Method for extracting and recovering germanium from germanium-containing waste hydrochloric acid solution

Abstract

The invention belongs to the technical field of resource regeneration, and particularly relates to a method for extracting and recovering germanium from a germanium-containing waste hydrochloric acid solution. The method comprises the steps of extraction separation, reverse extraction and germanium deposition enrichment. According to the method, amyl butyrate is adopted to extract and regenerate germanium from the germanium-containing high-concentration waste hydrochloric acid solution, and the method has the advantages that an extracting agent is more stable and environmentally friendly, the method is suitable for the germanium-containing hydrochloric acid solution with the HCl molar concentration larger than or equal to 6.5 mol / L, germanium and hydrochloric acid can be regenerated synchronously, the germanium recovery rate is higher, the recovery cost is lower, the process is simpler and the like.

Description

Technical Field

[0001] The present invention belongs to the technical field of resource recycling, and particularly relates to a method for extracting and recovering germanium from germanium-containing waste hydrochloric acid solution. Background Art

[0002] Germanium is a high-value rare and dispersed metal with extremely scarce content in the earth and an important semiconductor material. Germanium is mainly used in the fields of infrared material production, photovoltaic industry, optical fiber industry, PET catalytic industry, food and drug production, etc. Germanium has a wide range of applications in high-tech fields such as new energy, infrared optics, optical fiber, catalyst, electronics and solar energy.

[0003] Due to the complex process of germanium, the direct metal recovery rate in the production process is not high; and due to its high value and scarcity, it is essential and of great significance to conduct a systematic comprehensive recovery of germanium in the production process. The production process of high-purity germanium dioxide includes processes such as distillation, double distillation, hydrochloric acid extraction and purification, rectification, hydrolysis, washing, drying, etc. Since germanium tetrachloride and high-purity germanium dioxide are both soluble to a certain extent in aqueous solution or hydrochloric acid solution, the waste hydrochloric acid solution generated during the entire production process of high-purity germanium dioxide contains germanium. The germanium-containing waste hydrochloric acid solution includes the following four types: 1) waste absorption acid: after the germanium tetrachloride gas generated during the production of processes such as germanium chlorination distillation, chlorine passing and double distillation, and rectification is condensed, the germanium-containing tail gas is absorbed by hydrochloric acid to generate waste absorption acid; it contains 50 - 200 ug / mL of germanium and ≥9 mol / L of HCl; 2) double distillation waste acid: in the germanium double distillation process, crude germanium tetrachloride and analytical pure hydrochloric acid are added to a double distillation kettle and mixed, and then heated and distilled to obtain pure germanium tetrachloride, and the hydrochloric acid containing impurities remains in the double distillation kettle, which is the double distillation waste acid; it contains 100 - 400 ug / mL of germanium and 6.5 - 8.5 mol / L of HCl; 3) germanium tetrachloride extraction and purification loaded hydrochloric acid: crude germanium tetrachloride and hydrochloric acid are mixed and stirred, germanium tetrachloride is purified, and impurities such as arsenic enter the hydrochloric acid, which is the germanium tetrachloride extraction and purification loaded hydrochloric acid; it contains 100 - 200 ug / mL of germanium and 10 - 12 mol / L of HCl; 4) hydrolysis mother liquor: after high-purity germanium tetrachloride and high-purity water are mixed, a hydrolysis reaction occurs to generate high-purity germanium dioxide and hydrochloric acid, and the solution containing germanium and hydrochloric acid remaining after filtering germanium dioxide is the hydrolysis mother liquor; it contains 1000 - 1500 ug / mL of germanium and 4.5 - 5.5 mol / L of HCl. The characteristics of the above four solutions are high hydrochloric acid concentration and high germanium content, and less heavy metal and other impurities, and both germanium and hydrochloric acid have high recovery value.

[0004] Currently, the methods for recovering germanium from the above four germanium-containing waste hydrochloric acid solutions that are widely used industrially mainly involve first neutralizing the hydrochloric acid in the solution with an alkali, and then precipitating and enriching germanium by methods such as tannin germanium precipitation, zinc replacement method, or co-precipitation method with a germanium precipitant. The common disadvantage of the above methods is that a large amount of alkali is required to neutralize the hydrochloric acid in the solution, wasting hydrochloric acid and also incurring the cost of alkali neutralization. Moreover, the germanium concentrate recovered by the above methods has a low grade, generally with a germanium content of less than 5%, increasing the subsequent cost of germanium purification. In addition, due to the use of tannic acid, zinc, etc., the environmental protection treatment cost and pressure of the recovery system are greatly increased. The inventors previously developed a method for extracting and recovering germanium from a hydrochloric acid system using butyl acetate, but it is only applicable to the range where the molar concentration of HCl in the germanium-containing extractant is 5.5 - 6.5 mol / L. Once the molar concentration of HCl is higher than 6.5 mol / L, the decomposition ratio of the organic phase during extraction increases sharply with the increase in the molar concentration of HCl. When the molar concentration of HCl reaches 7 mol / L, the decomposition loss of butyl acetate reaches 5 - 8%; when the molar concentration of HCl is as high as 7.5 mol / L or higher, the decomposition loss of butyl acetate reaches more than 10%. This will cause two major problems. One is that the loss of the organic phase is too large and the industrial cost is too high; the other is that there will be organic residues in the hydrochloric acid after extraction, affecting the performance and reuse of the regenerated hydrochloric acid. Therefore, butyl acetate is not suitable for the extraction and regeneration of germanium-containing waste hydrochloric acid solutions with a molar concentration of HCl exceeding 6.5 mol / L. Summary of the Invention

[0005] To at least solve one of the above technical problems, the present invention provides a method for extracting and recovering germanium from a germanium-containing waste hydrochloric acid solution, which can synchronously extract and recover germanium and hydrochloric acid from a germanium-containing waste hydrochloric acid solution with a molar concentration of HCl greater than or equal to 6.5 mol / L at low cost, efficiently, and with a simple process.

[0006] A method for extracting and recovering germanium from a germanium-containing waste hydrochloric acid solution, comprising: Step 1) Extraction and separation Mix and stir the extraction organic phase with the germanium-containing waste hydrochloric acid solution, and let it stand for phase separation; obtain a germanium-containing organic phase and an aqueous phase; the extraction organic phase is a mixture of an extractant amyl butyrate and a modifier tributyl phosphate; the molar concentration of HCl in the germanium-containing waste hydrochloric acid solution is greater than or equal to 6.5 mol / L; Step 2) Back-extraction Mix and stir the germanium-containing organic phase obtained in Step 1) with the back-extraction solution, and let it stand for phase separation to obtain a germanium-containing back-extraction solution (i.e., an aqueous phase); the back-extraction solution is dilute hydrochloric acid or dilute sulfuric acid; Step 3) Germanium precipitation and enrichment First, add calcium hydroxide and polyferric sulfate to the germanium-containing back-extraction solution obtained in Step 2) to jointly capture and precipitate germanium; then add sodium hydroxide to adjust the pH to 7 - 9 for aging; after aging, perform solid-liquid separation to obtain a precipitate, which is dried to obtain a regenerated germanium raw material.

[0007] For the extraction organic phase of the present invention, amyl butyrate can effectively extract germanium in a hydrochloric acid system with a relatively high concentration (hydrochloric acid concentration is greater than or equal to 6.5 mol / L); adding a small amount of tributyl phosphate can effectively reduce the emulsification of the extraction organic phase and can accelerate the phase separation rate of extraction.

[0008] Preferably, in step 1), the volume ratio of the extractant amyl butyrate to the modifier tributyl phosphate in the extraction organic phase is (99.5 - 95):(0.5 - 5).

[0009] In some embodiments, the volume ratio of the extractant amyl butyrate to the modifier tributyl phosphate in the extraction organic phase is 99.5:0.5, 95:5, or 97:3.

[0010] Preferably, in step 1), the volume ratio of the germanium-containing waste hydrochloric acid solution to the extraction organic phase is (3 - 20):1, such as 3:1, 7:1, 10:1, or 20:1.

[0011] Preferably, in step 1), the mixing and stirring time (i.e., the extraction time) is 1 - 5 min.

[0012] Preferably, in step 1), the standing and phase separation time is 5 - 10 min.

[0013] Preferably, in step 1), the germanium-containing waste hydrochloric acid solution is transparent and free of suspended matter.

[0014] Preferably, in step 1), the molar concentration of HCl in the germanium-containing waste hydrochloric acid solution is 6.5 - 12.5 mol / L, more preferably 7 - 10 mol / L. In some specific embodiments, it is 6.5 mol / L, 7.0 mol / L, 7.5 mol / L, 7.6 mol / L, 8 mol / L, 8.5 mol / L, 9 mol / L, 9.5 mol / L, 10 mol / L, 12.1 mol / L, 12.5 mol / L.

[0015] The inventor of the present invention has found through research that in the extraction and separation process of step 1), when the molar concentration of HCl in the germanium-containing waste hydrochloric acid solution is greater than or equal to 6.5 mol / L, especially greater than or equal to 7 mol / L, amyl butyrate has a very high extraction rate for germanium, and due to the stable structure of amyl butyrate. Even when the molar concentration of HCl in the germanium-containing waste hydrochloric acid solution is greater than or equal to 10 mol / L, and even reaches 12.1 - 12.5 mol / L, the decomposition or loss of the organic phase is still extremely small; when the molar concentration of HCl in the germanium-containing waste hydrochloric acid solution is less than 7 mol / L, the extraction rate of amyl butyrate for germanium will decrease as the molar concentration of HCl in the aqueous phase decreases. That is, when the molar concentration of HCl in the germanium-containing waste hydrochloric acid solution is greater than or equal to 6.5 mol / L, it is within the better condition range for the extraction of germanium by amyl butyrate.

[0016] In step 1), the germanium-containing waste hydrochloric acid solution is any one or a mixture of several of the waste absorption acid, re-evaporation waste acid, hydrochloric acid-loaded solution obtained from the extraction and purification of germanium tetrachloride, and hydrolysis mother liquor generated during the production of high-purity germanium dioxide. At the same time, it is necessary to ensure that the molar concentration of HCl in the germanium-containing waste hydrochloric acid solution is greater than or equal to 6.5 mol / L. When it is a mixture, it can be mixed in any proportion, and at the same time, it is necessary to ensure that the molar concentration of HCl in the germanium-containing waste hydrochloric acid solution is greater than or equal to 6.5 mol / L.

[0017] In some specific embodiments, the germanium-containing waste hydrochloric acid solution is a mixture of the waste absorption acid, re-evaporation waste acid, hydrochloric acid-loaded solution obtained from the extraction and purification of germanium tetrachloride, and hydrolysis mother liquor in any proportion generated during the production of high-purity germanium dioxide; wherein the molar concentration of HCl is greater than or equal to 6.5 mol / L.

[0018] In step 1), germanium in the germanium-containing waste hydrochloric acid solution enters the organic phase during extraction and separation. The aqueous phase is a pure hydrochloric acid solution with very low metal impurity content, which can be returned to the germanium production line for recycling or used for the production of gallium and indium, etc.

[0019] Through the extraction and separation in step 1) of the present invention, while fully extracting germanium and a small amount of impurities in the germanium-containing waste hydrochloric acid solution into the organic phase, the hydrochloric acid solution is purified. The molar concentration of HCl in the aqueous phase after extraction and separation is greater than or equal to 6.3 mol / L, which can be returned to the germanium production line for recycling or used for the production of gallium and indium, etc.

[0020] In step 2) of the present invention, back-extraction is carried out. Utilizing the characteristic that germanium enters the organic phase containing amyl butyrate at high hydrochloric acid concentration and enters the aqueous phase at low hydrochloric acid concentration or zero hydrochloric acid concentration, when controlling the back-extraction liquid to be at low hydrochloric acid concentration or zero hydrochloric acid concentration and in a small volume, germanium is back-extracted into dilute hydrochloric acid or dilute sulfuric acid solution and effectively enriched. The enrichment ratio of germanium in the back-extraction liquid relative to the germanium-containing waste hydrochloric acid solution is greater than or equal to 6 times.

[0021] In step 2), germanium in the germanium-containing organic phase enters the stripping solution (i.e., dilute hydrochloric acid or dilute sulfuric acid) during stripping, and germanium is enriched in the aqueous phase; the organic phase is also regenerated and can be recycled to step 1).

[0022] Preferably, in step 2), the molar concentration of the dilute hydrochloric acid used during stripping should be controlled at 0.2 - 0.6 mol / L, or the molar concentration of the dilute sulfuric acid used during stripping should be controlled at 0.15 - 0.3 mol / L.

[0023] Preferably, in step 2), the volume ratio of the germanium-containing organic phase to the stripping solution is (2 - 8):1, such as 2:1, 5:1, or 8:1.

[0024] Preferably, in step 2), the mixing and stirring time (i.e., the stripping time) is 3 - 8 min.

[0025] Preferably, in step 2), the standing and phase separation time is 5 - 15 min.

[0026] Preferably, in step 3), the total mass of calcium hydroxide and polyferric sulfate added is 5 - 6 times the total mass of germanium in the germanium-containing waste hydrochloric acid solution; the mass ratio of the added calcium hydroxide to polyferric sulfate is 1:(2 - 3).

[0027] Preferably, in step 3), the aging time is greater than or equal to 60 min (e.g., 60 - 120 min).

[0028] Preferably, in step 3), the drying temperature is 160 - 200 °C, and the drying time is greater than or equal to 10 h.

[0029] In the present invention, in step 3), a combined germanium-trapping agent of calcium hydroxide and polyferric sulfate is added to the germanium-containing stripping solution, and the solution is neutralized with sodium hydroxide to adjust the pH to 7 - 9. Utilizing the property that germanates of heavy metals and alkaline earth metals are insoluble in water, iron and calcium in the solution form iron germanate and calcium germanate precipitates; some calcium will also form calcium sulfate precipitate. The main role of polyferric sulfate is to act as a high-performance inorganic polymer coagulant, which coagulates with other precipitates and jointly adsorbs germanium to form a coprecipitation. The above precipitates (i.e., germanium-rich precipitates) meet the requirements of the tertiary combined-state recycled germanium raw materials in "GB / T 23522 - 2023 Recycled Germanium Raw Materials" after drying and can be directly sold.

[0030] The method of the present invention separates germanium from hydrochloric acid solution through extraction separation and back-extraction, enriching germanium while regenerating hydrochloric acid; germanium is enriched in the back-extraction solution. In the germanium production process, germanium-containing materials need to be subjected to germanium chlorination distillation to convert germanium into germanium tetrachloride. If the germanium-containing back-extraction solution is directly subjected to germanium chlorination distillation, the water in the germanium-containing back-extraction solution will dilute the molar concentration of the added hydrochloric acid. To ensure the distillation yield of germanium, a high molar concentration of HCl in the solution during the reaction needs to be ensured, so this will result in an increase in the amount of hydrochloric acid added. However, in the present invention, the germanium-containing back-extraction solution is neutralized and germanium is enriched using a germanium precipitation agent. On the one hand, germanium can be further enriched to obtain a germanium concentrate with a higher germanium grade; on the other hand, less hydrochloric acid is consumed during subsequent germanium chlorination distillation, the cost is lower, and the germanium production efficiency is higher.

[0031] The mechanism of extracting and back-extracting germanium with amyl butyrate is as follows: In a hydrochloric acid solution with a high molar concentration, the oxygen atom in the extractant amyl butyrate releases a lone pair of electrons and is protonated to form a cation, and Ge forms a complex anion GeCl5 - , and the two exchange and associate in the aqueous phase to form an extraction complex. The chemical formula of amyl butyrate is C9H 18 O2 (represented by R in the equation), and the extraction equation is as follows: R + H + [RH] + GeCl4 + Cl - GeCl5 - [RH] + + GeCl5 - [RH] + ·GeCl5 - Back-extraction is the reverse reaction of extraction, and the equation is as follows: [RH] + ·GeCl5 - [RH] + + GeCl5 - [RH] + R + H + GeCl5 - GeCl4 + Cl - The mechanism of germanium extraction by amyl butyrate extractant is ion-association extraction, which can only be achieved in a high-concentration hydrochloric acid solution (when the molar concentration of HCl is greater than or equal to 7 mol / L, the germanium extraction rate is as high as over 98%; after the molar concentration of HCl is less than 7 mol / L, the germanium extraction rate decreases with the decrease of the molar concentration of HCl). Therefore, reducing the molar concentration of HCl in the solution to protonate the extractant group and decompose the GeCl5 - anionic complex can cause Ge 4+ to re-enter the aqueous phase, and this stripping is usually called hydrolysis stripping. Therefore, the stripping agent used in the stripping of the present invention is a dilute hydrochloric acid solution with the molar concentration of HCl controlled at 0.2 - 0.6 mol / L or a dilute sulfuric acid solution with the molar concentration of H2SO4 controlled at 0.15 - 0.3 mol / L. First, it can ensure that the initial molar concentration of HCl in the stripping agent reaches a lower value of 0.2 - 0.6 mol / L or 0 mol / L, and the stripping equilibrium moves to the right, with the highest stripping rate; second, the initial molar concentration of HCl or H2SO4 in the stripping agent is 0.2 - 0.6 mol / L or 0.15 - 0.3 mol / L, having a certain acidity, which can ensure that Ge and other trace metal impurities will not form hydrolysis precipitates when entering the aqueous phase, thus effectively avoiding the emulsification of the organic phase during the stripping process; in addition, if the molar concentration of HCl or H2SO4 in the stripping agent is too high, it will increase the consumption of sodium hydroxide when adjusting the pH value for germanium precipitation in the subsequent process.

[0032] Mechanism of germanium precipitation: After the free small amount of HCl or H2SO4 in the stripping solution is neutralized with flake caustic, the pH value is adjusted to 7 - 9. During the rising process of pH, germanium first forms the form of GeO2 or weakly dissociative H2GeO3, and then GeO2 in the solution is transformed into Na2GeO3. Na2GeO3 is easily soluble in water and generates GeO3 2－ ions, as shown in the reaction equations (1) and (2) in detail.

[0033] Using a mixture of calcium hydroxide and polyferric sulfate as a composite germanium precipitation agent, taking advantage of the characteristic that germanates of heavy metals and alkaline earth metals are insoluble in water, iron and calcium in the solution form iron germanate and calcium germanate precipitates; if dilute sulfuric acid is selected as the stripping solution in step 2), part of the calcium will also form calcium sulfate precipitates; polyferric sulfate itself is a high-performance inorganic polymer coagulant, which coagulates other precipitates and co-adsorbs germanium to form a co-polymerization precipitate to obtain a germanium concentrate with a germanium grade greater than 10%. Some examples of the reaction equations are as follows: If polyferric sulfate is added to the stripping solution and the final pH value of the solution is adjusted to 7 - 9, Fe 3+It will hydrolyze into Fe(OH)3 precipitate when the pH value is greater than 1.6, and the hydrolysis is complete when the pH value is greater than 5.2. The hydrolysis reaction is shown in Reaction Equation (3). Moreover, the Fe(OH)3 precipitate and other iron precipitate polymers have a strong adsorption capacity for Ge. Subsequently, Ge is adsorbed and the co-sedimentation process is completed through gravity.

[0034] In addition, Fe 3＋ reacts with GeO3 2－ to also obtain insoluble Fe2(GeO3)3 precipitate, thereby precipitating and enriching the germanium in the solution in the form of iron germanate, as detailed in Equation (4).

[0035] For example, when calcium hydroxide is added to the stripping solution, calcium reacts with sulfate to produce calcium sulfate precipitate, as shown in Reaction Equation (5). It, together with the iron precipitate polymer, has a strong adsorption capacity for Ge. Subsequently, Ge is adsorbed and the co-sedimentation process is completed through gravity.

[0036] In addition, when the final pH value of the solution is adjusted to 7 - 9, Ca 2＋ reacts with GeO3 2－ to obtain insoluble CaGeO3 precipitate, thereby precipitating and enriching the germanium in the solution in the form of calcium germanate, as detailed in Equation (6).

[0037] GeO2+2NaOH = Na2GeO3+H2O (1) H2GeO3+2NaOH = Na2GeO3+2H2O (2) Fe 3+ +3NaOH = 3Na + + Fe(OH)3↓ (3) 3Na2GeO3+2Fe 3+ = 6Na + +Fe2(GeO3)3↓ (4) Ca 2+ +SO4 2- = CaSO4↓ (5) Na2GeO3+CaCl2= 2NaCl+CaGeO3↓ (6) The present invention uses amyl butyrate as a germanium extractant and is supplemented with tributyl phosphate as a modifier to regenerate germanium and hydrochloric acid from germanium-containing waste hydrochloric acid solution. While fully resourceifying germanium and hydrochloric acid, the recovery rate of germanium is significantly increased, and the regeneration costs of germanium and hydrochloric acid are reduced. The advantages of the method of the present invention are as follows: The extraction rate and stripping rate of amyl butyrate extractant for germanium are both as high as over 98%; the enrichment ratio of germanium in the whole process from germanium-containing solution to germanium concentrate is as high as over 300 times; the structure of amyl butyrate is stable, and there is basically no loss during the extraction and stripping processes; both germanium and hydrochloric acid are fully regenerated, the whole process is environmentally friendly, and waste minimization is achieved; the regeneration process is short, the process is simple, the cost is low, the direct recovery rate of germanium is as high as over 95%, the direct recovery rate of hydrochloric acid is greater than 98%, and a higher enrichment ratio of germanium is obtained. Description of the Drawings

[0038] Figure 1 It is a schematic flow chart of the method for extracting and recovering germanium from germanium-containing waste hydrochloric acid solution in the embodiment of the present invention. Detailed Embodiments

[0039] In order to make the above objects, features and advantages of the present invention more obvious and understandable, the following detailed description of the specific embodiments of the present invention is provided. Many specific details are set forth in the following description in order to fully understand the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0040] For the numerical ranges in the present invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Each intermediate value within any stated value or stated range, as well as each smaller range between any other stated value or intermediate value within the stated range, is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded from the range.

[0041] Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the art to which the present invention pertains. Although the present invention only describes the preferred methods and materials, any methods and materials similar or equivalent to those described herein can also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials related to the documents. In case of conflict with any incorporated document, the content of this specification shall prevail.

[0042] Without departing from the scope or spirit of the present invention, various improvements and changes can be made to the specific embodiments of the description of the present invention, which are obvious to those skilled in the art. Other embodiments obtained from the description of the present invention are obvious to those skilled in the art. The description and examples of this application are merely exemplary.

[0043] Regarding the terms "comprising", "including", "having", "containing", etc. used herein, they are all open-ended terms, meaning including but not limited to.

[0044] The technical solutions described in the present invention, unless otherwise specified, are all conventional solutions in the art. The reagents or raw materials used, unless otherwise specified, are all purchased from commercial channels or are publicly available.

[0045] For the schematic flow diagram of the method for extracting and recovering germanium from a germanium-containing waste hydrochloric acid solution in the following examples, see Figure 1 . Example 1

[0046] The extraction organic phase in this example is a mixture of amyl butyrate and tributyl phosphate in a volume ratio of 99.5:0.5.

[0047] The germanium-containing waste hydrochloric acid solution in this example is a mixture of waste absorption acid, re-evaporated waste acid, hydrochloric acid-loaded germanium tetrachloride extraction and purification, and hydrolysis mother liquor produced during the production of high-purity germanium dioxide in a certain factory, in a volume ratio of 10:60:10:20, and the molar concentration of HCL in it is 7.6 mol / L.

[0048] This example provides a method for extracting and recovering germanium from a germanium-containing waste hydrochloric acid solution, including: Step 1) Extraction and separation: Mix the germanium-containing waste hydrochloric acid solution and the extraction organic phase in a volume ratio of 3:1 and stir (for 5 minutes), then let it stand for phase separation (for 10 minutes); obtain a germanium-containing organic phase and an aqueous phase; Step 2) Back-extraction: Mix the germanium-containing organic phase obtained in Step 1) and a dilute sulfuric acid solution with a molar concentration of 0.2 mol / L in a volume ratio of 2:1 and stir (for 8 minutes), then let it stand for phase separation (for 15 minutes); obtain a germanium-containing back-extraction solution (i.e., the aqueous phase); Step 3) Germanium precipitation and enrichment: First, add calcium hydroxide and polyferric sulfate to the germanium-containing back-extraction solution obtained in Step 2) to jointly capture and precipitate germanium; then add sodium hydroxide to adjust the pH to 7.5 and age for 120 minutes; after aging, perform solid-liquid separation to obtain a precipitate, which is dried (at 200 °C for 10 hours) to obtain a regenerated germanium raw material. Among them, the total mass of calcium hydroxide and polyferric sulfate added is 6 times the total mass of germanium in the germanium-containing waste hydrochloric acid solution; the mass ratio of calcium hydroxide to polyferric sulfate is 1:3.

[0049] Using the method of this example, the direct recovery rate of germanium is finally 95.7%. Example 2

[0050] In this example, the extraction organic phase is a mixture of amyl butyrate and tributyl phosphate at a volume ratio of 95:5.

[0051] The germanium-containing waste hydrochloric acid solution in this example is a mixture of waste absorption acid generated during the production of high-purity germanium dioxide in a certain factory and hydrochloric acid-loaded germanium tetrachloride extraction and purification at a volume ratio of 50:50, with a molar concentration of HCL of 12.1 mol / L.

[0052] This example provides a method for extracting and recovering germanium from a germanium-containing waste hydrochloric acid solution, including: Step 1) Extraction and separation: Mix the germanium-containing waste hydrochloric acid solution with the extraction organic phase at a volume ratio of 10:1 and stir (for 2 minutes), then let it stand for phase separation (for 5 minutes); obtain a germanium-containing organic phase and an aqueous phase; Step 2) Back-extraction: Mix the germanium-containing organic phase obtained in Step 1) with a dilute hydrochloric acid solution with a molar concentration of 0.5 mol / L at a volume ratio of 8:1 and stir (for 4 minutes), then let it stand for phase separation (for 6 minutes); obtain a germanium-containing back-extraction solution (i.e., the aqueous phase); Step 3) Germanium precipitation and enrichment: First, add calcium hydroxide and polyferric sulfate to the germanium-containing back-extraction solution obtained in Step 2) to jointly capture and precipitate germanium; then add sodium hydroxide to adjust the pH to 8.5 and age for 60 minutes; after aging, perform solid-liquid separation to obtain a precipitate, which is dried (at 160 °C for 12 hours) to obtain regenerated germanium raw materials. Among them, the total mass of calcium hydroxide and polyferric sulfate added is 5 times the total mass of germanium in the germanium-containing waste hydrochloric acid solution; the mass ratio of calcium hydroxide to polyferric sulfate is 1:2.5.

[0053] Using the method of this example, the direct recovery rate of germanium is 97.8%. Example 3

[0054] In this example, the extraction organic phase is a mixture of amyl butyrate and tributyl phosphate at a volume ratio of 97:3.

[0055] The germanium-containing waste hydrochloric acid solution in this example is a mixture of waste absorption acid, re-evaporated waste acid, hydrochloric acid-loaded germanium tetrachloride extraction and purification, and hydrolysis mother liquor generated during the production of high-purity germanium dioxide in a certain factory at a volume ratio of 30:30:30:10, with a molar concentration of HCL of 9.5 mol / L.

[0056] This example provides a method for extracting and recovering germanium from a germanium-containing waste hydrochloric acid solution, including: Step 1) Extraction and separation: Mix the germanium-containing waste hydrochloric acid solution with the extraction organic phase at a volume ratio of 7:1 and stir (for 3 minutes), then let it stand for phase separation (for 8 minutes); obtain a germanium-containing organic phase and an aqueous phase; Step 2) Back-extraction: Mix the germanium-containing organic phase obtained in Step 1) with a dilute hydrochloric acid solution having a molar concentration of 0.3 mol / L at a volume ratio of 8:1 and stir (for 6 minutes), then let it stand for phase separation (for 10 minutes); obtain a germanium-containing back-extraction solution (i.e., the aqueous phase). Step 3) Germanium precipitation and enrichment: First, add calcium hydroxide and polyferric sulfate to the germanium-containing back-extraction solution obtained in Step 2) to jointly capture and precipitate germanium; then add sodium hydroxide to adjust the pH to 8 and age for 90 minutes; after aging, perform solid-liquid separation to obtain a precipitate, and dry it (at 180 °C for 12 hours) to obtain the regenerated germanium raw material. Among them, the total mass of calcium hydroxide and polyferric sulfate added is 5.5 times the total mass of germanium in the germanium-containing waste hydrochloric acid solution; the mass ratio of calcium hydroxide to polyferric sulfate is 1:2.5.

[0057] Using the method of this example, the direct recovery rate of germanium is finally 97.2%. Example 4

[0058] The difference from Example 1 is only that: the germanium-containing waste hydrochloric acid solution is the double-distilled waste acid generated during the production of high-purity germanium dioxide in a certain factory, and the molar concentration of HCL in it is 6.5 mol / L.

[0059] Using the method of this example, the direct recovery rate of germanium is finally 95.2%.

[0060] The regenerated germanium raw materials prepared in the above examples all meet the requirements of the tertiary combined-state regenerated germanium raw materials in "GB / T 23522-2023 Regenerated Germanium Raw Materials" and can be directly sold. Comparative Example 1

[0061] The difference from Example 1 is only that: the germanium-containing waste hydrochloric acid solution is the hydrolysis mother liquor generated during the production of high-purity germanium dioxide in a certain factory, and the molar concentration of HCL in it is 5.5 mol / L.

[0062] Using the method of this comparative example, the direct recovery rate of germanium is finally 58.3%. Comparative Example 2

[0063] The difference from Example 1 is only that: in Step 1), the extraction organic phase is only amyl butyrate.

[0064] Using the method of this comparative example, the direct recovery rate of germanium is finally 93.2%, and a small amount of emulsification occurred in the amyl butyrate loaded with germanium during the extraction process. Comparative Example 3

[0065] The difference from Example 1 is only that: during germanium precipitation and enrichment in Step 3), only calcium hydroxide is added to the germanium-containing back-extraction solution to capture and precipitate germanium.

[0066] Using the method of this comparative example, the direct recovery rate of germanium is finally 67.7%. Comparative Example 4

[0067] The difference from Example 1 is only that: in step 3) for germanium precipitation and enrichment, only polymeric ferric sulfate is added to the germanium-containing stripping solution for germanium capture and precipitation.

[0068] For the method of this comparative example, the direct recovery rate of germanium is 91.6% finally. Comparative Example 5

[0069] The difference from Example 1 is only that: the germanium-containing waste hydrochloric acid solution is the waste absorption acid generated during the production of high-purity germanium dioxide in a certain factory, with the molar concentration of HCL being 9.0 mol / L, and the extraction organic phase in step 1) is butyl acetate.

[0070] For the method of this comparative example, the direct recovery rate of germanium is 77.5% finally, and the loss rate of butyl acetate is 25.3%, making it impossible to realize industrial application. Comparative Example 6

[0071] The difference from Example 1 is only that: the germanium-containing waste hydrochloric acid solution is the re-evaporation residual acid generated during the production of high-purity germanium dioxide in a certain factory, with the molar concentration of HCL being 7 mol / L; the extraction organic phase in step 1) is butyl acetate.

[0072] For the method of this comparative example, the direct recovery rate of germanium is 87.1% finally, and the loss rate of butyl acetate is 6.9%, making it impossible to realize industrial application.

[0073] Although the present invention has been described in detail above with general descriptions, specific embodiments and experiments, based on the present invention, some modifications or improvements can be made, which are obvious to those skilled in the art. Therefore, these modifications or improvements made without departing from the spirit of the present invention all fall within the scope of protection required by the present invention.

Claims

1. A method for extracting and recovering germanium from germanium-containing waste hydrochloric acid solution, characterized in that, Including: Step 1) Extraction and separation Mix and stir the extraction organic phase with the germanium-containing waste hydrochloric acid solution, and let it stand for phase separation; Obtain a germanium-containing organic phase and an aqueous phase; the extraction organic phase is a mixture of the extractant amyl butyrate and the modifier tributyl phosphate; the molar concentration of HCl in the germanium-containing waste hydrochloric acid solution is greater than or equal to 6.5 mol / L; Step 2) Back extraction Mix and stir the germanium-containing organic phase obtained in Step 1) with the back extraction solution, and let it stand for phase separation to obtain a germanium-containing back extraction solution; the back extraction solution is dilute hydrochloric acid or dilute sulfuric acid; Step 3) Germanium precipitation and enrichment First, add calcium hydroxide and polyferric sulfate to the germanium-containing back extraction solution obtained in Step 2) to jointly capture and precipitate germanium; then add sodium hydroxide to adjust the pH to 7 - 9 for aging; after aging, perform solid-liquid separation to obtain a precipitate, which is dried to obtain the regenerated germanium raw material.

2. The method for extracting and recovering germanium from germanium-containing waste hydrochloric acid solution according to claim 1, wherein In Step 1), the volume ratio of the extractant amyl butyrate to the modifier tributyl phosphate in the extraction organic phase is (99.5 - 95):(0.5 - 5).

3. The method for extracting and recovering germanium from germanium-containing waste hydrochloric acid solution according to claim 1 or 2, characterized in that, In Step 1), the volume ratio of the germanium-containing waste hydrochloric acid solution to the extraction organic phase is (3 - 20):

1.

4. The method for extracting and recovering germanium from germanium-containing waste hydrochloric acid solution according to claim 1 or 2, characterized in that, In Step 1), the mixing and stirring time is 1 - 5 min; the standing and phase separation time is 5 - 10 min.

5. The method for extracting and recovering germanium from a germanium-containing waste hydrochloric acid solution according to claim 1 or 2, characterized in that, In Step 1), the molar concentration of HCl in the germanium-containing waste hydrochloric acid solution is 6.5 - 12.5 mol / L.

6. The method for extracting and recovering germanium from germanium-containing waste hydrochloric acid solution according to claim 1 or 2, characterized in that, In Step 1), the germanium-containing waste hydrochloric acid solution is any one or a mixture of several of the waste absorption acid, re-evaporated waste acid, hydrochloric acid-loaded germanium tetrachloride extraction and purification, and hydrolysis mother liquor generated during the production of high-purity germanium dioxide.

7. The method for extracting and recovering germanium from germanium-containing waste hydrochloric acid solution according to claim 1 or 2, characterized in that, In Step 2), the molar concentration of the dilute hydrochloric acid is 0.2 - 0.6 mol / L or the molar concentration of the dilute sulfuric acid is 0.15 - 0.3 mol / L.

8. A method for extracting and recovering germanium from germanium-containing waste hydrochloric acid solution according to claim 1 or 2, characterized in that, In Step 2), the volume ratio of the germanium-containing organic phase to the back extraction solution is (2 - 8):

1.

9. The method for extracting and recovering germanium from germanium-containing waste hydrochloric acid solution according to claim 1 or 2, characterized in that, In Step 2), the mixing and stirring time is 3 - 8 min; the standing and phase separation time is 5 - 15 min.

10. The method for extracting and recovering germanium from germanium-containing waste hydrochloric acid solution according to claim 1 or 2, characterized in that, In Step 3), the total mass of calcium hydroxide and polyferric sulfate added is 5 - 6 times the total germanium mass in the germanium-containing waste hydrochloric acid solution; the mass ratio of the added calcium hydroxide to polyferric sulfate is 1:(2 - 3); the aging time is greater than or equal to 60 min.

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