Method for comprehensively recovering copper, arsenic and nickel from copper sulfate crystallization mother liquor

Abstract

The invention aims to provide a method for comprehensively recovering copper, arsenic and nickel from copper sulfate crystallization mother liquor, which comprises the following steps: filtering the copper sulfate crystallization mother liquor to obtain clear crystallization mother liquor, adsorbing to adsorb most antimony and bismuth to obtain crystallization mother liquor with low antimony and bismuth content, regenerating resin to obtain an antimony and bismuth product, and recycling the copper, arsenic and nickel from the crystallization mother liquor. The crystallization mother liquor is continuously fed into a reduction tank, sulfur dioxide gas is introduced while stirring, an arsenic trioxide product and waste acid are obtained after the reaction is completed and centrifugal separation is conducted, the waste acid is fed into a membrane filtering device and filtered to obtain recycled acid and copper-nickel liquid, the copper-nickel liquid is fed into a primary neutralization procedure, caustic soda is added for a reaction, and copper-arsenic slag and nickel-rich liquid are generated; and feeding the nickel-rich liquid into a primary neutralization process, and adding caustic soda for reaction to generate a nickel product. By adopting the technical scheme, elements such as copper, arsenic, antimony, bismuth and the like in the crystallization mother liquor can be comprehensively recovered, and efficient utilization of resources is realized.

Description

Technical Field

[0001] The present invention belongs to the technical field of non-ferrous metal metallurgy, and particularly relates to a method for comprehensively recovering copper, arsenic and nickel from copper sulfate crystallization mother liquor. Background Art

[0002] Copper sulfate crystallization mother liquor is the residual liquid remaining after evaporation and concentration of the mixed leaching of cupric oxide beryllium, black copper mud and electrolytically produced crude copper sulfate crystals generated during copper smelting, and then production of refined copper sulfate crystals. The copper sulfate crystallization mother liquor is rich in valuable elements such as copper, arsenic and nickel, and has the value of comprehensive recovery. For the utilization research of copper sulfate crystallization mother liquor, the most studied domestic method is the stepwise neutralization method. After the first step of neutralization to produce copper arsenate, further neutralization is carried out to produce nickel hydroxide products.

[0003] The difficulty in treating by the stepwise neutralization method lies in that the main product produced by the recovery of arsenic and copper is copper arsenate, and the impurity content in copper arsenate is high. At present, it has no industrial use and can only be treated as hazardous waste, increasing the further treatment cost. If the crystallization mother liquor is directly reduced to produce arsenic trioxide products, the content of antimony and bismuth in the crystallization mother liquor is high, the arsenic trioxide products produced by reduction are fine in particles, difficult to dry, high in production risk, and high in impurities, and cannot meet the requirements of national standard qualified products. Summary of the Invention

[0004] The present invention discloses a method for comprehensively recovering copper, arsenic and nickel from copper sulfate crystallization mother liquor to solve the above and any potential problems in the prior art.

[0005] To achieve the above object, the technical solution provided by the present invention is: a method for comprehensively recovering copper, arsenic and nickel from copper sulfate crystallization mother liquor, which specifically includes the following steps:

[0006] S1) The copper sulfate crystallization mother liquor is sent to a precision filter for filtration to remove suspended impurities, and a clarified crystallization mother liquor is obtained;

[0007] S2) The clarified crystallization mother liquor obtained in S1) is sent to a resin adsorption device to adsorb most of the antimony and bismuth, and a crystallization mother liquor with low antimony and bismuth content is obtained. After adding an eluent for elution, the resin is regenerated to obtain antimony and bismuth products;

[0008] S3) The crystallization mother liquor with low antimony and bismuth content obtained in S2) is sent to a reduction tank, sulfur dioxide gas is introduced, and the appropriate flow rate and stirring speed are controlled. After centrifugal separation, arsenic trioxide products and waste acid are obtained;

[0009] S4) The waste acid obtained in S3) is sent to a membrane filtration device, and after filtration, recovered acid and copper-nickel solution are obtained;

[0010] S5) The copper-nickel solution obtained in S4) is sent to a primary neutralization process, and caustic soda is added for reaction to generate copper-arsenic slag and nickel-rich solution;

[0011] S6) Feed the nickel-rich solution obtained in S5) into the secondary neutralization process, add caustic soda for reaction to produce nickel products.

[0012] Furthermore, the arsenic content in the copper sulfate crystallization mother liquor in S1) is 40 - 120 g / l, the copper content is 30 - 50 g / l, the antimony content is 1.5 - 2.5 g / l, and the bismuth content is 0.2 - 1.0 g / l.

[0013] Among them, the precision filter is a plate and frame filter press, the filter cloth is made of polyester, and the specification is 200 - 250 mesh.

[0014] Furthermore, the resin adsorption device in S2) is an antimony and bismuth ion selective adsorption resin and can be reused by elution; the removal rate of antimony and bismuth in the crystallization mother liquor with low antimony and bismuth content is greater than 90% compared with that before adsorption.

[0015] Among them, the eluent is hydrochloric acid, and the antimony bismuth product contains more than 20% antimony and more than 15% bismuth.

[0016] Furthermore, the specific steps in S3) are as follows:

[0017] S3.1) Feed the crystallization mother liquor obtained in S2) into the reduction tank, and set the stirring speed at 50 - 100 rpm.

[0018] S3.2) Introduce smelting flue gas, after reacting for 8 - 14 h, disconnect the SO 2 inlet valve, introduce air for SO 2 removal for 30 min to obtain a mixed slurry, which is sent to a centrifuge. After solid-liquid separation, arsenic trioxide products and waste acid are obtained.

[0019] Furthermore, the smelting flue gas contains SO 2 with a concentration of 8 - 14%.

[0020] Among them, the mesh number of the centrifuge filter screen is 250 mesh.

[0021] Among them, the waste acid contains less than 20 g / l arsenic and the copper concentration is 30 - 50 g / l.

[0022] Furthermore, the membrane filtration device in S4) is an anion exchange membrane, and the acid is recovered by diffusion dialysis with a recovery rate greater than 60%.

[0023] Furthermore, the main components of the copper arsenic slag in S5) are copper arsenate and copper hydroxide, and the removal rate of copper and arsenic reaches more than 95%.

[0024] Among them, the pH range of the primary neutralization is 5 - 6.

[0025] Further, the nickel product in the step S6) is nickel hydroxide, and the recovery rate of nickel reaches more than 95%;

[0026] Among them, the pH range of the secondary neutralization is 8-11.

[0027] The beneficial effects of the present invention are as follows: Due to the adoption of the above technical solution, the recovery method of the present invention adopts the idea of removing antimony and bismuth impurities first and then recovering arsenic, avoiding the problems of fine particles and high impurities in the arsenic trioxide product. At the same time, before recovering copper and nickel, diffusion dialysis is carried out to recover part of the acid, reducing the usage amount of caustic soda and lowering the reagent cost. Since most of the arsenic is extracted first, the amount of copper-arsenic slag is greatly reduced, reducing the generation amount of hazardous waste and the increase in cost brought by the treatment of hazardous waste. The preparation method has the characteristics of short process and low production cost. The equipment used is all common leaching equipment and pressure filtration equipment in hydrometallurgy, and the reagents used are also common chemical reagents, realizing the recovery of copper, arsenic, and nickel, and the produced products arsenic and nickel products can be directly sold as finished products. The copper product can be further returned to the pyrometallurgical system for copper smelting recovery. Description of the Drawings

[0028] Figure 1 It is the process flow diagram of a method for comprehensively recovering copper, arsenic, and nickel from copper sulfate crystallization mother liquor of the present invention.

[0029] Figure 2 It is the resin adsorption principle diagram in the process of the present invention. Specific Embodiments

[0030] The technical solutions of the present invention will be described in detail below with reference to the drawings and specific embodiments.

[0031] As Figure 1 shown, a method for comprehensively recovering copper, arsenic, and nickel from copper sulfate crystallization mother liquor of the present invention specifically comprises the following steps:

[0032] Precision filtration: Feed the copper sulfate crystallization mother liquor into a plate and frame filter press, and use filter cloth with a mesh number of 325-400 meshes. After filtration, the removal rate of suspended particles reaches more than 99%.

[0033] Removing antimony and bismuth impurities: Feed the obtained clarified crystallization mother liquor into a resin adsorption device to adsorb most of the antimony and bismuth, obtain a crystallization mother liquor with low antimony and bismuth content, add an eluent for elution, and after the resin is regenerated, obtain an antimony and bismuth product;

[0034] Reducing and recovering arsenic: Feed the crystallization mother liquor obtained in the previous step into a reduction tank, set the stirring speed at 50-100 rpm; introduce smelting flue gas (containing SO 2 with a concentration of 8-14%), after reacting for 8-14 h, disconnect the SO 2 inlet valve, and introduce air for SO 2After stripping for 30 minutes, a mixed slurry is obtained and fed into a centrifuge (with a filter mesh of 250 meshes). After solid-liquid separation, arsenic trioxide product and waste acid are obtained. The quality of arsenic trioxide reaches the national standard qualified product standard. The waste acid contains less than 20 g / l of arsenic and the copper concentration is 30 - 50 g / l, as Figure 2 shown.

[0035] The reaction principle is as follows:

[0036] H 3 AsO 4 +SO 2 =HAsO 2 +H 2 SO 4

[0037] HAsO 2 =As 2 O 3 +H 2 O

[0038] Membrane filtration for acid recovery: The waste acid obtained in the previous step is fed into a membrane filtration device, where the membrane filtration device is an anion exchange membrane, and acid is recovered by diffusion dialysis with a recovery rate greater than 60%.

[0039] Primary neutralization for copper and arsenic recovery: The copper-nickel solution obtained in the previous step is fed into the primary neutralization process, caustic soda is added, and the end-point pH is controlled to be 5 - 6. Copper and arsenic react to form copper-arsenic slag, and the excess copper reacts with caustic soda to form copper hydroxide. The reaction principle is as follows:

[0040] Cu 2+ +2OH - →Cu(OH) 2 ↓

[0041] Secondary neutralization for nickel recovery: The nickel-rich solution obtained in the previous step is fed into the secondary neutralization process, caustic soda is added, and the end-point pH is controlled to be 8 - 11. Nickel reacts with caustic soda to form nickel hydroxide. The reaction principle is as follows:

[0042] Ni 2+ +2OH - →Ni(OH) 2 ↓

[0043] Example 1: The main components of the copper sulfate crystallization mother liquor are as follows in terms of concentration (g / l): Cu 48.65, As 90.98, Sb 2.32, Bi 0.37, Ni 28.60, acidity 172.6. After being fed into a precision filtration press filter, a clarified crystallization mother liquor is produced, and then it is fed into a resin adsorption device to produce a crystallization mother liquor with low antimony and bismuth content. The antimony and bismuth concentrations are as follows in terms of (g / l): Sb 0.21, Bi 0.02, and the antimony and bismuth removal rates are 90.9% and 94.6% respectively. Continuing to be fed into a reduction tank, SO2 The smelting flue gas with a concentration of 12.4% is stirred at a speed of 50 rpm for 12 h. After desorbing for 30 min at the end of reduction, the reduced solution is filtered to produce arsenic trioxide and waste acid. The main components of the waste acid are as follows (concentration in g / l): Cu 46.53, As 18.25, Ni 27.30, acidity 210.6. The recovery rate of arsenic is 80.0%. It is then sent to a membrane filtration device for acid recovery by diffusion dialysis, producing recovered acid and a copper-nickel solution. The main components of the copper-nickel solution are as follows (concentration in g / l): Cu 40.28, As 14.11, Ni 25.28, acidity 70.8. The acid recovery rate is 66.4%. The copper-nickel solution is then sent to a primary neutralization process, and caustic soda is added until the pH reaches 5.6, obtaining copper-arsenic slag and a nickel-rich solution. The main components of the nickel-rich solution are as follows (concentration in g / l): Cu 1.82, As 0.62, Ni 23.22. The recovery rate of copper is 95.5%, and the recovery rate of arsenic is 95.6%. The nickel-rich solution is sent to a secondary neutralization process, and caustic soda is added until the pH reaches 10.8, obtaining nickel products and residual liquid. The main component of the residual liquid is as follows (concentration in g / l): Ni 0.45. The recovery rate of nickel is 98.1%.

[0044] Example 2: The main components of the copper sulfate crystallization mother liquor are as follows (concentration in g / l): Cu 56.05, As 110.08, Sb 2.28, Bi 0.52, Ni 26.30, acidity 150.4. After being sent to a precision filtration press filter, a clarified crystallization mother liquor is produced, and then it is sent to a resin adsorption device, producing a crystallization mother liquor with low antimony and bismuth content. The concentrations of antimony and bismuth are as follows (in g / l): Sb 0.13, Bi 0.01. The removal rates of antimony and bismuth are 94.3% and 98.1% respectively. It is then sent to a reduction tank, and SO 2Smelting flue gas with a concentration of 13.8%, stirring speed of 50 rpm, reduction time of 14 h. After desorbing for 30 min at the end of reduction, the reduced solution is filtered to produce arsenic trioxide and waste acid. The main components of the waste acid are as follows in terms of concentration (g / l): Cu 54.13, As 19.36, Ni 25.22, acidity 208.1. The recovery rate of arsenic is 82.4%. It is then sent to a membrane filtration device for acid recovery by diffusion dialysis, producing recovered acid and a copper-nickel solution. The main components of the copper-nickel solution are as follows in terms of concentration (g / l): Cu 45.13, As 15.81, Ni 22.31, acidity 71.6. The acid recovery rate is 65.6%. The copper-nickel solution is sent to a primary neutralization process, and caustic soda is added until the pH reaches 5.9 to obtain copper-arsenic slag and a nickel-rich solution. The main components of the nickel-rich solution are as follows in terms of concentration (g / l): Cu 1.66, As 0.38, Ni 21.29. The recovery rate of copper is 96.3%, and the recovery rate of arsenic is 97.6%. The nickel-rich solution is sent to a secondary neutralization process, and caustic soda is added until the pH reaches 9.2 to obtain a nickel product and a residual solution. The main component of the residual solution is as follows in terms of concentration (g / l): Ni 0.95. The recovery rate of nickel is 95.5%.

[0045] The above has introduced in detail a method for comprehensively recovering copper, arsenic, and nickel from copper sulfate crystallization mother liquor provided by an embodiment of the present application. The description of the above embodiments is only used to help understand the method and its core idea of the present application; at the same time, for those of ordinary skill in the art, according to the idea of the present application, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present application.

[0046] As used in the specification and claims, certain terms are used to refer to specific components. Those skilled in the art should understand that hardware manufacturers may use different terms to refer to the same component. The specification and claims do not use the difference in names as a way to distinguish components, but use the difference in functions of components as the criterion for distinction. As mentioned throughout the specification and claims, "comprising" and "including" are open-ended terms and should be interpreted as "comprising / including but not limited to". "Substantially" means within an acceptable error range. Those skilled in the art can solve the technical problem within a certain error range and basically achieve the technical effect. The subsequent description in the specification is a preferred implementation manner for implementing the present application, but the description is for the purpose of explaining the general principle of the present application and is not used to limit the scope of the present application. The protection scope of the present application shall be determined by the scope defined by the appended claims.

[0047] It should also be noted that the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, such that a commodity or system comprising a series of elements not only includes those elements but also includes other elements not expressly listed, or elements inherent to such commodity or system. Without further limitation, an element defined by the statement "comprising an..." does not exclude the presence of additional identical elements in the commodity or system comprising said element.

[0048] It should be understood that the term "and / or" used herein is merely a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B may represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " herein generally represents an "or" relationship between the associated objects before and after.

[0049] The above description shows and describes several preferred embodiments of the present application. However, as mentioned above, it should be understood that the present application is not limited to the form disclosed herein, should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be changed within the scope of the application concept described herein through the above teachings or the technology or knowledge in the relevant field. And any changes and modifications made by those skilled in the art that do not depart from the spirit and scope of the present application shall fall within the protection scope of the appended claims of the present application.

Claims

1. A method for comprehensively recovering copper, arsenic and nickel from copper sulfate crystallization mother liquor, characterized in that: The method specifically comprises the following steps: S1) filtering the copper sulfate crystallization mother liquor to be treated to obtain a clarified crystallization mother liquor; S2) sending the clarified crystallization mother liquor obtained in S1) to a resin adsorption device for treatment to obtain a crystallization mother liquor with low antimony and bismuth content; S3) sending the low antimony-bismuth crystallization mother liquor obtained in S2) into a reduction tank, stirring it at a certain rate, and introducing smelting flue gas at a certain flow rate to carry out a reduction reaction, and after the reaction is completed, obtaining arsenic trioxide product and waste acid after centrifugal separation; S4) sending the spent acid obtained in S3) into a membrane filtration device to obtain recovered acid and copper-nickel solution after diffusion dialysis; S5) sending the copper-nickel solution obtained in S4) to a primary neutralization step, adding a certain amount of caustic soda to react, and generating copper-arsenic slag and nickel-rich solution; S6) sending the nickel-rich solution obtained in S5) to a secondary neutralization process, adding a certain amount of caustic soda to react and generate a nickel product.

2. The method according to claim 1, characterized in that: The copper sulfate crystallization mother liquor in said S1) has an arsenic concentration of 40-120 g / l, a copper concentration of 30-50 g / l, an antimony concentration of 1.5-2.5 g / l, and a bismuth concentration of 0.2-1.0 g / l; The filtration adopts a plate and frame filter press, and the filter cloth is made of polyester with a specification of 325-400 meshes.

3. The method according to claim 1, characterized in that The resin in the resin adsorption device in S2) is an antimony-bismuth ion selective adsorption resin; The eluent is hydrochloric acid, and the antimony-bismuth product contains more than 20% antimony and more than 15% bismuth.

4. The method according to claim 1, characterized in that: The specific steps in S3) are: S3.1) sending the crystallization mother liquor obtained in S2) into a reduction tank, and setting the stirring speed to 50-100 rpm; S3.2) Smelting flue gas is introduced, and after reaction for 8 to 14 hours, air is introduced to remove SO2 for 30 minutes to obtain a mixed slurry.

5. The method according to claim 4, characterized in that The SO2 concentration in the smelting flue gas is 8-14%; The centrifuge filter mesh is 250 mesh; The waste acid contains less than 20 g / l of arsenic and 30 to 50 g / l of copper.

6. The method according to claim 1, characterized in that The membrane filtration device in S4) is an anion exchange membrane, and the acid is recovered by diffusion dialysis, with a recovery rate greater than 60%.

7. The method according to claim 1, characterized in that The pH range of the primary neutralization in S5) is 5-6.

8. The method according to claim 1, characterized in that The pH range of the secondary neutralization in S6) is 8-11.

9. The method according to claim 1, characterized in that: The arsenic recovery rate of the method is not less than 80.0%, and the copper and nickel recovery rates are not less than 95.0%.

10. A nickel hydroxide, characterized in that The nickel hydroxide is prepared by the method according to any one of claims 1 to 8.

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