JPS61111917A - Recovery of gallium - Google Patents

Abstract

PURPOSE:To recover gallium in high purity, economically, with little consumption of reagent, from a gallium-containing solution, by using an ion-exchanging or chelating adsorbent. CONSTITUTION:Gallium is recovered from a gallium-containing solution by the following 4 steps. (1) The gallium-containing solution is made to contact with an ion-exchanging or chelating adsorbent capable of adsorbing gallium, to effect the adsorption of gallium to said adsorbent. (2) The adsorbent containing gallium is optionally washed, and made to contact with a base solution containing a sulfide to elute the gallium from gallium-containing adsorbent to obtain eluted gallium solution. (3) The sulfide is removed from the eluted gallium solution to obtain purified gallium solution essentially free from sulfide, (4) Gallium or a gallium compound is recovered from the purified gallium solution essentially free from sulfide.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for recovering gallium from a solution containing gallium using an ion exchange or chelating adsorbent.

Commercial production of gallium is carried out using alumina production Bayer fluids, so-called aqueous sodium aluminate solutions or aqueous zinc ore acid leaching solutions. A method for recovering gallium from an aqueous sodium aluminate solution is to electrolyze the gallium in the solution using mercury as a cathode, convert the gallium in the solution into amalgam, hydrolyze the amalgam with one trowel of caustic alkali, and electrolyze the resulting aqueous alkali garmate solution. A method of recovering the sodium aluminate solution and blowing carbon dioxide gas into the sodium aluminate aqueous solution.
The alumina content in the sodium aluminate aqueous solution is mainly precipitated, carbon dioxide gas is blown into the solution in which the ratio of alumina content and gallium content is adjusted, the alumina content and gallium content are coprecipitated, and the coprecipitate is converted to caustic alkali. A method is known in which the aqueous alkaline garmic acid solution produced by dissolution is electrolyzed and recovered. In addition, as a method for recovering gallium from an aqueous zinc ore acid leaching solution, the zinc concentrate is calcined, the zinc leaching residue from which most of the zinc has been extracted is further subjected to sulfuric acid leaching, decopper removal, and then multiple A known method is to dissolve the gallium cake obtained through the extraction process in an alkali, and to electrolyze and recover the resulting aqueous alkaline garmic acid solution.

However, the former method of recovering gallium from a sodium aluminate aqueous solution has the disadvantage that a large amount of mercury is dissolved and lost in the sodium aluminate aqueous solution during amalgamation, and the latter method The use of sodium aluminate has the disadvantage that the caustic alkali content in the aqueous sodium aluminate solution is carbonated and lost. or,
When using zinc ore acid leachate as a target, there is a drawback that it requires a complicated extraction process because it contains various impurity elements.

Recently, as a method for recovering gallium from Bayer liquid, gallium was recovered from an aqueous sodium aluminate solution by liquid-liquid extraction using an extractant consisting essentially of water-insoluble substituted hydroxyquinolines and an extraction solvent consisting of an organic solvent. Methods have been proposed (JP-A-51-32411, JP-A-58-52289, JP-A-54-99726).
Publications, etc.).

However, in this method, the reagent used has poor alkali resistance, the substituents decompose during long-term use, water solubility increases, and the recovery rate of the reagent and gallium decreases, and the gallium recovery reagent used is a liquid. Therefore, a considerable amount of the recovered reagent is dissolved in the sodium aluminate aqueous solution and lost, and the contamination of the extractant during the buyer process may adversely affect the quality of the aluminum hydroxide. However, it has not yet been industrially satisfied.

For these reasons, the present inventors have previously developed a method for recovering gallium using an adsorbent having an amidoxime group (Japanese Unexamined Patent Publication No. 5
8-49620), ■=NOH and ■(5) A method for recovering gallium using an adsorbent having a functional group capable of forming a chelate bond via the functional group and gallium (Japanese Unexamined Patent Publication No. 58
-52450) and a method for recovering gallium using an adsorbent having an oxine ligand (Japanese Patent Application Laid-Open No. 58-96881).
A method for recovering gallium using an adsorbent having an 8-oxyquinoline group having an alkyl group having 1 to 5 carbon atoms at the 2nd position and an alkyl group having 1 to 20 carbon atoms at the 8th position. (Japanese Unexamined Patent Publication No. 58-6245), 1 carbon number in the 2nd position
A method for recovering gallium from Bayer's liquid using an adsorbent having an 8-oxyquinoline group having ~20 alkyl groups has also been proposed (Japanese Patent Application Laid-open No. 7412/1983).

However, when such an adsorbent is used to adsorb gallium in a sodium aluminate aqueous solution, and then the gallium adsorbed to the adsorbent is eluted with an eluent such as hydrochloric acid, sulfuric acid, or nitric acid, the adhering alkali on the adsorbent is The base in the adsorbent reacts with the eluent and the functional groups are decomposed by the heat of neutralization, or the base in the adsorbent reacts with the eluent and the heat of reaction causes deterioration of the functional groups and shortens the life of the adsorbent. There is an inconvenience of lowering the performance and losing economic efficiency.

In view of these circumstances, the present inventors conducted extensive research to find a method for recovering gallium that overcomes these disadvantages.
Discovered an economical method for recovering gallium from gallium-containing solutions using ion-exchange or chelating adsorbents,
The present invention has now been completed.

That is, the present invention provides a first step in which a solution containing gallium is brought into contact with an ion-exchange or chelating adsorbent having gallium adsorption ability to adsorb gallium onto the adsorbent; A second step in which gallium is eluted from the gallium-adsorbed adsorbent by contacting it with a basic solution containing sulfide either as it is or after washing; to obtain a gallium eluent; sulfide is removed from the gallium eluent; Provided is a method for recovering gallium, comprising: a third step of obtaining a gallium eluent that does not substantially contain sulfides; a fourth step of recovering gallium or a gallium compound from a gallium eluent that does not substantially contain sulfides. It is something to do.

As the gallium-containing solution to be treated in the method of the present invention, a strongly basic or acidic gallium-containing aqueous solution with a pH of 0.5 to 3 is usually applied, but of course other gallium-containing solutions can be used. It can be applied even if

In particular, the treatment liquid for the method of the present invention is a gallium-containing sodium aluminate aqueous solution (general composition, Ga + 0.01 to 0.51/l) used in the production process of Bayer process alumina.
, AzzOa? 50-120f/l.

Na2O; 100 to 200 y/l) is preferably used.

Further, as the ion exchange or chelating adsorbent in the present invention, any resin or compound having gallium adsorption ability can be used, and is not particularly limited.

Such ion-exchange or chelating adsorbents include, for example, resins or compounds having a functional group in the molecule that can form a chelate bond with NOH via the above-mentioned functional group and gallium; Resin or compound with metal salt of group, resin or compound with oxine ligand, -NH2, -OH,=O1-3H1=S
.

A resin or compound having a gallium adsorption ability containing one or more functional groups such as the following can be used. More specifically, polymers having nitrile groups such as acrylonitrile-divinylbenzene copolymers having amine-reactive groups or primary and/or secondary amino groups, styrene-divinylbenzene copolymers, phenolic resins, Polymers such as polyvinyl chloride, hydroxylamine, diethylenetriamine, guanidine, hydrazine, 2,4-diaminophenol, 2,2'-dihydroxy-5-diethylenetriamino-N.

N10, Sl obtained by reacting N'-ethanediylidene dianiline, acetylacetone, oxalyl chloride, etc.
Examples include resins or compounds having a functional group having a plurality of Lewis basic atoms such as.

The first step of the present invention, in which a gallium-containing solution is brought into contact with an ion exchange or chelating adsorbent having gallium adsorption capacity, and gallium is adsorbed onto the adsorbent, is generally carried out at a temperature of 80"C or less, preferably It is carried out at a temperature of 10-50°C.

Contact between the adsorbent and the gallium-containing solution may be carried out by selecting appropriate conditions. The contact method is not particularly limited, and for example, a method of immersing the adsorbent in a solution containing gallium, a method of passing a hegallium-containing solution through a column filled with the adsorbent, etc. are generally employed. However, from the viewpoint of processing operations, a method of passing a solution containing hegarium through a column filled with an adsorbent is preferably employed.

The amount of adsorbent used is not particularly limited and varies depending on the gallium concentration in the gallium-containing solution to be treated, the type of adsorbent used, etc., and is set appropriately according to each condition, but in general The ratio is such that 1 to 500 parts by volume of the gallium-containing solution are treated per part by volume of the adsorbent.

The ion-exchange or chelating adsorbent that has adsorbed gallium is then washed as is or with water or an alkaline aqueous solution as needed, and then brought into contact with a basic solution containing sulfide to adsorb gallium. A second step is performed in which gallium is eluted from the soaked adsorbent to obtain a gallium eluate.

As the eluent in this second step, a base solution containing sulfide that has gallium elubility and has a relatively low ability to degrade the functional groups of the adsorbent is used.

However, when a sulfide alone is used as an eluent, the elution rate is not very high at 20-50%, and when a base compound is used alone, elution does not occur substantially, but an eluent using a combination of both The elution can be carried out extremely efficiently. Furthermore, the use of this eluent has the advantage that other heavy metals adsorbed on the adsorbent can be separated as precipitates without being dissolved in the eluent.

The basic solution containing sulfide is not particularly limited as long as it contains a sulfide and a basic compound that exhibits gallium elubility, but generally it contains a water-soluble inorganic sulfide and a basic compound, and The concentration is 0.
An aqueous solution having a molecular weight of 1N or more is used.

Preferably, a mixed aqueous solution having an inorganic sulfide concentration of 0.5 to 8N and a basic compound concentration of 1 to 7N is used.

When an aqueous base solution with a sulfide concentration of less than 0.1 N is used as an eluent, it is not preferable because gallium elution does not substantially occur or the gallium elution rate is slow and elution takes a long time.

Furthermore, if the concentration of the base is less than 0.1 normal, elution of gallium will not substantially occur, which is not preferable.

Examples of sulfides that are constituents of the eluent used in the method of the present invention include sodium sulfide, sodium hydroxide, ammonium sulfide, hydrogen sulfide, potassium sulfide, ammonium hydrogen sulfide, sodium hydrogen sulfide, lithium sulfide, barium sulfide,
Examples include water-soluble inorganic sulfides such as magnesium sulfide.

Other basic compounds include inorganic alkali compounds such as sodium hydroxide, potassium hydroxide, calcium hydroxide, magnesium hydroxide, and ammonia, and water-soluble organic amines such as ethylenediamine, diethylenetriamine, diethylamine, and triethylamine. It will be done. Such a sulfide and a basic compound are mixed and used as an aqueous solution.

The eluent is basically used as an aqueous solution as described above, but it may contain an organic solvent as long as it does not interfere with the contact treatment.

The amount of eluent used is not particularly limited and varies depending on the type and concentration of the eluent, the type of adsorbent, the amount of adsorbed gallium and impurity metals, etc., but this should be determined by conducting preliminary experiments as appropriate. I can do it.

The contact temperature between the adsorbent adsorbing gallium and the eluent is not particularly limited, but it is generally carried out at a temperature of 80"C or less, preferably 10 to 50"C.

The contact time is also not particularly limited.

The contact method is not particularly limited, and examples include a method in which the eluent is passed through a column filled with a resinous adsorbent that adsorbs gallium, and a resinous adsorbent that adsorbs gallium into the eluent. The methods employed include immersing the sample in a liquid and then separating it by filtration, adding a liquid adsorbent adsorbing gallium to an eluent, stirring the mixture, and then allowing it to stand still for separation.

The gallium eluate obtained by the above method is then subjected to a third step of removing sulfides contained in the gallium eluate, which is a feature of the method of the present invention.

Through this third step, the gallium eluent is made into a gallium eluent substantially free of sulfide.

Here, the gallium eluent that does not substantially contain sulfide means an eluent in which the sulfide concentration in the eluent is generally 3% by weight or less, preferably 1% by weight or less.

If the sulfide concentration in the gallium eluent is 3% by weight or more, or if the next 4th step of gallium recovery processing is performed without removing sulfide in the eluent, for example, gallium recovery may be When electrolytic treatment is used, there is a problem that the electrolytic reaction of the large amount of sulfide present in the eluent occurs, and the desired electrolysis of gallium in the eluent does not occur efficiently. In some cases, sulfide also causes the inconvenience of consuming the neutralizing agent, and since a large amount of hydrogen sulfide is generated on the acidic side, it is necessary to treat the hydrogen sulfide to prevent pollution. do not have.

The method for removing sulfide from the gallium eluent is not particularly limited as long as it does not involve a significant loss of eluted gallium, but generally the following two-time heating concentration treatment,
This is carried out by cooling treatment, Ω reaction treatment, or a combination thereof.

The double heating concentration treatment is a method of heating the gallium eluent under reduced pressure or normal pressure to remove sulfide in gaseous or solid form. Normally, when the sulfide has a high vapor pressure, such as ammonium sulfide, it is recovered by distillation in a gaseous state, but when it is a sulfide with a low vapor pressure, such as sodium sulfide, it is made into a slurry and recovered as a solid content (gallium exists in dissolved form on the liquid side of the slurry.) is separated and removed.

This method generally involves a
It is carried out by heating and concentrating under conditions of 0 to 100°C. Therefore, when a sulfide with a low vapor pressure is used as a component of an eluent, the slurry obtained after the heating concentration treatment is filtered to recover the sulfide as a solid substance, and the recovered sulfide is reused as a solid substance. Gallium elution Can be used repeatedly as a single agent.

β) Cooling treatment is to precipitate and separate sulfides by cooling the gallium eluent.

Sulfides that are solid at room temperature, such as sodium sulfide and sodium hydrosulfide, have low solubility in the presence of a base, so the sulfides can be precipitated relatively easily by cooling the gallium elution. A known technique may be used as the cooling method. Further, the cooling temperature, cooling time, etc. vary depending on the type and content of sulfide and basic compound in the eluent, and can be set by appropriately conducting preliminary experiments. Usually, sulfides can be precipitated by cooling to 7 to -20°C. The sulfides precipitated by the cooling process are
It is separated into a gallium-containing eluent and solid sulfide by filtration or the like.

In addition, the Ω reaction treatment means that the gallium eluent obtained in the second step is mixed with air, oxygen, hydrogen peroxide, ozone, sodium hypochlorite, calcium chlorate, sodium hypobromite, chlorine, bromine, etc.
Inject oxidizing agents such as potassium permanganate, sodium chlorate, ammonium perchlorate, potassium perchlorate, sodium perchlorate, magnesium perchlorate, sodium peroxide, potassium peroxide, calcium peroxide, barium peroxide, etc. or a method of oxidizing sulfide by adding metal ions such as iron, copper, lead, zinc, tin, etc. A method of precipitating sulfide ions as metal sulfide by adding metal ions such as iron, copper, lead, zinc, tin, etc. A method of oxidizing sulfide electrochemically means a method of chemically converting sulfides into other compounds.

Among these, the oxidation method using an oxidizing agent is preferable because the impurity content of recovered gallium and hydroxide is small and the treatment method is simple. Oxidation methods with oxidizing agents are preferably used. In the case of oxidative decomposition, the valence of the sulfur atom in the sulfide changes from -2 to +2. In the case of the metal sulfide precipitation method, it is carried out using 172 to 1 equivalents of the sulfide.

Although the treatment temperature varies depending on the type and amount of the drug, it is usually carried out at 0 to 800°C, and generally at room temperature. Although it is possible to carry out the reaction at a temperature of 0''C or lower, it is not preferable because the reaction rate between the sulfide and the drug becomes slow.The reaction pressure can also be carried out at normal pressure or elevated pressure.

The processing time for sulfide and chemicals depends on the processing temperature, the type of chemicals,
Depending on the amount, these conditions can be set by conducting preliminary experiments, but usually 5 minutes to
It can be carried out within 24 hours.

Through the reaction treatment described above, sulfide is chemically converted into other compounds to obtain a gallium eluent in which substantially no sulfide is dissolved. Submitted to the process.

The sulfide recovered by either method can be reused as a gallium eluent component.

Further, each sulfide removal method can be carried out in combination as appropriate.

The sulfide-free gallium eluate obtained in the third step is subjected to a process for recovering gallium in the fourth step.

Gallium is generally recovered from the gallium eluate by reducing or treating the eluate with chemicals.

The above-mentioned reduction treatment means that in the third step, the gallium eluent that does not substantially contain cosulfides is chemically treated with a reducing agent or electrolytically treated to reduce the gallate ions that do not dissolve gallium and form a synergist, thereby reducing metallic gallium. It is intended to be collected as such.

■Chemical treatment with a reducing agent involves adding a reducing agent such as gallium eluent 1 (granular, powdered, or ribbon-like aluminum, zinc, calcium, magnesium, lithium aluminum hydride, sodium borohydride, or hydrogen, and causing a reduction reaction. This is the way to do it.

The reducing agent used in the reduction reaction is at least the equivalent number of the reaction for converting +3-valent gallium of the gallate ion into zero-valent gallium, preferably 1.2 to 10 times the amount of the reducing agent.

The treatment temperature varies depending on the type of reducing agent and the type of mouse, but it is usually carried out at room temperature to 500''C, generally 40 to 300''C.

Although the reaction temperature can be carried out at room temperature or lower, it is not preferable because the reaction rate between the gallate ions and the reducing agent becomes slow. Moreover, the reaction pressure can be carried out under normal pressure or increased pressure.

The treatment time for the reducing agent and gallium eluent varies depending on the treatment temperature, type and amount of the reducing agent, and these conditions can be set by conducting preliminary experiments, but it is usually 30 minutes to 24 hours. It can be implemented within a range.

■Electrolytic treatment refers to the gallium eluent obtained in the third step, which is substantially free of cosulfide, as it is, or, if necessary, electrolytic interfering elements such as vanadium and heavy metals contained in the eluent in small amounts. After the removal and purification treatment is performed by the method described above, electrolysis is performed, and the galmate ions dissolved in the eluent are recovered as metal gallium. Known conditions are adopted for the electrolysis conditions, generally room temperature to 80"C, electrolysis voltage 0
．． It is carried out at 5-5V and an electrolytic current of 0.5-5A. By the method of the invention, generally more than 99% by weight, if desired,
Metallic gallium with a purity of 99.9-99.999% can be obtained.

In addition, chemical treatment, which is a method of recovering gallium from the gallium eluent that is substantially free of sulfide obtained in the third step, is a method of recovering gallium from the gallium eluent obtained in the third step. It is intended to be precipitated or extracted and recovered as such.

(2) Neutralization is a method in which an acid is added to the gallium eluate obtained in the third step that is substantially free of sulfide, and gallium is precipitated and separated from the gallium eluate as gallium hydroxide.

The acid used for neutralization is not particularly limited as long as it reacts with the basic compound, but mineral acids such as sulfuric acid, hydrochloric acid, nitric acid, and phosphoric acid are generally used.

The amount of acid used is preferably such that about an equivalent amount of the basic compound is added and the pH of the eluent is within the range of 4 to 10.

The neutralization treatment is generally carried out by adding an acid as a neutralizing agent to the eluent while stirring, but is not limited thereto.

The neutralization treatment is generally performed by stirring and melting at a temperature of 0 to 100"C for about 1 minute to 8 hours.

By the above method, gallium is efficiently precipitated as gallium hydroxide. The precipitated gallium hydroxide undergoes solid-liquid separation and is separated into a neutralized liquid and gallium hydroxide.

Gallium hydroxide obtained by solid-liquid separation is usually dissolved again in an aqueous solution of sodium hydroxide or the like to make an electrolytic solution, and then subjected to electrolysis and used to recover metallic gallium.

@Chelate treatment with other agents involves adding a chelating agent to the gallium eluent that is substantially free of sulfide obtained in the third step.
This is a method of recovering and separating gallium from a gallium eluent as a gallium compound, which is a complex of a chelating agent and gallium.

The chelating agent used in the treatment with other chelating agents is not particularly limited as long as it reacts with gallium ions to form a chelate that is poorly soluble or insoluble in the gallium eluent; examples of such chelating agents include 7-( 1-nonyl-2-propenyl)-8-hydroxyquinolitool, 2-hydroxy-5-nonylbenzophenone oxime, 1-hydroxy-2-ethylhexyl-11-ethylpentyl ketone oxime, 2-hydroxy-8-chloro -5-nonylbenzophenone oxime, dodecylbenzamide oxime, 2-hydroxy-5-nonylbenzamide oxime,
Examples include 7-dodecyl-8-hydroxyquinolitool.

The chelating agent may be kerosene, as it is or as necessary.
Dilute with an organic solvent such as petroleum ether, cyclohexane, hexane, or toluene.

Can be used. The dilution ratio of the chelating agent and the organic solvent is not particularly limited, but it is generally preferable to use the chelating agent dissolved in an amount of 8 to 803i% relative to the organic solvent.

The amount of the chelating agent used in the chelation treatment of the gallium eluent is not particularly limited, but it may be used in a proportion such that 0.1 to 10 parts by weight of the gallium eluent is treated per 1 part by weight of the chelating agent.

Chelation treatment is generally performed at a temperature of 0 to 80°C for 1 minute to
The mixture may be kept in contact with stirring for about 8 hours.

By the above method, when a chelating agent is added to the gallium eluent and a stirring contact treatment is performed, depending on the type and amount of the chelating agent, the dilution state of the chelating agent, the type of the diluent, etc.
A gallium compound, which is a complex of a chelating agent and gallium, precipitates or undergoes phase separation from the gallium eluent. The precipitated or phase-separated gallium compound is subjected to solid-liquid separation or liquid separation to recover the gallium compound. The recovered gallium compound is usually brought into contact with a 1 to 5N mineral acid aqueous solution to break the complex formation between the chelating agent and gallium, and after back-extracting gallium to the mineral acid aqueous solution, gallium is extracted by a known method. It is used to collect as.

The substantially gallium-free base solution obtained by solid-liquid separation or liquid separation can be used again as an eluent after adjusting the concentration.

After eluting gallium, the adsorbent can be used as is or as needed with water and/or sodium hydroxide, potassium hydroxide, calcium hydroxide, magnesium hydroxide,
After treatment with a basic aqueous solution such as ammonia, or an acidic aqueous solution such as hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, etc., it can be used repeatedly as an adsorbent for adsorbing gallium.

If gallium is recovered from a gallium-containing solution by the method of the present invention as described above, deterioration of the adsorbent can be significantly improved, the amount of reagent used is small, and highly pure gallium can be produced economically. It can be recovered and its industrial value is extremely high.

The present invention will be explained below with reference to Examples.

Example 1 [First step 1 ton of cosalicyaldoxime-resorcinol-formalin resin adsorbent was charged into a column with an inner diameter of 10 (7), and Ga of 30"C was flowed upward from the bottom of the column: 180119/11
NazO: 1871/L1Az:421/! ! An aqueous sodium aluminate solution from an alumina manufacturing process using the Bayer process was passed through the tube at a flow rate of 717 hours for 15 hours.

The gallium concentration in the effluent was 48 xi/l.

[Second step] After the completion of the liquid passage in the first step, an eluent 81 consisting of a mixed aqueous solution containing 2N sodium hydrogen sulfide and 1N caustic potassium at 60°C was passed from the top of the column for 180 minutes. 8 tons of eluent with a gallium concentration of 1790119/l was obtained. The gallium elution rate was 99.5%.

[Third step] The gallium eluent obtained in the second step was filtered, and 1 t of P liquid from which heavy metal sulfides were removed and 4 moles of oxygen were charged into an autoclave, and oxidation reaction treatment was performed at 250"C for 1 hour. The concentration of sodium hydrogen sulfide in the eluent after the oxidation reaction is 0.
．． It was 0.3% by weight.

[Fourth step] 98 g of sulfuric acid with a concentration of 50% by weight was added to the sulfide-free gallium eluent obtained in the third step, and after neutralization treatment, filtering and washing with water resulted in 1 as elemental gallium. A cake 4.061 of gallium hydroxide containing .71f with a moisture content of 73% by weight was obtained.

The above process of melting the adsorbent regenerated in the second step with the gallium-containing sodium aluminate aqueous solution was repeated to recover gallium.

As a result, the amount of gallium element in the 60th recovered gallium hydroxide water cake was L 17 f. Also, iron, lead,
The total content of impurity metal elements of vanadium, arsenic, and copper is 0.
It was 2 to 0.3% by weight.

Comparative Example 1 In the method of Example 1, the eluent in the second step was heated to 20'C.
1 N sulfuric acid aqueous solution and omitting the third step,
11111 The treatment was carried out in exactly the same manner except that a 50% by weight aqueous solution of caustic soda of Usagi was used for the neutralization treatment in the fourth step.

As a result, the amounts of gallium elements in the recovered gallium hydroxide hydrous cake at the 1st and 60th repetitions were L, L, and L, respectively.
It was 709 and o, t o y. Further, the content of impurity metal elements such as iron, lead, vanadium, arsenic, and copper was 8 to 13% by weight.

Comparative Example 2 In the method of Example 1, the process was carried out in the same manner as the first and second steps of Example 1, except that the eluent coating in the second step was replaced with a 5N aqueous solution of caustic soda containing only a basic compound. However, the gallium concentration in the eluent is 18
rlQ/l, and the gallium elution rate was 0.7%.

Comparative Example 3 In the method of Example 1, the eluent in the second step was replaced with a 2N sodium sulfide aqueous solution, and the gallium eluent substantially free of sulfide in the fourth step was treated in the third step. Since the pH was 9.7, which was in the neutralization range, the treatment was carried out in exactly the same manner as in Example 1, except that no neutralization treatment was performed.

The gallium concentration of the gallium eluent in the second step is 670q
/l, and the gallium elution rate was 37%. The concentration of sodium sulfide in the eluent after the oxidation treatment in the third step is 0.0
It was 2% by weight. Further, the amount of gallium element recovered in the first step of the fourth step was 0.64y, and the amount of gallium element recovered in the 60th step was 0.521y. The amount of gallium recovered is 37 in Example 1.
It was ~44%. Further, the total content of impurity metal elements of iron, lead, vanadium, arsenic, and copper was 0.2 to 0.3 weight percent.

Example 2 Gallium elution with a gallium concentration of 1770 ray/l obtained by carrying out the first to third steps in exactly the same manner as in Example 1 and containing substantially no sulfide (sodium hydrosulfide concentration of 0.03 ray/l) After adding 50 g of 2-hydroxy-5-nonylbenzamidoxime (chelating agent) to 1 t of liquid and stirring for 30 minutes, the resulting chelate complex mixture of 2-hydroxy-5-nonylbenzamidoxime and potassium was filtered. separated.

When the obtained chelate complex compound was brought into stirring contact with 3N sulfuric acid, which is a back-extracting agent, the chelate complex collapsed and
2-Hydroxy-5-nonylbenzamide oxime was separated from the sulfuric acid as an oil layer.

The oil layer and the sulfuric acid aqueous layer were separated, and when 6 g of caustic soda was added to the obtained sulfuric acid aqueous layer to neutralize it, white hydroxide and gallium were precipitated. When this was filtered, washed with water and dried, 2.749 gallium hydroxide cake containing 1.58 f of gallium was obtained.

The above process of bringing the adsorbent regenerated in the second step into contact with the gallium-containing sodium aluminate aqueous solution was repeated to recover gallium.

As a result, the amount of gallium element in the 600th recovered gallium hydroxide cake was 1.13f. In addition, the total content of impurity metal elements of iron, lead, vanadium, arsenic, and copper is 0.05~
It was 0.2% by weight.

Example 3 [First step] 0.75 t of vinylamidoxime-divinylbenzene copolymer resin (adsorbent) obtained by reacting acrylonitrile and divinylbenzene copolymer with hydroxyamine was charged into a column with an inner diameter of 10 F, and Ga at 40°C with upward flow from the bottom: 11110 q/11 NagO: 187
An aqueous sodium aluminate solution containing f/l and At: 42 f/L from an alumina manufacturing process by the Bayer method was passed through the tube at a flow rate of 7500 mmh for 8 hours. The concentration of gallium in the effluent was 24vt.

An approximately 5 N aqueous solution of caustic soda 0.751 was passed through the adsorbent layer adsorbing gallium from the top of the column in a downward flow for 15 minutes.
Washed.

[Second Step] Next, 6 tons of eluent consisting of 2N sodium sulfide and 5N caustic soda aqueous solution was passed from the top of the column for 90 minutes, resulting in eluent 6 with a gallium concentration of 15521111/l.
t was obtained.

[Third Step] When 1 ton of the gallium eluent obtained in the second step was cooled to 3"C, held for 30 minutes, and then filtered, 0.85 mol of sodium sulfide, 0.83 mol of caustic soda, and gallium were found. 146 mol of filtration residue containing 102M9, 0.15 mol of sodium sulfide, 4.67 mol of caustic soda, 1 mol of gallium
．． A gallium eluent 934- containing 451 and having a sodium sulfide concentration of 1.0% by weight was obtained. This gallium eluent 9
84fnt was added with 277 g of hydrogen peroxide solution with a concentration of 25% by weight and subjected to an oxidation reaction treatment at room temperature for 2 hours to oxidize and decompose the sodium sulfide contained in the eluent, resulting in a sodium sulfide concentration of 0.601% by weight. A gallium eluent containing substantially no sulfide in the eluent was obtained.

[Fourth Step] When the gallium eluent obtained by the above method was subjected to constant current electrolysis at 50°C using a stainless steel plate as a cathode and a nickel plate as an anode, gallium metal 1.28F with a purity of 99.999% by weight was obtained. was gotten.

The above process of bringing the adsorbent regenerated in the second step into contact with the gallium-containing sodium aluminate aqueous solution was repeated to recover gallium.

As a result, the amount of gallium metal recovered for the fifth time was 1.20 f.
Met. The purity of the obtained gallium was 99.
It was 99-99.999% by weight.

Comparative Example 4 After adsorbing gallium onto an adsorbent in the same manner as in the first step of Example 3, a gallium eluent was obtained using a 20"C 1N aqueous hydrochloric acid solution as an eluent, and then the eluent was diluted with caustic soda. After filtering and recovering the gallium hydroxide produced, 4 containing caustic soda equivalent to 6 times the amount of gallium.
A 0% by weight aqueous solution of caustic soda was added to obtain an aqueous solution in which gallium hydroxide was dissolved in sodium garmate.

This aqueous solution was electrolytically treated in the same manner as in Example 3.

As a result, the amounts of gallium metal recovered in the first and fifth times were 1.09N and 0.771, respectively, and the purity of the obtained gallium was 99.8% by weight.

Comparative Example 5 Sodium sulfide concentration 6 obtained by processing in the same manner as in Example 3 except that the third step was not performed in the method of Example 3.
．． An eluent containing 38% by weight and a gallium concentration of 1552 trq/z was electrolytically treated in the same manner, but no gallium precipitation was observed after 12 hours of electrolytic treatment.

Example 4 A gallium eluent with a gallium concentration of 14971/l and a sodium sulfide concentration of 0.01% by weight, which was obtained by performing the first to third steps in the same manner as in Example 3, was charged into a 5 t autoclave. under hydrogen pressure, 230~270″
When light treatment was carried out with C for 12 hours, 1.62f of gallium metal with a purity of 99.7% was obtained.

Further, the above process of bringing the adsorbent regenerated in the second step into contact with the gallium-containing sodium aluminate aqueous solution was repeated to recover gallium.

As a result, the amount of gallium metal recovered for the fifth time was 1.60f. The purity of the gallium obtained was 99.7.
It was 99.9% by weight.

Example 5 [First step] Chelate resin (adsorbent) 100-, which is a condensate of acetophenone oxime/8-hydroxyquinoline/resorcin/formalin, Ga: F17tq/l, Zn:
p 1 (1,7
5 tons of zinc slag leachate was brought into contact with stirring at room temperature for 12 hours, and gallium was adsorbed onto the chelate resin.

After the contact treatment, when the chelate resin was distributed from house to house, Fl'[[
The gallium concentration therein was 191'J/l.

[Second process Chelate fdll & wao that adsorbed gallium.

- After washing with water, the column was packed into a column with an inner diameter of 2. When 1 ton of eluent consisting of a mixture containing 1N ammonium sulfide and 8N caustic soda was flowed down from the top of the column over a period of 2 hours, the gallium concentration was One ton of eluent of 1480 my/l was obtained.

[Third Step] One ton of the eluent obtained in the second step was filtered to remove heavy metal sulfides, and then heated to distill off the volatile components of the eluent. When 720 fnt of distillate was distilled out, it was cooled and filtered, and ammonium sulfide, the eluent component used in the second step, was recovered in the distillate side in an amount of about 100M, and 53% of caustic soda was collected in the filtration residue side. %, 12% by weight of gallium was recovered, and 88% by weight of gallium and 47% by weight of caustic soda were recovered on the P liquid side.
The ammonium sulfide concentration present in weight percent is 0. An eluent was obtained that was substantially free of sulfides of O1 or less size.

[Fourth step] To this gallium eluent, a 36% by weight aqueous hydrochloric acid solution equivalent to the amount of caustic soda contained in the gallium eluent was added for neutralization treatment, and gallium hydroxide was precipitated.As gallium, t, Cake with a moisture content of 88% by weight of gallium hydroxide containing aoy 2.71! was gotten. The above process of bringing the chelate resin regenerated in the second step into contact with the zinc slag leachate was repeated to recover gallium. As a result, the amount of gallium in the 10th recovered gallium hydroxide water cake was 1.24y. Also, iron,
The total content of the metal elements zinc, manganese, nickel, copper, and cadmium was 0.1% by weight.

Comparative Example 6 The method of Example 5 except that the eluent in the second step was replaced with 2N sulfuric acid, the third step was not performed, and an equivalent amount of 50% by weight aqueous caustic sonida solution was used in the neutralization treatment in the fourth step. were treated in exactly the same way.

As a result, the amount of gallium in the recovered gallium hydroxide water cake after the 1st and 10th repetition was 1.29N, respectively.
and 0.85f.

Further, the total content of impurity metal elements such as iron, zinc, manganese, nickel, copper, and cadmium was 30 to 87% by weight.

Example 6 [First step] Ion exchange adsorbent 300- obtained by reacting guanidine with acrylonitrile-divinylbenzene copolymer and gallium scrap were leached with nitric acid, and gallium concentration 801' obtained by adding caustic soda. 19/11 Arsenic concentration 2
1 t of 108 qit aqueous solution of I) H2,5 was stirred and contacted for 8 hours and then filtered. The gallium concentration in the P solution is 28
9/l.The ion-exchange adsorbent adsorbing gallium was packed into a column with an inner diameter of 20 m (23
Washing was performed by passing 0- ion-exchanged water from the top of the column for 15 minutes.

[Second step] Next, 4.5 t of a mixed aqueous solution of 2N sodium sulfide and 5N trimethylamine heated to 45°C was passed from the top of the column over a period of 4 hours, and the effluent was divided into 100-unit portions at the bottom of the column. When the sample was taken, the gallium concentration of the eluent mixture aOO-, which flowed out at 800 to 500 days, was 8488 ml/l.

[Third Step] The mixture 800- of the eluent obtained at the 800th to 500th points obtained in the second step was heated to 65 to 100°C to distill off trimethylamine and water from the eluent.

When 210 ml of distillate was distilled out, it was cooled and filtered. Approximately 100% by weight of trimethylamine, the eluent component used in the second step, was recovered in the distillate, and 93% of the sodium sulfide was collected in the filtration residue. 21. Filter cake 4 containing 0.48 g corresponding to 17% by weight of M and gallium
0.8f was recovered, and on the P liquid side there were 2.06g, equivalent to 81% by weight of gallium, and 1.06g, equivalent to 7% of sodium sulfide.
A substantially sulfide-free eluent 68y containing 6fI was obtained.

4th step] Hydrochloric acid 2.51 at a concentration of 36% by weight was added to the eluent 689 obtained by the above method for neutralization, and then filtered and washed with water, resulting in gallium hydroxide containing 1.98y as gallium. A cake of 5.081% with a water content of 75% by weight was obtained.

The above process of bringing the adsorbent regenerated in the second step into contact with the gallium-containing liquid was repeated to recover gallium. As a result, the amount of gallium in the 10th recovered gallium hydroxide water cake was 1.94F. Further, the content of arsenic element was 0.05% by weight.

Claims (4)

[Claims] (1) A first step in which a solution containing gallium is brought into contact with an ion exchange or chelating adsorbent having gallium adsorption capacity to adsorb gallium onto the adsorbent; After washing, a second step of contacting with a basic solution containing sulfide to elute gallium from the adsorbent adsorbing gallium to obtain a gallium eluent; remove sulfide from the gallium eluent to substantially remove sulfide. A method for recovering gallium, comprising: a third step of obtaining a gallium eluent that does not contain sulfide; and a fourth step of recovering gallium or a gallium compound from the gallium eluent that does not substantially contain sulfide. (2) In the second step, a sulfide-containing base solution having a sulfide concentration of 0.5 to 3N and a base concentration of 1 to 7N is used. Collection method. (3) The method for recovering gallium according to claim 1, wherein in the third step, sulfide is removed until the sulfide concentration in the gallium eluent becomes 3% by weight or less. (4) The method for recovering gallium according to claim 1 or 3, wherein in the third step, the sulfide is removed by oxidizing the sulfide with an oxidizing agent.