophobic oxine derivatives, the reagent has low selectivity for gallium.
The problem is that the recovery efficiency is poor and the functionality is noticeably degraded due to elution of the reagent into the aqueous solution. Furthermore, the method using an iminodiacetic acid-based chelate resin has the drawbacks of low selectivity for gallium and the necessity of placing strict limits on the speed at which the chelate resin contacts with a solution containing gallium. Furthermore, although methods using chelate resins having amidoxime or oxine as functional groups have the advantage of adsorbing gallium from alkaline solutions,
Since elution and recovery of gallium requires a highly concentrated strong mineral acid or heating, 1. To recover metallic gallium by electrolysis using a commonly used method.

It must be returned to alkalinity again, which complicates the process. Furthermore, considering the general acid resistance and heat resistance of the chelate resin, this method cannot be said to be fully economically satisfactory.

Due to these circumstances, even though the demand for metallic gallium has increased significantly with the development of the electronic industry such as the semiconductor sector, there is still no method of separation and recovery of gallium that is economically satisfactory on an industrial scale. The method has not been established. Therefore,9 the present inventors conducted extensive studies to establish a new gallium separation9 recovery method that overcomes the above-mentioned disadvantages.As a result, a membrane containing a specific compound with chelate-forming ability selectively separates gallium from one side to the other. Adsorbs and moves on the membrane surface.

The present invention was achieved by discovering that desorption occurs on the other membrane surface.

[Means for solving problems]

However, R1 is a linear 9-branched or alicyclic alkyl group or alkenyl group having 3 to 3 carbon atoms.
R2 haphenylene 7 group, naphthylene group, hydrophenylene group or hydronaphthylene group, X is a hydrogen atom, an inorganic or organic ammonium ion or an alkali metal such as sodium or potassium, n is O, l,
2 are shown respectively. An object of the present invention is to provide a method for selectively separating and recovering gallium from a gallium-containing solution, which is characterized by using a membrane containing a hydrophobic compound having an N-nitrone hydroxyamine group represented by the following formula as a carrier.

As the hydrophobic compound having an N-nitrone hydroxyamino group (hereinafter referred to as a chelate compound) represented by R1, for example, propyl, hexyl, octyl,
Dodecyl, octadecyl, eicosyl, tocosyl, triancontyl, gropenyl, hexenyl, octenyl,
Dodecenyl, octatecenyl, eicosenyl, tococenyl, triancontenyl, cyclopropyl, cyclohexyl.

Cyclooctyl, dicycloglovir, dicyclohexyl, dicyclooctyl, tricyclopropyl.

Tricyclohexyl, tricyclooctyl, cyclopropenyl, cyclohexenyl, cyclooctenyl, dicyclopropenyl, dicyclohexenyl.

N-nitrone hydroxylamine having a dicyclooctenyl, tricyclopropenyl, tricyclohexenyl, tricyclooctenyl group, or a substituent having hydrophobicity equivalent to these groups.

N-nitrosophthylhydroxylamine, N-nitrosonaphthylhydroxylamine or hydrogenated products of these phenyl and naphthyl groups, and N-nitrone hydroxylamine, or their inorganic or organic ammonium salts or alkali metal salts such as sodium or potassium. can be mentioned. In particular, N-nitron phenylhydroxylamine ammonium salt or N-nitron naphthylhydroxylamine ammonium salt having a hydrophobic substituent 'f' is preferably used.

The membrane used in the present invention includes an impregnated membrane in which the chelate compound is dissolved in a hydrophobic solvent and impregnated into a porous polymer membrane, an emulsion membrane stabilized with a surfactant, or an emulsion membrane in which the chelate compound is dissolved in a hydrophobic solvent and impregnated into a porous polymer membrane. Examples include blended membranes prepared by blending with a polymer and forming into a membrane. The hydrophobic solvent used when preparing the impregnated membrane and emulsified membrane can dissolve the chelating agent, and even those with extremely low solubility in water can be used.
Examples include kerosene, xylene, diethylbenzene, tetrachloroethane, diphenyl ether, or those having hydrophobic properties equivalent to these. In addition, a porous polymer membrane is a membrane-like polymer material that has a large number of fine through holes, and examples of the materials include T-bar, polyethylene, polypropylene, cellulose acetate, Teflon, polyvinyl chloride,
Examples include polyvinylidene fluoride, polycarbonate, polysulfone, polyamide, polyimide, and the like.

Furthermore, hydrophobic polymers are preferred as the membrane material used in preparing the blend membrane9, such as polyethylene, polypropylene, and polybutadiene.

Polymethyl methacrylate, polystyrene, polyacrylonitrile, polyvinyl chloride, polyvinylidene chloride,
Polyvinylidene fluoride, Teflon.

Examples include silicone rubber.

The shape of the membrane may be either a flat membrane or a hollow fiber membrane.

The gallium-containing solution in the present invention is not particularly limited as long as it is a gallium-containing solution. for example,
Gallium obtained in the industrial aluminum manufacturing process
Examples include aluminum mixed liquid, aluminum alloy manufacturing waste liquid, and leachate of zinc sulfide ore, germanite, etc.
Considering the industrial scale and commercial value, it is called Bayer liquid, which is produced in the process of producing alumina by the Bayer method. A gallium-aluminum mixture liquid in which most of the aluminum content has been removed and the gallium concentration ratio is increased is preferably used.

In order to selectively separate and recover gallium from a solution containing gallium according to the present invention, a membrane containing the chelate compound is provided between the gallium supply phase solution and the gallium permeation phase solution, and the two are brought into contact with each other. For example, a diaphragm method or a hollow fiber membrane method is often employed. The amount of the chelate compound to be used is appropriately selected depending on the gallium concentration on the feed phase solution side.

The operating temperature is 5 to 70°C, preferably 10 to 50°C. Further, the solution containing gallium on the supply side is preferably acidic, and particularly preferably has a pH of 1 to 4. Further, in order to increase the permeation rate, it is preferable to lower the pH of the gallium permeation phase solution side than that of the feed phase solution side or to pressurize the feed phase solution side.

〔Effect of the invention〕

Therefore, by such a simple operation, gallium can be selectively separated and recovered from a gallium-containing solution.9 Metallic gallium can be recovered by using the recovered solution as it is or by preparing a sodium gallinate solution, for example, and electrolyzing it by the common element method. Obtainable.

According to the present invention described in detail above, the selectivity for gallium is higher than that of the current method or a method of separating and recovering gallium using a known chelating agent or chelate resin. Furthermore, since the present invention uses a membrane, the extraction and elution of gallium can be carried out in one process, whereas in conventional methods using chelating agents or chelate resins, extraction and elution of gallium must be handled as separate processes. Its value is also great from the point of view of efficient separation and recovery of gallium.

The present invention will be explained in more detail below by way of examples.

Note that the present invention is not limited to the following examples.

〔Example〕

Examples 1 to 5 A porous Teflon flat membrane was impregnated with a kerosene solution of a hydrophobic compound having an N-nitrosohydroxyamino group represented by the following general formula at a concentration of 0.03 mm (surface area: 3 cr).
1, film thickness 100 μm) was prepared.

General formula: R1 (-R2÷nN-0-X poison=.

200 ppm of gallium and 400.00 p of aluminum adjusted to pH 3.5 in the feed phase (left side) through the membrane
Aqueous solution 50-1 containing pm(rAf)/(GJ = 200) The aqueous solution adjusted to pH 1.0 was charged into the permeation phase (right side), and both phases were stirred at room temperature. The concentrations of gallium and aluminum in the permeation phase (right side) after 50 hours are shown in Table 1.

Example 6 The same procedure as in Example 1 was carried out except that N-nitron phenylhydroxylamine ammonium salt having an n-dodecyl group as a hydrophobic substituent was used as the chelate compound.

Example 7 The same procedure as in Example 1 was carried out except that kerosene/1,1,2.2-tetrac, loloethane 7/3 (vol ratio) was used as the hydrophobic solvent.

Example day: Kerosene/diphenyl ether 7 as a hydrophobic agent
/ 3 (VOl ratio) was used, but the same operation as in Example 1 was performed.

Example 9 A membrane was prepared by blending polyethylene with N-nitron phenylhydroxylamine ammonium salt having an n-octadecyl group as a hydrophobic substituent.

The procedure was the same as in Example 1 except that a blend film prepared by hot press molding was used.

Example 10 The same procedure as in Example 9 was carried out except that polyacrylonitrile was used as the hydrophobic polymer and the film was formed by the solvent casting method.

The above results are shown in Table 2.

Claims (2)

[Claims] (1) General formula ▲ Numerical formula, chemical formula, table, etc. ▼ (However, R_1 is a linear, branched, or alicyclic alkyl group or alkenyl group having 3 to 30 carbon atoms, and R_2 is a phenylene group or naphthylene group. , a hydrophenylene group or a hydronaphthylene group, X is a hydrogen atom, an inorganic or organic ammonium ion, or an alkali metal such as sodium or potassium, and n is 0, 1, or 2, respectively. 1. A method for selectively separating and recovering gallium from a solution containing gallium, the method comprising using a membrane containing a hydrophobic compound having the following properties. (2) The method for selectively separating and recovering gallium according to claim 1, wherein the solution containing gallium is an acidic aqueous solution.