Method for separating copper and germanium from multi-component sulfate solution

Abstract

The invention relates to a method for separating copper and germanium from a multi-component sulfate solution, and belongs to the technical field of zinc hydrometallurgy. According to the technical scheme, the method comprises the following steps: reducing the content of sulfuric acid in a multi-component sulfate solution by using a neutralizing agent, and carrying out liquid-solid separation to obtain a low-acid multi-component sulfate solution; excessive iron powder is added into the low-acid multi-component sulfate solution, and copper-arsenic slag and replacement filtrate are obtained through liquid-solid separation; and precipitating indium and germanium in the replacement filtrate, and carrying out liquid-solid separation to obtain an indium and germanium enriched product and indium and germanium precipitated filtrate. According to the method, direct separation of copper and germanium in the multi-component sulfate solution is achieved, the copper and germanium separation and recovery process is greatly simplified, reagent consumption is low, energy consumption is low, the copper rate of germanium entering the copper arsenic slag is smaller than 3%, and the copper replacement rate is larger than 98%.

Description

Technical Field

[0001] This invention belongs to the field of zinc hydrometallurgical technology, specifically, it relates to a method for separating copper and germanium from a multi-component sulfate solution. Background Technology

[0002] When zinc roasted ore is processed using a fully wet process, the zinc roasted ore is first subjected to neutral leaching and weak acid / low acid leaching. The acid leaching residue produced by the weak acid / low acid leaching is then subjected to enhanced leaching to leach zinc, iron, copper, indium and germanium from the acid leaching residue, resulting in a copper-germanium sulfate solution.

[0003] In existing technologies, the recovery of copper and germanium from sulfate solutions suffers from problems such as long processes and high recovery costs. For example, the technical solution disclosed in Chinese patent CN110093506A involves mixing germanium-zinc leaching residue with zinc concentrate to obtain a germanium- and copper-containing filtrate. Iron powder is then added to the germanium- and copper-containing filtrate to replace the germanium and copper, resulting in germanium-copper precipitate slag. More than 99% of the germanium enters the germanium-copper precipitate slag, which is then fed into a germanium-copper recovery system. This method cannot directly separate germanium and copper; a germanium-copper recovery system is required to separate the two, resulting in multiple steps, a long process, and high production costs. Chinese patent CN113088710A discloses a method for separating copper and germanium from replacement slag. The technical solution involves washing the copper-germanium replacement slag, adding acid to the washed filter cake for oxygen pressure leaching, allowing copper to enter the solution, and germanium to precipitate into iron-germanium slag. The iron-germanium slag is then fed into a fuming furnace or rotary kiln to recover germanium. The filtrate is electrowinning to produce No. 1 cathode copper, and the electrowinning waste is returned to oxygen pressure leaching. This method also suffers from problems such as numerous steps, long process, high reagent consumption, and high production costs. Chinese patent CN120555735A discloses a technical solution for separating copper and germanium from sulfate solution: controlling the H2SO4 content in the sulfate solution to 10-50 g / L, adding iron powder in a short amount to replace copper and remove chloride ions, and obtaining sponge copper after liquid-solid separation; adding a neutralizing agent and a germanium precipitant to the replacement solution, and obtaining germanium-enriched material after liquid-solid separation. However, this method can only process solutions that do not contain arsenic or Fe. 3+ Sulfate solutions, if the sulfate solution contains arsenic or has a high arsenic content, and contains Fe... 3+ At this time, the separation effect of copper and germanium deteriorates sharply, and the proportion of germanium entering the sponge copper increases significantly. Summary of the Invention

[0004] To overcome the problems existing in the prior art, the present invention provides a method for separating copper and germanium from a multi-component sulfate solution.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solution: The method for separating copper and germanium from a multi-component sulfate solution includes the following steps: The sulfuric acid content in the multi-component sulfate solution was reduced by a neutralizing agent, and a low-acid multi-component sulfate solution was obtained by liquid-solid separation. Excess iron powder was added to a low-acid, multi-component sulfate solution, and copper-arsenic slag and displacement filtrate were obtained by liquid-solid separation. The indium-germanium precipitate was obtained by displacing the filtrate and then subjected to liquid-solid separation to obtain an indium-germanium enrichment and an indium-germanium precipitate filtrate.

[0006] Preferably, the sulfuric acid content of the low-acid multi-component sulfate solution is 2-8 g / L.

[0007] Preferably, the excess iron powder is iron powder added in an amount equal to the Cu content in a low-acid multi-component sulfate solution. 2+ +Fe 3+ 1.1 to 1.3 times the theoretical reaction amount.

[0008] Preferably, the multi-component sulfate solution contains, in addition to Zn, H2SO4, and Fe, 2+ Cu 2+ In addition to Cl and Ge, it also contains at least Fe. 3+ As, In and SiO2.

[0009] Further preferably, the multi-component sulfate solution contains 70-120 g / L Zn and 1 g / L Cu. 2+ 800–2800 mg / L, containing 500–1400 mg / L of As, 500–1000 mg / L of Cl, and Fe. 2+ 20–45 g / L, containing Fe 3+ 0.5~1.5g / L, containing H2SO4 10~50g / L, containing Ge 10~50mg / L, containing In 10~60mg / L, containing SiO2 500~2000mg / L.

[0010] Preferably, the replacement filtrate contains Cu 2+ 10–50 mg / L.

[0011] Preferably, the indium-germanium precipitate filtrate contains Ge ≤ 0.5 mg / L.

[0012] Preferably, the neutralizing agent is zinc oxide.

[0013] More preferably, the zinc oxide is zinc roasted ore and / or zinc oxide powder.

[0014] Beneficial effects of the invention: This invention achieves the direct separation of copper and germanium in a multi-component sulfate solution by reducing the sulfuric acid content and controlling the amount of iron powder added. During the iron powder replacement process, copper and some arsenic are replaced to obtain copper-arsenic slag, and less than 3% of germanium will enter the copper-arsenic slag. This directly achieves the separation of copper and germanium in the multi-component sulfate solution, greatly shortening the copper-germanium separation process, and with low reagent consumption and low energy consumption.

[0015] The method of this invention can achieve copper and germanium separation in one step with more than 98% copper and less than 3% germanium entering copper-arsenic slag, and the separation is thorough. This effectively solves the problems of the long copper-germanium separation process and poor copper-germanium separation in multi-component sulfates in the prior art. Detailed Implementation

[0016] 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.

[0017] In the description of this invention, it should be understood that the weights of the relevant components mentioned in the embodiments of this invention can refer not only to the specific content of each component, but also to the proportional relationship between the weights of the components. Therefore, any scaling up or down of the content of the relevant components according to the embodiments of this invention is within the scope of this invention. Specifically, the weights mentioned in the embodiments of this invention can be well-known mass units in the metallurgical / chemical fields such as g, kg, and t, and the volume units can be mL, L, and m. 3 Units of volume commonly known in the metallurgical / chemical fields.

[0018] The operation methods involved in the embodiments of the present invention can be intermittent or continuous. That is, the neutralization / displacement can be intermittent, followed by material discharge, or the neutralization / displacement and continuous material discharge can be continuous.

[0019] The example includes the following steps: Step S100: The sulfuric acid content in the multi-component sulfate solution is reduced by a neutralizing agent, and a low-acid multi-component sulfate solution is obtained by liquid-solid separation.

[0020] In the example, the multi-component sulfate solution contains Zn, H2SO4, and Fe. 2+ Cu 2+ In addition to Cl and Ge, it also contains at least Fe. 3+ As, In and SiO2.

[0021] Specifically, the multi-component sulfate solution contains 70–120 g / L of Zn and 1 g / L of Cu. 2+ 800–2800 mg / L, containing As 500–1400 mg / L, containing Cl 500–1000 mg / L, containing Fe 2+ 20–45 g / L, containing Fe 3+0.5~1.5g / L, containing H2SO4 10~50g / L, containing Ge 10~50mg / L, containing In 10~60mg / L, containing SiO2 500~2000mg / L.

[0022] Compared with the sulfate solution in the prior art (CN120555735A), the sulfate solution in this application also contains Fe. 3+ Sulfate solutions contain components such as Cu, As, In, and SiO2, making their composition more complex. During iron powder replacement, the multi-component sulfate solution contains only Cu... 2+ In addition to the reaction between Ge and iron powder, Fe 3+ It will undergo a disproportionation reaction with iron powder, and some of the As in the solution will... 3+ Convergence Cu 2+ It can also react with iron powder to form AsCu3 precipitate. Therefore, the reaction of iron powder displacing multi-component sulfate solution is numerous and complex.

[0023] The inventors of this application used the process conditions of the prior art (CN120555735A) to directly replace the multi-component sulfate solution with iron powder, and the results are shown in Table 1.

[0024] Table 1. Germanium incorporation into copper-arsenic slag when iron powder directly replaces multi-component sulfate solution. As shown in Table 1, even with a slight addition of iron powder, the germanium infiltration rate into the copper-arsenic slag under the existing technological conditions is as high as 16-30%, indicating poor copper-germanium separation. The copper-arsenic slag contains only 0.08-0.10% chlorine, demonstrating that the multi-component sulfate solution lacks dechlorination capability even under the existing technological conditions. Based on the germanium infiltration rate into the copper-arsenic slag and the dechlorination results, the sulfuric acid content disclosed in the existing technology is not suitable for separating copper and germanium from multi-component sulfate solutions.

[0025] The inventors of this application used a neutralizing agent to reduce the sulfuric acid content in a multi-component sulfate solution before replacing it with iron powder, and the results are shown in Table 2.

[0026] Table 2. Results of iron powder displacement when reducing the acid content of multi-component sulfate solution As shown in Table 2, reducing the sulfuric acid content in the multi-component sulfate solution drastically decreased the rate of germanium loss into copper and arsenic slag during iron powder replacement. When the sulfuric acid content in the multi-component sulfate solution reached 9 g / L, the germanium loss rate increased significantly. Therefore, the sulfuric acid content in the multi-component sulfate solution was reduced to 2–8 g / L. However, the copper replacement rate remained low, indicating that the amount of iron powder added in the existing technology was also unsuitable for replacing Cu in the multi-component sulfate solution. 2+ .

[0027] In some embodiments, a neutralizing agent is used to reduce the sulfuric acid content in a multi-component sulfate solution. The neutralizing agent is zinc oxide, specifically zinc roasted ore, and / or zinc oxide powder. In the example, under conditions of 70–80°C and 0.5–1.0 h, a neutralizing agent was added to reduce the sulfuric acid content in the multi-component sulfate solution from 10–50 g / L to 2–8 g / L. The slurry was then subjected to liquid-solid separation using conventional methods to obtain a low-acid multi-component sulfate solution.

[0028] In step S200, iron powder is added to a low-acid multi-component sulfate solution, and copper-arsenic slag and displacement filtrate are obtained through liquid-solid separation.

[0029] The inventors used a multi-component sulfate solution with the sulfuric acid content reduced to 5 g / L to re-explore the amount of iron powder to add, and the results are shown in Table 3.

[0030] Table 3. Re-exploration of iron powder addition, germanium addition to copper arsenic slag, and copper replacement rate. The results in Table 3 show that, according to Cu 2+ +Fe 3+ When iron powder is added at 1.1 to 1.3 times the theoretical reaction amount, the copper replacement rate is 98.06 to 98.53%, and the germanium content in the copper-arsenic slag is 1.79 to 2.78%. When the amount of iron powder is less than 1.1 times, the copper replacement rate decreases, and when the amount of iron powder is greater than 1.3 times, the germanium content in the copper-arsenic slag increases sharply. By pressing Cu 2+ +Fe 3+ Theoretically, adding iron powder causes copper and some arsenic to be replaced in copper-arsenic slag, while only a small amount of germanium enters the slag, thus achieving direct separation of copper and germanium. When the amount of iron powder added is less than 1.1 times the copper-arsenic slag, the rate of germanium entering the slag is lower, but the copper replacement rate decreases. When the amount of iron powder added is greater than 1.3 times the copper-arsenic slag, the copper replacement rate increases, but this causes a sharp increase in the rate of germanium entering the slag. Therefore, the optimal amount of iron powder added is Cu. 2+ +Fe 3+ The optimal reaction rate is 1.1 to 1.3 times the theoretical reaction rate.

[0031] In the example, the iron powder is of industrial grade, and the amount of iron powder added is equal to the Cu content in the low-acid multi-component sulfate solution. 2+ +Fe 3+ 1.1 to 1.3 times the theoretical reaction amount.

[0032] In the example, iron powder was added and reacted for 0.5 to 1.0 h at a temperature of 60–80 °C; the slurry was separated into liquid and solid phases using conventional methods to obtain copper-arsenic slag and displacement filtrate.

[0033] In some embodiments, the replacement filtrate contains Cu 2+10–50 mg / L.

[0034] In step S300, the replacement filtrate is precipitated with indium and germanium using conventional methods, followed by liquid-solid separation to obtain an indium and germanium-enriched product and an indium and germanium-precipitated filtrate. The indium and germanium-precipitated filtrate contains Ge ≤ 0.5 mg / L.

[0035] Through the above implementation steps, germanium and copper in the multi-component sulfate solution are separated into copper-arsenic slag and indium-germanium concentrate, with the germanium incorporation rate into the copper-arsenic slag being less than 3%, thereby achieving direct separation of germanium and copper in the multi-component sulfate solution.

[0036] To illustrate the present invention more clearly, the following embodiments are provided for detailed explanation.

[0037] Example 1 The multi-component sulfate solution used contains 70 g / L Zn and 1 g / L Cu. 2+ 2800 mg / L, containing As 1400 mg / L, containing Cl 1000 mg / L, containing Fe 2+ 20g / L, containing Fe 3+ 0.5 g / L, containing 50 g / L H2SO4, 50 mg / L Ge, 60 mg / L In, and 500 mg / L SiO2.

[0038] Zinc oxide powder was added to a multi-component sulfate solution to adjust the sulfuric acid content. The temperature was 70℃, and the time was 1.0 h. After liquid-solid separation, a low-acid multi-component sulfate solution with a sulfuric acid content of 2.1 g / L was obtained. Iron powder was added to 2000 mL of the low-acid multi-component sulfate solution. The amount of iron powder added was equal to the Cu content in the multi-component sulfate solution. 2+ +Fe 3+ The reaction volume was 1.1 times the theoretical reaction amount. At 60℃, the reaction time was 1.0 h. After liquid-solid separation, a volume of 1980 mL containing Cu was obtained. 2+ The displacement filtrate and copper-arsenic slag contained 49 mg / L. Indium and germanium were precipitated from 1950 mL of the displacement filtrate using conventional methods, followed by liquid-solid separation to obtain an indium-germanium enrichment and a filtrate containing 0.46 mg / L of germanium. The dry weight of the copper slag was 9.2 g, containing 0.0312 wt% Ge. The germanium incorporation rate into the copper-arsenic slag was 2.87% (based on the germanium content of the copper-arsenic slag), and the copper displacement rate was 98.27% (based on the copper content of the displacement filtrate).

[0039] Example 2 The multi-component sulfate solution used contained 120 g / L of Zn and 120 g / L of Cu. 2+ 800 mg / L, contains As 500 mg / L, contains Cl 500 mg / L, contains Fe 2+ 45g / L, containing Fe 3+1.5 g / L, containing 10 g / L H2SO4, 10 mg / L Ge, 10 mg / L In, and 2000 mg / L SiO2.

[0040] Zinc roasted ore was added to a multi-component sulfate solution to adjust the sulfuric acid content. The temperature was 80℃ and the time was 0.5 h. After liquid-solid separation, a low-acid multi-component sulfate solution with a sulfuric acid content of 7.9 g / L was obtained. Iron powder was added to 4000 mL of the low-acid multi-component sulfate solution. The amount of iron powder added was equal to the Cu content in the multi-component sulfate solution. 2+ +Fe 3+ The reaction volume was 1.3 times the theoretical reaction amount. At 80℃, the reaction time was 0.5 hours. After liquid-solid separation, a volume of 3970 mL containing Cu was obtained. 2+ The displacement filtrate and copper-arsenic slag contained 12 mg / L. Indium and germanium were precipitated from 3950 mL of the displacement filtrate using conventional methods, followed by liquid-solid separation to obtain an indium-germanium enrichment and a filtrate containing 0.16 mg / L of germanium. The dry weight of the copper slag was 5.3 g, containing 0.02186 wt% Ge. The germanium incorporation rate into the copper-arsenic slag was 2.90% (based on the germanium content of the copper-arsenic slag), and the copper displacement rate was 98.51% (based on the copper content of the displacement filtrate).

[0041] Comparative Example 1 The multi-component sulfate solution from Example 1 was used.

[0042] Take 2000 mL of the untreated multi-component sulfate solution and add iron powder. The amount of iron powder added is equal to the Cu content in the multi-component sulfate solution. 2+ +Fe 3+ The reaction volume was 1.1 times the theoretical reaction amount. At 60℃, the reaction time was 1.0 h. After liquid-solid separation, a volume of 1970 mL containing Cu was obtained. 2+ The displacement filtrate and copper-arsenic slag were 47 mg / L. The dry weight of the copper slag was 9.2 g, containing 0.4863 wt% Ge. The germanium content in the copper-arsenic slag was 44.74% (based on the germanium content of the copper-arsenic slag), and the copper displacement rate was 98.35% (based on the copper content of the displacement filtrate).

[0043] Comparative Example 2 The multi-component sulfate solution from Example 1 was used.

[0044] Take 2000 mL of the untreated multi-component sulfate solution and add iron powder. The amount of iron powder added is equal to the Cu content in the multi-component sulfate solution. 2+ The reaction volume was 0.85 times the theoretical reaction amount. At 60℃, the reaction time was 1.0 h. After liquid-solid separation, a volume of 1960 mL containing Cu was obtained. 2+ The displacement filtrate and copper-arsenic slag were 1096 mg / L. The dry weight of the copper slag was 5.7 g, containing 0.5106 wt% Ge. The germanium content in the copper-arsenic slag was 29.10% (based on the germanium content of the copper-arsenic slag), and the copper displacement rate was 61.64% (based on the copper content of the displacement filtrate).

[0045] Table 4 compares the effects of Examples 1-2 and Comparative Examples 1-2.

[0046] Table 4 Comparison of Results As shown in Table 4, in Examples 1 and 2, the sulfuric acid content in the multi-component sulfate solution was reduced to 2–8 g / L, and the amount of iron powder added was the same as that in the low-acid multi-component sulfate solution containing Cu. 2+ +Fe 3+ When the theoretical reaction amount is 1.1 to 1.3 times, the germanium-to-copper arsenic slag ratio is less than 3%, the copper replacement rate is greater than 98%, and the copper-germanium separation is complete; in Comparative Example 1, the sulfuric acid content in the multi-component sulfate solution is 50 g / L, and the amount of iron powder added is the same as that in the low-acid multi-component sulfate solution containing Cu. 2+ +Fe 3+ At 1.1 times the theoretical reaction amount, the germanium-to-copper-arsenic slag ratio was 44.74%. Although the copper replacement rate was greater than 98%, the high germanium-to-copper-arsenic slag ratio indicated thorough copper-germanium separation. In Comparative Example 2, the multi-component sulfate solution contained 50 g / L of sulfuric acid, and the amount of iron powder added was the same as that in the low-acid multi-component sulfate solution containing Cu. 2+ At 0.85 times the theoretical reaction amount, the germanium incorporation rate into the copper-arsenic slag was 29.10%, and the copper replacement rate was 61.64%. Not only was the germanium incorporation rate into the copper-arsenic slag high, but the separation of copper and germanium was incomplete, and the copper replacement rate was also low. A comparison of Examples 1 and 2 with Comparative Examples 1 and 2 shows that the process parameters in the prior art (CN120555735A) are not suitable for separating copper and germanium from a multi-component sulfate solution.

[0047] In the description of this specification, references to terms such as "some embodiments" or "examples" indicate that a specific feature or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. The illustrative expressions of the above terms in this specification do not necessarily refer to the same embodiment or example. Furthermore, the specific features or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and / or combine the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0048] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A method for separating copper and germanium from a multi-component sulfate solution, characterized in that, Includes the following steps: The sulfuric acid content in the multi-component sulfate solution was reduced by a neutralizing agent, and a low-acid multi-component sulfate solution was obtained by liquid-solid separation. Excess iron powder was added to a low-acid, multi-component sulfate solution, and copper-arsenic slag and displacement filtrate were obtained by liquid-solid separation. The indium-germanium precipitate was obtained by displacing the filtrate and then subjected to liquid-solid separation to obtain an indium-germanium enrichment and an indium-germanium precipitate filtrate.

2. The method according to claim 1, characterized in that, The sulfuric acid content of the low-acid multi-component sulfate solution is 2-8 g / L.

3. The method according to claim 1, characterized in that, The excess iron powder mentioned refers to the amount of iron powder added to the Cu in a low-acid, multi-component sulfate solution. 2+ +Fe 3+ 1.1 to 1.3 times the theoretical reaction amount.

4. The method according to claim 1, characterized in that, The multi-component sulfate solution contains Zn, H2SO4, and Fe. 2+ Cu 2+ In addition to Cl and Ge, it also contains at least Fe. 3+ As, In and SiO2.

5. The method according to claim 1 or 4, characterized in that, The multi-component sulfate solution contains 70–120 g / L Zn and 1 g / L Cu. 2+ 800–2800 mg / L, containing As 500–1400 mg / L, containing Cl 500–1000 mg / L, containing Fe 2+ 20–45 g / L, containing Fe 3+ 0.5~1.5g / L, containing H2SO4 10~50g / L, containing Ge 10~50mg / L, containing In 10~60mg / L, containing SiO2 500~2000mg / L.

6. The method according to claim 1, characterized in that, The replacement filtrate contains Cu 2+ 10–50 mg / L.

7. The method according to claim 1, characterized in that, The indium-germanium precipitate filtrate contains Ge ≤ 0.5 mg / L.

8. The method according to claim 1, characterized in that, The neutralizing agent is zinc oxide.

9. The method according to claim 1 or 8, characterized in that, The zinc oxide is zinc roasted ore and / or zinc oxide powder.

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