Method for recovering germanium, gallium and zinc from zinc oxide smoke dust rich in germanium and gallium

Abstract

The invention discloses a method for recovering germanium, gallium and zinc from zinc oxide smoke dust rich in germanium and gallium, and belongs to the technical field of recovery of scattered metals. The smoke dust and the high-acid leaching liquid are subjected to size mixing according to the liquid-solid ratio of (6-8): 1 and react for 1-2 h at the temperature of 60-80 DEG C, and the final acid concentration is 5-20 g / L; ore pulp and supernate are separated in sequence, concentrated sulfuric acid and waste electrolyte are added into underflow and filter pressing residues according to the liquid-solid ratio of (2-4): 1, high-acid leaching is conducted, reaction is conducted for 2-3 h at the temperature of 80-90 DEG C, and the final acid concentration is 20-30 g / L; and separating ore pulp, carrying out underflow filter pressing to obtain lead slag, and returning supernate and filtrate to the low-acid leaching section. A germanium precipitation agent is added after the low-acid leaching solution is dechlorinated, a reaction is conducted for 5-6 h at the temperature of 50-70 DEG C, the pH value of the solution obtained after germanium precipitation is 4.5-4.8, the germanium content is smaller than 0.5 mg / L, and germanium-rich slag is obtained after ore pulp is subjected to filter pressing. A neutralizer is added into the germanium-deposited liquid, the pH of the end point of first-section neutralization is 5-5.2, and gallium-rich slag is obtained after ore pulp is subjected to filter pressing; after the first-stage neutralization, liquid is subjected to second-stage neutralization, the pH value of the end point of the second-stage neutralization is 5.4-6, filter residues are returned to the first-stage neutralization section after ore pulp filter pressing, and zinc ingots are produced from liquid after the second-stage neutralization. The method can efficiently separate germanium, gallium and zinc, and is short in process flow and simple to operate.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of scattered metal recovery, and particularly relates to a method for recovering germanium, gallium and zinc from germanium and gallium-rich zinc oxide dust. BACKGROUND

[0002] Germanium is stable in air. In oxygen, a passivating oxide layer is formed at temperatures above 400°C. This layer is destroyed by water vapor. Germanium resists concentrated hydrochloric acid and hydrofluoric acid even at boiling point, but reacts slowly with hot sulfuric acid. It dissolves in nitric acid at room temperature to form a nitrate, and in alkaline media in the presence of an oxidizing agent to form a germanate with hydrogen peroxide. Germanium and silicon are miscible and form a continuous series of alloys. The main extraction methods of germanium include extracting germanium from zinc-germanium leaching solution, which can use tannin germanium precipitation method, ultrasonic enhanced leaching method and extraction method; extracting germanium from germanium ore, which can use alkaline slurry roasting method and reduction volatilization method; extracting germanium from industrial waste residue, which can use acid leaching method and sodium carbonate roasting-organic acid leaching method; other extraction methods of germanium also include chlorination distillation method and ion exchange method.

[0003] More than 90% of gallium in the world is recovered as a by-product in the production of alumina. The main enrichment of gallium is sodium aluminate mother liquor in the production of bauxite for alumina, leaching residue in the hydrometallurgical zinc smelting process, chlorination residue or residue in the germanium extraction process by chlorination distillation, and vanadium slag in titanovanadinite and coal dust in the coal combustion process. The main metallurgical extraction technologies of gallium include electrolysis method, extraction method, ion exchange method and membrane separation method, and the occurrence of gallium in the above raw materials is different, and the extraction methods are various. In the extraction process, gallium often needs to be enriched for many times, and usually needs to be combined with multiple methods.

[0004] At present, the technology for recovering leaching germanium and gallium from zinc oxide dust wet leaching solution mainly includes full-solution extraction method, which has a large amount of solution into the extraction system, and the extraction system is very complex. Therefore, it is urgent to develop a method for recovering germanium, gallium and zinc from germanium and gallium-rich zinc oxide dust, to improve the separation and recovery efficiency of germanium and gallium, reduce the loss of germanium and gallium, optimize the process flow, and improve the resource recycling rate. SUMMARY

[0005] The purpose of the present application is to provide a method for recovering germanium, gallium and zinc from germanium and gallium-rich zinc oxide dust.

[0006] The purpose of the present application is achieved by the method for recovering germanium, gallium and zinc from germanium and gallium-rich zinc oxide dust, which comprises the following steps: The germanium-rich, gallium-rich zinc oxide dust and high-acid leaching process return leaching liquid are mixed and slurried at a liquid-solid ratio of 6-8:1, then sent to a low-acid reaction tank, heated and controlled at a reaction temperature of 60-80℃, a reaction time of 1-2h and a final acid concentration of 5-20g / L; after the reaction is completed, the ore slurry is sent to a thickener for clarification and separation, the supernatant after clarification is sent to a filter press for solid-liquid separation, and the obtained filtrate is the low-acid leaching liquid, the thickened underflow after clarification and the filter cake after pressure filtration are mixed with concentrated sulfuric acid and electrolytic process return waste electrolyte at a liquid-solid ratio of 2-4:1 to enter the high-acid leaching process, heated and controlled at a reaction temperature of 80-90℃, a reaction time of 2-3h and a final acid concentration of 20-30g / L; after the reaction is completed, the ore slurry is sent to a thickener for clarification and separation, the underflow after clarification is sent to a filter press for pressure filtration, and the filter cake after pressure filtration is lead residue, and the supernatant after clarification and the filtrate are all returned to the low-acid leaching process.

[0007] The low-acid leaching liquid is sent to a germanium precipitation process after removing chlorine, germanium precipitant is added, the germanium precipitation temperature is controlled at 50-70℃, the germanium precipitation time is 5-6h, the pH of the germanium precipitation liquid is 4.5-4.8, the germanium content of the germanium precipitation liquid is less than 0.5mg / L, after the germanium precipitation is completed, the ore slurry is sent to a filter press for solid-liquid separation, and the filter cake after pressure filtration is germanium-rich residue, and the germanium precipitation liquid enters a two-stage neutralization and gallium precipitation process.

[0008] The germanium precipitation liquid enters a two-stage neutralization and gallium precipitation process, CaCO3 is added as a neutralizing agent, the pH of the neutralization end point in the first stage is controlled at 5-5.2, after the first-stage neutralization is completed, the ore slurry is sent to a filter press for solid-liquid separation, and the filter cake after pressure filtration is gallium-rich residue; the liquid after the first-stage neutralization is subjected to a second-stage neutralization and gallium precipitation, the pH of the neutralization end point in the second stage is controlled at 5.4-6, after the second-stage neutralization is completed, the ore slurry is sent to a filter press for solid-liquid separation, and the filter cake after pressure filtration is all returned to the first-stage neutralization process, and the liquid after the second-stage neutralization is subjected to impurity removal, purification, electrolysis and casting to produce zinc ingots.

[0009] The principle of the technical solution described in the present application is that: Under the condition of heating, germanium can undergo a redox reaction with sulfuric acid. Concentrated sulfuric acid has strong oxidizing properties and can oxidize germanium to a high-valence compound, while being reduced to sulfur dioxide (SO2). The chemical equation of the reaction is as follows: Ge + 2H2SO4 = Ge(SO4)2 + 2SO2↑ + 2H2O Germanium (Ge) is oxidized to germanium sulfate (Ge(SO4)2) with a +4 valence, and the sulfur element in concentrated sulfuric acid is partially reduced to sulfur dioxide (SO2) with a +4 valence, while water is generated. After adding the germanium precipitant CaCO3, CaCO3 gradually dissolves in the Ge(SO4)2 solution, releasing CO2 gas, while generating white Ge(OH)4 precipitate and CaSO4. The chemical equation of the reaction is as follows: Ge(SO4)2 + 2CaCO3 + 2H2O = Ge(OH)4↓ + 2CaSO4 + 2CO2↑ In the dilute sulfuric acid system, the gallium in the germanium-rich, gallium zinc oxide dust reacts with sulfuric acid to generate Ga2(SO4)3. Ga2(SO4)3 is a strong acid weak base salt, which will hydrolyze in water to make the solution acidic; CaCO3 is a strong base weak acid salt, which will weakly hydrolyze in water to make the solution alkaline. In the two-stage neutralization process, after mixing, the hydrogen ions and carbonate ions generated by hydrolysis combine to generate carbon dioxide and water, which promotes the hydrolysis reaction of gallium sulfate and calcium carbonate to the end to generate calcium sulfate, gallium hydroxide precipitate and carbon dioxide gas. Under the condition of excess CaCO3, Ga2(SO4)3 in the leaching solution can be enriched in the form of precipitate in the slag to form a gallium-rich slag. The chemical reaction is as follows: 2Ga + 3H2SO4(dilute) = Ga2(SO4)3 + 3H2↑ Ga2(SO4)3 + 3CaCO3 + 3H2O = 3CaSO4 + 2Ga(OH)3 + 3CO2↑ The technical solution described in the present application has the following advantages compared with the prior art: Compared with the traditional full-solution germanium and gallium extraction process, the germanium-rich slag after germanium precipitation can be calcined, and the mature "chlorination distillation + rectification + hydrolysis" germanium refining process is used to produce GeO2. The gallium-rich slag is refined by extraction process, which can greatly reduce the amount of solution entering the extraction in the gallium refining process, greatly reduce the size of the gallium extraction system, and greatly reduce the consumption of extractant, solvent oil and other auxiliary materials, thereby minimizing the construction investment and operating cost of the gallium refining system. At the same time, germanium and gallium are all dissolved into the solution in the low-acid leaching process, and then the germanium and gallium are all enriched in the precipitate by one-stage germanium precipitation and two-stage gallium precipitation, thereby minimizing the loss of germanium and gallium in the wet leaching stage and improving the recovery rate of germanium and gallium. In summary, the present application belongs to a high-efficiency clean production process, and has the characteristics of short process flow and simple operation. BRIEF DESCRIPTION OF DRAWINGS

[0010] Figure 1 The process flow chart of the technical solution described in the present application. DETAILED DESCRIPTION

[0011] The present application will be further described below, but in no way limits the present application, any transformation or replacement based on the teaching of the present application belongs to the protection scope of the present application.

[0012] The method for recovering germanium, gallium and zinc from germanium-rich, gallium zinc oxide dust according to the present application comprises the following steps: The germanium-rich, gallium-rich zinc oxide fume and the leaching solution returned from the high-acid leaching process are mixed and grinded at a liquid-solid ratio of 6-8:1, and then sent to a low-acid reaction tank, heated and controlled at a reaction temperature of 60-80 DEG C, a reaction time of 1-2 h and a final acid concentration of 5-20 g / L; after the reaction is completed, the ore slurry is sent to a thickener for clarification and separation, the supernatant after clarification is sent to a filter press for solid-liquid separation, and the obtained filtrate is the low-acid leaching solution, the thickened underflow after clarification and the filter cake after pressure filtration are mixed with concentrated sulfuric acid and waste electrolyte returned from the electrolysis process at a liquid-solid ratio of 2-4:1, and then sent to the high-acid leaching process, heated and controlled at a reaction temperature of 80-90 DEG C, a reaction time of 2-3 h and a final acid concentration of 20-30 g / L; after the reaction is completed, the ore slurry is sent to a thickener for clarification and separation, the underflow after clarification is sent to a filter press for pressure filtration, and the filter cake after pressure filtration is lead residue, and the supernatant after clarification and the filtrate are all returned to the low-acid leaching process.

[0013] The low-acid leaching solution is sent to a germanium precipitation process after removal of chlorine, germanium precipitant is added, the germanium precipitation temperature is controlled at 50-70 DEG C, the germanium precipitation time is 5-6 h, the pH of the germanium precipitation solution is 4.5-4.8, the germanium content of the germanium precipitation solution is less than 0.5 mg / L, and after the germanium precipitation is completed, the ore slurry is sent to a filter press for solid-liquid separation, and the filter cake after pressure filtration is germanium-rich residue; the germanium precipitation solution is sent to a two-stage neutralization and gallium precipitation process.

[0014] The germanium precipitation solution is sent to a two-stage neutralization and gallium precipitation process, CaCO3 is added as a neutralizing agent, the pH of the neutralization end point in the first stage is controlled at 5-5.2, the ore slurry after the first-stage neutralization is sent to a filter press for solid-liquid separation, and the filter cake after pressure filtration is gallium-rich residue; the solution after the first-stage neutralization is subjected to a second-stage neutralization and gallium precipitation, the pH of the neutralization end point in the second stage is controlled at 5.4-6, the ore slurry after the second-stage neutralization is sent to a filter press for solid-liquid separation, the filter cake after pressure filtration is all returned to the first-stage neutralization process, and the solution after the second-stage neutralization is subjected to impurity removal, purification, electrolysis and casting to produce zinc ingots.

[0015] The germanium content in the germanium-rich, gallium-rich zinc oxide fume is greater than 0.03%, and the gallium content is greater than 0.01%.

[0016] The mixed and grinded slurry is only added with newly prepared sulfuric acid during commissioning; during production, the leaching solution returned from the high-acid leaching process is all supplemented.

[0017] During commissioning, the initial acid concentration of the newly prepared sulfuric acid is 40-60 g / L.

[0018] During production, the initial acid concentration of the leaching solution returned from the high-acid leaching process is controlled at 40-60 g / L.

[0019] The concentrated sulfuric acid is only supplemented in the high-acid leaching process, and the initial acid concentration of the high-acid leaching process is controlled at 120-160 g / L.

[0020] The germanium precipitant is any one of lime or tannin.

[0021] The amount of the germanium precipitant is determined according to the pH at the end of the germanium precipitation process, and the pH at the end of the germanium precipitation process is 4.5-4.8.

[0022] The amount of the neutralizing agent is determined according to the pH at the end of the neutralization and gallium precipitation process, and the pH at the end of the first-stage neutralization is 5-5.2, and the pH at the end of the second-stage neutralization is 5.4-6.

[0023] In the second-stage neutralization and gallium precipitation process, the neutralizing agent needs to be added in excess.

[0024] The heating is steam heating.

[0025] Example 1

[0026] The germanium-rich, gallium-rich zinc oxide dust and the leaching solution returned from the high-acid leaching process are mixed and slurried at a liquid-solid ratio of 6:1, and then pumped into a low-acid reaction tank, heated by steam, with the reaction temperature controlled at 60°C, the reaction time controlled at 2h, and the final acid concentration controlled at 5g / L; after the reaction is completed, the slurry is pumped into a thickener for clarification and separation, the supernatant after clarification is pumped into a filter press for solid-liquid separation, and the obtained filtrate is the low-acid leaching solution; the thickener underflow after clarification and the filter press residue after filtration are mixed with concentrated sulfuric acid and waste electrolyte returned from the electrolysis process at a liquid-solid ratio of 2:1, and then fed into the high-acid leaching process, heated by steam, with the reaction temperature controlled at 80°C, the reaction time controlled at 3h, and the final acid concentration controlled at 20g / L; after the reaction is completed, the slurry is pumped into a thickener for clarification and separation, the underflow after clarification is pumped into a filter press for filtration, and the filter residue after filtration is lead residue, which can be sold; the supernatant after clarification and the filtrate are all returned to the low-acid leaching process.

[0027] The low-acid leaching solution is fed into the germanium precipitation process after removal of chlorine, and lime is added as the germanium precipitant, with the germanium precipitation temperature controlled at 50°C, the germanium precipitation time controlled at 6h, the pH of the solution after germanium precipitation controlled at 4.5-4.6, and the germanium content of the solution after germanium precipitation controlled at 0.45mg / L; after the germanium precipitation is completed, the slurry is pumped into a filter press for solid-liquid separation, and the filter residue after filtration is germanium-rich residue; the solution after germanium precipitation is fed into the two-stage neutralization and gallium precipitation process.

[0028] The solution after germanium precipitation is fed into the two-stage neutralization and gallium precipitation process, and CaCO3 is added as the neutralizing agent, with the pH at the end of the first-stage neutralization controlled at 5-5.1; after the first-stage neutralization is completed, the slurry is pumped into a filter press for solid-liquid separation, and the filter residue after filtration is gallium-rich residue; to ensure complete precipitation of gallium, the solution after the first-stage neutralization is subjected to the second-stage neutralization and gallium precipitation, and the neutralizing agent CaCO3 needs to be added in excess, with the pH at the end of the second-stage neutralization controlled at 5.4-5.5; after the second-stage neutralization is completed, the slurry is pumped into a filter press for solid-liquid separation, and the filter residue after filtration is all returned to the first-stage neutralization process; the solution after the second-stage neutralization is subjected to impurity removal, purification, electrolysis and casting to produce zinc ingots.

[0029] Example 2

[0030] The germanium-rich, gallium-rich zinc oxide fume and high-acid leaching process return leaching liquid are mixed and slurried at a liquid-solid ratio of 7:1, then pumped to a low-acid reaction tank, steam is introduced for heating, the reaction temperature is controlled at 70°C, the reaction time is 1.5h, and the final acid concentration is 12g / L; after the reaction is completed, the ore slurry is pumped to a thickener for clarification and separation, the supernatant after clarification is pumped to a filter press for solid-liquid separation, and the obtained filtrate is the low-acid leaching liquid, the thickener underflow after clarification and the filter cake after pressure filtration are mixed with concentrated sulfuric acid and electrolysis process return waste electrolyte at a liquid-solid ratio of 3:1 to enter the high-acid leaching process, steam is introduced for heating, the reaction temperature is controlled at 85°C, the reaction time is 2.5h, and the final acid concentration is 25g / L; after the reaction is completed, the ore slurry is pumped to a thickener for clarification and separation, the underflow after clarification is pumped to a filter press for pressure filtration, and the filter cake after pressure filtration is lead residue which can be sold, and the supernatant after clarification and the filtrate are all returned to the low-acid leaching process.

[0031] The low-acid leaching liquid is introduced into the germanium precipitation process after removing chlorine, tannin is added as a germanium precipitant, the germanium precipitation temperature is controlled at 60°C, the germanium precipitation time is 5.5h, the pH of the germanium precipitation liquid is 4.7~4.8, the germanium content of the germanium precipitation liquid is 0.37mg / L, and after the germanium precipitation is completed, the ore slurry is pumped to a filter press for solid-liquid separation, and the filter cake after pressure filtration is germanium-rich residue, and the germanium precipitation liquid is introduced into the two-stage neutralization and gallium precipitation process.

[0032] The germanium precipitation liquid is introduced into the two-stage neutralization and gallium precipitation process, CaCO3 is added as a neutralizing agent, the one-stage neutralization end-point pH is controlled at 5.1~5.2, after the one-stage neutralization is completed, the ore slurry is pumped to a filter press for solid-liquid separation, and the filter cake after pressure filtration is gallium-rich residue; in order to ensure complete precipitation of gallium, the one-stage neutralization liquid is subjected to two-stage neutralization and gallium precipitation, the neutralizing agent CaCO3 needs to be added in excess, the two-stage neutralization end-point pH is controlled at 5.6~5.8, after the two-stage neutralization is completed, the ore slurry is pumped to a filter press for solid-liquid separation, and the filter cake after pressure filtration is all returned to the one-stage neutralization process, and the two-stage neutralization liquid is subjected to impurity removal, purification, electrolysis and casting to produce zinc ingots.

[0033] Example 3

[0034] The germanium-rich, gallium-rich zinc oxide fume and high-acid leaching process return leaching liquid are mixed and grinded at a liquid-solid ratio of 8:1, then pumped to a low-acid reaction tank, steam is introduced for heating, the reaction temperature is controlled at 80°C, the reaction time is 1h, and the final acid concentration is 20g / L; after the reaction is completed, the slurry is pumped to a thickener for clarification and separation, the supernatant after clarification is pumped to a filter press for solid-liquid separation, the obtained filtrate is the low-acid leaching liquid, the thickened underflow after clarification and the filter cake after pressure filtration are mixed with concentrated sulfuric acid and electrolysis process return waste electrolyte at a liquid-solid ratio of 4:1, introduced into the high-acid leaching process, steam is introduced for heating, the reaction temperature is controlled at 90°C, the reaction time is 2h, and the final acid concentration is 30g / L; after the reaction is completed, the slurry is pumped to a thickener for clarification and separation, the underflow after clarification is pumped to a filter press for pressure filtration, and the filter cake after pressure filtration is lead slag which can be sold, and the supernatant after clarification and the filtrate are all returned to the low-acid leaching process.

[0035] The low-acid leaching liquid is introduced into the germanium precipitation process after removing chlorine, tannin is added as a germanium precipitant, the germanium precipitation temperature is controlled at 70°C, the germanium precipitation time is 5h, the pH of the germanium precipitation liquid is 4.5-4.7, the germanium content of the germanium precipitation liquid is 0.41mg / L, after the germanium precipitation is completed, the slurry is pumped to a filter press for solid-liquid separation, and the filter cake after pressure filtration is germanium-rich residue, and the germanium precipitation liquid is introduced into the two-stage neutralization and gallium precipitation process.

[0036] The germanium precipitation liquid is introduced into the two-stage neutralization and gallium precipitation process, CaCO3 is added as a neutralizing agent, the pH of the first-stage neutralization end point is controlled at 5-5.2, after the first-stage neutralization is completed, the slurry is pumped to a filter press for solid-liquid separation, and the filter cake after pressure filtration is gallium-rich residue; in order to ensure complete precipitation of gallium, the first-stage neutralization liquid is subjected to two-stage neutralization and gallium precipitation, the neutralizing agent CaCO3 needs to be added in excess, the pH of the second-stage neutralization end point is controlled at 5.7-6, after the second-stage neutralization is completed, the slurry is pumped to a filter press for solid-liquid separation, the filter cake after pressure filtration is all returned to the first-stage neutralization process, and the second-stage neutralization liquid is subjected to impurity removal, purification, electrolysis and casting to produce zinc ingots.

Claims

1. A method for recovering germanium, gallium, and zinc from germanium-, gallium- rich zinc oxide dust, characterized by, The method comprises the following steps: The germanium-rich, gallium-rich zinc oxide dust and the leaching solution returned from the high-acid leaching process are mixed and grinded at a liquid-solid ratio of 6-8:1, and then sent to a low-acid reaction tank, heated and controlled at a reaction temperature of 60-80 DEG C, a reaction time of 1-2 h and a final acid concentration of 5-20 g / L; after the reaction is completed, the slurry is sent to a thickener for clarification and separation, the supernatant after clarification is sent to a filter press for solid-liquid separation, and the obtained filtrate is the low-acid leaching solution; the thickened underflow after clarification and the filter cake after pressure filtration are mixed with concentrated sulfuric acid and waste electrolyte returned from the electrolysis process at a liquid-solid ratio of 2-4:1, and then sent to the high-acid leaching process, heated and controlled at a reaction temperature of 80-90 DEG C, a reaction time of 2-3 h and a final acid concentration of 20-30 g / L; after the reaction is completed, the slurry is sent to a thickener for clarification and separation, and the underflow after clarification is sent to a filter press for pressure filtration, and the filter cake after pressure filtration is lead residue, and the supernatant after clarification and the filtrate are all returned to the low-acid leaching process; The low-acid leaching solution is sent to a germanium precipitation process after removal of chlorine, germanium precipitant is added, the germanium precipitation temperature is controlled at 50-70 DEG C, the germanium precipitation time is 5-6 h, the pH of the germanium precipitation solution is 4.5-4.8, the germanium content of the germanium precipitation solution is less than 0.5 mg / L, and after the germanium precipitation is completed, the slurry is sent to a filter press for solid-liquid separation, and the filter cake after pressure filtration is germanium-rich residue, and the germanium precipitation solution is sent to a two-stage neutralization and gallium precipitation process; The germanium precipitation solution is sent to a two-stage neutralization and gallium precipitation process, CaCO3 is added as a neutralizing agent, the pH of the neutralization end point of the first stage is controlled at 5-5.2, the slurry after the first stage of neutralization is sent to a filter press for solid-liquid separation, and the filter cake after pressure filtration is gallium-rich residue; the solution after the first stage of neutralization is subjected to a second stage of neutralization and gallium precipitation, the pH of the neutralization end point of the second stage is controlled at 5.4-6, the slurry after the second stage of neutralization is sent to a filter press for solid-liquid separation, the filter cake after pressure filtration is all returned to the first stage of neutralization, and the solution after the second stage of neutralization is subjected to impurity removal, purification, electrolysis and casting to produce zinc ingots.

2. The method for recovering germanium, gallium, and zinc from germanium- and gallium-rich zinc oxide fumes according to claim 1, characterized in that, The germanium content of the germanium-rich, gallium-rich zinc oxide dust is greater than 0.03%, and the gallium content is greater than 0.01%.

3. The method for recovering germanium, gallium, and zinc from germanium- and gallium-rich zinc oxide fumes according to claim 1, characterized in that, The mixed and grinded slurry is added with newly prepared sulfuric acid only during commissioning; during production, the newly prepared sulfuric acid is all supplemented into the leaching solution returned from the high-acid leaching process.

4. The method for recovering germanium, gallium, and zinc from germanium- and gallium-rich zinc oxide fumes according to claim 3, characterized in that, During commissioning, the initial acid concentration of the newly prepared sulfuric acid is 40-60 g / L.

5. The method of recovering germanium, gallium, zinc from germanium, gallium zinc oxide rich dust according to claim 3, characterized in that, During production, the initial acid concentration of the leaching solution returned from the high-acid leaching process is controlled at 40-60 g / L.

6. The method of recovering germanium, gallium, zinc from germanium, gallium zinc oxide rich dust according to claim 5, characterized in that, The initial acid concentration of the high-acid leaching process is controlled at 120-160 g / L.

7. The method of recovering germanium, gallium, zinc from germanium, gallium zinc oxide rich dust according to claim 1, characterized in that, The germanium precipitant is any one of lime or tannin.

8. The method of recovering germanium, gallium, zinc from germanium, gallium zinc oxide rich dust according to claim 7, characterized in that, The addition amount of the germanium precipitant is determined according to the pH of the germanium precipitation process, and the pH of the germanium precipitation process is 4.5-4.

8.

9. The method of recovering germanium, gallium, zinc from germanium, gallium zinc oxide rich dust according to claim 1, characterized in that, The addition amount of the neutralizing agent is determined according to the pH of the neutralization and gallium precipitation process, the pH of the neutralization end point of the first stage is 5-5.2, and the pH of the neutralization end point of the second stage is 5.4-6.

10. The method of recovering germanium, gallium, zinc from germanium, gallium zinc oxide rich dust according to claim 9, characterized in that, During the second stage of neutralization and gallium precipitation, the neutralizing agent needs to be added in excess.

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