A method for extracting and recovering germanium from waste hydrochloric acid solution containing germanium

Abstract

The present invention belongs to the field of resource regeneration technology, and specifically relates to a method for extracting and recovering germanium from waste hydrochloric acid solutions containing germanium. The method comprises extraction and separation, stripping, and precipitation and enrichment of germanium. The method utilizes amyl butyrate to extract and regenerate germanium from high-concentration waste hydrochloric acid solutions containing germanium. This method has the advantages of a more stable extractant, environmental friendliness, compatibility with germanium-containing hydrochloric acid solutions with a molar concentration of HCl greater than or equal to 6.5 mol / L, simultaneous regeneration of germanium and hydrochloric acid, higher germanium recovery rates, lower recovery costs, and a simpler process.

Description

Technical Field

[0001] The 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 highly valuable, rare earth metal and an important semiconductor material. Germanium is primarily used in the production of infrared materials, photovoltaics, optical fiber, PET catalysts, and food and pharmaceutical production. Germanium has a wide range of applications in new energy, infrared optics, optical fibers, catalysts, and high-tech fields such as electronics and solar energy.

[0003] Due to the complex production process, direct metal recovery rates during germanium production are low. Furthermore, due to its high value and scarcity, systematic and comprehensive recovery of germanium during production is essential and crucial. The production of high-purity germanium dioxide includes distillation, re-distillation, hydrochloric acid extraction and purification, rectification, hydrolysis, washing, and drying. Because both germanium tetrachloride and high-purity germanium dioxide are soluble in both aqueous and hydrochloric acid solutions, the waste hydrochloric acid solution generated throughout the high-purity germanium dioxide production process contains germanium. The waste hydrochloric acid solution containing germanium includes the following four types: 1) Waste absorption acid: After the germanium tetrachloride gas generated in the production process of germanium chlorination distillation, chlorine re-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 or more of HCl; 2) Re-distillation waste acid: In the germanium re-distillation process, crude germanium tetrachloride and analytical grade hydrochloric acid are added to the re-distillation kettle and mixed, and then the pure germanium tetrachloride is distilled out by heating and raising the temperature. The hydrochloric acid containing impurities remains in the re-distillation kettle, which is the re-distillation waste acid; it contains 100-400 ug / mL of germanium. 100-200 μg / mL of germanium and 10-12 mol / L of HCl. 4) Hydrolysis mother liquor: High-purity germanium tetrachloride and high-purity water are mixed and hydrolyzed to produce high-purity germanium dioxide and hydrochloric acid. After filtering the germanium dioxide, the remaining solution containing germanium and hydrochloric acid is the hydrolysis mother liquor. It contains 1000-1500 μg / mL of germanium and 4.5-5.5 mol / L of HCl. All four solutions are characterized by high hydrochloric acid concentration and high germanium content, and low levels of impurities such as heavy metals. Both the germanium and hydrochloric acid have high recovery value.

[0004] The methods currently used more frequently in industry to recover germanium from the above four types of germanium-containing waste hydrochloric acid solutions are mainly to first neutralize the hydrochloric acid in the solution with alkali, and then precipitate and enrich the germanium using tannin precipitation, zinc replacement, or co-precipitation with a germanium precipitator. The common disadvantage of the above methods is that a large amount of alkali is required to neutralize the hydrochloric acid in the solution, which wastes hydrochloric acid and also requires the cost of alkali neutralization. Moreover, the grade of the germanium concentrate recovered by the above methods is low, with a general germanium content of less than 5%, which increases the cost of subsequent germanium purification. In addition, the use of tannic acid and zinc greatly increases the cost and pressure of environmental protection treatment of the recovery system. 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 of 5.5-6.5 mol / L molar concentration of HCl in the germanium-containing extract. 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 of 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 reaches 7.5 mol / L or higher, the decomposition loss of butyl acetate reaches over 10%. This leads to two major problems: first, excessive organic phase loss, which makes industrialization costly; second, organic residues in the hydrochloric acid after extraction affect 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 HCl molar concentrations exceeding 6.5 mol / L. Summary of the Invention

[0005] To solve at least 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 simultaneously extract and recover germanium and hydrochloric acid from a germanium-containing waste hydrochloric acid solution with an HCl molar concentration greater than or equal to 6.5 mol / L at low cost, high efficiency and simple process.

[0006] A method for extracting and recovering germanium from a waste hydrochloric acid solution containing germanium comprises:

[0007] Step 1) Extraction and separation

[0008] The extracted organic phase is mixed with the germanium-containing waste hydrochloric acid solution and stirred, and allowed to stand for phase separation; thereby obtaining a germanium-containing organic phase and an aqueous phase; the extracted organic phase is a mixture of amyl butyrate as an extractant and tributyl phosphate as a modifier; and the molar concentration of HCl in the germanium-containing waste hydrochloric acid solution is greater than or equal to 6.5 mol / L;

[0009] Step 2) Stripping

[0010] The germanium-containing organic phase obtained in step 1) is mixed with a stripping solution and stirred, and allowed to stand for phase separation to obtain a germanium-containing stripping solution (i.e., an aqueous phase); the stripping solution is dilute hydrochloric acid or dilute sulfuric acid;

[0011] Step 3) Germanium enrichment

[0012] First, calcium hydroxide and polyferric sulfate are added to the germanium-containing stripping solution obtained in step 2) to jointly capture the precipitated germanium; then sodium hydroxide is added to adjust the pH to 7-9 for aging; after aging, solid-liquid separation is performed to obtain a precipitate, which is dried to obtain the regenerated germanium raw material.

[0013] In the extraction organic phase of the present invention, amyl butyrate can effectively extract germanium in a relatively high concentration hydrochloric acid system (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 accelerate the phase separation speed of the extraction.

[0014] Preferably, in step 1), the volume ratio of the extractant amyl butyrate to the modifier tributyl phosphate in the extracted organic phase is (99.5-95): (0.5-5).

[0015] In some embodiments, the volume ratio of the extractant amyl butyrate to the modifier tributyl phosphate in the extracted organic phase is 99.5:0.5, 95:5, or 97:3.

[0016] Preferably, in step 1), the volume ratio of the germanium-containing waste hydrochloric acid solution to the extracted organic phase is (3-20):1, for example, 3:1, 7:1, 10:1 or 20:1.

[0017] Preferably, in step 1), the mixing and stirring time (ie, extraction time) is 1-5 minutes.

[0018] Preferably, in step 1), the standing time for phase separation is 5-10 minutes.

[0019] Preferably, in step 1), the germanium-containing waste hydrochloric acid solution is transparent and free of suspended matter.

[0020] 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, the molar concentration 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, or 12.5 mol / L.

[0021] The inventors have found that during the extraction and separation process of step 1), when the molar concentration of HCl in the waste hydrochloric acid solution containing germanium 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 because amyl butyrate has a stable structure. Even when the molar concentration of HCl in the waste hydrochloric acid solution containing germanium is greater than or equal to 10 mol / L, or even when it reaches 12.1-12.5 mol / L, the decomposition or loss of the organic phase is still very small; when the molar concentration of HCl in the waste hydrochloric acid solution containing germanium is less than 7 mol / L, the extraction rate of germanium by amyl butyrate will decrease as the molar concentration of HCl in the aqueous phase decreases. That is, when the molar concentration of HCl in the waste hydrochloric acid solution containing germanium is greater than or equal to 6.5 mol / L, it is within the optimal condition range for extracting germanium with amyl butyrate.

[0022] In step 1), the germanium-containing waste hydrochloric acid solution is any one or a mixture of waste absorption acid, re-distilled waste acid, loaded hydrochloric acid from extraction and purification of germanium tetrachloride, and hydrolysis mother liquor generated during the production of high-purity germanium dioxide, and the molar concentration of HCl in the germanium-containing waste hydrochloric acid solution must be greater than or equal to 6.5 mol / L. When the mixture is used, the mixture may be mixed in any proportion, and the molar concentration of HCl in the germanium-containing waste hydrochloric acid solution must be greater than or equal to 6.5 mol / L.

[0023] In some specific embodiments, the germanium-containing waste hydrochloric acid solution is a mixture of waste absorption acid, double-distilled waste acid, loaded hydrochloric acid purified by extraction of germanium tetrachloride, and hydrolysis mother liquor in any proportions generated in the production process of high-purity germanium dioxide; wherein the molar concentration of HCl is greater than or equal to 6.5 mol / L.

[0024] In step 1), the germanium in the waste hydrochloric acid solution containing germanium 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 in the production of gallium and indium.

[0025] The present invention uses step 1) extraction and separation to fully extract germanium and a small amount of impurities in the germanium-containing waste hydrochloric acid solution into the organic phase, while purifying the hydrochloric acid solution. The molar concentration of HCl in the aqueous phase after extraction and separation is greater than or equal to 6.3 mol / L, and can be returned to the germanium production line for recycling or used in the production of gallium and indium.

[0026] Step 2) of the present invention utilizes the properties of germanium: it enters the organic phase containing amyl butyrate at high hydrochloric acid concentrations and enters the aqueous phase at low or zero hydrochloric acid concentrations. By controlling the stripping solution to have a low or zero hydrochloric acid concentration and a small volume, germanium is stripped into a dilute hydrochloric acid or dilute sulfuric acid solution, achieving effective enrichment. The germanium enrichment ratio in the stripping solution is greater than or equal to 6 times that of the germanium-containing waste hydrochloric acid solution.

[0027] In step 2), during stripping, the germanium in the organic phase containing germanium enters the stripping solution (i.e., dilute hydrochloric acid or dilute sulfuric acid), and the germanium is enriched in the aqueous phase; the organic phase is also regenerated and can be returned to step 1) for recycling.

[0028] Preferably, in step 2), the molar concentration of the dilute hydrochloric acid used in the stripping process must be controlled within the range of 0.2-0.6 mol / L or the molar concentration of the dilute sulfuric acid used in the stripping process must be controlled within the range of 0.15-0.3 mol / L.

[0029] Preferably, in step 2), the volume ratio of the germanium-containing organic phase to the stripping solution is (2-8):1, for example, 2:1, 5:1, or 8:1.

[0030] Preferably, in step 2), the mixing and stirring time (ie, stripping time) is 3-8 minutes.

[0031] Preferably, in step 2), the standing time for phase separation is 5-15 minutes.

[0032] 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 and polyferric sulfate is 1:(2-3).

[0033] Preferably, in step 3), the aging time is greater than or equal to 60 min (eg, 60-120 min).

[0034] Preferably, in step 3), the drying temperature is 160-200° C., and the drying time is greater than or equal to 10 hours.

[0035] In step 3), the present invention adds a combined collector consisting of calcium hydroxide and polyferric germanium sulfate to the germanium-containing stripping solution. The solution is then neutralized with sodium hydroxide and the pH adjusted to 7-9. Leveraging the insolubility of heavy metal and alkaline earth metal germanates in water, the iron and calcium in the solution react to form ferric germanate and calcium germanate precipitates; some calcium also precipitates as calcium sulfate. The polyferric sulfate serves as a high-performance inorganic polymer coagulant, coagulating other precipitates and then co-adsorbing germanium to form a copolymerized precipitate. After drying, the resulting precipitate (i.e., the germanium-rich precipitate) meets the requirements for tertiary combined regenerated germanium raw materials in GB / T 23522-2023 Regenerated Germanium Raw Materials and can be sold directly.

[0036] The method of the present invention separates germanium from a hydrochloric acid solution through extraction and stripping, enriching germanium while regenerating hydrochloric acid; germanium is enriched in the stripping solution. In the germanium production process, germanium-containing materials must undergo germanium chlorination distillation to convert the germanium into germanium tetrachloride. If the germanium-containing stripping solution is directly subjected to germanium chlorination distillation, the water in the germanium-containing stripping solution will dilute the molar concentration of the hydrochloric acid added. To ensure the distillation yield of germanium, it is necessary to maintain a high molar concentration of HCl in the solution during the reaction, which will result in an increase in the amount of hydrochloric acid added. The present invention, however, neutralizes the germanium-containing stripping solution and uses a germanium precipitating agent to precipitate and enrich the germanium. On the one hand, the germanium can be further enriched to obtain a germanium-enriched product with a higher germanium content; on the other hand, less hydrochloric acid is consumed during the subsequent germanium chlorination distillation, resulting in lower costs and higher germanium production efficiency.

[0037] The mechanism of extraction and stripping of germanium with amyl butyrate is as follows:

[0038] In a high molar concentration hydrochloric acid solution, the oxygen atom in the extractant amyl butyrate releases a lone pair of electrons, protonates to form a cation, and Ge generates a coordinated anion GeCl5 - The two exchange and associate in the aqueous phase to form an extractant. The chemical formula of amyl butyrate is C9H 18 O2 (represented by R in the equation), the extraction equation is as follows:

[0039] R + H + [RH] +

[0040] GeCl4+ Cl - GeCl5 -

[0041] [RH] + + GeCl5 - [RH] + ·GeCl5 -

[0042] Stripping is the reverse reaction of extraction, and the equation is as follows:

[0043] [RH] + ·GeCl5 - [RH] + + GeCl5 -

[0044] [RH] + R + H +

[0045] GeCl5 - GeCl4+ Cl -

[0046] The mechanism of extracting germanium by amyl butyrate is ion-association extraction, which can only be achieved in a high concentration of 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 98% or more; when the molar concentration of HCl is less than 7 mol / L, the germanium extraction rate decreases as the molar concentration of HCl decreases). Therefore, reducing the molar concentration of HCl in the solution will protonate the extractant group and make GeCl5 - The decomposition of the coordinated anion can make Ge 4+ Re-entering the aqueous phase, this stripping is usually called hydrolysis stripping. Therefore, the stripping agent used during the stripping of the present invention is a dilute hydrochloric acid solution with a molar concentration of HCl controlled at 0.2-0.6mol / L or a dilute sulfuric acid solution with a molar concentration of H2SO4 controlled at 0.15-0.3mol / L. First, it can be ensured that the molar concentration of the initial HCl of the stripping agent reaches a lower value of 0.2-0.6mol / L or 0 mol / L, the stripping equilibrium proceeds to the right, and the stripping rate is the highest; second, the molar concentration of the initial HCl or H2SO4 of the stripping agent is 0.2-0.6mol / L or 0.15-0.3mol / L, which has a certain acidity, and can ensure that Ge and other trace metal impurities will not generate hydrolysis precipitation when entering the aqueous phase, thereby 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, the consumption of sodium hydroxide will be increased when the pH value of the subsequent germanium precipitation is adjusted.

[0047] Mechanism of germanium precipitation: After a small amount of free HCl or H2SO4 in the stripping solution is neutralized with caustic soda, the pH value is adjusted to 7-9. During the pH rise, germanium first generates GeO2 or weakly dissociated H2GeO3. Then the GeO2 in the solution is converted into Na2GeO3. Na2GeO3 is easily soluble in water to generate GeO3. 2－ ions, as shown in reaction equations (1) and (2).

[0048] A mixture of calcium hydroxide and polyferric sulfate is used as a composite germanium precipitant. Taking advantage of the insolubility of heavy metal and alkaline earth metal germanates in water, iron and calcium in the solution form iron germanate and calcium germanate precipitates. As in step 2), dilute sulfuric acid is used as the stripping solution, so some calcium will also form calcium sulfate precipitates. Polyferric sulfate itself is a high-performance inorganic polymer coagulant. After coagulating other precipitates, it co-adsorbs germanium to form a copolymerized precipitate, resulting in a germanium concentrate with a germanium content greater than 10%. An example of the reaction equation is as follows:

[0049] If polyferric sulfate is added to the stripping solution and the pH value of the solution is adjusted to 7-9, Fe 3+When the pH value is greater than 1.6, it will be hydrolyzed into Fe(OH)3 precipitate, and when the pH value is greater than 5.2, the hydrolysis is complete. The hydrolysis reaction is shown in reaction equation (3). The Fe(OH)3 precipitate and other iron precipitation polymers have strong adsorption properties for Ge, and then adsorb germanium and complete the co-sedimentation process by gravity.

[0050] In addition, Fe 3＋ With GeO3 2－ The reaction can also obtain insoluble Fe2(GeO3)3 precipitate, thereby precipitating and enriching the germanium in the solution in the form of iron germanate, as shown in equation (4).

[0051] If calcium hydroxide is added to the stripping solution, calcium and sulfate react to produce calcium sulfate precipitate, as shown in reaction equation (5), which together with the iron precipitation polymer has a strong adsorption capacity for Ge, and then adsorbs germanium and completes the co-precipitation process by gravity.

[0052] In addition, the end point pH of the solution is adjusted to 7-9, Ca 2＋ With GeO3 2－ The reaction produces an insoluble CaGeO3 precipitate, thereby enriching the germanium in the solution in the form of calcium germanate, as shown in Equation (6).

[0053] GeO2+2NaOH = Na2GeO3+H2O (1)

[0054] H2GeO3+2NaOH = Na2GeO3+2H2O (2)

[0055] Fe 3+ +3NaOH = 3Na + + Fe(OH)3↓ (3)

[0056] 3Na2GeO3+2Fe 3+ = 6Na + +Fe2(GeO3)3↓ (4)

[0057] Ca 2+ +SO4 2- = CaSO4↓ (5)

[0058] Na2GeO3+CaCl2= 2NaCl+CaGeO3↓ (6)

[0059] The present invention uses amyl butyrate as a germanium extraction agent supplemented with tributyl phosphate as a modifier to regenerate germanium and hydrochloric acid from a waste hydrochloric acid solution containing germanium. This method, while fully utilizing the resources of germanium and hydrochloric acid, significantly improves the recovery rate of germanium and reduces the regeneration costs of germanium and hydrochloric acid. The advantages of the method of the present invention are: the amyl butyrate extractant has a germanium extraction rate and stripping rate of over 98%; the enrichment ratio of germanium in the entire process from the germanium-containing solution to the germanium concentrate is over 300 times; the amyl butyrate structure is stable, with essentially no loss during the extraction and stripping processes; both germanium and hydrochloric acid are fully regenerated, making the entire process environmentally friendly and minimizing waste; the regeneration process is short, simple, and low-cost; the direct recovery rate of germanium is over 95%, the direct recovery rate of hydrochloric acid is greater than 98%, and a higher germanium enrichment ratio is achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] Figure 1 The figure is a flow chart of a method for extracting and recovering germanium from waste hydrochloric acid solution containing germanium according to an embodiment of the present invention. DETAILED DESCRIPTION

[0061] To make the above-mentioned objects, features, and advantages of the present invention more readily apparent, specific embodiments of the present invention are described in detail below. The following description sets forth numerous specific details to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways than those described herein, and those skilled in the art may make similar modifications without departing from the scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0062] For numerical ranges herein, it is understood that each intervening value between the upper and lower limits of the range is also specifically disclosed. Each smaller range between any stated value or intervening value in a stated range and any other stated value or intervening value in that stated range is also encompassed within the present invention. The upper and lower limits of these smaller ranges may independently be included or excluded in the range.

[0063] Unless otherwise indicated, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein may also be used in the practice 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 associated with the documents. In the event of any conflict with any incorporated document, the contents of this specification shall prevail.

[0064] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention without departing from the scope or spirit of the invention. Other embodiments will be apparent to those skilled in the art from the present invention. The present description and examples are intended to be illustrative only.

[0065] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0066] The technical solutions described in the present invention, unless otherwise specified, are all conventional solutions in the art, and the reagents or raw materials used, unless otherwise specified, are purchased from commercial channels or are publicly available.

[0067] The following example shows a process flow diagram of the method for extracting and recovering germanium from waste hydrochloric acid solution containing germanium. Figure 1 . Example 1

[0068] The organic phase extracted in this embodiment is a mixture of amyl butyrate and tributyl phosphate in a volume ratio of 99.5:0.5.

[0069] The germanium-containing waste hydrochloric acid solution in this embodiment is a mixture of waste absorption acid, double-distilled waste acid, loaded hydrochloric acid for extraction and purification of germanium tetrachloride, and hydrolysis mother liquor in a volume ratio of 10:60:10:20, generated in the production process of high-purity germanium dioxide in a certain factory, wherein the molar concentration of HCL is 7.6 mol / L.

[0070] This embodiment provides a method for extracting and recovering germanium from a waste hydrochloric acid solution containing germanium, comprising:

[0071] Step 1) Extraction and separation: The germanium-containing waste hydrochloric acid solution and the extracted organic phase were mixed and stirred at a volume ratio of 3:1 (time of 5 minutes), and allowed to stand for phase separation (time of 10 minutes); thereby obtaining a germanium-containing organic phase and an aqueous phase;

[0072] Step 2) stripping: the germanium-containing organic phase obtained in step 1) was mixed with a dilute sulfuric acid solution having a molar concentration of 0.2 mol / L at a volume ratio of 2:1 and stirred (for 8 minutes), and allowed to stand for phase separation (for 15 minutes); thereby obtaining a germanium-containing stripping solution (i.e., an aqueous phase);

[0073] Step 3) Precipitated Germanium Enrichment: Calcium hydroxide and polyferric sulfate are first added to the germanium-containing strip solution obtained in Step 2) to jointly capture the precipitated germanium. Sodium hydroxide is then added to adjust the pH to 7.5 and age the solution for 120 minutes. After aging, solid-liquid separation is performed to obtain a precipitate, which is then dried (200°C, 10 hours) to obtain the regenerated germanium raw material. The total mass of the calcium hydroxide and polyferric sulfate added is six 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.

[0074] Using the method of this embodiment, the final direct yield of germanium is 95.7%. Example 2

[0075] The organic phase extracted in this embodiment is a mixture of amyl butyrate and tributyl phosphate in a volume ratio of 95:5.

[0076] The germanium-containing waste hydrochloric acid solution in this embodiment is a mixture of waste absorption acid generated in the production process of high-purity germanium dioxide in a certain factory and loaded hydrochloric acid for extraction and purification of germanium tetrachloride in a volume ratio of 50:50, wherein the molar concentration of HCL is 12.1 mol / L.

[0077] This embodiment provides a method for extracting and recovering germanium from a waste hydrochloric acid solution containing germanium, comprising:

[0078] Step 1) Extraction and separation: The germanium-containing waste hydrochloric acid solution and the extracted organic phase were mixed and stirred at a volume ratio of 10:1 (time for 2 minutes), and allowed to stand for phase separation (time for 5 minutes); thereby obtaining a germanium-containing organic phase and an aqueous phase;

[0079] Step 2) Stripping: The germanium-containing organic phase obtained in step 1) was mixed with a dilute hydrochloric acid solution having a molar concentration of 0.5 mol / L at a volume ratio of 8:1 and stirred (for 4 minutes), and allowed to stand for phase separation (for 6 minutes) to obtain a germanium-containing stripping solution (i.e., an aqueous phase);

[0080] Step 3) Precipitated Germanium Enrichment: Calcium hydroxide and polyferric sulfate are first added to the germanium-containing strip solution obtained in Step 2) to jointly capture the precipitated germanium. Sodium hydroxide is then added to adjust the pH to 8.5 and age the solution for 60 minutes. After aging, solid-liquid separation is performed to obtain a precipitate, which is then dried (160°C, 12 hours) to obtain the regenerated germanium raw material. The total mass of the 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.

[0081] Using the method of this embodiment, the final direct yield of germanium is 97.8%. Example 3

[0082] The organic phase extracted in this embodiment is a mixture of amyl butyrate and tributyl phosphate in a volume ratio of 97:3.

[0083] The germanium-containing waste hydrochloric acid solution in this embodiment is a mixture of waste absorption acid, double-distilled waste acid, loaded hydrochloric acid for extraction and purification of germanium tetrachloride, and hydrolysis mother liquor in a volume ratio of 30:30:30:10, generated in the production process of high-purity germanium dioxide in a certain factory, wherein the molar concentration of HCL is 9.5 mol / L.

[0084] This embodiment provides a method for extracting and recovering germanium from a waste hydrochloric acid solution containing germanium, comprising:

[0085] Step 1) Extraction and separation: The germanium-containing waste hydrochloric acid solution and the extracted organic phase were mixed and stirred at a volume ratio of 7:1 (time for 3 minutes), and allowed to stand for phase separation (time for 8 minutes); thereby obtaining a germanium-containing organic phase and an aqueous phase;

[0086] Step 2) Stripping: The germanium-containing organic phase obtained in step 1) was mixed with a dilute hydrochloric acid solution having a molar concentration of 0.3 mol / L at a volume ratio of 8:1 and stirred (for 6 minutes), and allowed to stand for phase separation (for 10 minutes) to obtain a germanium-containing stripping solution (i.e., an aqueous phase);

[0087] Step 3) Precipitated Germanium Enrichment: Calcium hydroxide and polyferric sulfate are first added to the germanium-containing strip solution obtained in Step 2) to jointly capture the precipitated germanium. Sodium hydroxide is then added to adjust the pH to 8 and age the solution for 90 minutes. After aging, solid-liquid separation is performed to obtain a precipitate, which is then dried (180°C, 12 hours) to obtain the regenerated germanium raw material. The total mass of the 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.

[0088] Using the method of this embodiment, the final direct yield of germanium is 97.2%. Example 4

[0089] The only difference from Example 1 is that the germanium-containing waste hydrochloric acid solution is the double-distilled waste acid generated in the production process of high-purity germanium dioxide in a certain factory, and the molar concentration of HCL contained therein is 6.5 mol / L.

[0090] Using the method of this embodiment, the final direct yield of germanium is 95.2%.

[0091] The regenerated germanium raw materials prepared in the above examples all meet the requirements of the three-level combined regenerated germanium raw materials in "GB / T 23522-2023 Regenerated Germanium Raw Materials" and can be sold directly. Comparative Example 1

[0092] The only difference from Example 1 is that the germanium-containing waste hydrochloric acid solution is the hydrolysis mother liquor produced in the production process of high-purity germanium dioxide in a certain factory, and the molar concentration of HCL therein is 5.5 mol / L.

[0093] The final direct yield of germanium in this comparative example method is 58.3%. Comparative Example 2

[0094] The only difference from Example 1 is that the extracted organic phase in step 1) is only amyl butyrate.

[0095] In this comparative example method, the final direct yield of germanium was 93.2%, and a small amount of emulsification occurred in the germanium-loaded amyl butyrate during the extraction process. Comparative Example 3

[0096] The only difference from Example 1 is that in step 3), during the enrichment of precipitated germanium, only calcium hydroxide is added to the germanium-containing stripping solution to capture the precipitated germanium.

[0097] The final direct yield of germanium in this comparative example method is 67.7%. Comparative Example 4

[0098] The only difference from Example 1 is that in step 3), during the enrichment of precipitated germanium, only polyferric sulfate is added to the germanium-containing stripping solution to capture the precipitated germanium.

[0099] The final direct yield of germanium in this comparative example method is 91.6%. Comparative Example 5

[0100] The only difference from Example 1 is that the germanium-containing waste hydrochloric acid solution is waste absorption acid generated in the production process of high-purity germanium dioxide in a certain factory, the molar concentration of HCl is 9.0 mol / L, and the organic phase extracted in step 1) is butyl acetate.

[0101] In this comparative example method, the final direct recovery rate of germanium is 77.5%, and the loss rate of butyl acetate is 25.3%, which cannot be realized in industrial application. Comparative Example 6

[0102] The only difference from Example 1 is that the germanium-containing waste hydrochloric acid solution is the re-distilled residual acid produced in the production process of high-purity germanium dioxide in a certain factory, the molar concentration of HCl is 7 mol / L, and the organic phase extracted in step 1) is butyl acetate.

[0103] In this comparative example method, the final direct yield of germanium is 87.1%, and the butyl acetate loss rate is 6.9%, which cannot be realized in industrial application.

[0104] Although the present invention has been described in detail above using general explanations, specific embodiments, and experiments, it will be apparent to those skilled in the art that modifications and improvements may be made based on the present invention. Therefore, such modifications and improvements, which do not depart from the spirit of the present invention, are intended to be within the scope of protection claimed herein.

Claims

1. A method for extracting and recovering germanium from waste hydrochloric acid solution containing germanium, characterized in that: include: Step 1) Extraction and separation The extracted organic phase and the germanium-containing waste hydrochloric acid solution are mixed and stirred, and allowed to stand for phase separation; Obtaining a germanium-containing organic phase and an aqueous phase; the extracted 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 7 mol / L; Step 2) Stripping The germanium-containing organic phase obtained in step 1) is mixed with a stripping solution and stirred, and allowed to stand for phase separation to obtain a germanium-containing stripping solution; the stripping solution is dilute hydrochloric acid or dilute sulfuric acid; Step 3) Germanium enrichment First, calcium hydroxide and polyferric sulfate are added to the germanium-containing stripping solution obtained in step 2) to jointly capture the precipitated germanium; then sodium hydroxide is added to adjust the pH to 7-9 for aging; after aging, solid-liquid separation is performed to obtain a precipitate, which is dried to obtain the regenerated germanium raw material.

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

3. A method for extracting and recovering germanium from a waste hydrochloric acid solution containing germanium 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 extracted organic phase is (3-20):

1.

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

5. A method for extracting and recovering germanium from a waste hydrochloric acid solution containing germanium 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. A method for extracting and recovering germanium from a waste hydrochloric acid solution containing germanium 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 waste absorption acid, double-distilled waste acid, loaded hydrochloric acid for extraction and purification of germanium tetrachloride, and hydrolysis mother liquor generated in the production process of high-purity germanium dioxide.

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

1.

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

10. A method for extracting and recovering germanium from a waste hydrochloric acid solution containing germanium 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 mass of germanium in the germanium-containing waste hydrochloric acid solution; the mass ratio of the added calcium hydroxide and polyferric sulfate is 1:(2-3); and the aging time is greater than or equal to 60 minutes.

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