Method for cooperatively treating germanium deep processing wastewater and recovering germanium

Abstract

The invention relates to a method for cooperatively treating germanium deep processing wastewater and recovering germanium, belongs to the technical field of germanium deep processing wastewater treatment, and aims at the composition characteristics that germanium-containing wastewater such as distillation raffinate, tail absorption liquid, hydrolysis mother liquor, material washing water and ingot washing water generated in the germanium deep processing process is wide in source and different in component such as pH value, germanium concentration and impurity content. Germanium is directly and efficiently recovered from the germanium-containing wastewater by adopting a synergistic mixing-ion exchange process and is output in a high-purity GeO2 product form, chlorine is output in a hydrochloric acid form and is used in the process, the germanium recovery process is greatly simplified, the germanium recovery rate is remarkably increased, meanwhile, the treatment cost of the chlorine-containing wastewater is reduced, and the method is suitable for industrial production. The method has the technical advantages of simple process flow, high comprehensive recovery rate, cleanness, high efficiency and the like.

Description

Technical Field

[0001] This invention belongs to the field of germanium deep processing wastewater treatment technology, specifically, it relates to a method for synergistically treating germanium deep processing wastewater and recovering germanium. Background Technology

[0002] Currently, the industrial process of producing zone-melted germanium ingots from germanium concentrate or germanium-rich materials involves a process of chlorination distillation-redistillation-rectification-hydrolysis-reduction-zone smelting. The germanium-containing wastewater generated in this process, including distillation residue, tailings, hydrolysis mother liquor, washing water, and ingot washing water, comes from a wide range of sources and varies in pH and impurity content.

[0003] For these germanium-containing wastewaters, the current main methods for recovering germanium are neutralization precipitation or evaporation concentration. Neutralization precipitation involves adding an alkaline reagent (usually a basic sodium salt) to neutralize and precipitate impurities, a process that consumes a large amount of alkali. Germanium is dispersed in the neutralization residue and liquid, making further effective recovery difficult and resulting in germanium resource loss. Simultaneously, this process generates wastewater containing sodium and chlorine, which must be removed before discharge or utilization. Evaporation concentration is typically used to crystallize sodium chloride, but the recovered sodium chloride has a high impurity content, making resource utilization difficult, and the evaporation concentration process is extremely energy-intensive. During evaporation concentration, germanium and impurities are all enriched in the crystallization residue, requiring further treatment of the residue to enrich germanium before chlorination distillation. This method does not solve the technical challenge of separating germanium from impurities.

[0004] In summary, the current methods for treating the large volume and wide distribution of germanium-containing wastewater generated by germanium deep processing systems are relatively crude. The recovered germanium requires further treatment, and the recovery rate is low. Existing technologies also suffer from problems such as high energy consumption and the potential generation of secondary hazardous waste. Summary of the Invention

[0005] To overcome the problems existing in the background technology, this invention provides a method for the synergistic treatment and recovery of germanium from germanium deep-processing wastewater. This method unifies the treatment of large quantities of germanium deep-processing wastewater from various sources, achieving germanium enrichment and recovery. It greatly simplifies the germanium recovery process from germanium deep-processing wastewater, directly producing high-purity germanium products without the need for further impurity removal. The method of this invention can simultaneously recover and treat germanium from germanium deep-processing wastewater from different sources, and the germanium recovery is unaffected by impurities in the water, achieving synergistic treatment of germanium deep-processing wastewater.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solution: The method for co-treating germanium deep-processing wastewater and recovering germanium includes the following steps: Step 1: Co-mixing: Mix the distillation residue from the pretreated germanium deep processing process with the tail liquid, ingot washing water and material washing water from the germanium deep processing process, and control the pH of the mixture to 2-6. Step 2 Adsorption and Separation: The mixture produced in Step 1 is passed through ion exchange columns in sequence. The adsorbed liquid with a residual germanium ion concentration ≤1mg / L is used as qualified feed liquid and enters the water treatment process through the open circuit of the system. The adsorbed liquid with a residual germanium ion concentration >1mg / L enters the next stage ion exchange column step by step until the qualified concentration is reached and then the open circuit is opened. The saturated germanium-loaded resin enters the desorption and enrichment process. Step 3: Desorption and enrichment: Desorb the germanium-loaded resin to obtain a high-germanium desorption solution with a germanium concentration ≥8000 mg / L, a low-germanium desorption solution with a germanium concentration <8000 mg / L, and regenerated resin; Step 4 Concentration: The low-germanium desorption solution produced in Step 3 is continuously evaporated and concentrated to obtain a high-germanium concentrate with a germanium concentration >8000 mg / L. This concentrate is then mixed with the high-germanium desorption solution and fed into the chlorination distillation process.

[0007] Furthermore, the pretreatment described in step 1 refers to the negative pressure evaporation of the distillation residue generated during the deep processing of germanium, which causes hydrogen chloride to continuously volatilize and obtain dilute hydrochloric acid and a dechlorination solution with a pH of 1.5 to 2.5. The dechlorination solution is then mixed with other wastewater from the deep processing of germanium.

[0008] Furthermore, the high-germanium desorption solution from step 3 and the high-germanium concentrate from step 4 are mixed and processed in the following steps: Step 5 Chlorination distillation: Add concentrated hydrochloric acid to the mixture of high germanium desorption solution and high germanium concentrate for chlorination distillation to obtain germanium tetrachloride and chlorination distillation residue. Germanium tetrachloride enters the hydrolysis process, and chlorination distillation residue is returned to the pretreatment process in step 1. Step 6 Hydrolysis: Germanium chloride is continuously added to highly conductive pure water for hydrolysis to obtain GeO2 and hydrolysis mother liquor. The hydrolysis mother liquor is returned to step 3. Step 7 Washing: Stir and wash GeO2 in highly conductive water to obtain GeO2 product and washing water. The washing water is returned to step 1.

[0009] The beneficial effects of this invention are: (1) The present invention adopts a synergistic mixing-ion exchange method to directly and efficiently recover germanium from germanium-containing wastewater, and the germanium is produced in the form of high-purity GeO2 product, which does not require further impurity removal. It has the advantages of short process flow, high germanium recovery rate and good product quality. It avoids the shortcomings of the existing process, which uses a crude treatment method of neutralization precipitation-acid dissolution of germanium-containing slag-secondary enrichment of germanium-chlorination distillation for distillation residue, tail liquid, hydrolysis mother liquor, washing water, and ingot washing water without exception. This method results in large reagent consumption, large amount of hazardous waste residue, high cost of high-chlorine wastewater treatment, lengthy germanium recovery process and low germanium recovery rate.

[0010] (2) This invention not only achieves short-range and efficient recovery of germanium from various types of wastewater and produces high-purity GeO2 products, but also converts chlorine into hydrochloric acid products for use in the process, saving reagent consumption and reducing the treatment cost of chlorine-containing wastewater. Attached Figure Description

[0011] Figure 1 This is a process flow diagram of the present invention. Detailed Implementation

[0012] To make the objectives, technical solutions, and beneficial effects of this invention clearer, the technical solutions of this invention will be described in detail below. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are all within the scope of protection of this invention.

[0013] A method for co-treating germanium deep-processing wastewater and recovering germanium includes the following: The distillation residue in step 1 of this embodiment is germanium-containing distillation residue produced in the process of chlorination distillation-re-distillation-hydrolysis-reduction-zone melting proposed in the background art.

[0014] Step 1: Collaborative Mixing (1) Under the conditions of 60-80℃ and 0.01-0.09MPa, the distillation residue (containing 20-100 mg / L Ge and 20-30% hydrochloric acid by mass) is evaporated under negative pressure for 120-240 min to continuously volatilize the hydrogen chloride in it to obtain a dilute hydrochloric acid with a concentration of 15-20% and a dechlorination solution with a pH of 1.5-2.5.

[0015] The hydrochloric acid content in the distillation residue is as high as 20-30% by mass. Industrially, sodium hydroxide or lime is usually used for neutralization, resulting in a large consumption of reagents such as sodium hydroxide, and the generated high-chlorine wastewater requires further harmless treatment. This invention uses negative pressure evaporation to continuously volatilize the hydrogen chloride to reduce its acidity, eliminating the need for alkali neutralization. It also avoids the problems of germanium loss and difficulties in germanium recovery caused by germanium entering the neutralization residue.

[0016] (2) Mix the pretreated distillation residue (dechlorination solution), tailings (containing 3000-8000 mg / L Ge, pH 8-10), hydrolysis mother liquor (containing 800-900 mg / L Ge, hydrochloric acid mass fraction 12-15%), washing water (containing 500-1500 mg / L Ge, hydrochloric acid mass fraction 1-2%), and washing solution (containing 1000-2000 mg / L Ge, pH 2-4), and control the pH of the mixture to 2-6.

[0017] The distillation residue, tailings, hydrolysis mother liquor, washing water, and ingot washing water produced during the deep processing of germanium have different pH values ​​in addition to different germanium contents. Mixing them together can adjust the acidity and facilitate centralized recovery of germanium.

[0018] Step 2 Adsorption Separation: The mixed solution from Step 1 is sequentially passed through 2-4 ion exchange columns packed with macroporous chelating resin in series at a flow rate of 1-4 BV. The adsorbed solution with a residual germanium ion concentration ≤1 mg / L is used as the qualified feed solution and enters the water treatment process through an open circuit. The adsorbed solution with a residual germanium ion concentration >1 mg / L is passed through each subsequent ion exchange column until the germanium concentration meets the requirements, at which point the system is opened, and the saturated germanium-loaded resin enters the desorption enrichment process. The germanium adsorption rate reaches over 99% during the adsorption separation process.

[0019] Step 3: Desorption and Enrichment: The dilute hydrochloric acid from Step 1 is added to the mother liquor from Step 6 to obtain a desorbent with a hydrochloric acid mass fraction of 15-20%. This desorbent is used to desorb germanium from the germanium-supported resin. High-germanium desorbate with a germanium concentration ≥8000 mg / L flows into a storage tank, while low-germanium desorbate with a germanium concentration <8000 mg / L is concentrated. The germanium desorption rate reaches over 98% during the desorption and enrichment process.

[0020] Adsorption and desorption are not only the separation and enrichment process of germanium, but also the purification process, producing a high-purity germanium-rich solution. The high-germanium-rich solution can be directly entered into the chlorination distillation process, which completely changes the current chemical precipitation-chlorination distillation process technology route. It has the advantages of simple process flow, small germanium recycling loss, and small reagent consumption.

[0021] Step 4 Concentration: The low germanium desorption solution with germanium concentration <8000 mg / L from Step 3 is continuously concentrated at 70-85℃ until the germanium concentration >8000 mg / L, to obtain a germanium concentrate, which is then pumped into a storage tank and mixed with the high germanium desorption solution.

[0022] Step 5: Chlorination distillation: Add 30-33% hydrochloric acid to the mixture of high-germanium desorption solution and germanium concentrate, and perform chlorination distillation at 85-95℃ for 1-4 hours until the residual germanium concentration in the distillation residue is <100mg / L. This process produces a primary GeCl4 product with a purity of 4N-5N. The remaining distillation residue is returned to the pretreatment step in Step 1. The primary GeCl4 product is redistilled again at 85-95℃ to obtain a high-purity GeCl4 product with a purity of 6N-7N. The initial distillation tail liquid and the redistillation tail liquid are returned to the co-mixing step in Step 1.

[0023] Step 6: Hydrolysis: High-purity GeCl4 is continuously added to high-purity water with a resistivity of 13 MΩ·cm to obtain primary GeO2 product and hydrolysis mother liquor. The hydrolysis mother liquor is then returned to the desorption enrichment process. The direct recovery rate of germanium during the hydrolysis process reaches over 98%.

[0024] Step 7 Washing: The primary GeO2 product is washed with stirring in high-purity water with a resistivity of 13 MΩ·cm to obtain 7N-8N high-purity GeO2 product and washing water. The washing water is returned to the co-mixing process in Step 1. The direct recovery rate of germanium during the washing process is over 99%. The overall recovery rate of germanium throughout the entire process is greater than 97%.

[0025] To illustrate the present invention more clearly, the following embodiments will be described in detail.

[0026] Example 1 A method for co-treating germanium deep-processing wastewater and recovering germanium includes the following steps: Step 1: Collaborative Mixing (1) Under the conditions of 70℃ and 0.01MPa, the distillation residue (containing 20 mg / L Ge and 24% hydrochloric acid by mass) was evaporated under negative pressure for 120 min to continuously volatilize the hydrogen chloride in it to obtain a dilute hydrochloric acid with a concentration of 18% and a dechlorination solution with pH 2.0.

[0027] (2) The dechlorination solution, tail absorption liquid (containing 8000 mg / L Ge, pH 9), hydrolysis mother liquor (containing 800 mg / L Ge, hydrochloric acid mass fraction 12%), washing water (containing 900 mg / L Ge, hydrochloric acid mass fraction 1%), and washing water (containing 1000 mg / L Ge, pH 3) are mixed to obtain a mixture with pH 4.

[0028] Step 2 Adsorption Separation: The mixed solution from step 1 is passed sequentially through four ion exchange columns packed with macroporous chelating resin at a flow rate of 4 BV. The adsorbed solution with a residual germanium ion concentration ≤1 mg / L is used as the qualified feed solution and enters the water treatment process through an open circuit. The adsorbed solution with a residual germanium ion concentration >1 mg / L enters the next stage ion exchange column step by step until the germanium concentration is qualified and then the circuit is opened. The saturated germanium-loaded resin enters the desorption and enrichment process.

[0029] The adsorption rate of germanium in the adsorption separation process was 99.4%, and the residual germanium ion concentration in the qualified feed solution was 0.4 mg / L.

[0030] Step 3: Desorption and enrichment The dilute hydrochloric acid produced in step 1 is added to the hydrolysis mother liquor from the hydrolysis process to obtain a desorbent with a hydrochloric acid mass fraction of 15% for desorption onto the germanium-supported resin. High-germanium desorbate with a germanium concentration ≥8000 mg / L, discharged from the ion exchange column, flows into a storage tank, while low-germanium desorbate with a germanium concentration <8000 mg / L enters the concentration and enrichment process. The germanium desorption rate during the desorption and enrichment process is 98.6%.

[0031] Step 4: Concentration and Enhancement Step 3: The low germanium desorption solution with a germanium concentration of <8000 mg / L is concentrated in a concentration tank at 80°C until its germanium concentration is >8000 mg / L. Then the process is stopped and the solution is pumped into a high germanium desorption solution storage tank.

[0032] Step 5: Chlorination distillation Add 30% hydrochloric acid to the mixture of high-germanium desorption solution and germanium concentrate, and directly perform chlorination distillation at 85℃ for 4 hours until the residual germanium concentration in the distillation residue is <100mg / L. This process produces a primary GeCl4 product with a purity of 4N. The residual distillation residue is returned to the pretreatment process. The primary GeCl4 product is redistilled again at 95℃ to obtain a high-purity GeCl4 product with a purity of 6N. The tail liquid from the initial distillation and the tail liquid from the redistillation are returned to the co-mixing process in step 1.

[0033] Step 6 Hydrolysis: High-purity GeCl4 was continuously added to high-purity water with a resistivity of 13 MΩ·cm to obtain a primary product of GeO2 and a hydrolysis mother liquor containing 800 mg / L Ge and 12% hydrochloric acid by mass. The hydrolysis mother liquor was then returned to the desorption enrichment process. The direct recovery rate of germanium during the hydrolysis process reached over 98%.

[0034] Step 7: Washing The primary GeO2 product was stirred and washed in high-purity water with a resistivity of 13 MΩ·cm to obtain 8N high-purity GeO2 product and washing water containing 900 mg / L Ge and 1% hydrochloric acid by mass. The washing water was returned to the co-mixing process.

[0035] The direct recovery rate of germanium during the washing process reaches over 99.7%. The overall germanium recovery rate throughout the entire process is 97.9%.

[0036] Example 2 A method for co-treating germanium deep-processing wastewater and recovering germanium includes the following steps: Step 1: Collaborative Mixing (1) Under the conditions of 80℃ and 0.09MPa, the distillation residue (containing 100 mg / L Ge and 20% hydrochloric acid by mass) was evaporated under negative pressure for 180 min to continuously volatilize the hydrogen chloride in it to obtain a 20% dilute hydrochloric acid and a dechlorination solution with pH 2.5.

[0037] (2) The dechlorination solution, tailing solution (containing 3000 mg / L Ge, pH 8), hydrolysis mother liquor (containing 830 mg / L Ge, 13% hydrochloric acid by mass), washing water (containing 500 mg / L Ge, 1.5% hydrochloric acid by mass), and washing solution (containing 2000 mg / L Ge, pH 2) are mixed to obtain a mixture with pH 2.

[0038] Step 2 Adsorption Separation: The ion exchange column is packed with macroporous chelating resin. The mixed solution from step 1 is passed sequentially through two ion exchange columns connected in series at a flow rate of 2 BV. The adsorbed solution with a residual germanium ion concentration ≤1 mg / L is used as the qualified feed solution and enters the water treatment process through an open circuit. The adsorbed solution with a residual germanium ion concentration >1 mg / L enters the next stage ion exchange column step by step until the germanium concentration is qualified and then the circuit is opened. The saturated germanium-loaded resin enters the desorption and enrichment process.

[0039] The adsorption rate of germanium in the adsorption separation process was 99.6%, and the residual germanium ion concentration in the qualified feed solution was 0.7 mg / L.

[0040] Step 3: Desorption and enrichment The dilute hydrochloric acid produced in step 1 is added to the hydrolysis mother liquor produced in step 6 to obtain a desorbent with a hydrochloric acid mass fraction of 18% to desorb germanium-supported resin. Among them, the high germanium desorbent with a germanium concentration ≥8000 mg / L discharged from the ion exchange column flows into the storage tank, and the low germanium desorbent with a germanium concentration <8000 mg / L enters the concentration and enrichment process.

[0041] Step 4: Concentration and Enhancement Step 3: The low germanium desorption solution with a germanium concentration of <8000 mg / L is continuously concentrated in a concentration tank at 70°C until its germanium concentration is >8000 mg / L. Then, the process is stopped and the solution is pumped into a high germanium desorption solution storage tank.

[0042] The desorption rate of germanium during the desorption enrichment process reached 98.5%.

[0043] Step 5: Chlorination distillation Add 33% hydrochloric acid to the mixture of high-germanium desorption solution and germanium concentrate, and directly perform chlorination distillation at 95°C for 2 hours until the residual germanium concentration in the distillation residue is <100mg / L. This process produces a primary GeCl4 product with a purity of 5N. The residual distillation residue is returned to the pretreatment step 1. The primary GeCl4 product is redistilled again at 90°C to obtain a high-purity GeCl4 product with a purity of 7N. The initial distillation tail liquid and the redistillation tail liquid are returned to the co-mixing step 1.

[0044] Step 6 Hydrolysis: High-purity GeCl4 was continuously added to high-purity water with a resistivity of 13 MΩ·cm to obtain a primary product of GeO2 and a hydrolysis mother liquor containing 830 mg / L Ge and 13% hydrochloric acid by mass. The hydrolysis mother liquor was then returned to the desorption enrichment process. The direct recovery rate of germanium during the hydrolysis process was 98.7%.

[0045] Step 7: Washing The GeO2 product was washed with high-purity water with a resistivity of 13 MΩ·cm by stirring to obtain 8N high-purity GeO2 product and washing water containing 500 mg / L Ge and 1.5% hydrochloric acid by mass. The washing water was returned to the co-mixing process. The direct recovery rate of germanium during the washing process was over 99.3%.

[0046] The overall recovery rate of germanium throughout the entire process was 98.4%.

[0047] Example 3 A method for co-treating germanium deep-processing wastewater and recovering germanium includes the following steps: Step 1: Collaborative Mixing (1) Under the conditions of 60℃ and 0.06MPa, the distillation residue (containing 50 mg / L Ge and 30% hydrochloric acid by mass) was evaporated under negative pressure for 240 min to continuously volatilize the hydrogen chloride in it to obtain a 15% dilute hydrochloric acid and a dechlorination solution with pH 1.5.

[0048] (2) The dechlorination solution, tailing solution (containing 4000 mg / L Ge, pH 10), hydrolysis mother liquor (containing 900 mg / L Ge, 15% hydrochloric acid by mass), washing water (containing 1500 mg / L Ge, 2% hydrochloric acid by mass), and washing solution (containing 1500 mg / L Ge, pH 4) are mixed to obtain a mixture with pH 6.

[0049] Step 2 Adsorption Separation: The mixed solution from step 1 is passed sequentially through three ion exchange columns packed with macroporous chelating resin at a flow rate of 1 BV. The adsorbed solution with a residual germanium ion concentration ≤1 mg / L is used as the qualified feed solution and enters the water treatment process through an open circuit. The adsorbed solution with a residual germanium ion concentration >1 mg / L is passed through each subsequent ion exchange column until the germanium concentration meets the requirements, at which point the system is opened, and the saturated germanium-loaded resin enters the desorption and enrichment process.

[0050] The adsorption rate of germanium in the adsorption separation process was 99.7%, and the residual germanium ion concentration in the qualified feed solution was 0.4 mg / L.

[0051] Step 3: Desorption and enrichment Add the dilute hydrochloric acid produced in step 1 to the hydrolysis mother liquor produced in step 6 to obtain a desorbent with a hydrochloric acid mass fraction of 20% to desorb germanium-supported resin. Among them, the high germanium desorbent with a germanium concentration ≥8000 mg / L discharged from the ion exchange column flows into the storage tank, and the low germanium desorbent with a germanium concentration <8000 mg / L enters the concentration and enrichment process.

[0052] The desorption rate of germanium during the desorption enrichment process reached 98.9%.

[0053] Step 4: Concentration and Enhancement Step 3: The low germanium desorption solution with a germanium concentration of <8000 mg / L is continuously concentrated in a concentration tank at 85°C until its germanium concentration is >8000 mg / L. Then, the process is stopped and the solution is pumped into a high germanium desorption solution storage tank.

[0054] Step 5: Chlorination distillation Add 32% hydrochloric acid to the mixture of high-germanium desorption solution and germanium concentrate, and directly perform chlorination distillation at 90℃ for 1 hour until the residual germanium concentration in the distillation residue is <100mg / L. This process produces a primary GeCl4 product with a purity of 4N. The residual distillation residue is returned to the pretreatment step 1. The primary GeCl4 product is redistilled again at 85℃ to obtain a high-purity GeCl4 product with a purity of 7N. The initial distillation tail liquid and the redistillation tail liquid are returned to the co-mixing step 1.

[0055] Step 6 Hydrolysis: High-purity GeCl4 is continuously added to high-purity water with a resistivity of 13 MΩ·cm to obtain a primary product of GeO2 and a hydrolysis mother liquor containing 900 mg / L Ge and 15% hydrochloric acid by mass. The hydrolysis mother liquor is then returned to the desorption enrichment process.

[0056] The direct recovery rate of germanium during the hydrolysis process reached 98.5%.

[0057] Step 7: Washing The GeO2 product was stirred and washed in high-purity water with a resistivity of 13 MΩ·cm to obtain 7N high-purity GeO2 product and washing water containing 1500 mg / L Ge and 2% hydrochloric acid by mass. The washing water was returned to the co-mixing process.

[0058] The direct recovery rate of germanium during the washing process reached 99.2%. The overall recovery rate of germanium throughout the entire process was 97.8%.

[0059] Comparative Example 1 A method for treating germanium deep-processing wastewater and recovering germanium includes the following steps: Step 1: Collaborative Mixing Take equal amounts of the same distillation residue, tailings, hydrolysis mother liquor, washing water, and washing solution as in Example 3, and mix them.

[0060] Step 2 Adsorption Separation: The mixed solution from step 1 is passed sequentially through 10 ion exchange columns packed with macroporous chelating resin at a flow rate of 1 BV. The adsorbed solution with a residual germanium ion concentration ≤1 mg / L is used as the qualified feed solution and enters the water treatment process through an open circuit. The adsorbed solution with a residual germanium ion concentration >1 mg / L is passed through each subsequent ion exchange column until the germanium concentration meets the requirements, at which point the circuit is opened, and the saturated germanium-loaded resin enters the desorption and enrichment process.

[0061] The adsorption rate of germanium in the adsorption separation process was 22.3%, and the residual germanium ion concentration in the qualified feed solution was 0.4 mg / L.

[0062] Step 3: Desorption and enrichment Hydrochloric acid is added to the hydrolysis mother liquor produced in step 6 as a desorbent to desorb the germanium-loaded resin. The high germanium desorbent with a germanium concentration ≥8000 mg / L discharged from the ion exchange column flows into the storage tank, while the low germanium desorbent with a germanium concentration <8000 mg / L enters the concentration and enrichment process.

[0063] The desorption rate of germanium during the desorption enrichment process reached 85.5%.

[0064] Step 4: Concentration and Enhancement Step 3: The low germanium desorption solution with a germanium concentration of <8000 mg / L is continuously concentrated in a concentration tank at 85°C until its germanium concentration is >8000 mg / L. Then, the process is stopped and the solution is pumped into a high germanium desorption solution storage tank.

[0065] Step 5: Chlorination distillation Add 32% hydrochloric acid to the mixture of high-germanium desorption solution and germanium concentrate, and directly perform chlorination distillation at 90℃ for 1 hour until the residual germanium concentration in the distillation residue is <100mg / L. This process produces a primary GeCl4 product with a purity of 4N. The residual distillation residue is returned to the pretreatment step 1. The primary GeCl4 product is redistilled again at 85℃ to obtain a high-purity GeCl4 product with a purity of 7N. The initial distillation tail liquid and the redistillation tail liquid are returned to the co-mixing step 1.

[0066] Step 6 Hydrolysis: High-purity GeCl4 is continuously added to high-purity water with a resistivity of 13 MΩ·cm to obtain a primary product of GeO2 and a hydrolysis mother liquor containing 900 mg / L Ge and 15% hydrochloric acid by mass. The hydrolysis mother liquor is then returned to the desorption enrichment process.

[0067] The direct recovery rate of germanium during the hydrolysis process reached 98.5%.

[0068] Step 7: Washing The GeO2 product was stirred and washed in high-purity water with a resistivity of 13 MΩ·cm to obtain 7N high-purity GeO2 product and washing water containing 1500 mg / L Ge and 2% hydrochloric acid by mass. The washing water was returned to the co-mixing process.

[0069] The direct recovery rate of germanium during the washing process reached 99.2%. The overall germanium recovery rate throughout the entire process was 18.6%.

[0070] In this comparative example, since the hydrochloric acid mass fraction of the distillation residue is as high as 30%, after being directly mixed with the tailings, hydrolysis mother liquor, washing water and ingot washing water without negative pressure evaporation treatment, the hydrochloric acid concentration of the mixture is also high. Even if the number of ion exchange columns is increased from 3 to 10 during the adsorption separation process, the adsorption rate of germanium still decreases from 99.7% to 22.3%, resulting in a total germanium recovery rate of only 18.6%. Moreover, additional hydrochloric acid needs to be added in step 3 for desorption enrichment, which increases reagent costs.

[0071] Comparative Example 2 A method for treating germanium deep-processing wastewater and recovering germanium includes the following steps: Step 1: Collaborative Mixing Take the same amount of distillation residue, tailings, hydrolysis mother liquor, washing water, and ingot washing water as in Example 3, mix them, and continuously add soda ash to the mixture to adjust the acidity until pH 1.5. After the reaction is complete, separate the liquid and solid to obtain filter residue and filtrate. The filter residue contains 270 g / t of germanium, and the filtrate contains 400 mg / L of germanium. The mixing and acid adjustment process generates a large amount of hazardous waste containing germanium slag, and 47% of the germanium is lost by entering the slag.

[0072] Step 2 Adsorption Separation: The filtrate from step 1 is passed sequentially through three ion exchange columns packed with macroporous chelating resin at a flow rate of 1 BV. The adsorbed solution with a residual germanium ion concentration ≤1 mg / L is used as the qualified feed solution and enters the water treatment process from the system open circuit. The adsorbed solution with a residual germanium ion concentration >1 mg / L is passed through each subsequent ion exchange column until the germanium concentration meets the requirements, at which point the system is opened circuit, and the saturated germanium-loaded resin enters the desorption and enrichment process. The germanium adsorption rate during the adsorption separation process is 99.1%.

[0073] Step 3: Desorption and enrichment A desorbent with a hydrochloric acid mass fraction of 20% was used to desorb germanium from the germanium-supported resin. High-germanium desorbate (≥8000 mg / L) exiting the ion exchange column flowed into a storage tank, while low-germanium desorbate (<8000 mg / L) entered the concentration and enrichment process. The germanium desorption rate during the desorption and enrichment process was 98.93%.

[0074] Step 4: Concentration and Enhancement Step 3: The low germanium desorption solution with a germanium concentration of <8000 mg / L is continuously concentrated in a concentration tank at 85°C until its germanium concentration is >8000 mg / L. Then, the process is stopped and the solution is pumped into a high germanium desorption solution storage tank.

[0075] Step 5: Chlorination distillation Add 32% hydrochloric acid to the mixture of high-germanium desorption solution and germanium concentrate, and directly perform chlorination distillation at 90℃ for 1 hour until the residual germanium concentration in the distillation residue is <100mg / L. This process produces a primary GeCl4 product with a purity of 4N. The residual distillation residue is returned to the pretreatment step 1. The primary GeCl4 product is redistilled again at 85℃ to obtain a high-purity GeCl4 product with a purity of 7N. The initial distillation tail liquid and the redistillation tail liquid are returned to the co-mixing step 1.

[0076] Step 6 Hydrolysis: High-purity GeCl4 was continuously added to high-purity water with a resistivity of 13 MΩ·cm to obtain a primary product of GeO2 and a hydrolysis mother liquor containing 900 mg / L Ge and 15% hydrochloric acid by mass. The hydrolysis mother liquor was then returned to the desorption enrichment process. The direct recovery rate of germanium during the hydrolysis process reached 98.5%.

[0077] Step 7: Washing The GeO2 product was stirred and washed in high-purity water with a resistivity of 13 MΩ·cm to obtain 7N high-purity GeO2 product and washing water containing 1500 mg / L Ge and 2% hydrochloric acid by mass. The washing water was returned to the co-mixing process.

[0078] The direct recovery rate of germanium during the washing process reached 99.0%. The overall germanium recovery rate of the entire process was 45.7%.

[0079] In this comparative example, the concentration of hydrochloric acid in the distillation residue was reduced by alkali neutralization. The process generated a large amount of germanium-containing neutralization residue, and the loss of germanium in the residue was as high as 47%, resulting in a total germanium recovery rate of only 45.7%. Moreover, additional hydrochloric acid was required for desorption and enrichment in step 3, which increased reagent costs.

[0080] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A method for co-treating germanium deep-processing wastewater and recovering germanium, characterized in that, Includes the following steps: Step 1: Co-mixing: Mix the distillation residue from the pretreated germanium deep processing process with the tail liquid, ingot washing water and material washing water from the germanium deep processing process, and control the pH of the mixture to 2-6. Step 2 Adsorption and Separation: The mixture produced in Step 1 is passed through ion exchange columns in sequence. The adsorbed liquid with a residual germanium ion concentration ≤1mg / L is used as qualified feed liquid and enters the water treatment process through the open circuit of the system. The adsorbed liquid with a residual germanium ion concentration >1mg / L enters the next stage ion exchange column step by step until the qualified concentration is reached and then the open circuit is opened. The saturated germanium-loaded resin enters the desorption and enrichment process. Step 3: Desorption and enrichment: Desorb the germanium-loaded resin to obtain a high-germanium desorption solution with a germanium concentration ≥8000 mg / L, a low-germanium desorption solution with a germanium concentration <8000 mg / L, and regenerated resin; Step 4 Concentration: The low-germanium desorption solution produced in Step 3 is continuously evaporated and concentrated to obtain a high-germanium concentrate with a germanium concentration >8000 mg / L. This concentrate is then mixed with the high-germanium desorption solution and fed into the chlorination distillation process.

2. The method for co-treating germanium deep-processing wastewater and recovering germanium according to claim 1, characterized in that, The pretreatment described in step 1 refers to the negative pressure evaporation of the distillation residue generated during the deep processing of germanium, which causes hydrogen chloride to continuously volatilize and obtain dilute hydrochloric acid and a dechlorination solution with a pH of 1.5 to 2.

5. The dechlorination solution is then mixed with other wastewater from the deep processing of germanium.

3. The method for synergistically treating germanium deep-processing wastewater and recovering germanium according to claim 1 or 2, characterized in that, The high-germanium desorption solution from step 3 and the high-germanium concentrate from step 4 are mixed and processed as follows: Step 5 Chlorination distillation: Add concentrated hydrochloric acid to the mixture of high germanium desorption solution and high germanium concentrate for chlorination distillation to obtain germanium tetrachloride and chlorination distillation residue. Germanium tetrachloride enters the hydrolysis process, and chlorination distillation residue is returned to the pretreatment process in step 1. Step 6 Hydrolysis: Germanium chloride is continuously added to highly conductive pure water for hydrolysis to obtain GeO2 and hydrolysis mother liquor. The hydrolysis mother liquor is returned to step 3. Step 7 Washing: Stir and wash GeO2 in highly conductive water to obtain GeO2 product and washing water. The washing water is returned to step 1.

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