Method for comprehensively recovering valuable metals from antimony-based adsorbent purified liquid

Abstract

The invention provides a method for comprehensively recovering valuable metals from liquid purified by an antimony-based adsorbent, and belongs to the field of hydrometallurgy. The method comprises the following steps: (1) primary electrodeposition copper removal; (2) primary purification and impurity removal; (3) secondary electrodeposition copper removal; (4) secondary purification and impurity removal; (5) diffusion dialysis; (6) neutralizing to remove iron; (7) nickel precipitation by oxalic acid; and (8) roasting to obtain the high-purity nickel oxide powder. The treated object is the copper electrolyte subjected to purification and impurity removal through the antimony-based adsorbent, and the content of arsenic, antimony and bismuth impurities is remarkably reduced. By means of the method, it can be guaranteed that the quality of electric copper reaches the A-level copper standard, meanwhile, generation of highly toxic H3As gas is avoided, the comprehensive utilization efficiency of valuable metal resources in purified liquid is high, and the method is suitable for industrial application of copper electrolyte purification.

Description

Technical Field

[0001] The present invention belongs to the field of hydrometallurgy, and particularly relates to a method for comprehensively recovering valuable metals from the purified solution of an antimony-based adsorbent. Background Art

[0002] During the electrolytic refining process, some impurities in the copper anode plate dissolve with copper and enter the electrolyte. As the concentration of copper ions in the electrolyte continuously increases, impurity ions also accumulate in the electrolyte to a certain concentration, which may cause the composition of the electrolyte to deviate from the technical condition control range. At this time, artificial regulation is required to purify the electrolyte to ensure the quality of cathode copper.

[0003] At present, the main methods for purifying and removing impurities from copper electrolyte include electrodeposition for removing copper and arsenic, solvent extraction, ion exchange, chemical precipitation, and adsorption. Electrodeposition for removing copper and arsenic is a traditional electrolyte purification method. The electrolyte taken out of the circuit is periodically circulated through multiple copper-removing electrolytic cells, and impurities such as As, Sb, and Bi are also discharged and precipitated on the cathode together with Cu, so as to achieve the purpose of removing copper and arsenic from the electrolyte. Due to different electrolysis methods, it is divided into intermittent copper-removing method, periodic reverse current electrolysis method, limiting current density method, continuous induced copper-removing and arsenic-removing electrowinning method, controlled cathode potential electrowinning method, and cyclone electrowinning method. Among them, continuous induced copper-removing and arsenic-removing is a relatively widely used electrolyte purification method in industry at present. Other methods, namely auxiliary methods for purifying copper electrolyte, can only selectively remove one or two of the impurity elements of arsenic, antimony, and bismuth, and have problems such as long process flow, low impurity removal rate, and high production cost, such as extraction method and ion exchange method. Precipitation methods are used more frequently, including seed precipitation, addition of oxides for precipitation, alcohol precipitation, oxidation precipitation, cooling precipitation, hydrogen sulfide precipitation, and barium salt precipitation. Among them, the purification of copper electrolyte by adding antimony oxide, bismuth oxide, and arsenic oxide has been studied more, that is, by using the fact that As, Sb, and Bi in the solution can undergo a coprecipitation reaction under certain conditions to form precipitates with very low solubility and enter the anode slime, and it is integrated into the self-purification system. The self-purification technology has high impurity removal efficiency and low energy consumption, and has certain industrial application prospects.

[0004] CN110669932A (A method for comprehensive utilization of resources in copper electrolyte purification) discloses a method for comprehensive utilization of resources in copper electrolyte purification. After the copper electrolyte is purified and removed impurities by a promoter, diffusion dialysis is used to separate sulfuric acid and sulfates from the self-purified solution, and the method of adding alkali to precipitate iron, copper, and nickel step by step is adopted. However, the interference of impurity ion concentration in the purified solution is not considered, and the impurity content of the obtained product is relatively high. CN105603190A (A method for purifying and recovering valuable metals from copper electrolyte) discloses a method for purifying and recovering valuable metals from copper electrolyte. Arsenic sulfide slag is used to remove impurities from copper electrolyte, and copper is recovered in the form of copper sulfide, antimony in the form of antimony sulfide, arsenic in the form of arsenic oxide, bismuth in the form of bismuth oxychloride, and nickel in the form of nickel hydroxide. However, the adsorbent cannot be recycled, and the value of the obtained product is not high. CN110983376A (A copper electrolyte purification process) discloses a copper electrolyte purification process: including primary electrowinning to remove copper, secondary cyclone electrowinning to remove copper, sulfur dioxide pre-reduction, and sulfide precipitation method to remove arsenic and impurities. The content of valuable metals in the sulfide precipitation slag of this process is relatively high, and the maximum recovery of valuable metal resources cannot be achieved. CN109536992A (A method for purifying copper electrolyte by two-stage removal and two-stage electrodeposition) discloses a method for purifying copper electrolyte by two-stage removal and two-stage electrodeposition. This process adopts one-stage electrowinning, one-stage impurity removal, second-stage impurity removal, and second-stage electrowinning to recover copper. This process can ensure that the quality of electrode copper reaches the A-grade copper standard, but does not consider the treatment of impurity removal slag and the recovery of valuable metals such as nickel and iron.

[0005] In the traditional copper electrolyte purification process, a continuous induced copper and arsenic removal technology is adopted. When the copper ion concentration is reduced to less than 5 g / L, arsenic precipitates on the cathode in the form of H 3 As, which may endanger human health, deteriorate the production environment. The produced black copper plates and black copper mud are returned to the smelting system, resulting in low resource utilization rate and high energy consumption. Therefore, in this application, a stibium-based adsorbent is used for purification and impurity removal, which is coordinated in the self-purification system, and the removal rate of impurity ions is high. Among them, directly returning the purified solution to the copper electrolysis system may cause problems such as imbalance of copper and acid concentrations in the electrolysis system. In view of the above problems, this application proposes a method for comprehensively recovering valuable metals from the purified solution of the stibium-based adsorbent, which can ensure that the quality of electrolytic copper reaches the A-grade copper standard, and at the same time avoid the generation of highly toxic H 3 As gas, and the comprehensive utilization efficiency of valuable metal resources in the purified solution is high, which is suitable for industrial application of copper electrolyte purification. Summary of the Invention

[0006] The first object of the present invention is to provide a method that can effectively reduce the concentrations of arsenic, antimony, and bismuth impurity ions in the purified solution of the stibium-based adsorbent.

[0007] The second object of the present invention is to provide a method for improving the utilization rate of copper ion resources in the purified solution of the antimony-based adsorbent. The copper ion concentration after the first electrowinning is 2-5 g / L, and the copper ion concentration after the second electrowinning is 0.1-0.5 g / L;

[0008] The third object of the present invention is to provide a method for the value-added utilization of nickel resources in the purified solution of the antimony-based adsorbent.

[0009] To achieve the above object, the following technical solutions are adopted:

[0010] For the first object, "to provide a method for effectively reducing the concentration of arsenic ions in the purified solution of the antimony-based adsorbent", the arsenic, antimony, and bismuth ions in the copper electrolyte are removed by the sulfur dioxide reduction process coupled with the high-valent antimony-based compound, and the impurity ions are removed in the form of arsenic antimonate, bismuth antimonate, and antimony antimonate.

[0011] For the second object, "to provide a method for improving the utilization rate of copper ion resources in the purified solution of the antimony-based adsorbent". After the copper electrolyte is purified and decontaminated by the antimony-based adsorbent, the contents of arsenic, antimony, and bismuth are significantly reduced. The first electrowinning is used to remove copper, and the copper ion concentration in the solution after copper removal is 2-5 g / L. At this time, the concentration of impurity ions increases. The reduction process is coupled with the high-valent antimony-based compound for purification and decontamination, and the concentration of impurity ions is significantly reduced. Then, the second electrowinning is carried out to remove copper. The copper ion concentration in the solution after copper removal is 0.1-0.5 g / L.

[0012] For the third object, "to provide a method for the value-added utilization of nickel resources in the purified solution of the antimony-based adsorbent", after the second electrowinning of the copper electrolyte to remove copper, sodium sulfide is used for protective decontamination. After diffusion dialysis, the sulfate is obtained, and iron is removed by hydrolysis and neutralization, nickel is precipitated by oxalic acid, and high-purity nickel oxide powder can be obtained after oxidation roasting, realizing the value-added utilization of nickel resources.

[0013] For the above technical solutions, the details are as follows:

[0014] S1: Purification of copper electrolyte. Antimony oxide is added to the solution and stirred to form a colloidal solution, which is then added to the copper electrolyte for adsorption and impurity removal;

[0015] S2: Solid-liquid separation. After solid-liquid separation, the loaded adsorption residue is subjected to desorption and regeneration to obtain the purified solution for comprehensive recovery of valuable metals;

[0016] S3: First electrowinning. The purified solution is subjected to the first electrowinning to remove copper by using the direct current electrowinning technology;

[0017] S4: First impurity removal. The solution after the first copper removal is subjected to chemical impurity removal by using the reduction process coupled with the high-valent antimony-based compound;

[0018] S5: Second electrowinning. The first purification slag and the loaded adsorbent are used for the desorption unit, and the solution after impurity removal is subjected to the second electrowinning to remove copper.

[0019] S6: Secondary impurity removal. Sodium sulfide is added to the solution after secondary copper removal for protective impurity removal, and the secondary purification slag is obtained and returned to the smelting system.

[0020] S7: Diffusion dialysis. The secondary purified solution undergoes diffusion dialysis to obtain sulfuric acid and sulfates. The sulfuric acid is returned to the electrolysis system, and the sulfates are used for subsequent purification and impurity removal.

[0021] S8: Neutralization for iron removal. The sulfates are hydrolyzed and adjusted with alkali for iron removal to obtain iron hydroxide precipitate.

[0022] S9: Nickel precipitation with oxalate. Oxalate is added to the solution after iron removal to precipitate nickel, and solid nickel oxalate precipitate is obtained.

[0023] S10: Oxidative roasting. The nickel oxalate is washed, dried, and then subjected to oxidative roasting to obtain high-purity nickel oxide powder.

[0024] Optionally: In the antimony oxide described in step S1, the mass ratio of Sb 2 O 5 to Sb 2 O 3 is 0 - 0.1:1, the molar ratio of arsenic ion concentration to antimony-based compound is 1:0.6 - 1, the adsorption temperature is 30 - 80°C, the time is 15 - 120 min, and the rotation speed is 100 - 500 rpm.

[0025] Optionally: For the electrolytic copper removal described in step S3, the electrolysis temperature is 50 - 80°C, the current density is 240 - 280 A / m 2 , the electrolysis time is 5 - 60 min, and the copper ion concentration in the solution after copper removal is 2 - 5 g / L.

[0026] Optionally: For the primary impurity removal described in step S4, the reducing agent includes one or more of SO 2 , sodium sulfite, sodium bisulfite, potassium bisulfite, potassium sulfite, ammonium sulfite; the high-valent antimony oxides include one or more of sodium antimonate, potassium antimonate, sodium antimonate; the molar ratio of antimony in the high-valent antimony oxide to arsenic in the solution should be between 0.8 - 1.

[0027] Optionally: For the electrolytic copper removal described in step S5, the electrolysis temperature is 50 - 80°C, the current density is 210 - 240 A / m 2 , the electrolysis time is 5 - 60 min, and the copper ion concentration in the solution after copper removal is 0.1 - 0.5 g / L.

[0028] Optionally: For the secondary impurity removal described in step S6, the impurity removal agent includes one or more of sodium sulfide, potassium sulfide, ammonium sulfide.

[0029] Optionally, for the neutralization and iron removal in step S8, the alkaline substance includes one or more of sodium hydroxide, potassium hydroxide, sodium carbonate, and potassium carbonate, and the pH of the solution ranges from 2.7 to 8;

[0030] Optionally, for the nickel precipitation with oxalic acid in step S9, the precipitant includes one or more of sodium oxalate, potassium oxalate, and ammonium oxalate, the alkaline substance includes one or more of sodium hydroxide, potassium hydroxide, and ammonium hydroxide, and the pH of the solution ranges from 8 to 14;

[0031] Optionally, for the oxidative roasting in step S10, the roasting temperature is 300 - 600 °C and the roasting time is 30 - 120 min;

[0032] The beneficial effects of the present invention are as follows: This application can ensure that the quality of electrolytic copper meets the A - grade copper standard, while avoiding the generation of highly toxic H 3 As gas. The comprehensive utilization efficiency of valuable metal resources in the purified solution is high, making it suitable for industrial applications in the purification of copper electrolyte. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a process flow chart of a method for comprehensively recovering valuable metals from the purified solution of an antimony - based adsorbent provided by the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0034] To make the above - mentioned features and advantages of the present invention more obvious and understandable, specific embodiments are given below for detailed description. Unless otherwise specified, the methods of the present invention are all conventional methods in the art.

[0035] Example 1

[0036] Take 1 L of copper electrolytic refining electrolyte, with the molar ratio of Sb 2 O 5 to Sb 2 O 3 being 0.1:1, the molar ratio of arsenic ions to the antimony - based compound being 1:0.6, the adsorption temperature being 30 °C, the time being 15 min, and the rotation speed being 100 rpm; after the reaction, the loaded adsorbent is taken out for desorption and regeneration; the purified solution is subjected to primary electrowinning at an electrolysis temperature of 50 °C and a current density of 240 A / m 2 , and the electrolysis time being 5 min; sulfur dioxide is introduced into the electrowinning solution for a period of time, and then sodium antimonate is added for primary impurity removal. After impurity removal, the solution is subjected to secondary electrowinning for copper removal at an electrolysis temperature of 50 °C and a current density of 210 A / m 2 , and the electrolysis time being 10 min; for the solution after secondary copper removal, diffusion dialysis is carried out, iron is removed by hydrolysis of sulfates, nickel is precipitated with oxalic acid, and finally it is roasted at 300 °C for 30 minutes, and the roasted product is nickel oxide.

[0037] Table 1 The composition of the electrolyte used in Example 1 is as follows

[0038] Cu As Sb Bi <![CDATA[H 2 SO 4 > Before adsorption, g / L 24.5 12.4 0.42 0.52 182.5 After purification, g / L 25.2 4.16 0.14 0.08 181.3 After the first electrowinning, g / L 4.8 4.15 0.14 0.08 181.5 After the first impurity removal, g / L 4.8 1.12 0.08 0.03 181.5 After the second electrowinning, g / L 0.23 1.11 0.08 0.03 181.6 After the second impurity removal, g / L 0.01 0.01 0.01 0.01 181.3

[0039] Example 2

[0040] Take 1 L of copper electrolytic refining electrolyte, and the molar ratio of Sb 2 O 5 to Sb 2 O 3 is 0.05:1, the molar ratio of arsenic ion concentration to antimony-based compound is 1:0.8, the adsorption temperature is 50 °C, the time is 30 min, and the rotation speed is 300 rpm; after the reaction, the loaded adsorbent is taken out for desorption and regeneration; the purified solution is subjected to primary electrowinning, the electrolysis temperature is 60 °C, and the current density is 260 A / m 2 , the electrolysis time is 30 min; sulfur dioxide is introduced into the solution after electrowinning for a period of time, and then sodium antimonate is added for primary impurity removal. The solution after impurity removal is subjected to secondary electrowinning to remove copper, the electrolysis temperature is 60 °C, and the current density is 220 A / m 2 , the electrolysis time is 30 min; for the solution after secondary copper removal, diffusion dialysis is carried out, sulfate is used for iron removal by hydrolysis, nickel is precipitated by oxalic acid, and finally it is calcined at 400 °C for 120 minutes, and the calcined product is nickel oxide.

[0041] Table 2 The composition of the electrolyte used in Example 2 is as follows

[0042]

[0043]

[0044] Example 3

[0045] Take 1 L of copper electrolytic refining electrolyte, and the molar ratio of Sb 2 O 5 to Sb 2 O 3 is 0.01:1, the molar ratio of arsenic ion concentration to antimony-based compound is 1:1, the adsorption temperature is 80 °C, the time is 120 min, and the rotation speed is 400 rpm; after the reaction, the loaded adsorbent is taken out for desorption and regeneration; the purified solution is subjected to primary electrowinning, the electrolysis temperature is 50 °C, and the current density is 280 A / m 2 , the electrolysis time is 60 min; sulfur dioxide is introduced into the solution after electrowinning for a period of time, and then sodium antimonate is added for primary impurity removal. The solution after impurity removal is subjected to secondary electrowinning to remove copper, the electrolysis temperature is 80 °C, and the current density is 240 A / m 2 , the electrolysis time is 60 min; for the solution after secondary copper removal, diffusion dialysis is carried out, sulfate is used for iron removal by hydrolysis, nickel is precipitated by oxalic acid, and finally it is calcined at 500 °C for 60 minutes, and the calcined product is nickel oxide.

[0046] Table 3 The composition of the electrolyte used in Example 3 is as follows

[0047] Cu As Sb Bi <![CDATA[H 2 SO 4 > Before adsorption, g / L 24.5 12.4 0.42 0.52 182.5 After purification, g / L 24.6 3.12 0.10 0.05 181.1 After the first electrowinning, g / L 2.0 3.11 0.10 0.05 181.1 After the first impurity removal, g / L 2.0 0.06 0.09 0.02 181.2 After the second electrowinning, g / L 0.1 0.05 0.08 0.02 181.7 After the second impurity removal, g / L 0.01 0.01 0.01 0.01 181.3

[0048] Example 4

[0049] Take 1 L of copper electrolytic refining electrolyte, and make the molar ratio of Sb 2 O 5 to Sb 2 O 3 be 0:1, the molar ratio of arsenic ion concentration to antimony-based compound be 1:0.65, the adsorption temperature be 70 °C, the time be 60 min, and the rotation speed be 300 rpm; after the reaction ends, take out the loaded adsorbent for desorption and regeneration; the purified solution is subjected to primary electrowinning, the electrolysis temperature is 70 °C, and the current density is 250 A / m 2 , and the electrolysis time is 20 min; sulfur dioxide is introduced into the solution after electrowinning for a period of time, and then sodium antimonate is added for primary impurity removal. After impurity removal, the solution is subjected to secondary electrowinning to remove copper, the electrolysis temperature is 50 °C, and the current density is 230 A / m 2 , and the electrolysis time is 20 min; diffusion dialysis is carried out on the solution after secondary copper removal, iron is removed by hydrolysis of sulfate, nickel is precipitated by oxalic acid, and finally calcined at 600 °C for 90 minutes, and the calcined product is nickel oxide.

[0050] Table 4 The composition of the electrolyte used in Example 4 is as follows

[0051]

[0052]

[0053] For those skilled in the art, various corresponding changes and deformations can be given according to the above technical solutions and concepts, and all these changes and deformations should be included in the protection scope of the claims of the present invention.

Claims

1. A method for comprehensive recovery of valuable metals from liquid purified by an antimony-based adsorbent, characterized in that: The following steps are involved: S1: Copper electrolyte purification: adding antimony-based adsorbent into copper electrolyte for adsorption and impurity removal; S2: solid-liquid separation, loading adsorption residue for analytical regeneration, and the purified liquid is used for comprehensive recovery of valuable metals; S3: Primary electrowinning: DC electrowinning technology is used to perform primary electrowinning and copper removal on the purified liquid; S4: Primary impurity removal: chemical impurity removal is performed on the liquid after primary copper removal by using a reduction process coupled with a high-valent antimony-based compound; S5: Secondary electrowinning: The primary purification slag cooperates with the loaded adsorbent to carry out the analysis unit, and the impurity-removed liquid undergoes secondary electrowinning copper removal treatment; S6: Secondary impurity removal: Sodium sulfide is added to the secondary copper removal solution for protective impurity removal, and the secondary purified slag is returned to the smelting system; S7: Diffusion Dialysis: The secondary purified liquid is subjected to diffusion dialysis to obtain sulfuric acid and sulfate, wherein the sulfuric acid is returned to the electrolysis system and the sulfate is used for subsequent purification and impurity removal; S8: Neutralization and iron removal: The sulfate is hydrolyzed and alkali-adjusted to remove iron, and iron hydroxide precipitation is obtained; S9: Oxalic acid nickel precipitation: add oxalate to the de-iron solution to precipitate nickel to obtain solid nickel oxalate precipitate; S10: Oxidation roasting: The nickel oxalate is washed with water, dried, and then oxidized and roasted to obtain nickel oxide.

2. The method according to claim 1, characterized in that: In step S1, the mass ratio of Sb2O5 to Sb2O3 in the antimony-based adsorbent is 0-0.1:1, the molar ratio of arsenic ion concentration to antimony-based compound is 1:0.6-1, the adsorption temperature is 30-80 °C, the time is 15-120 min, and the rotation speed is 100-500 rpm.

3. The method according to claim 1, characterized in that: The electrolytic copper removal in step S3 is carried out at an electrolysis temperature of 50-80°C and a current density of 240-280 A / m 2 The electrolysis time is 5-60 min, and the copper ion concentration in the solution after decopperization is 2-5 g / L.

4. The method according to claim 1, characterized in that: In the primary impurity removal described in step S4, the reducing agent is at least one of SO2, sodium sulfite, sodium bisulfite, potassium bisulfite, potassium sulfite, and ammonium sulfite; the high-valent antimony oxide is at least one of sodium antimonate, potassium antimonate, and ammonium antimonate; and the molar ratio of antimony in the high-valent antimony oxide to arsenic in the solution is 0.8-1.

5. The method according to claim 1, characterized in that: The electrolytic copper removal in step S5 is carried out at an electrolysis temperature of 50-80°C and a current density of 210-240 A / m 2 The electrolysis time is 5-60 min, and the copper ion concentration in the solution after decopperization is 0.1-0.5 g / L.

6. The method according to claim 1, characterized in that: In the secondary impurity removal described in step S6, the impurity remover is at least one of sodium sulfide, potassium sulfide and ammonium sulfide.

7. The method according to claim 1, characterized in that: In the neutralization and iron removal in step S8, the alkaline substance is at least one of sodium hydroxide, potassium hydroxide, sodium carbonate and potassium carbonate, and the pH of the solution is 2.7-8.

8. The method according to claim 1, characterized in that: In the oxalic acid nickel precipitation described in step S9, the precipitant is at least one of sodium oxalate, potassium oxalate, and ammonium oxalate, the alkaline substance is at least one of sodium hydroxide, potassium hydroxide, and ammonium hydroxide, and the solution pH is 8-14.

9. The method according to claim 1, characterized in that: The oxidation roasting in step S10 has a roasting temperature of 300-600° C. and a roasting time of 30-120 min.

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