A method for recovering rare earths and gallium from TGG crystal waste

Abstract

The present invention relates to a method for recovering rare earths and gallium from TGG crystal waste, comprising the following steps: S1, roasting: crushing the TGG crystal waste, mixing the waste fine powder with an alkali solution in a reaction molar ratio based on gallium oxide uniformly, soaking, and roasting to obtain a roasted product; S2, leaching: adding water to the roasted product obtained in S1, stirring for leaching, and then performing solid-liquid separation to obtain solid phase B, washing solid phase B until the washing water is neutral, and combining the filtrate and the washing liquid to obtain liquid phase A; S3, recovering rare earths: dissolving solid phase B in hydrochloric acid, and filtering to obtain a terbium rare earth feed liquid, and returning the insoluble matter to step S1 for treatment; S4, recovering gallium: first introducing CO2 into liquid phase A until the pH = 10.0 - 10.2, filtering off the precipitate, then adding oxalic acid solid accounting for 0.5 - 1.5% of the volume of the filtrate to the filtrate, introducing CO2 again until the pH = 8.5 - 9.0, keeping warm at 80°C for 1 - 4 h, filtering and washing the precipitate with hot deionized water, and calcining to obtain gallium oxide. The process of the present invention is simple in operation, short in process flow, high in efficiency, with the primary yield of terbium element being greater than 96% and the primary yield of gallium element being above 90%.

Description

Technical Field

[0001] The present invention relates to a method for recovering rare earths and gallium from TGG crystal waste, belonging to the technical field of resource recovery. Background Art

[0002] Rare earth elements have been widely used in the fields of electronics, petrochemical industry, metallurgy, machinery, energy, light industry, environmental protection, agriculture, etc. The application of rare earths can produce fluorescent materials, rare earth metal hydride battery materials, electric light source materials, permanent magnet materials, hydrogen storage materials, catalytic materials, precision ceramic materials, laser materials, superconducting materials, magnetostrictive materials, magnetic refrigeration materials, magneto-optical storage materials, optical fiber materials, etc.

[0003] Terbium is an important heavy rare earth element. Most of its applications involve high-tech fields, which are cutting-edge projects with intensive technology and knowledge, and are also projects with significant economic benefits, having an attractive development prospect and being irreplaceable in some application fields. For example, it is used as an activator for the green phosphor in rare earth trichromatic fluorescent powder; for magneto-optical storage materials, currently amorphous metal terbium-transition metal alloy thin films have been used to manufacture high-performance magneto-optical discs. Terbium is also used to manufacture magneto-optical glass. Terbium-containing Faraday rotatory glass is a key material for manufacturing rotators, isolators, and circulators in laser technology. The development and research of terbium-dysprosium-iron magnetostrictive alloy (TerFenol) have opened up new uses for terbium. Since the abundance of terbium in the earth's crust is very low, accounting for less than 0.01% in total rare earths, the price of terbium has always been relatively high, and people have been researching ways to minimize and reduce the use of terbium in order to reduce production costs.

[0004] Gallium is a rare and scattered metal with a low melting point and high boiling point, and has the reputation of "the backbone of the electronics industry". Compounds of gallium are high-quality semiconductor materials and are widely used in the optoelectronics industry and microwave communication industry, for manufacturing microwave communication and microwave integration, infrared optics and infrared detection devices, integrated circuits, light-emitting diodes, etc. For example, the red and green lights we see on computers are emitted by gallium phosphide diodes. Currently, the consumption of metallic gallium in the semiconductor industry accounts for about 80% - 85% of the total consumption. The content of gallium in the earth's crust is 0.0015%, and it does not exist in the state of pure metal. It is usually obtained as a by-product when extracting aluminum from bauxite or zinc from zinc ore. Although the gallium resources contained in bauxite and zinc ore are relatively abundant, the amount of gallium resources that can be developed and recovered currently is very small.

[0005] TGG is a terbium gallium garnet with the molecular formula Tb3Ga5O 12。The TGG crystal is a high-performance magneto-optical crystal in the visible and infrared bands, with a high Verdet constant, a low absorption coefficient, a high thermal conductivity, a high laser damage threshold, and excellent optical quality. All these advantages make the TGG crystal suitable for constructing Faraday effect devices and make up for the deficiencies of YIG crystals in the visible and near-infrared spectral regions. As an ideal magneto-optical material, the TGG crystal is in the stage of rapid development and mass production as an optical isolator for fiber lasers in the visible and infrared bands.

[0006] With the continuous exploitation and utilization of rare earth mineral resources, the rare earth resources are continuously decreasing. The recycling of waste resources of rare earth-containing products has attracted more and more attention. The TGG crystal contains both high-valent rare earth terbium elements and scarce metal gallium elements. For cost considerations, some other low-valent rare earth elements may be doped. Therefore, the TGG crystal waste is a secondary resource with very high recycling value. The TGG crystal waste is mainly generated during the crystal production and processing processes. For example, the crystal growth is not ideal or has defects during the production process, or the performance fails to meet the technical standards due to production conditions and cannot be remelted; more are some scraps and cuttings generated during the crystal processing process. Therefore, recovering high-value rare earth elements and scarce gallium elements from the TGG crystal waste containing rare earth and gallium has high economic value and social significance. At present, the recycling of TGG crystal waste mainly targets some tailings or bottom materials. After being crushed, elements are added according to the component detection results for secondary crystal pulling. This kind of recycling has great limitations. It can only recycle tailings or bottom materials with relatively certain components, and the quality of the crystal products obtained by secondary crystal pulling is significantly reduced. The separate recovery of each element has not been reported. Summary of the Invention

[0007] The present invention provides a method for recovering rare earth and gallium from TGG crystal waste, which can realize the recovery of rare earth elements and gallium elements; the process flow is short, the operation is simple, and the recovery rate is high.

[0008] The present invention is realized through the following technical solutions:

[0009] A method for recovering rare earth and gallium from TGG crystal waste, comprising the following steps:

[0010] S1, Roasting: Crush the TGG crystal waste. Mix the waste fine powder with the alkali solution in a molar ratio based on gallium oxide uniformly, soak it, and then roast it to obtain the roasted product. The alkali solution is a solution of sodium hydroxide and / or potassium hydroxide, and the mass percentage concentration of the alkali solution is 30%-60%. Based on gallium oxide, the reaction molar ratio of the waste to the alkali in the alkali solution is M(gallium oxide):M(alkali)=1:(2.1-2.5). Soaking can make the alkali solution penetrate into the waste. The longer the soaking time, the more beneficial it is to improve the roasting effect and shorten the roasting time. The soaking time can be 1-36h. Roasting can be carried out in stages. The preferred conditions are to keep the temperature at 120-200°C for 4-12 hours and at 400-800°C for 6-12 hours. After roasting, the rare earth elements exist in the form of oxides insoluble in water, while the gallium element exists in the form of sodium gallate soluble in water. Taking sodium hydroxide as an example, the chemical reaction equation is as follows:

[0011]

[0012] Meanwhile, we also found that when mixing the solid alkali with the waste, the reaction efficiency is very low, that is, most of the crystal waste does not react, and it takes many times to completely process the waste. While using the alkali solution can well avoid this problem, the reaction efficiency is above 90%, which can effectively reduce the number of treatment times. Generally, it can be completely processed in 1-2 times.

[0013] S2, Leaching: Add water to the roasted product obtained in S1, stir and leach, then separate the solid and liquid to obtain solid phase B. Wash solid phase B until the washing water is neutral, and combine the filtrate and the washing liquid to obtain liquid phase A. Considering cost and efficiency, the liquid-solid mass ratio of the leaching water to the roasted product in step S2 is preferably (1.5-3):1. At this time, solid phase B is rare earth oxide and a small amount of unreacted crystal waste, and liquid phase A is an alkaline solution of sodium gallate.

[0014] S3, Recycling rare earth: Add hydrochloric acid to solid phase B, dissolve the rare earth oxide, and filter to obtain the terbium rare earth feed liquid. The filter residue is a small amount of unreacted crystal waste, which is returned to the beginning step S1 for reprocessing.

[0015] The terbium rare earth feed liquid obtained in step S3 can be further separated by extraction, precipitated, and calcined to obtain terbium oxide with a rare earth purity greater than 4N.

[0016] S4, Recycling gallium: First, introduce CO2 into liquid phase A until the pH = 10.0-10.2, filter off the precipitate, then add 0.5-1.5% of oxalic acid solid based on the volume of the filtrate to the filtrate, introduce CO2 again until the pH = 8.5-9.0, keep the temperature at 80°C for 1-4h, filter and wash the precipitate with hot deionized water, and then calcine to obtain gallium oxide. The calcination temperature is 300-500°C and the time is 1-12h.

[0017] Since trace amounts of aluminum element may be contained in the TGG crystal waste and exist in the liquid phase A in the form of sodium aluminate, the pH value for sodium aluminate to transform into aluminum hydroxide precipitate is 10 - 10.6, while the pH value for sodium gallate to transform into gallium hydroxide is below 9.7. Carbon dioxide is first introduced until the pH = 10.0 - 10.2 to convert aluminum into aluminum hydroxide precipitate, which is then removed by filtration, thus achieving the separation of aluminum and gallium. Solid oxalic acid accounting for 0.5 - 1.5% of the volume of the filtrate is added to the filtrate, and gallium hydroxide precipitate begins to form. Generally, gallium hydroxide is an amorphous precipitate (flocculent or colloidal) and is very likely to adsorb and entrap some impurities or ions. Due to the addition of oxalic acid, the amorphous gallium hydroxide precipitate transforms into a crystalline precipitate and forms crystal seeds. When carbon dioxide is introduced again until the pH = 8.5 - 9.0, all gallium is converted into crystalline gallium hydroxide precipitate (fine granular), effectively avoiding the adsorption and entrapment of impurity ions (such as sodium ions) by the amorphous gallium hydroxide precipitate. The obtained gallium hydroxide is relatively pure and it is very easy to remove the free impurity ions by washing.

[0018] Since the gallium content in the TGG crystal waste is relatively high and the impurities are relatively few, therefore, the liquid phase A obtained in step 2 is a sodium gallate alkaline solution. So, for the recovery of gallium, metallic gallium can also be directly prepared by electrolysis after preparing the solution. Since the gallium concentration in the liquid phase A obtained in step S2 (calculated as gallium oxide) is relatively low (C 氧化镓 <10 g / L), the method for preparing the solution is to concentrate the liquid phase A until the gallium concentration (calculated as gallium oxide) is 50 - 60 g / L and add sodium hydroxide until the concentration is 100 - 200 g / L.

[0019] The gallium oxide obtained in step S4 can also be used to prepare metallic gallium by electrolysis after preparing the solution. The method for preparing the solution is to dissolve gallium oxide with sodium hydroxide until the gallium concentration (calculated as gallium oxide) is 50 - 60 g / L and the sodium hydroxide concentration is 100 - 200 g / L.

[0020] The gallium-containing alkaline solution after preparing the solution above can be electrolyzed. The electrolysis conditions are as follows: voltage 4 - 6 V, current density 5 - 20 A / dm 2 , electrolysis temperature 35 - 45 °C, the anode is a platinum sheet, the cathode is a platinum wire, and the electrolytic cell material is plexiglass or PVC.

[0021] The process of the present invention has simple operation, short process flow, and high efficiency, solving the problems of the recovery of rare earth elements and gallium elements in the TGG crystal waste. The primary recovery rate of terbium element is greater than 96%, the primary recovery rate of gallium element is above 90%, the purity of metallic gallium prepared by electrolysis is greater than 99.99%, and the electrolysis efficiency is above 32%. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is the process flow diagram of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0023] To describe the present invention more clearly, the present invention will be further described in detail below with reference to the accompanying drawings.

[0024] Example 1

[0025] Weigh 10 Kg of TGG crystal waste, crush it to less than 100 mesh, and mix the gallium (calculated as gallium oxide) in the waste fine powder with 60% sodium hydroxide solution evenly at a molar ratio of M gallium oxide: M base = 1:2.1, soak for 12 h, roast and keep warm at 120 °C for 12 h, then raise the temperature to 600 °C and continue to roast and keep warm for 10 hours to obtain a roasted product; the roasted product is stirred and leached with water at a liquid-solid ratio of 1.5:1, and then solid-liquid separation is carried out to obtain solid phase B. Wash solid phase B until the washing water is neutral, and combine the filtrate and the washing liquid to obtain liquid phase A; dissolve solid phase B in hydrochloric acid, filter to obtain a terbium rare earth feed liquid, and return the filter residue to the starting step to react with the alkali solution again until all are processed; pass CO2 into liquid phase A at a speed of 10 ml / min until pH = 10.0, generating a trace amount of flocculent precipitate, filter, then add oxalic acid solid according to 0.5% of the liquid phase volume, stir and dissolve, and then pass CO2 into it at a speed of 10 ml / min until pH = 8.5 to generate a white crystalline precipitate. Keep warm at above 80 °C for 1 h, filter, wash the precipitate with deionized water, and then calcine at 300 °C for 12 h to obtain gallium oxide powder. After detection, the contents of chloride ions and sodium ions in the gallium oxide are both less than 300 ppm.

[0026] Example 2

[0027] Weigh 10 Kg of TGG crystal waste, crush it to less than 100 mesh, and mix the gallium (calculated as gallium oxide) in the waste fine powder with 30% potassium hydroxide solution evenly at a molar ratio of M gallium oxide: M base = 1:2.3, soak for 1 h, roast and keep warm at 200 °C for 4 h, then raise the temperature to 400 °C and continue to roast and keep warm for 12 hours to obtain a roasted product; the roasted product is stirred and leached with water at a liquid-solid ratio of 2.5:1, and then solid-liquid separation is carried out to obtain solid phase B. Wash solid phase B until the washing water is neutral, and combine the filtrate and the washing liquid to obtain liquid phase A; dissolve solid phase B in hydrochloric acid, filter to obtain a terbium rare earth feed liquid, and return the filter residue to the starting step to react with the alkali solution again until all are processed; pass CO2 into liquid phase A at a speed of 5 ml / min until pH = 10.2, generating a trace amount of flocculent precipitate, filter, then add oxalic acid solid according to 1.5% of the liquid phase volume, stir and dissolve, and then pass CO2 into it at a speed of 20 ml / min until pH = 9.0 to generate a white crystalline precipitate. Keep warm at above 80 °C for 2 h, filter, wash the precipitate with deionized water, and then calcine at 500 °C for 1 h to obtain gallium oxide powder. After detection, the contents of chloride ions and sodium ions in the gallium oxide are both less than 300 ppm.

[0028] Example 3

[0029] Weigh 20 Kg of TGG crystal waste, crush it to less than 100 mesh, and mix the gallium (calculated as gallium oxide) in the waste fine powder evenly with a mixed solution of 40% sodium hydroxide and potassium hydroxide (1:1) at a molar ratio of M gallium oxide:M base = 1:2.5. Soak for 36 h, roast at 150 °C for 8 h, then raise the temperature to 800 °C and continue roasting for 6 h to obtain a roasted product; soak the roasted product by stirring with water at a liquid-solid ratio of 3:1, then perform solid-liquid separation to obtain solid phase B. Wash solid phase B until the washing water is neutral, and combine the filtrate and the washing liquid as liquid phase A; dissolve solid phase B in hydrochloric acid, filter to obtain a terbium rare earth feed solution, and return the filter residue to the starting step to react with the alkali solution again until all is processed; pass CO2 into liquid phase A at a speed of 8 ml / min until pH = 10.1 to generate a trace amount of flaky precipitate, filter, then add oxalic acid solid at 1% of the liquid phase volume, stir to dissolve, and then pass CO2 at a speed of 15 ml / min until pH = 8.8 to generate a white crystalline precipitate. Keep it at a temperature above 80 °C for 4 h, filter, wash the precipitate with deionized water, and then calcine at 400 °C for 8 h to obtain gallium oxide powder. After testing, the contents of chloride ions and sodium ions in the gallium oxide are both less than 300 ppm.

[0030] Example 4

[0031] Weigh 20 Kg of TGG crystal waste, crush it to less than 100 mesh, and mix the gallium (calculated as gallium oxide) in the waste fine powder evenly with 50% sodium hydroxide solution at a molar ratio of M gallium oxide:M base = 1:2.2. Soak for 24 h, roast at 180 °C for 6 h, then raise the temperature to 700 °C and continue roasting for 8 h to obtain a roasted product; soak the roasted product by stirring with water at a liquid-solid ratio of 3:1, then perform solid-liquid separation to obtain solid phase B. Wash solid phase B until the washing water is neutral, and combine the filtrate and the washing liquid as liquid phase A; dissolve solid phase B in hydrochloric acid, filter to obtain a terbium rare earth feed solution, and return the filter residue to the starting step to react with the alkali solution again until all is processed; pass CO2 into liquid phase A at a speed of 5 ml / min until pH = 10.0 to generate a trace amount of flaky precipitate, filter, then add oxalic acid solid at 0.5% of the liquid phase volume, stir to dissolve, and then pass CO2 at a speed of 10 ml / min until pH = 9.0 to generate a white crystalline precipitate. Keep it at a temperature above 80 °C for 3 h, filter, wash the precipitate with deionized water, and then calcine at 450 °C for 4 h to obtain gallium oxide powder. After testing, the contents of chloride ions and sodium ions in the gallium oxide are both less than 300 ppm.

[0032] Example 5

[0033] Follow the processing steps of Example 1. Weigh 10 Kg of TGG crystal waste, crush it to less than 100 mesh, and mix the gallium in the waste fine powder (calculated as gallium oxide) with 60% sodium hydroxide solution evenly according to the molar ratio M gallium oxide:M alkali = 1:2.1. Soak for 12 h, calcine at 120 °C for 12 h, then raise the temperature to 600 °C and continue to calcine for 10 hours to obtain the calcined product; add water to the calcined product according to the liquid-solid ratio of 1.5:1, stir and leach, then perform solid-liquid separation to obtain solid phase B. Wash solid phase B until the washing water is neutral, and combine the filtrate and washing liquid to obtain liquid phase A; dissolve solid phase B in hydrochloric acid, filter to obtain terbium rare earth feed liquid, and return the filter residue to the starting step to react with the alkali solution again until all is processed; the terbium rare earth feed liquid is separated by extraction, precipitated, and calcined to obtain terbium oxide with a purity greater than 4N.

[0034] Perform liquid making on liquid phase A, heat and concentrate it to a Ga2O3 concentration of 50 g / L, and adjust the sodium hydroxide concentration to 100 g / L with sodium hydroxide. Use electrolysis to produce metallic gallium. The voltage is 4 V, and the current density is 5 A / dm 2 , maintain the electrolysis temperature at 35 - 45 °C, use a platinum sheet as the anode, a platinum wire as the cathode, and the electrolytic cell material is plexiglass. The obtained metallic gallium has a purity greater than 99.99%, and the electrolysis efficiency is 32.3%.

[0035] Example 6

[0036] Follow the processing steps of Example 4. Weigh 20 Kg of TGG crystal waste, crush it to less than 100 mesh, and mix the gallium in the waste fine powder (calculated as gallium oxide) with 50% sodium hydroxide solution evenly according to the molar ratio M gallium oxide:M alkali = 1:2.2. Soak for 24 h, calcine at 180 °C for 6 h, then raise the temperature to 700 °C and continue to calcine for 8 hours to obtain the calcined product; add water to the calcined product according to the liquid-solid ratio of 3:1, stir and leach, then perform solid-liquid separation to obtain solid phase B. Wash solid phase B until the washing water is neutral, and combine the filtrate and washing liquid to obtain liquid phase A; dissolve solid phase B in hydrochloric acid, filter to obtain terbium rare earth feed liquid, and return the filter residue to the starting step to react with the alkali solution again until all is processed; the terbium rare earth feed liquid is separated by extraction, precipitated, and calcined to obtain terbium oxide with a purity greater than 4N.

[0037] Perform liquid making on liquid phase A, heat and concentrate it to a Ga2O3 concentration of 60 g / L, and adjust the sodium hydroxide concentration to 200 g / L with sodium hydroxide. Use electrolysis to produce metallic gallium. The voltage is 6 V, and the current density is 20 A / dm 2 , maintain the electrolysis temperature at 35 - 45 °C, use a platinum sheet as the anode, a platinum wire as the cathode, and the electrolytic cell material is PVC board. The obtained metallic gallium has a purity greater than 99.99%, and the electrolysis efficiency is 32.6%.

[0038] Example 7

[0039] The gallium oxide obtained in Example 2 was used for liquor preparation, dissolved in sodium hydroxide solution, and the concentration of Ga2O3 was adjusted to 60 g / L and the concentration of sodium hydroxide was adjusted to 200 g / L. Electrolysis was used to produce metallic gallium. The voltage was 6 V and the current density was 20 A / dm 2 , the electrolysis temperature was maintained at 35 - 45 °C, the anode was a platinum sheet, the cathode was a platinum wire, and the electrolytic cell material was plexiglass. The purity of the obtained metallic gallium was greater than 99.99%, and the electrolysis efficiency was 33.2%.

[0040] Example 8

[0041] The gallium oxide obtained in Example 3 was used for liquor preparation, dissolved in sodium hydroxide solution, and the concentration of Ga2O3 was adjusted to 50 g / L and the concentration of sodium hydroxide was adjusted to 100 g / L. Electrolysis was used to produce metallic gallium. The voltage was 4 V and the current density was 5 A / dm 2 , the electrolysis temperature was maintained at 35 - 45 °C, the anode was a platinum sheet, the cathode was a platinum wire, and the electrolytic cell material was a PVC board. The purity of the obtained metallic gallium was greater than 99.99%, and the electrolysis efficiency was 32.8%.

[0042] Examples 1 - 4 were calculated based on the amount of terbium oxide rare earth and gallium oxide powder in the final terbium feed liquor for output. The input-output result data is shown in the following table:

[0043]

[0044] The results of the above examples show that the present invention can realize the recovery of terbium and gallium elements in TGG crystal waste, and the primary recovery rate of terbium element is above 96%, and the primary recovery rate of gallium element exceeds 90%. It is also possible to further electrolyze the recovered gallium to obtain metallic gallium with a purity above 99.99%, and the electrolysis efficiency is above 32%.

[0045] Obviously, the above examples are merely examples for clearly illustrating the present invention, rather than limitations on the implementation manners. It is not necessary and impossible to enumerate all the implementation manners here. For those of ordinary skill in the art, other different forms of changes or variations can be made based on the above description, and the obvious changes or variations derived therefrom are still within the protection scope of the present invention.

Claims

1. A method for recovering rare earths and gallium from TGG crystal waste, characterized in that, It includes the following steps: S1, roasting: Crush the TGG crystal waste to less than 100 mesh. Mix the waste fine powder evenly with the alkali solution according to the reaction molar ratio based on gallium oxide, soak it, and roast it to obtain the roasted product; S2, leaching: Add water to the roasted product in S1, stir and leach, then perform solid-liquid separation to obtain solid phase B. Wash solid phase B until the washing water is neutral, and combine the filtrate and the washing liquid to form liquid phase A; S3, recovering rare earth: Dissolve solid phase B in hydrochloric acid, and filter to obtain the terbium rare earth liquor. The insoluble matter is returned to step S1 for treatment; S4, recovering gallium: First, introduce CO2 into liquid phase A until the pH is 10.0 - 10.2, filter off the precipitate. Then, add oxalic acid solid accounting for 0.5 - 1.5% of the volume of the filtrate to the filtrate, introduce CO2 again until the pH is 8.5 - 9.0, keep it warm at above 80 °C for 1 - 4 h, filter and wash the precipitate with deionized water, and calcine it to obtain gallium oxide; The alkali solution described in step S1 is a solution of sodium hydroxide and / or potassium hydroxide.

2. The method according to claim 1, wherein: The reaction molar ratio described in step S1 is M gallium oxide:M alkali = 1:(2.1 - 2.5).

3. The method according to claim 1, wherein: The mass percentage concentration of the alkali solution described in step S1 is 30% - 60%.

4. The method according to claim 1, wherein: The soaking time described in step S1 is 1 - 36 h.

5. The method according to claim 1, characterized in that: The roasting in step S1 is carried out in stages, keeping it warm at 120 - 200 °C for 4 - 12 hours and at 400 - 800 °C for 6 - 12 hours.

6. The method according to claim 1, wherein: The liquid-solid mass ratio of water to the roasted product in step S2 is (1.5 - 3):

1.

7. The method according to claim 1, characterized in that: The calcination temperature in step S4 is 300 - 500 °C, and the time is 1 - 12 h.

8. The method according to claim 7, characterized in that: The ventilation rate of introducing CO2 for the first time in step S4 is 5 - 10 L / min.

9. The method according to claim 7, characterized in that: The ventilation rate of introducing CO2 again in step S4 is 10 - 20 L / min.

10. According to the method described in any one of claims 1-9, characterized in that: The terbium rare earth liquor in step S3 is further subjected to extraction separation, precipitation, and calcination to obtain terbium oxide with a rare earth purity greater than 4N.

11. According to the method described in any one of claims 1-9, characterized in that: Replace step S4 with concentrating the liquid phase A described in step S2 to a gallium concentration of 50 - 60 g / L based on gallium oxide, adding sodium hydroxide to a concentration of 100 - 200 g / L, and using electrolysis to produce metallic gallium.

12. The method according to any one of claims 1-9, characterized in that: Completely dissolve the gallium oxide obtained in step S4 with sodium hydroxide, adjust the gallium concentration to 50 - 60 g / L based on gallium oxide, add sodium hydroxide to a concentration of 100 - 200 g / L, and use electrolysis to produce metallic gallium.

13. The method according to claim 11, characterized in that: The conditions of the electrolysis method are as follows: the voltage is 4 - 6V, the current density is 5 - 20 A / dm 2 , the electrolysis temperature is 35 - 45 °C, the anode is a platinum sheet, the cathode is a platinum wire, and the electrolytic cell is made of plexiglass or PVC board.

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