JPS61201621A - Selective separation and recovering method for gallium - Google Patents

Abstract

PURPOSE:To separate and recover Ga efficiently with simple procedure and high selectivity by allowing a chelate agent comprising a specified hydrophobic compd. to contact with soln. contg. Ga. CONSTITUTION:A chelate agent comprising a hydrophobic compd. having an N-nitroso hydroxylamino group expressed by the formula [wherein R1 is 3-30C linear or branched or alicyclic alkyl, alkenyl; R2 is (hydro)phenylene, or (hydro) butylene; X is H, inorg. or org. ammonium ion, Na, K; (n) is 0-2] is allowed to contact with a soln. contg. Ga such as a liquid mixture contg. Ga-Al produced in the industrial stage for producing Al, at 5-70 deg.C for >=several minutes. The pH of the soln. is adjusted, if necessary, to 0-2.

Description

DETAILED DESCRIPTION OF THE INVENTION 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 specific chelating agent.

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 raw aluminum ore, such as bauxite, coal smoke, zinc sulfide ore, and germanic ore, so 9.1
Various efforts have been made to collect the waste, which requires a lot of effort and expense. In other words, it is a simple process and has few harmful effects.

The development of a stone removal technique 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 mixture containing a large amount of aluminum, called Bayer liquid, which is used to produce alumina from bauxite by the Bayer process. It is.

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

Most of the gallium is transferred 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, this is separated into P.

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

This P 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.), adsorption separation method using a chelate resin having an iminodiacetic acid group as a functional group (Japanese Unexamined Patent Publication No. 58-4273'i'
No. 9, etc.) Amidoxime in the 9 functional group.

Adsorption separation method using chelate resin containing oxine (JP-A-58-49620, JP-A-5B-968)
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. Further, the method using an iminodiacetic acid-based chelate resin has the drawbacks of low selectivity for gallium and the necessity of placing strict restrictions on the speed at which the chelate resin comes into contact 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, 9 metal gallium can be recovered 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, although the demand for metallic gallium has increased significantly with the development of the electronic industry sector such as the semiconductor sector, there is still no method for separating gallium that is economically satisfactory on an industrial scale. 9 Collection method has not been established.

Therefore, the present inventors conducted intensive studies to establish a new method for separating and recovering gallium that overcomes the above-mentioned disadvantages, and discovered that a specific chelating agent selectively extracts gallium.1 The present invention has been developed. Reached.

or alicyclic alkyl group or alkenyl group +
``2 is a phenylene 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, and n is 0.1.
2 are shown respectively. An object of the present invention is to provide a method for selective separation and recovery of gallium, which is characterized in that a hydrophobic compound having an N-nitrone hydroxyamino group represented by the following formula is brought into contact with a solution containing gallium.

Examples of hydrophobic compounds (hereinafter referred to as chelating agents) include propyl and hexyl as +RI.

Octyl, dodecyl, octadecyl, eicosyl.

Tocosyl, triancontyl, flobenyl, hexenyl, octenyl, dodecenyl, octadecenyl, eicosenyl, tocosenyl l)9 Ancontenyl, cyclopropyl, cyclohexyl, cyclooctyl, dicyclopropyl, dicyclohexyl.

Dicyclooctyl, tricyclopropyl, tricyclohexyl, tricyclooctyl, cyclopropenyl, cyclohexenyl, cyclooctenyl.

dicyclopropenyl, dicyclohexenyl, dicyclooctenyl, tricyclopropenyl) I) N-nitrone hydroxylamine having a cyclohexenyl or tricyclooctenyl group or a substituent with hydrophobicity equivalent to these groups , N-nitrone phenylhydroxylamine and N-nitrosonaphthylhydroxylamine or their hydrogenated products of 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-nitrosonaphthylhydroxylamine ammonium salt having a hydrophobic substituent is preferably used.

The gallium-containing solution in the present invention is not particularly limited as long as it is a gallium-containing solution. Examples include gallium-aluminum mixed liquid obtained in the industrial aluminum manufacturing process, aluminum alloy manufacturing waste liquid, and leachate of zinc sulfide ore, germanite, etc. However, considering the industrial scale and commercial value, the Bayer method can be used. It is called Bayer liquid, which is produced during the alumina manufacturing process.

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.

To selectively separate and recover gallium from a gallium-containing solution according to the present invention, it is sufficient to simply bring the gallium-containing solution into contact with the chelating agent.

There are no particular restrictions on the method of contact.

Generally, the chelating agent is added directly to a solution containing gallium and stirred, the chelating agent is packed in a cylindrical column and the gallium-containing solution is passed through the column, or the chelating agent is dissolved in a hydrophobic organic solvent. A so-called solvent extraction method or the like is employed in which this is brought into contact with a solution containing gallium. However, in consideration of equipment, ease of operation, processing capacity, efficiency, etc., it is preferable to adopt a method in which the chelating agent is directly added to the gallium-containing solution and stirred. The amount of the chelating agent to be used is appropriately selected depending on the gallium concentration in the solution. The operating temperature is 5 to 70°C, preferably 10 to 50°C. Further, a contact time of several minutes or more is usually sufficient. Furthermore, the solution containing gallium is preferably acidic, particularly pHo-2.

By such a simple operation, gallium can be selectively separated and recovered from a gallium-containing solution such as Bayer's solution.

Alternatively, the chelating agent may be supported or immobilized on a resin, silica gel, or the like.

Of course, selective separation and recovery of gallium is possible.

Examples of the shape include powder, porous sphere, fiber, film, membrane, and colloid.

Furthermore, liquid films such as an impregnated membrane in which a porous polymer membrane is impregnated with a hydrophobic solution of the chelating agent or an emulsion membrane stabilized by a surfactant are also considered to have similar functions.

When the chelating agent that has adsorbed gallium is adsorbed under acidic conditions, gallium can be eluted by contacting it with a stronger acid or alkali. especially,
When contacting with an alkali, the concentration of the alkaline aqueous solution can be selected from a wide range; for example, a sodium galmate solution with an appropriate concentration can be easily prepared. Metallic gallium can be obtained from the gallium thus eluted by directly electrolyzing the eluent by a known method.

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. In addition, the adsorbed gallium can be efficiently separated and recovered with a simple operation, and the adsorbed gallium can be easily eluted with an alkaline aqueous solution, and the eluent can be used as an electrolyte, so it can be incorporated into the current gallium electrolysis process. is also of great value.

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.

Examples 1 to 5 4.2 tons of a hydrophobic compound having an N-nitrone hydroxyamino group represented by the following general formula was mixed with 200 ppm of gallium and 4 aluminum adjusted to pH 1.0.
The mixture was added to 100 g of an aqueous solution containing 0,000 ppm, stirred at room temperature for 2 hours, and then filtered to separate the P solution. After washing one of the metal chelates with water, 50% of a 0.1N aqueous sodium hydroxide solution was added, stirred at room temperature for 15 minutes, and treated with P to obtain a recovered solution in which gallium was eluted. The results are shown in Table 1.

Table 1 General formula: R, (-R2-)I, N-0-XN=0 Example 6 The pH of an aluminum aqueous solution containing gallium was adjusted to 0.3, and a 1N aqueous sodium hydroxide solution was used as an eluent. The procedure was the same as in Example 1 except that .

Example The same procedure as in Example 1 was carried out except that the pH of the aluminum aqueous solution containing magallium was adjusted to 0.

Example 8 The same procedure as in Example 1 was carried out except that 3.3t of N-nitrosophenylhydroxylamine ammonium salt having an n-dodecyl group as a hydrophobic substituent was used as the chelating agent.

Example 9 The same procedure as in Example 8 was carried out except that the pH of the aluminum aqueous solution containing gallium was adjusted to 1.5.

Example 10 The same procedure as in Example 1 was carried out except that N-nitrosophenylhydroxylamine ammonium salt 4.5# having an n-eicosyl group as a hydrophobic substituent was used as the chelating agent.

Example 11 The same procedure as in Example 10 was carried out except that the pH of the aluminum aqueous solution containing gallium was adjusted to 0.5.

The above results are shown in Table 2.

Table 2 N=0 Patent applicant: Ube Industries Co., Ltd. Procedural amendment 9th month of ψ, 6θ, Showa

Claims (1)

[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 phenylene 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, and n is 0, 1, or 2, respectively. - A method for selective separation and recovery of gallium, which comprises bringing a hydrophobic compound having a nitrosohydroxyamino group into contact with a solution containing gallium. 2. The method for selectively separating and recovering gallium according to claim 1, wherein the gallium-containing solution is an acidic aqueous solution.