Method for recycling high-purity germanium in hydrolysis mother liquor by utilizing multi-stage separation and sedimentation technology

Abstract

The invention relates to a method for recycling high-purity germanium in hydrolysis mother liquor by using a multi-stage separation and sedimentation technology. The method comprises the following steps: (1) adding clear water into a hydrolysis mother solution to adjust the pH value to 7, stirring, standing for settling, and centrifugally filtering to obtain a germanium dioxide product and a primary centrifuged solution; (2) adding clear water into the primary centrifuged liquid, mixing, stirring, standing for settling, and centrifugally filtering to obtain a germanium dioxide product and a secondary centrifuged liquid; and (3) adding clear water into the secondary centrifuged liquid, mixing, stirring, standing for settling, and centrifugally filtering to obtain a germanium dioxide product and a tertiary centrifuged liquid. According to the scheme provided by the invention, the method is simple and convenient in operation steps, and the germanium in the hydrolysis mother liquor can be efficiently recovered without adding any chemical reagent in the recovery process aiming at the occasion that the germanium content in the hydrolysis mother liquor is 2g / L or above.

Description

Technical Field

[0001] The present application relates to the field of chemical production recovery technology, and in particular to a method for recovering high-purity germanium in a hydrolysis mother liquor by using a multi-stage separation and sedimentation technology. Background Art

[0002] Germanium dioxide is the dioxide of germanium, and its electronic formula is the same as that of carbon dioxide. It is a white powder or colorless crystal, and has two types: hexagonal system, which is slightly soluble in water, and tetragonal system, which is insoluble. With the development of technology, germanium dioxide is widely used in the production of high-purity metallic germanium, germanium compounds, chemical catalysts, pharmaceutical industry, PET resin, electronic devices, etc. In the prior art, during the preparation of germanium dioxide by ultrasonic hydrolysis, part of the germanium-containing material is lost through the centrifugal filter cloth during the centrifugal separation process, forming a hydrolysis mother liquor, thereby causing material loss.

[0003] In order to recover germanium in the hydrolysis mother liquor, a "process method for comprehensive recovery of germanium in hydrolysis mother liquor and wash water" is disclosed in publication number CN101892397B. In this method, the solution is first neutralized with alkali until white flocs appear, and then in the first stage, at a pH value of 9, ferric chloride is added to hydrolyze to completely generate Fe(OH)3, which adsorbs and precipitates Ge, which lasts for 24 hours; in the second stage, the pH value is adjusted to 8, and ferric chloride is added to adsorb and precipitate Ge, which lasts for 24 hours; in the third stage, the pH value is adjusted to 7, and ferric chloride is added to adsorb and precipitate Ge, which lasts for 24 hours; after three precipitations, it is determined that the supernatant contains less than 10ppm of germanium.

[0004] Although this method achieves efficient recovery of germanium, the recovery rate of germanium reaches more than 98.5%. However, the germanium content contained in the hydrolysis mother liquor of the treatment object targeted by this method is extremely low. According to the records of the embodiment of its specification, it is only 800ppm, and its application scenarios are relatively limited. Furthermore, in the recovery process of this method, on the one hand, it is necessary not only to adjust different pH values ​​in three stages, but also to add ferric chloride for adsorption; that is, the recovery process not only requires the addition of alkali to increase the pH, but also the addition of acid to lower the pH. At the same time, each stage requires the addition of ferric chloride for adsorption recovery. The entire recovery process is cumbersome and requires the addition of many reagents, which is not convenient for industrial application. Summary of the invention

[0005] In order to solve or partially solve the problems existing in the related art, the present application provides a method for recovering high-purity germanium in a hydrolysis mother liquor by using a multi-stage separation and sedimentation technology. The method has simple operation steps. When the germanium content in the hydrolysis mother liquor is above 2g / L, the recovery process does not involve the addition of any chemical reagents to achieve efficient recovery of germanium in the hydrolysis mother liquor.

[0006] The present application provides a method for recovering high-purity germanium in a hydrolysis mother liquor by using a multi-stage separation and sedimentation technology, comprising the following steps:

[0007] (1) adding clean water to the hydrolysis mother liquor to adjust the pH value to 7, stirring, standing for sedimentation, and centrifuging to obtain a germanium dioxide product and a centrifuged liquid;

[0008] (2) adding clean water to the liquid after the first centrifugation, mixing, stirring, standing for sedimentation, and centrifugation filtering to obtain a germanium dioxide product and a liquid after the second centrifugation;

[0009] (3) Add clean water to the liquid after the second centrifugation, mix, stir, let stand and settle, and centrifuge to obtain the germanium dioxide product and the liquid after the third centrifugation.

[0010] Furthermore, in step (2), the volume ratio of the liquid after the first centrifugation to the clean water is 2:1; and in step (3), the volume ratio of the liquid after the second centrifugation to the clean water is 4:1.

[0011] Furthermore, in order to improve the recovery effect and efficiency of germanium, polyacrylamide with a mass percentage concentration of 1‰ is added in the steps (1), (2) and (3) after stirring, and the addition amount is 1% by mass.

[0012] Furthermore, in order to shorten the processing time, on the basis of ensuring the recovery rate, after adding the flocculant polyacrylamide, the steps (1), (2) and (3) can be left to settle for 2-4 hours to achieve efficient recovery.

[0013] Furthermore, the liquid after the three centrifugations is returned to step (1) and used together with clean water to adjust the pH value of the hydrolysis mother liquor to 7.

[0014] Furthermore, the germanium content in the hydrolysis mother liquor is greater than 2 g / L.

[0015] Mechanism of this application:

[0016] The applicant has found that when treating the hydrolysis mother liquor, clean water is added to the hydrolysis mother liquor to adjust the pH to neutral, and then the hydrolysis mother liquor is subjected to multiple static sedimentation and centrifugal filtration, so that the germanium in the hydrolysis mother liquor can be efficiently recovered; the role of adding clean water is, on the one hand, to neutralize the slightly acidic hydrolysis mother liquor, and on the other hand, its role is to supplement the amount of solvent, which is conducive to the sedimentation and collection of more germanium.

[0017] The technical solution provided by this application may have the following beneficial effects:

[0018] (1) The method for recovering germanium from the hydrolysis mother liquor in the present application does not require the addition of acid or alkali solution for pH control, and only requires the addition of clean water. At the same time, clean water is added to supplement the solvent to dilute the hydrolysis mother liquor and the corresponding centrifuged liquid, and then the germanium is efficiently recovered by static sedimentation and centrifugal filtration. The whole method has few steps, is easy to control, has low cost, and is convenient for industrial use.

[0019] (2) The method of the present application can be used to obtain a small-particle ultra-high-purity germanium dioxide product. The average particle size of the germanium dioxide product obtained in the present application is 30 microns, and the purity can be directly supplied to the lower stage of production and manufacturing for reduction into a zone melting germanium product. DETAILED DESCRIPTION

[0020] The embodiments of the present application will be described in more detail below. Although the embodiments of the present application are shown, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to make the present application more thorough and complete, and to fully convey the scope of the present application to those skilled in the art.

[0021] Example 1

[0022] A method for recovering high-purity germanium from a hydrolysis mother liquor using a multi-stage separation and sedimentation technology comprises the following steps:

[0023] (1) adding clean water to the hydrolysis mother liquor to adjust the pH value to 7, stirring, standing and settling for 6 hours, and centrifuging to obtain a germanium dioxide product and a centrifuged liquid; the germanium content in the hydrolysis mother liquor is 3580 mg / L;

[0024] (2) adding clean water to the liquid after the first centrifugation and mixing, wherein the amount of clean water added is half the volume of the liquid after the first centrifugation, stirring, standing and settling for 6 hours, and centrifugally filtering to obtain a germanium dioxide product and a liquid after the second centrifugation;

[0025] (3) Add clean water to the liquid after the second centrifugation and mix. The amount of clean water added is one-fourth of the volume of the liquid after the second centrifugation. Stir and let it stand for 6 hours. Centrifuge and filter to obtain the germanium dioxide product and the liquid after the third centrifugation.

[0026] After analysis and testing, the germanium content in the liquid after three centrifugations was 1060 mg / L, and the recovery rate of germanium was 70.39%.

[0027] The germanium dioxide products obtained in step (1), step (2) and step (3) are mixed uniformly and then the purity and particle size of the germanium dioxide are tested. The average purity is 99.9999% and the average particle size is 30 microns.

[0028] Example 2

[0029] A method for recovering high-purity germanium from a hydrolysis mother liquor using a multi-stage separation and sedimentation technology comprises the following steps:

[0030] (1) adding clean water to the hydrolysis mother liquor to adjust the pH value to 7, stirring, standing and settling for 6 hours, and centrifuging to obtain a germanium dioxide product and a centrifuged liquid; the germanium content in the hydrolysis mother liquor is 2860 mg / L;

[0031] (2) adding clean water to the liquid after the first centrifugation and mixing, wherein the amount of clean water added is one third of the volume of the liquid after the first centrifugation, stirring, standing and settling for 6 hours, and centrifugally filtering to obtain a germanium dioxide product and a second centrifugation liquid;

[0032] (3) Add clean water to the liquid after the second centrifugation and mix. The amount of clean water added is one-fourth of the volume of the liquid after the second centrifugation. Stir and let it stand for 6 hours. Centrifuge and filter to obtain the germanium dioxide product and the liquid after the third centrifugation.

[0033] After analysis and testing, the germanium content in the liquid after three centrifugations was 925 mg / L, and the recovery rate of germanium was 67.66%.

[0034] The germanium dioxide products obtained in step (1), step (2) and step (3) are mixed uniformly and then the purity and particle size of the germanium dioxide are tested. The average purity is 99.9999% and the average particle size is 32 microns.

[0035] Example 3

[0036] A method for recovering high-purity germanium from a hydrolysis mother liquor using a multi-stage separation and sedimentation technology comprises the following steps:

[0037] (1) adding clean water to the hydrolysis mother liquor to adjust the pH value to 7, stirring, standing and settling for 6 hours, and centrifuging to obtain a germanium dioxide product and a centrifuged liquid; the germanium content in the hydrolysis mother liquor is 2680 mg / L;

[0038] (2) adding clean water to the liquid after the first centrifugation and mixing, wherein the amount of clean water added is one third of the volume of the liquid after the first centrifugation, stirring, standing and settling for 6 hours, and centrifugally filtering to obtain a germanium dioxide product and a second centrifugation liquid;

[0039] (3) Add clean water to the liquid after the second centrifugation and mix it. The amount of clean water added is one fifth of the volume of the liquid after the second centrifugation. Stir it, let it stand and settle for 6 hours, and centrifuge to obtain the germanium dioxide product and the liquid after the third centrifugation.

[0040] After analysis and testing, the germanium content in the liquid after three centrifugations was 983 mg / L, and the recovery rate of germanium was 63.32%.

[0041] The germanium dioxide products obtained in step (1), step (2) and step (3) are mixed uniformly and then the purity and particle size of the germanium dioxide are tested. The average purity is 99.9999% and the average particle size is 34 microns.

[0042] Example 4

[0043] A method for recovering high-purity germanium from a hydrolysis mother liquor using a multi-stage separation and sedimentation technology comprises the following steps:

[0044] (1) adding clean water to the hydrolysis mother liquor to adjust the pH value to 7, stirring, standing and settling for 4 hours, and centrifuging to obtain a germanium dioxide product and a centrifuged liquid; the germanium content in the hydrolysis mother liquor is 3345 mg / L;

[0045] (2) adding clean water to the liquid after the first centrifugation and mixing, wherein the amount of clean water added is half the volume of the liquid after the first centrifugation, stirring, standing and settling for 4 hours, and centrifugally filtering to obtain a germanium dioxide product and the liquid after the second centrifugation;

[0046] (3) Add clean water to the liquid after the second centrifugation and mix. The amount of clean water added is one-fourth of the volume of the liquid after the second centrifugation. Stir and let it stand for 4 hours to settle. Centrifuge and filter to obtain the germanium dioxide product and the liquid after the third centrifugation.

[0047] Wherein, in the steps (1), (2) and (3), polyacrylamide with a mass percentage concentration of 1‰ is added after stirring, and the addition amount is 1% by mass.

[0048] After analysis and testing, the germanium content in the liquid after three centrifugations was 924 mg / L, and the recovery rate of germanium was 72.38%.

[0049] The germanium dioxide products obtained in step (1), step (2) and step (3) are mixed uniformly and then the purity and particle size of the germanium dioxide are tested. The average purity is 99.9999% and the average particle size is 29 microns.

[0050] Example 5

[0051] A method for recovering high-purity germanium from a hydrolysis mother liquor using a multi-stage separation and sedimentation technology comprises the following steps:

[0052] (1) adding clean water to the hydrolysis mother liquor to adjust the pH value to 7, stirring, standing and settling for 2 hours, and centrifuging to obtain a germanium dioxide product and a centrifuged liquid; the germanium content in the hydrolysis mother liquor is 3278 mg / L;

[0053] (2) adding clean water to the liquid after the first centrifugation and mixing, wherein the amount of clean water added is one quarter of the volume of the liquid after the first centrifugation, stirring, standing and settling for 2 hours, and centrifugally filtering to obtain a germanium dioxide product and the liquid after the second centrifugation;

[0054] (3) Add clean water to the liquid after the second centrifugation and mix. The amount of clean water added is one-fourth of the volume of the liquid after the second centrifugation. Stir and let it stand for 2 hours to settle. Centrifuge and filter to obtain the germanium dioxide product and the liquid after the third centrifugation.

[0055] Wherein, in step (1), step (2) and step (3), polyacrylamide with a mass percentage concentration of 1‰ is added after stirring, and the addition amount is 1% by mass percentage of the mixed solution.

[0056] After analysis and testing, the germanium content in the liquid after three centrifugations was 975 mg / L, and the recovery rate of germanium was 70.26%.

[0057] The germanium dioxide products obtained in step (1), step (2) and step (3) are mixed uniformly and then the purity and particle size of the germanium dioxide are tested. The average purity is 99.9999% and the average particle size is 28 microns.

[0058] It can be seen from Examples 1-3 that the amount of clean water added to the centrifuged liquid affects the recovery of germanium. The more clean water is added, the higher the recovery rate of germanium. However, in order to facilitate the treatment of the centrifuged liquid, the amount of clean water added should not be too much.

[0059] The results of Examples 4-5 show that static sedimentation after adding the flocculant can help further shorten the recovery time of germanium.

[0060] Comparative Example 1

[0061] The difference between Comparative Example 1 and Example 1 is that clean water is not added in step (1), step (2) and step (3), and the other operations are the same.

[0062] Comparative Example 1 The germanium content in the hydrolysis mother liquor was 3580 mg / L, and the germanium content in the liquid after three centrifugations was 2125 mg / L. The recovery rate of germanium was 40.64%.

[0063] This comparative example shows that adding clean water is crucial for the recovery of germanium. If no clean water is added and only static sedimentation and centrifugal filtration are relied on, the recovery rate of germanium is significantly lower than that of the experimental group with clean water added for recovery.

[0064] Comparative Example 2

[0065] The difference between Comparative Example 1 and Example 1 is that no clean water is added in step (1), and the other operations are the same.

[0066] Comparative Example 1 The germanium content in the hydrolysis mother liquor was 3580 mg / L, and the germanium content in the liquid after three centrifugations was 1724 mg / L. The recovery rate of germanium was 51.84%.

[0067] This comparative example shows that, on the one hand, adding clean water is crucial for the recovery of germanium. When clean water is not added in step (1) and clean water is added in steps (2) and (3), the recovery rate of germanium can be improved compared with the case where no clean water is added in comparative example 1. However, since clean water is not added in step (1) to adjust the pH, the entire recovery process is in a weakly acidic environment (the hydrolysis mother liquor is weakly acidic and contains 3.5% HCL). The results show that its recovery rate is not as good as that of the experimental group in which clean water is added to adjust the pH for recovery.

[0068] The embodiments of the present application have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or improvements to the technology in the market, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. A method for recovering high-purity germanium from hydrolysis mother liquor using multi-stage separation and sedimentation technology, characterized in that: The following steps are involved: (1) adding clean water to the hydrolysis mother liquor to adjust the pH value to 7, stirring, standing and settling, and centrifuging to obtain a germanium dioxide product and a centrifuged liquid; (2) adding clean water to the liquid after the first centrifugation, mixing, stirring, standing for sedimentation, and centrifugation filtering to obtain a germanium dioxide product and a liquid after the second centrifugation; (3) Add clean water to the liquid after the second centrifugation, mix, stir, let stand and settle, and centrifuge to obtain the germanium dioxide product and the liquid after the third centrifugation.

2. The method according to claim 1, characterized in that The volume ratio of the liquid to the clean water after the first centrifugation in step (2) is 2:1; the volume ratio of the liquid to the clean water after the second centrifugation in step (3) is 4:

1.

3. The method according to claim 1, characterized in that In the steps (1), (2) and (3), polyacrylamide with a mass percentage concentration of 1‰ is added after stirring, and the addition amount is 1% by mass.

4. The method according to claim 1, characterized in that: The liquid after the three centrifugations is returned to step (1) and used together with clean water to adjust the pH value of the hydrolysis mother liquid to 7.

5. The method according to claim 1, characterized in that The germanium content in the hydrolysis mother liquor is greater than 2 g / L.

6. The method according to claim 3, characterized in that In the steps (1), (2) and (3), the mixture is allowed to stand and settle for 2-4 hours.