A process for separating copper and nickel from secondary nickel return material

Abstract

The invention discloses a process for separating copper and nickel from secondary nickel return materials, and relates to the technical field of hydrometallurgy. The process comprises the following steps: adding the secondary nickel return materials to an alkali solution for alkali leaching, filtering to obtain an alkali leaching solution and an alkali leaching residue; adding the alkali leaching residue to an acid solution for acid leaching, filtering to obtain an acid leaching solution and an acid leaching residue; adding the alkali leaching solution to the acid leaching solution, stirring for reaction, filtering to obtain a filter residue and a neutralization solution; injecting the neutralization solution into an adsorption device, performing desorption after adsorption to obtain a copper ion desorption solution and a nickel ion desorption solution, and performing electrodeposition operations respectively to obtain copper metal and nickel metal. The invention adopts the technical route of alkali leaching-acid leaching-neutralization-adsorption separation, selectively dissolving copper by alkali leaching, dissolving nickel by acid leaching, regulating pH in the neutralization process to realize impurity separation, and finally performing graded adsorption of copper and nickel ions by using a modified adsorbent.

Description

Technical Field

[0001] The invention relates to the technical field of hydrometallurgy, and in particular to a process for separating copper and nickel by secondary nickel return. Background Art

[0002] Secondary nickel returns usually refer to recyclable materials such as nickel-containing waste and scraps generated during the smelting and processing of nickel. These materials can be put back into production after proper treatment, which is an important way to recycle nickel resources. As an important source of secondary nickel returns, the treatment and recycling of copper smelting slag is of great significance.

[0003] Most nickel pyrometallurgical processes use nickel sulfide and other nickel-containing ores as raw materials. Since copper and nickel are commonly found in natural ores, it is necessary to separate the copper-nickel polymetallic ores through flotation to obtain nickel concentrate with a higher nickel content and copper concentrate with a higher copper content, which are then sent to the nickel pyrometallurgical system and copper pyrometallurgical system for smelting respectively.

[0004] In this process, a small amount of nickel still remains in the separated copper concentrate, which will be discharged in the form of slag during the copper smelting process to form copper smelting slag. This slag mainly includes Kaldor slag and self-heating furnace slag, which usually contains 35-40% copper and 14-16% nickel, as well as a small amount of iron and cobalt. Due to the high copper content, it cannot be directly sent to the nickel pyrometallurgical system for treatment; at the same time, it contains a large amount of nickel, which will cause serious loss of nickel if sent to the copper pyrometallurgical system for treatment.

[0005] This results in a large amount of slag being piled up, resulting in a huge waste of resources. At present, the methods for processing this type of secondary nickel return mainly include pyrometallurgy and hydrometallurgy. Although the pyrometallurgy process is relatively mature, it has problems such as high energy consumption, serious environmental pollution, and low metal recovery rate. Hydrometallurgy has gradually become a research hotspot due to its advantages such as low energy consumption, low pollution, and good selectivity.

[0006] CN113430386A discloses a method for enriching copper and nickel from secondary nickel return material of copper smelting slag, belonging to the technical field of hydrometallurgy, wherein the secondary nickel return material is a copper slag return material with Cu / Ni≤2:1 obtained by multi-stage crushing, fine grinding and sorting of copper smelting slag, and the secondary nickel return material is slurried in a sulfuric acid solution to obtain a slurry, and further pre-leached at normal pressure and leached under pressure to obtain a leachate enriched in nickel and copper.

[0007] The existing technology for separating and recovering copper and nickel from secondary nickel return materials of copper smelting slag has a low metal recovery rate, so there is an urgent need to provide a high-efficiency and high-yield secondary nickel return copper and nickel separation process. Summary of the invention

[0008] In order to solve the shortcomings of the prior art, the purpose of the present invention is to provide a process for separating copper and nickel from secondary nickel return materials, adopting an alkali leaching-acid leaching-neutralization-adsorption separation technical route, selectively dissolving copper by alkali leaching, dissolving nickel by acid leaching, and controlling the pH in the neutralization process to achieve impurity separation, and finally using a modified adsorbent for graded adsorption of copper and nickel ions.

[0009] In order to achieve the above object, the present invention adopts the following technical solution:

[0010] A process for separating copper and nickel from secondary nickel return material comprises the following steps:

[0011] (1) adding the secondary nickel return material into an alkali solution for alkali leaching, and filtering to obtain an alkali leaching solution and an alkali leaching residue;

[0012] Preferably, in step (1), the alkali solution is a 2-6 mol / L NaOH solution and / or a KOH solution, and the ratio of the secondary nickel return material to the alkali solution is 1 g: 10-20 mL; and the alkali leaching conditions are alkali leaching at 75-90° C. for 1-4 h.

[0013] Specifically, in step (1), the alkali solution can be 2, 3, 4, 5, 6 mol / L NaOH solution and / or KOH solution; the dosage ratio of the secondary nickel return material to the alkali solution can be 1 g: 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 mL; the alkali leaching temperature can be 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90°C; and the alkali leaching time can be 1, 2, 3, 4 h.

[0014] (2) adding the alkali leaching residue into acid solution for acid leaching, and filtering to obtain the acid leaching solution and acid leaching residue;

[0015] Preferably, in step (2), the acid solution is a mixture of 5-20wt% sulfuric acid and 10-30wt% hydrogen peroxide, the volume ratio of sulfuric acid to hydrogen peroxide is 90-95:10-5; the dosage ratio of alkaline leaching residue to acid solution is 1g:10-20mL; and the acid leaching conditions are acid leaching at 60-90°C for 1-4h.

[0016] Specifically, in step (2), the acid solution can be a mixture of 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 wt% sulfuric acid and 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30 wt% hydrogen peroxide; the volume ratio of sulfuric acid to hydrogen peroxide can be 90:10, 91:9, 92:8, 93:7, 94:6 , 95:5; the dosage ratio of alkaline leaching residue to acid solution can be 1g:10,11,12,13,14,15,16,17,18,19,20mL; the acid leaching temperature can be 60,61,62,63,64,65,66,67,68,69,70,71,72,73,74,75,76,77,78,79,80,81,82,83,84,85,86,87,88,89,90℃, and the acid leaching time can be 1,2,3,4h.

[0017] (3) adding the alkaline leaching solution to the acid leaching solution, stirring to react, and filtering to obtain a residue and a neutralized solution;

[0018] Preferably, in step (3), the stirring reaction condition is to stir the acid extract at 40-60° C., then slowly add the alkaline extract until the pH of the solution reaches 5.0, then stop adding, keep warm and stir for 20-40 minutes, and then filter.

[0019] Specifically, the acid extract can be stirred at 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60°C, and then the alkali extract can be slowly added to stop adding when the pH of the solution reaches 5.0, and the mixture can be kept warm and stirred for 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40 minutes and then filtered.

[0020] (4) The neutralized solution is injected into the adsorption equipment, and after the adsorption is completed, desorption is performed to obtain copper ion desorption solution and nickel ion desorption solution, which are then subjected to electrolysis operations to obtain copper metal and nickel metal respectively.

[0021] Preferably, in step (4), the adsorption is divided into three stages: the neutralization solution is injected into the adsorption device at 2-5 mL / min until the copper ion concentration in the effluent no longer decreases and then the process is stopped; the neutralization solution is injected into the adsorption device at 6-10 mL / min until the copper ion concentration in the effluent no longer decreases and then the process is stopped; the effluent from the first two stages is injected into the second adsorption column at 1-3 mL / min until the nickel ion concentration in the effluent no longer decreases and then the process is stopped.

[0022] Specifically, in step (4), the adsorption is divided into three stages: the neutralization solution can be injected into the adsorption device at 2, 2.5, 3, 3.5, 4, 4.5, 5 mL / min until the copper ion concentration in the outlet liquid no longer decreases and then the process is stopped; the neutralization solution can be injected into the adsorption device at 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, 10 mL / min until the copper ion concentration in the outlet liquid no longer decreases and then the process is stopped;

[0023] Preferably, in step (4), the desorption is performed by washing the first adsorption column and the second adsorption column with 5-30wt% sulfuric acid respectively; after the first adsorption column is desorbed, a copper ion desorption liquid and a modified adsorbent are obtained, and after the second adsorption column is desorbed, a nickel ion desorption liquid and a modified adsorbent are obtained.

[0024] Specifically, in step (4), desorption can be performed by washing the first adsorption column and the second adsorption column with 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, and 30 wt % sulfuric acid, respectively.

[0025] Preferably, in step (4), the adsorption device comprises a first adsorption column and a second adsorption column which are connected in sequence, and the first adsorption column and the second adsorption column are both filled with a modified adsorbent. The preparation method of the modified adsorbent comprises the following steps:

[0026] a. Add polyacrylamide to a methanol / water mixed solvent, stir to dissolve, then add glutaraldehyde aqueous solution and thiourea, adjust the pH, stir to react in the dark, dialyze, freeze and dry the product to obtain a light yellow intermediate;

[0027] Modification of polyacrylamide is achieved by aldehyde-amine condensation: polyacrylamide is dissolved in a methanol / water mixed solvent, glutaraldehyde is added to introduce active aldehyde groups, and thiourea is added to provide free amino groups. Under alkaline conditions, the aldehyde groups at both ends of the glutaraldehyde molecule react with the amino groups on the polyacrylamide and the amino groups on the thiourea molecule to form a C=N double bond, achieving cross-linking between molecules and grafting the thiourea group onto the polymer chain.

[0028] Preferably, in step a, the volume ratio of methanol to deionized water in the methanol / water mixed solvent is 10-20:90-80, the concentration of the glutaraldehyde aqueous solution is 20-30wt%; the dosage ratio of polyacrylamide, methanol / water mixed solvent, glutaraldehyde aqueous solution, and thiourea is 0.8-1.2g:100-150mL:0.5-2mL:0.3-0.6g.

[0029] Preferably, in step a, the pH is adjusted to 8.0-9.0; and the stirring reaction conditions are 40-55° C. and in the dark for 4-7 hours.

[0030] Preferably, in step a, the reaction solution is transferred into a dialysis bag with a molecular weight cutoff of 3500Da, dialyzed with deionized water for 36 to 72 hours, the dialysate is replaced every 6 to 12 hours, and the dialyzed solution is freeze-dried to obtain a light yellow solid intermediate.

[0031] b. Disperse the intermediate in a DMF / water mixed solvent, stir to swell, add a DMF solution of tetrakis(4-carboxyphenyl)porphine, mix evenly, add EDC and NHS, and then add PBS buffer, stir to react in the dark, precipitate the product, centrifuge, wash, and dry to obtain a modified adsorbent.

[0032] Amidation is used to connect porphine molecules: the cross-linked intermediate is swollen in a DMF / water mixed solvent to fully expand its network structure and expose the reactive amino sites. A DMF solution of tetrakis(4-carboxyphenyl)porphine is added, and the EDC / NHS system is introduced. In this system, EDC first reacts with the carboxyl group on the porphine to form an unstable O-acylurea intermediate, and NHS then attacks the intermediate to form an active ester. Finally, the amino group on the intermediate attacks the carbonyl carbon atom of the active ester to form a stable amide bond (-CO-NH-) through a nucleophilic substitution reaction.

[0033] Preferably, in step b, the volume ratio of DMF and deionized water in the DMF / water mixed solvent is 1:1-2; the concentration of tetrakis(4-carboxyphenyl)porphine in the DMF solution of tetrakis(4-carboxyphenyl)porphine is 0.1 g / 10-15 mL; the pH of the PBS buffer is 7.2-7.4; the dosage ratio of the intermediate, the DMF / water mixed solvent, the DMF solution of tetrakis(4-carboxyphenyl)porphine, EDC, NHS, and the PBS buffer is 0.8-1.2 g: 60-90 mL: 20-30 mL: 0.4-0.6 g: 0.2-0.3 g: 15-25 mL.

[0034] Preferably, in step b, the stirring and swelling conditions are stirring at room temperature for 2 to 3 hours; and the light-proof stirring reaction conditions are stirring at 20 to 25° C. for 20 to 28 hours.

[0035] Preferably, in step b, the reaction solution is added to deionized water to precipitate the product, the precipitate is collected by centrifugation, the precipitate is washed with deionized water and methanol for 2 to 3 times in sequence, and vacuum dried to obtain a modified adsorbent.

[0036] Compared with the prior art, the present invention has the following beneficial effects:

[0037] 1. The present invention provides a secondary nickel return material sorting process, which adopts the technical route of alkali leaching-acid leaching-neutralization-adsorption separation, selectively dissolves copper by alkali leaching, dissolves nickel by acid leaching, and separates impurities by regulating pH during the neutralization process. Finally, the modified adsorbent is used for graded adsorption of copper and nickel ions. The process flow is simple, the operating conditions are mild, and the separation efficiency is high. The three-stage adsorption mode is innovatively designed: first, a low flow rate operation is adopted to make the solution fully contact with the adsorbent, ensuring that the copper ions can fully interact with the coordination sites on the surface of the adsorbent to achieve high selective adsorption; in the second stage, the flow rate is increased, and the strong binding effect between copper ions and adsorbent is utilized to promote the newly adsorbed copper ions to gradually replace the adsorbed nickel ions until the nickel ions on the first adsorption column are completely replaced; finally, the nickel-containing effluent is passed through the second adsorption column at a low flow rate to ensure that the nickel ions are fully in contact with the fresh adsorbent to achieve deep separation. This flow rate gradient control based on ion exchange kinetics, combined with the design of double columns in series, makes full use of the selectivity difference of the modified adsorbent for copper and nickel ions, and the final product has high purity and is suitable for industrial application.

[0038] 2. The present invention provides a method for preparing a modified adsorbent, firstly, glutaraldehyde is used to react with polyacrylamide and thiourea to form a cross-linked network with a -CS-NH- structure; then, tetrakis(4-carboxyphenyl)porphine is connected to the network structure through an amide bond through an EDC / NHS activation system. The synthetic route has mild reaction conditions, controllable steps, and a stable product structure.

[0039] 3. The present invention provides a modified adsorbent having multiple synergistic adsorption mechanisms: first, the -NH 2 The active groups can form stable chelates with metal ions through coordination, and show good adsorption sensitivity even under low concentration conditions. Secondly, the sulfur atom in the thiourea group (-CS-NH-) introduced by the Schiff base reaction has unique soft base properties. According to the theory of hard and soft acids and bases, it reacts with Cu, which has soft acid properties. 2+ There is a strong coordination tendency between ions, and Ni 2+The interaction between the porphyrin ring and the copper ion is relatively weak, thereby achieving preferential selective adsorption of copper ions. The second key component of the modified adsorbent is the porphyrin macrocyclic structure, which enhances the adsorption capacity of metal ions through multiple action mechanisms: the N atom on the porphyrin ring can form a coordination bond with the metal ion; the large π conjugated system provides an electrostatic adsorption site; and the four phenyl substituents and carboxyl functional groups of the porphyrin ring provide additional binding sites. This multiple action not only improves the adsorption capacity, but also accelerates the adsorption kinetics. It is particularly noteworthy that the modified adsorbent has unique structural flexibility: the π conjugated system of the porphyrin macrocyclic ring has a certain conformational variability, the rotational freedom between the substituents and the variability of the coordination effect, so that the entire adsorption system forms an open flexible network structure. This structural feature can dynamically adjust the spatial orientation of the adsorption site, increase the contact opportunity between the metal ion and the active site, and thus significantly improve the adsorption efficiency and selectivity. This "flexible capture" mechanism is an important guarantee for the excellent performance of the modified adsorbent of the present invention. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical solution and advantages of the present invention clearer, the present invention is further described in detail below in conjunction with embodiments. Of course, the specific embodiments described here are only used to explain the present invention and are not used to limit the present invention.

[0041] Unless otherwise specified, the chemical reagents and materials in the present invention are purchased from commercial sources or synthesized from raw materials purchased from commercial sources.

[0042] Polyacrylamide with a weight average molecular weight of 200,000 to 1,000,000 was purchased from Nanjing Xianglingde Chemical Co., Ltd.

[0043] The secondary nickel return material is copper smelting slag containing copper and nickel, and its typical composition is: Ni: 16.37%, Cu: 38.23%, Fe: 4.47%, Co: 0.16%, which is crushed to 5~20mm.

[0044] A process for separating copper and nickel from secondary nickel return material comprises the following steps:

[0045] (1) Add 0.8-1.2 g of polyacrylamide to 100-150 mL of a methanol / water mixed solvent (the volume ratio of methanol to deionized water is 10-20:90-80), stir to dissolve, then add 0.5-2 mL of a 20-30 wt% glutaraldehyde aqueous solution and 0.3-0.6 g of thiourea, adjust the pH to 8.0-9.0, stir and react at 40-55 °C in the dark for 4-7 h, transfer the reaction solution into a dialysis bag with a molecular weight cutoff of 3500 Da, dialyze with deionized water for 36-72 h, replace the dialyzate every 6-12 h, and freeze-dry the dialyzed solution to obtain a light yellow solid intermediate;

[0046] (2) Disperse 0.8-1.2 g of the intermediate in 60-90 mL of a DMF / water mixed solvent (the volume ratio of DMF to deionized water is 1:1-2), stir and swell at room temperature for 2-3 h, add 20-30 mL of a DMF solution of tetrakis(4-carboxyphenyl)porphine (the concentration of tetrakis(4-carboxyphenyl)porphine is 0.1 g / 10-15 mL), mix well, add 0.4-0.6 g of EDC and 0.2-0.3 g of NHS, and then add 15-25 mL of PBS buffer (pH 7.2-7.4), stir and react at 20-25 °C in the dark for 20-28 h, add the reaction solution into deionized water to precipitate the product, collect the precipitate by centrifugation, wash the precipitate with deionized water and methanol 2-3 times in sequence, and dry it in vacuo to obtain a modified adsorbent;

[0047] (3) Add 1 g of secondary nickel return material to 10-20 mL of 2-6 mol / L NaOH solution and / or KOH solution for alkaline leaching at 75-90 °C for 1-4 h, and filter to obtain the alkaline leaching solution and alkaline leaching residue;

[0048] (4) Add 1 g of alkaline leaching residue to 10-20 mL of acid solution (a mixture of 5-20 wt% sulfuric acid and 10-30 wt% hydrogen peroxide, with a volume ratio of sulfuric acid to hydrogen peroxide of 90-95:10-5) and leaching at 60-90 °C for 1-4 h, then filter to obtain the acid leaching solution and acid leaching residue;

[0049] (5) Stir the acid extract at 40-60°C, then slowly add the alkaline extract until the pH of the solution reaches 5.0, then stop adding, keep warm and stir for 20-40 minutes, then filter to obtain the residue and neutralization solution;

[0050] (6) injecting the neutralized liquid into an adsorption device, wherein the adsorption device comprises a first adsorption column and a second adsorption column connected in sequence, wherein the first adsorption column and the second adsorption column are both filled with a modified adsorbent;

[0051] The adsorption is divided into three stages: the neutralization solution is injected into the adsorption device at 2~5mL / min until the copper ion concentration in the effluent no longer decreases; the neutralization solution is injected into the adsorption device at 6~10mL / min until the copper ion concentration in the effluent no longer decreases; the effluent from the first two stages is injected into the second adsorption column at 1~3mL / min until the nickel ion concentration in the effluent no longer decreases;

[0052] After the adsorption is completed, the first adsorption column and the second adsorption column are rinsed with 5-30wt% sulfuric acid for desorption. After the first adsorption column is desorbed, a copper ion desorption liquid and a modified adsorbent are obtained. After the second adsorption column is desorbed, a nickel ion desorption liquid and a modified adsorbent are obtained. The copper ion desorption liquid and the nickel ion desorption liquid are respectively subjected to electrolytic deposition operations to obtain copper metal and nickel metal.

[0053] The present invention will be further described below through specific embodiments.

[0054] Example 1

[0055] A process for separating copper and nickel from secondary nickel return material comprises the following steps:

[0056] (1) Add 1.2 g of polyacrylamide to 120 mL of a methanol / water mixed solvent (the volume ratio of methanol to deionized water is 20:80), stir to dissolve, then add 2 mL of a 25 wt% glutaraldehyde aqueous solution and 0.6 g of thiourea, adjust the pH to 8.5, and react at 55 °C in the dark for 4 h. Transfer the reaction solution to a dialysis bag with a molecular weight cutoff of 3500 Da, dialyze with deionized water for 60 h, replace the dialysate every 12 h, and freeze-dry the dialyzed solution to obtain a light yellow solid intermediate.

[0057] (2) Disperse 1.2 g of the intermediate in 80 mL of a DMF / water mixed solvent (the volume ratio of DMF to deionized water is 1:2), stir and swell at room temperature for 3 h, add 30 mL of a DMF solution of tetrakis(4-carboxyphenyl)porphine (the concentration of tetrakis(4-carboxyphenyl)porphine is 0.1 g / 10 mL), mix well, add 0.6 g of EDC and 0.3 g of NHS, and then add 20 mL of PBS buffer (pH 7.4), stir and react at 25 °C in the dark for 28 h, add the reaction solution into deionized water to precipitate the product, collect the precipitate by centrifugation, wash the precipitate with deionized water and methanol three times in sequence, and dry it in vacuum to obtain a modified adsorbent;

[0058] (3) Add 100 g of secondary nickel return material into 1500 mL of 4 mol / L NaOH solution for alkaline leaching at 80 °C for 2 h, and filter to obtain the alkaline leaching solution and alkaline leaching residue;

[0059] (4) Add 100 g of alkaline leaching residue into 1500 mL of acid solution (a mixture of 15 wt% sulfuric acid and 20 wt% hydrogen peroxide, with a volume ratio of sulfuric acid to hydrogen peroxide of 90:10) and leaching at 75 °C for 2 h, then filter to obtain the acid leaching solution and acid leaching residue;

[0060] (5) Stir the acid extract at 50°C, then slowly add the alkaline extract until the pH of the solution reaches 5.0, then stop adding, keep warm and stir for 30 minutes, then filter to obtain the residue and neutralization solution;

[0061] (6) injecting the neutralized liquid into an adsorption device, wherein the adsorption device comprises a first adsorption column and a second adsorption column connected in sequence, wherein the first adsorption column and the second adsorption column are both filled with a modified adsorbent;

[0062] The adsorption is divided into three stages: the neutralization solution is injected into the adsorption device at 2 mL / min until the copper ion concentration in the effluent no longer decreases; the neutralization solution is injected into the adsorption device at 6 mL / min until the copper ion concentration in the effluent no longer decreases; the effluent from the first two stages is injected into the second adsorption column at 1 mL / min until the nickel ion concentration in the effluent no longer decreases;

[0063] After the adsorption is completed, the first adsorption column and the second adsorption column are rinsed with 20wt% sulfuric acid for desorption. After the first adsorption column is desorbed, a copper ion desorption liquid and a modified adsorbent are obtained. After the second adsorption column is desorbed, a nickel ion desorption liquid and a modified adsorbent are obtained. The copper ion desorption liquid and the nickel ion desorption liquid are respectively subjected to electrolytic deposition operations to obtain copper metal and nickel metal.

[0064] Example 2

[0065] A process for separating copper and nickel from secondary nickel return material comprises the following steps:

[0066] (1) Add 1.1 g of polyacrylamide to 120 mL of a methanol / water mixed solvent (the volume ratio of methanol to deionized water is 16:84), stir to dissolve, then add 1.5 mL of a 25 wt% glutaraldehyde aqueous solution and 0.5 g of thiourea, adjust the pH to 8.5, and react at 50 °C in the dark for 5 h. Transfer the reaction solution to a dialysis bag with a molecular weight cutoff of 3500 Da, dialyze with deionized water for 60 h, replace the dialyzate every 12 h, and freeze-dry the dialyzed solution to obtain a light yellow solid intermediate.

[0067] (2) Disperse 1.1 g of the intermediate in 80 mL of a DMF / water mixed solvent (the volume ratio of DMF to deionized water is 1:2), stir and swell at room temperature for 2.5 h, add 25 mL of a DMF solution of tetrakis(4-carboxyphenyl)porphine (the concentration of tetrakis(4-carboxyphenyl)porphine is 0.1 g / 10 mL), mix well, add 0.5 g of EDC and 0.25 g of NHS, and then add 20 mL of PBS buffer (pH 7.4), stir and react at 24 °C in the dark for 22 h, add the reaction solution into deionized water to precipitate the product, collect the precipitate by centrifugation, wash the precipitate with deionized water and methanol three times in sequence, and dry it in vacuo to obtain a modified adsorbent;

[0068] (3) Add 1 g of secondary nickel return material into 15 mL of 4 mol / L KOH solution and leaching at 80 °C for 2 h, then filter to obtain the leaching solution and leaching residue;

[0069] (4) Add 1 g of alkaline leaching residue into 15 mL of acid solution (a mixture of 15 wt% sulfuric acid and 20 wt% hydrogen peroxide, with a volume ratio of sulfuric acid to hydrogen peroxide of 90:10) and leaching at 75 °C for 2 h. Filter to obtain the acid leaching solution and acid leaching residue;

[0070] (5) Stir the acid extract at 50°C, then slowly add the alkaline extract until the pH of the solution reaches 5.0, then stop adding, keep warm and stir for 30 minutes, then filter to obtain the residue and neutralization solution;

[0071] (6) injecting the neutralized liquid into an adsorption device, wherein the adsorption device comprises a first adsorption column and a second adsorption column connected in sequence, wherein the first adsorption column and the second adsorption column are both filled with a modified adsorbent;

[0072] The adsorption is divided into three stages: the neutralization solution is injected into the adsorption device at 3 mL / min until the copper ion concentration in the effluent no longer decreases; the neutralization solution is injected into the adsorption device at 7 mL / min until the copper ion concentration in the effluent no longer decreases; the effluent from the first two stages is injected into the second adsorption column at 2 mL / min until the nickel ion concentration in the effluent no longer decreases;

[0073] After the adsorption is completed, the first adsorption column and the second adsorption column are rinsed with 20wt% sulfuric acid for desorption. After the first adsorption column is desorbed, a copper ion desorption liquid and a modified adsorbent are obtained. After the second adsorption column is desorbed, a nickel ion desorption liquid and a modified adsorbent are obtained. The copper ion desorption liquid and the nickel ion desorption liquid are respectively subjected to electrolytic deposition operations to obtain copper metal and nickel metal.

[0074] Example 3

[0075] A process for separating copper and nickel from secondary nickel return material comprises the following steps:

[0076] (1) Add 1.0 g of polyacrylamide to 120 mL of a methanol / water mixed solvent (the volume ratio of methanol to deionized water is 14:86), stir to dissolve, then add 1.0 mL of a 25 wt% glutaraldehyde aqueous solution and 0.4 g of thiourea, adjust the pH to 8.5, and react at 45 °C in the dark for 6 h. Transfer the reaction solution to a dialysis bag with a molecular weight cutoff of 3500 Da, dialyze with deionized water for 60 h, replace the dialysate every 12 h, and freeze-dry the dialyzed solution to obtain a light yellow solid intermediate.

[0077] (2) Disperse 1.0 g of the intermediate in 80 mL of DMF / water mixed solvent (the volume ratio of DMF to deionized water is 1:1), stir and swell at room temperature for 2.5 h, add 24 mL of DMF solution of tetrakis(4-carboxyphenyl)porphine (the concentration of tetrakis(4-carboxyphenyl)porphine is 0.1 g / 12 mL), mix well, add 0.5 g of EDC and 0.25 g of NHS, and then add 20 mL of PBS buffer (pH 7.4), stir and react at 22 °C in the dark for 25 h, add the reaction solution into deionized water to precipitate the product, collect the precipitate by centrifugation, wash the precipitate with deionized water and methanol three times in sequence, and dry it in vacuum to obtain a modified adsorbent;

[0078] (3) Add 1 g of secondary nickel return material into 15 mL of 4 mol / L NaOH solution and leaching at 80 °C for 2 h, and filter to obtain the leaching solution and leaching residue;

[0079] (4) Add 1 g of alkaline leaching residue into 15 mL of acid solution (a mixture of 15 wt% sulfuric acid and 20 wt% hydrogen peroxide, with a volume ratio of sulfuric acid to hydrogen peroxide of 90:10) and leaching at 75 °C for 2 h. Filter to obtain the acid leaching solution and acid leaching residue;

[0080] (5) Stir the acid extract at 50°C, then slowly add the alkaline extract until the pH of the solution reaches 5.0, then stop adding, keep warm and stir for 30 minutes, then filter to obtain the residue and neutralization solution;

[0081] (6) injecting the neutralized liquid into an adsorption device, wherein the adsorption device comprises a first adsorption column and a second adsorption column connected in sequence, wherein the first adsorption column and the second adsorption column are both filled with a modified adsorbent;

[0082] The adsorption is divided into three stages: the neutralization solution is injected into the adsorption device at 4 mL / min until the copper ion concentration in the effluent no longer decreases; the neutralization solution is injected into the adsorption device at 8 mL / min until the copper ion concentration in the effluent no longer decreases; the effluent from the first two stages is injected into the second adsorption column at 2 mL / min until the nickel ion concentration in the effluent no longer decreases;

[0083] After the adsorption is completed, the first adsorption column and the second adsorption column are rinsed with 20wt% sulfuric acid for desorption. After the first adsorption column is desorbed, a copper ion desorption liquid and a modified adsorbent are obtained. After the second adsorption column is desorbed, a nickel ion desorption liquid and a modified adsorbent are obtained. The copper ion desorption liquid and the nickel ion desorption liquid are respectively subjected to electrolytic deposition operations to obtain copper metal and nickel metal.

[0084] Example 4

[0085] A process for separating copper and nickel from secondary nickel return material comprises the following steps:

[0086] (1) Add 0.8 g of polyacrylamide to 120 mL of a methanol / water mixed solvent (the volume ratio of methanol to deionized water is 10:90), stir to dissolve, then add 0.5 mL of a 25 wt% glutaraldehyde aqueous solution and 0.3 g of thiourea, adjust the pH to 8.5, and react at 40 °C in the dark for 7 h. Transfer the reaction solution to a dialysis bag with a molecular weight cutoff of 3500 Da, dialyze with deionized water for 60 h, replace the dialysate every 12 h, and freeze-dry the dialyzed solution to obtain a light yellow solid intermediate.

[0087] (2) Disperse 0.8 g of the intermediate in 80 mL of DMF / water mixed solvent (the volume ratio of DMF to deionized water is 1:1), stir and swell at room temperature for 2 h, add 20 mL of DMF solution of tetrakis(4-carboxyphenyl)porphine (the concentration of tetrakis(4-carboxyphenyl)porphine is 0.1 g / 10 mL), mix well, add 0.4 g of EDC and 0.2 g of NHS, and then add 20 mL of PBS buffer (pH 7.4), stir and react at 20 ° C in the dark for 28 h, add the reaction solution into deionized water to precipitate the product, collect the precipitate by centrifugation, wash the precipitate with deionized water and methanol three times in sequence, and dry it in vacuum to obtain a modified adsorbent;

[0088] (3) Add 1 g of secondary nickel return material into 15 mL of 4 mol / L KOH solution and leaching at 80 °C for 2 h, then filter to obtain the leaching solution and leaching residue;

[0089] (4) Add 1 g of alkaline leaching residue into 15 mL of acid solution (a mixture of 15 wt% sulfuric acid and 20 wt% hydrogen peroxide, with a volume ratio of sulfuric acid to hydrogen peroxide of 90:10) and leaching at 75 °C for 2 h. Filter to obtain the acid leaching solution and acid leaching residue;

[0090] (5) Stir the acid extract at 50°C, then slowly add the alkaline extract until the pH of the solution reaches 5.0, then stop adding, keep warm and stir for 30 minutes, then filter to obtain the residue and neutralization solution;

[0091] (6) injecting the neutralized liquid into an adsorption device, wherein the adsorption device comprises a first adsorption column and a second adsorption column connected in sequence, wherein the first adsorption column and the second adsorption column are both filled with a modified adsorbent;

[0092] The adsorption is divided into three stages: the neutralization solution is injected into the adsorption device at 5 mL / min until the copper ion concentration in the effluent no longer decreases; the neutralization solution is injected into the adsorption device at 10 mL / min until the copper ion concentration in the effluent no longer decreases; the effluent from the first two stages is injected into the second adsorption column at 3 mL / min until the nickel ion concentration in the effluent no longer decreases;

[0093] After the adsorption is completed, the first adsorption column and the second adsorption column are rinsed with 20wt% sulfuric acid for desorption. After the first adsorption column is desorbed, a copper ion desorption liquid and a modified adsorbent are obtained. After the second adsorption column is desorbed, a nickel ion desorption liquid and a modified adsorbent are obtained. The copper ion desorption liquid and the nickel ion desorption liquid are respectively subjected to electrolytic deposition operations to obtain copper metal and nickel metal.

[0094] Comparative Example 1

[0095] A process for separating copper and nickel from secondary nickel return material comprises the following steps:

[0096] (1) Add 1.2 g of polyacrylamide to 120 mL of a methanol / water mixed solvent (the volume ratio of methanol to deionized water is 20:80), stir to dissolve, then add 2 mL of a 25 wt% glutaraldehyde aqueous solution and 0.6 g of thiourea, adjust the pH to 8.5, and react at 55 °C in the dark for 4 h. Transfer the reaction solution to a dialysis bag with a molecular weight cutoff of 3500 Da, dialyze with deionized water for 60 h, replace the dialysate every 12 h, and freeze-dry the dialyzed solution to obtain a light yellow solid intermediate.

[0097] (2) Add 1 g of secondary nickel return material into 15 mL of 4 mol / L NaOH solution and perform alkaline leaching at 80 °C for 2 h, and filter to obtain the alkaline leaching solution and alkaline leaching residue;

[0098] (3) Add 1 g of alkaline leaching residue into 15 mL of acid solution (a mixture of 15 wt% sulfuric acid and 20 wt% hydrogen peroxide, with a volume ratio of sulfuric acid to hydrogen peroxide of 90:10) and leaching at 75 °C for 2 h. Filter to obtain the acid leaching solution and acid leaching residue;

[0099] (4) Stir the acid extract at 50°C, then slowly add the alkaline extract until the pH of the solution reaches 5.0, then stop adding, keep warm and stir for 30 minutes, then filter to obtain the residue and neutralized solution;

[0100] (5) injecting the neutralized liquid into an adsorption device, wherein the adsorption device comprises a first adsorption column and a second adsorption column connected in sequence, wherein the first adsorption column and the second adsorption column are both filled with an intermediate;

[0101] The adsorption is divided into three stages: the neutralization solution is injected into the adsorption device at 2 mL / min until the copper ion concentration in the effluent no longer decreases; the neutralization solution is injected into the adsorption device at 6 mL / min until the copper ion concentration in the effluent no longer decreases; the effluent from the first two stages is injected into the second adsorption column at 1 mL / min until the nickel ion concentration in the effluent no longer decreases;

[0102] After the adsorption is completed, the first adsorption column and the second adsorption column are rinsed with 20wt% sulfuric acid for desorption. After the first adsorption column is desorbed, a copper ion desorption liquid and an intermediate are obtained. After the second adsorption column is desorbed, a nickel ion desorption liquid and an intermediate are obtained. The copper ion desorption liquid and the nickel ion desorption liquid are respectively subjected to electrolytic deposition operation to obtain copper metal and nickel metal.

[0103] Comparative Example 2

[0104] A process for separating copper and nickel from secondary nickel return material comprises the following steps:

[0105] (1) Add 1 g of secondary nickel return material into 15 mL of 4 mol / L NaOH solution and leaching at 80 °C for 2 h, then filter to obtain the leaching solution and leaching residue;

[0106] (2) Add 1 g of alkaline leaching residue into 15 mL of acid solution (a mixture of 15 wt% sulfuric acid and 20 wt% hydrogen peroxide, with a volume ratio of sulfuric acid to hydrogen peroxide of 90:10) and leaching at 75 °C for 2 h. Filter to obtain the acid leaching solution and acid leaching residue;

[0107] (3) Stir the acid extract at 50°C, then slowly add the alkaline extract until the pH of the solution reaches 5.0, then stop adding, keep warm and stir for 30 minutes, then filter to obtain the residue and neutralized solution;

[0108] (4) injecting the neutralized liquid into an adsorption device, wherein the adsorption device comprises a first adsorption column and a second adsorption column connected in sequence, wherein the first adsorption column and the second adsorption column are both filled with polyacrylamide;

[0109] The adsorption is divided into three stages: the neutralization solution is injected into the adsorption device at 2 mL / min until the copper ion concentration in the effluent no longer decreases; the neutralization solution is injected into the adsorption device at 6 mL / min until the copper ion concentration in the effluent no longer decreases; the effluent from the first two stages is injected into the second adsorption column at 1 mL / min until the nickel ion concentration in the effluent no longer decreases;

[0110] After the adsorption is completed, the first adsorption column and the second adsorption column are rinsed with 20wt% sulfuric acid for desorption. After the first adsorption column is desorbed, copper ion desorption liquid and polyacrylamide are obtained. After the second adsorption column is desorbed, nickel ion desorption liquid and polyacrylamide are obtained. The copper ion desorption liquid and the nickel ion desorption liquid are respectively subjected to electrolytic deposition operation to obtain copper metal and nickel metal.

[0111] The contents of copper and nickel in the copper metal and nickel metal finally obtained by electrowinning in Examples 1 to 4 and Comparative Examples 1 to 2 were measured, and the recovery rate was calculated based on the weight of the copper metal and nickel metal obtained by electrowinning:

[0112] Copper recovery rate = (weight of copper in copper metal / weight of copper in secondary nickel return) × 100%;

[0113] Nickel recovery rate = (weight of nickel in nickel metal / weight of nickel in secondary nickel return) × 100%;

[0114] See Table 1 for specific data.

[0115] Table 1 Adsorption performance test results

[0116]

[0117] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A process for separating copper and nickel from secondary nickel return material, characterized in that: The steps include: (1) adding the secondary nickel return material into an alkali solution for alkali leaching, and filtering to obtain an alkali leaching solution and an alkali leaching residue; (2) adding the alkali leaching residue into acid solution for acid leaching, and filtering to obtain the acid leaching solution and acid leaching residue; (3) adding the alkaline leaching solution to the acid leaching solution, stirring to react, and filtering to obtain a residue and a neutralized solution; (4) injecting the neutralized solution into the adsorption equipment, and performing desorption after the adsorption is completed to obtain copper ion desorption solution and nickel ion desorption solution, and performing electrolytic deposition operations respectively to obtain copper metal and nickel metal; In step (4), the adsorption is divided into three stages: the neutralization solution is injected into the adsorption device at 2-5 mL / min until the copper ion concentration in the effluent no longer decreases and then the process is stopped; the neutralization solution is injected into the adsorption device at 6-10 mL / min until the copper ion concentration in the effluent no longer decreases and then the process is stopped; the effluent from the first two stages is injected into the second adsorption column at 1-3 mL / min until the nickel ion concentration in the effluent no longer decreases and then the process is stopped; In step (4), the desorption is performed by washing the first adsorption column and the second adsorption column with 5-30wt% sulfuric acid respectively; after the first adsorption column is desorbed, a copper ion desorption liquid and a modified adsorbent are obtained, and after the second adsorption column is desorbed, a nickel ion desorption liquid and a modified adsorbent are obtained; In step (4), the adsorption device comprises a first adsorption column and a second adsorption column which are connected in sequence, and the first adsorption column and the second adsorption column are both filled with a modified adsorbent. The preparation method of the modified adsorbent comprises the following steps: a. Add polyacrylamide to a methanol / water mixed solvent, stir to dissolve, then add glutaraldehyde aqueous solution and thiourea, adjust the pH, stir to react in the dark, dialyze, freeze and dry the product to obtain a light yellow intermediate; b. Disperse the intermediate in a DMF / water mixed solvent, stir to swell, add a DMF solution of tetrakis(4-carboxyphenyl)porphine, mix evenly, add EDC and NHS, and then add PBS buffer, stir to react in the dark, precipitate the product, centrifuge, wash, and dry to obtain a modified adsorbent.

2. The process for separating copper and nickel from secondary nickel return material according to claim 1, characterized in that: In step (1), the alkali solution is a 2-6 mol / L NaOH solution and / or KOH solution, and the ratio of the secondary nickel return material to the alkali solution is 1 g: 10-20 mL; the alkali leaching conditions are alkali leaching at 75-90° C. for 1-4 h; in step (2), the acid solution is a mixed solution of 5-20 wt% sulfuric acid and 10-30 wt% hydrogen peroxide, and the volume ratio of sulfuric acid to hydrogen peroxide is 90-95:10-5; the ratio of the alkali leaching residue to the acid solution is 1 g: 10-20 mL; and the acid leaching conditions are acid leaching at 60-90° C. for 1-4 h.

3. The process for separating copper and nickel from secondary nickel return material according to claim 1, characterized in that: In step (3), the stirring reaction condition is to stir the acid extract at 40-60°C, then slowly add the alkali extract until the pH of the solution reaches 5.0, then stop adding, keep warm and stir for 20-40 minutes, and then filter.

4. The process for separating copper and nickel from secondary nickel return material according to claim 1, characterized in that: In step a, the volume ratio of methanol to deionized water in the methanol / water mixed solvent is 10-20:90-80, the concentration of the glutaraldehyde aqueous solution is 20-30wt%; the amount ratio of polyacrylamide, methanol / water mixed solvent, glutaraldehyde aqueous solution and thiourea is 0.8-1.2g:100-150mL:0.5-2mL:0.3-0.6g.

5. The process for separating copper and nickel from secondary nickel return material according to claim 1, characterized in that: In step a, the pH is adjusted to 8.0-9.0; the stirring reaction conditions are 40-55° C. and protected from light for 4-7 hours.

6. The process for separating copper and nickel from secondary nickel return material according to claim 1, characterized in that: In step b, the volume ratio of DMF and deionized water in the DMF / water mixed solvent is 1:1-2; the concentration of tetrakis(4-carboxyphenyl)porphine in the DMF solution of tetrakis(4-carboxyphenyl)porphine is 0.1 g / 10-15 mL; the pH value of the PBS buffer is 7.2-7.4; the dosage ratio of the intermediate, the DMF / water mixed solvent, the DMF solution of tetrakis(4-carboxyphenyl)porphine, EDC, NHS, and the PBS buffer is 0.8-1.2 g: 60-90 mL: 20-30 mL: 0.4-0.6 g: 0.2-0.3 g: 15-25 mL.

7. The process for separating copper and nickel from secondary nickel return material according to claim 1, characterized in that: In step b, the stirring and swelling conditions are stirring at room temperature for 2 to 3 hours; the light-proof stirring reaction conditions are stirring at 20 to 25° C. in the dark for 20 to 28 hours.

Images