A nickel-cobalt hydrometallurgical recycling process

Abstract

This invention discloses a nickel-cobalt hydrometallurgical recycling process, belonging to the field of hydrometallurgical technology. On one hand, this invention converts magnesium sulfate solution wastewater into magnesium salt solution, replacing sodium hydroxide in saponification with the organic phase, while also saving water in the production line. It also recycles carbon dioxide waste gas, achieving resource conversion and reuse of industrial waste gas. On the other hand, it prepares functional materials to achieve efficient recovery of cobalt and nickel from waste liquid: utilizing Zn... 2+ Coordination activation forms a resin filter membrane with a coordination trap on its surface, which efficiently captures cobalt and nickel ions in waste liquid; a carboxyl-functionalized dimethylglyoxime ligand is pre-synthesized using dimethylglyoxime and bromoacetic acid, and a MOF with a dimethylglyoxime group is directly constructed for chelating Ni. 2+ The prepared adsorption particles undergo secondary adsorption in the waste liquid after passing through the resin, resulting in an extremely high recovery rate of cobalt and nickel ions in the waste liquid. This hydrometallurgical process achieves both recovery and recycling.

Description

Technical Field

[0001] This invention relates to the field of hydrometallurgical technology, specifically a nickel-cobalt hydrometallurgical recycling process. Background Technology

[0002] Laterite nickel ore typically refers to a raw ore containing 0.8%–3.0% nickel and 0.02%–0.3% cobalt. The nickel and cobalt are valuable elements that need to be recovered. In addition, the ore contains certain amounts of impurities such as iron, aluminum, calcium, magnesium, and silicon. These inexpensive base metals not only have low economic value but are also extremely difficult to recover, and are usually treated as solid waste. Furthermore, the hydrometallurgical process of the ore generates significant amounts of carbon dioxide emissions. Since the solid, liquid, and gaseous waste generated during processing cannot be recycled, it can potentially cause significant environmental harm. Therefore, it has long lacked development prospects in my country.

[0003] Currently, nickel-cobalt hydrometallurgical recycling technology is gaining increasing attention globally, especially in the fields of electric vehicles and renewable energy storage, where the demand for nickel and cobalt, as crucial raw materials, is rapidly increasing. Internationally, many countries and companies are actively conducting research on nickel-cobalt recycling and reuse, primarily focusing on optimizing resource utilization efficiency and reducing environmental impact. Research institutions and companies in Europe and North America possess strong R&D capabilities in nickel-cobalt hydrometallurgical technology, particularly in waste treatment and metal extraction technologies, achieving significant results. Meanwhile, some Asian economies, such as South Korea and Japan, are also actively exploring hydrometallurgical processes in the development of new materials and the recycling of waste batteries.

[0004] Thanks to technological advancements in recent years, the maturity of hydrometallurgical technologies has improved, resulting in a relatively complete set of nickel-cobalt extraction and purification processes. These processes have been applied to varying degrees under high, low, and normal pressure conditions, significantly improving metal recovery and purification rates. Meanwhile, some advanced technologies, such as selective leaching, ion exchange, and solvent extraction, have shown promising application prospects in laboratory settings and small-scale industrial production. Currently, domestic enterprises are still in the catch-up stage in this field, but with the promotion of relevant policies and the gradual maturation of technologies, breakthroughs in application scale and technological innovation are likely to be achieved in the future.

[0005] In the future, nickel-cobalt hydrometallurgical recycling technology will develop towards higher efficiency, environmental protection, and economic benefits. With global recognition of sustainable development goals and the gradual improvement of relevant regulations and policies, enterprises will inevitably place greater emphasis on integrating the concept of a circular economy into their production models and technological innovations. In this process, the increasing maturity of intelligent and automated production technologies, as well as the application of emerging technologies such as the Internet of Things and big data, are expected to significantly improve the efficiency of nickel-cobalt recycling. Furthermore, with the continued growth in demand for electric vehicles and energy storage equipment, the shortage of nickel-cobalt resources is becoming increasingly prominent, which will further stimulate huge investments in this field to support the development of new materials and the application of recycled resources. Therefore, the synergistic effect of the upstream and downstream of the industrial chain will gradually emerge, promoting the comprehensive development of nickel-cobalt hydrometallurgical technology. Summary of the Invention

[0006] The purpose of this invention is to provide a nickel-cobalt hydrometallurgical recycling process to solve the problems existing in the prior art.

[0007] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a nickel-cobalt hydrometallurgical recycling process, the process comprising the following steps:

[0008] (1) Pre-treat and acid leaching the laterite nickel ore; during the leaching process, first apply 2-4 hours of ultrasound with a power of 250-350W, then apply 4-6 hours of high pressure with a pressure of 1.5-2.0MPam to obtain the leachate.

[0009] (2) Add CaCO3 to the leachate to neutralize to pH=4.0; filter to remove precipitate; use the magnesium bicarbonate regenerated in step (6) as saponifying agent to react with the blank organic phase for saponification; the CO2 generated by saponification is processed by the gas recovery device and then transported to step (6).

[0010] (3) After the saponification is completed, the organic phase and the filtered leachate are subjected to an extraction reaction; the extraction temperature is 40℃, the extraction stage is 10 stages, the volume ratio of organic phase to liquid is 1:1, and the blank organic phase after back-extraction is returned to step (2) to be saponified again.

[0011] (4) Take the magnesium sulfate waste liquid after extraction and filter it through a resin filter membrane at a flow rate of 3-5 BV / h; then add adsorption particles to the filtered waste liquid at a rate of 1-5 g / L, stir for 20-40 min, and the remaining waste liquid after recovery is the recovered waste liquid.

[0012] (5) Take the recovered waste liquid and slowly add it to a strong alkali aqueous solution. The molar ratio of magnesium sulfate to strong alkali is 1:1. React at room temperature for 1.5-3.5 hours and the reaction temperature is 40-60℃.

[0013] (6) After the reaction is completed, a vacuum filter is used to filter part of the slurry. The filtered aqueous phase is returned to the pretreatment section of step (1) or a strong alkaline aqueous solution is prepared. The filter residue and the remaining unfiltered mixed slurry are put into a high-pressure reactor. Then, CO2 gas is introduced into the reactor under stirring. After the reaction is completed, solid-liquid separation is performed. The solid is insoluble barium sulfate, and the liquid aqueous phase is magnesium bicarbonate solution.

[0014] Further, the pretreatment in step (1) is as follows: the laterite nickel ore is crushed to 80 mesh size, roasted at 680-720℃ for 2 hours to dehydrate, then leached with 15wt% HF at a solid-liquid ratio of 1:3, stirred at room temperature for 1 hour, filtered and dried to obtain pretreated ore; the acid leaching of the laterite nickel ore is as follows: it is leached with concentrated sulfuric acid at a concentration of 200-300g / L at a solid-liquid ratio of 1:4, and then 0.5wt% H2O2 is added, and stirred at 80℃ under normal pressure for 6-10 hours.

[0015] Furthermore, in step (2), the volume ratio of the organic phase to the aqueous phase during saponification is 1:2, the blank organic phase is P204 or P507, the concentration of the blank organic phase is 20%, the saponification temperature is 30℃, and the saponification time is 10min.

[0016] Further, the preparation method of the resin filter membrane in step (4) is as follows: Polyvinylpyrrolidone is added to N-methylpyrrolidone at a concentration of 5-10 wt%, and magnetically stirred for 3 hours. Polyacrylic acid with a molecular weight of 25w and a concentration of 10 wt% is slowly added, and stirring is continued for 12 hours. The temperature is controlled at 40°C. The solution is transferred to a sealed container and allowed to stand for 24 hours for vacuum degassing. The degassed casting solution is poured onto a clean glass plate, and the thickness is controlled to be 400 μm using a film scraper. Then, the glass plate is immediately immersed in a room temperature deionized water bath for 30 minutes to obtain a microporous polyacrylic acid resin membrane with a pore size of 0.5 μm. The resin membrane is immersed in a 3-aminopropyltriethoxysilane / toluene solution with a mass fraction of 5-8% and a solid-liquid ratio of 1:10. Nitrogen gas is introduced for protection, and the mixture is refluxed at 80°C for 6 hours. The reagents were removed by centrifugation, and the membrane was then washed three times alternately with toluene and ethanol, followed by vacuum drying at 60°C for 12 hours to obtain an aminated resin membrane. The aminated resin membrane was then immersed in a 2.5% (w / w) glutaraldehyde aqueous solution with a solid-liquid ratio of 1:10 and a pH of 7.0. The solution was shaken at 40°C for 4 hours, filtered, washed, and dried to obtain an aldehyde-activated resin membrane. L-histidine was then dissolved in a phosphate buffer solution at pH 8.0 (0.1 M). The aldehyde-activated resin membrane was added to this solution with a histidine:aldehyde molar ratio of 1-1.2:1. The solution was shaken at 50°C for 12 hours, then transferred to 0.1 M ethanolamine to block residual aldehyde groups for 2 hours. The membrane was then filtered, washed, and dried to obtain a histidine-modified resin membrane. The histidine-modified resin membrane was then immersed in a 0.05 M ZnSO4 aqueous solution. 2+The resin filter membrane was prepared by shaking at 25°C for 4 hours with histidine in a molar ratio of 1.5-2.0:1, followed by filtration, washing, and drying.

[0017] Furthermore, the used resin filter membrane is desorbed using 0.5M H2SO4 and 0.1M ascorbic acid.

[0018] Further, the preparation method of the adsorbent particles in step (4) is as follows: 10g of dimethylglyoxime and 9.8g of succinic anhydride are dissolved in 100mL of acetonitrile, 0.1g of DMAP catalyst is added, and the mixture is refluxed at 80℃ for 24h. The solvent is removed by rotary evaporation, and the mixture is recrystallized from ethanol to obtain the dimethylglyoxime functionalized ligand. 0.15-0.17g of dimethylglyoxime functionalized ligand, 0.18-0.22g of zirconium tetrachloride, 30ml of DMF and 1ml of acetic acid are mixed and crystallized at 120℃ for 24h. Then, the mixture is washed three times with methanol and activated under vacuum at 150℃ for 12h to obtain MOF with dimethylglyoxime group as adsorbent particles.

[0019] Furthermore, the recovered adsorbed particles are desorbed using 0.1M EDTA-2Na.

[0020] Furthermore, the reaction temperature in step (4) is 25-35℃ throughout the process.

[0021] Furthermore, the source of the strong alkaline aqueous solution in step (5) is: solid barium sulfate is washed twice with deionized water, dried at 100°C for 2 hours, calcined to prepare barium oxide, and then mixed with deionized water to react. The solid-liquid mass ratio is 1:3-5, the reaction time is 2 hours, and a strong alkaline aqueous solution is formed, which is then recycled in the production process.

[0022] Furthermore, in step (6), the CO2 gas flow rate is 1-3 L / min, the pressure inside the vessel is maintained at 0.5-0.6 MPa, the reaction time is 1.5-3.5 h, the temperature is 5-35 °C, and the stirring speed is 250-350 rpm.

[0023] Compared with the prior art, the beneficial effects achieved by the present invention are:

[0024] On the one hand, the production system achieves infinite recycling through waste utilization and turning waste into treasure: magnesium impurities carried in the ore are used to form a magnesium sulfate solution in the wastewater through pretreatment / leaching / extraction processes. This solution is then converted into a soluble magnesium salt solution, replacing sodium hydroxide in saponification with the organic phase, thus turning waste into treasure, saving auxiliary materials, and effectively reducing production costs. The generation of soluble sodium salts during production is eliminated, enabling the production line to use water once and indefinitely. Furthermore, carbon dioxide waste gas generated during industrial production is fully recovered and utilized, achieving the resource conversion and reuse of industrial waste gas.

[0025] On the other hand, the preparation of functional materials enables efficient recovery of cobalt and nickel from waste liquid: first, the surface of the microporous polymer resin is aminated, then histidine is directionally grafted through Schiff base synthesis, and then Zn... 2+ Coordination activation forms a resin filter membrane with a coordination trap on its surface, efficiently capturing cobalt and nickel ions in waste liquid. A dimethylglyoxime functionalized ligand is pre-synthesized using dimethylglyoxime and succinic anhydride as raw materials. Ring-opening releases free carboxyl groups for coordination, while the retained oxime group chelates Ni. 2+ Carboxylated dimethylglyoxime was reacted with metal nodes in a solvent to directly construct MOFs with dimethylglyoxime groups. The prepared adsorption particles were then subjected to secondary adsorption in the waste liquid after passing through the resin, resulting in an extremely high recovery rate of cobalt and nickel ions in the waste liquid. Detailed Implementation

[0026] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0027] Example 1

[0028] (1) The laterite nickel ore was crushed to 80 mesh size, roasted at 680℃ for 2h to dehydrate, and then leached with 15wt% HF at a solid-liquid ratio of 1:3. The mixture was stirred at room temperature for 1h at a stirring speed of 60rpm. The solid was filtered and then dried at 50℃ for 6h to obtain pretreated ore. The pretreated ore was leached with concentrated sulfuric acid at a concentration of 200g / L at a solid-liquid ratio of 1:4. Then 0.5wt% H2O2 was added, and the mixture was stirred at 80℃ under normal pressure for 6h at a stirring speed of 60rpm. During the leaching process, the ore was first subjected to 2h of ultrasound at a power of 250W, and then subjected to 4h of high pressure at a pressure of 1.5MPa to obtain the leachate.

[0029] (2) Add CaCO3 to the leachate to neutralize to pH=4.0; filter to remove precipitate; use the magnesium bicarbonate regenerated in step (6) as saponifying agent to react with the blank organic phase P204 for saponification. The volume ratio of organic phase to water phase during saponification is 1:2, the concentration of blank organic phase is 20%, the saponification temperature is 30℃, and the saponification time is 10min. The CO2 generated by saponification is treated by a gas recovery device and then transported to step (6).

[0030] (3) After the saponification is completed, the organic phase and the filtered leachate are subjected to an extraction reaction; the extraction temperature is 40℃, the extraction stage is 10 stages, the volume ratio of organic phase to liquid is 1:1, and the blank organic phase after back-extraction is returned to step (2) to be saponified again.

[0031] (4) Take the magnesium sulfate waste liquid after extraction and filter it through a resin filter membrane at a flow rate of 3 BV / h; then add adsorption particles to the filtered waste liquid at a dosage of 1 g / L, stir for 20 min at a stirring speed of 120 rpm, and the remaining liquid after recovery is the recovered waste liquid; the reaction temperature throughout the process is 25℃; the preparation method of the resin filter membrane is as follows: add polyvinylpyrrolidone to N-methylpyrrolidone at a concentration of 5 wt%, stir magnetically for 3 h at a stirring speed of 60 rpm, and slowly add the fractional polymerase. Polyacrylic acid with a molecular weight of 25w and a concentration of 10wt% was stirred for 12 hours at a temperature controlled at 40℃. The solution was then transferred to a sealed container and allowed to stand for 24 hours for vacuum degassing. The degassed casting solution was poured onto a clean glass plate, and the thickness was controlled to 400μm using a film scraper. The glass plate was then immediately immersed in a room temperature deionized water bath for 30 minutes to obtain a microporous polyacrylic acid resin membrane with a pore size of 0.5μm. The resin was then immersed in a 5% (w / w) solution of 3-aminopropyltriethoxysilane / toluene for solid-liquid polymerization. The reaction mixture was prepared by mixing a 1:10 ratio of solids and liquids under nitrogen protection and refluxing at 80°C for 6 hours. The reagents were removed by centrifugation at 8000 rpm for 10 minutes. The mixture was then washed three times alternately with toluene and ethanol, and finally dried under vacuum at 60°C for 12 hours at a vacuum degree of 0.085 MPa to obtain the aminated resin. The aminated resin was then immersed in a 2.5% (w / w) glutaraldehyde aqueous solution with a solid-liquid ratio of 1:10 and a pH of 7.0. The mixture was shaken at 40°C for 4 hours, filtered, and the solid was washed twice with deionized water. After drying at ℃ for 12 h, aldehyde-activated resin was obtained. Then, L-histidine was dissolved in phosphate buffer (pH 8.0) at a concentration of 0.1 M. The aldehyde-activated resin was added to this solution, with a histidine:aldehyde molar ratio of 1:1. The mixture was shaken at 50 °C for 12 h, then transferred to 0.1 M ethanolamine to block residual aldehyde groups for 2 h. After removal, the resin was washed twice with deionized water and then dried at 40 °C for 5 h to obtain histidine-modified resin. The histidine-modified resin was then immersed in a 0.05 M ZnSO4 aqueous solution. 2+A resin filter membrane was prepared by shaking at 25°C for 4 hours with histidine in a molar ratio of 1.5:1, washing four times with deionized water, and then drying at 30°C for 12 hours. The used resin filter membrane was desorbed using 0.5M H₂SO₄ and 0.1M ascorbic acid. The adsorbent particles were prepared by dissolving 10g of dimethylglyoxime and 9.8g of succinic anhydride in 100mL of acetonitrile, and adding 0.1g of... DMAP catalyst was refluxed at 80℃ for 24 h, solvent was removed by rotary evaporation at 60℃, and recrystallized from ethanol to obtain dimethylglyoxime functionalized ligands. 0.15 g of dimethylglyoxime functionalized ligands, 0.18 g of zirconium tetrachloride, 30 ml of DMF, and 1 ml of acetic acid were mixed and crystallized at 120℃ for 24 h. The mixture was then washed three times with methanol and activated under vacuum at 150℃ for 12 h at a vacuum degree of 0.085 MPa to obtain MOFs with dimethylglyoxime groups, which were used as adsorbent particles. The recovered adsorbent particles were desorbed using 0.1 M EDTA-2Na.

[0032] (5) Take the recycled waste liquid and slowly add strong alkaline aqueous solution. The molar ratio of magnesium sulfate to strong alkali is 1:1. React at room temperature for 1.5 hours and the reaction temperature is 40℃. The source of the strong alkaline aqueous solution is: solid barium sulfate is washed twice with deionized water, dried at 100℃ for 2 hours, calcined to prepare barium oxide, and then mixed with deionized water. The solid-liquid mass ratio is 1:3 and the reaction time is 2 hours to form a strong alkaline aqueous solution, which is then recycled in the production process.

[0033] (6) After the reaction is completed, a vacuum filter is used to filter part of the slurry. The filtrate water is returned to step (2) for raw material slurrying or for the preparation of strong alkali solution. The filter residue and the remaining unfiltered mixed slurry are put into a high-pressure reactor. Then, CO2 gas is introduced into the reactor under stirring. The gas flow rate is 1L / min. The pressure inside the reactor is kept at 0.5MPa. The reaction is carried out for 1.5h. The temperature is 5℃. The stirring speed is 250rpm. After the reaction is completed, solid-liquid separation is carried out. The solid is insoluble barium sulfate and the liquid phase is magnesium bicarbonate solution.

[0034] Example 2

[0035] (1) The laterite nickel ore was crushed to 80 mesh size, roasted at 700℃ for 2h to dehydrate, and then leached with 15wt% HF at a solid-liquid ratio of 1:3. The mixture was stirred at room temperature for 1h at a stirring speed of 60rpm. The solid was filtered and then dried at 50℃ for 6h to obtain pretreated ore. The pretreated ore was leached with concentrated sulfuric acid at a concentration of 250g / L at a solid-liquid ratio of 1:4. Then 0.5wt% H2O2 was added, and the mixture was stirred at 80℃ under normal pressure for 8h at a stirring speed of 60rpm. During the leaching process, the ore was first subjected to 3h of ultrasound at a power of 300W, and then subjected to 5h of high pressure at a pressure of 1.75MPa to obtain the leachate.

[0036] (2) Add CaCO3 to the leachate to neutralize to pH=4.0; filter to remove precipitate; use the magnesium bicarbonate regenerated in step (6) as saponifying agent to react with the blank organic phase P204 for saponification. The volume ratio of organic phase to water phase during saponification is 1:2, the concentration of blank organic phase is 20%, the saponification temperature is 30℃, and the saponification time is 10min. The CO2 generated by saponification is treated by a gas recovery device and then transported to step (6).

[0037] (3) After the saponification is completed, the organic phase and the filtered leachate are subjected to an extraction reaction; the extraction temperature is 40℃, the extraction stage is 10 stages, the volume ratio of organic phase to liquid is 1:1, and the blank organic phase after back-extraction is returned to step (2) to be saponified again.

[0038] (4) Take the magnesium sulfate waste liquid after extraction and filter it through a resin filter membrane at a flow rate of 4 BV / h; then add adsorption particles to the filtered waste liquid at a dosage of 3 g / L, stir for 30 min at a stirring speed of 120 rpm, and the remaining liquid after recovery is the recovered waste liquid; the reaction temperature throughout the process is 30℃; the resin filter membrane is prepared by adding polyvinylpyrrolidone to N-methylpyrrolidone at a concentration of 7.5 wt%, stirring magnetically for 3 h at a stirring speed of 60 rpm, and slowly adding... Polyacrylic acid with a molecular weight of 25w and a concentration of 10wt% was stirred for 12 hours at a temperature controlled at 40℃. The solution was then transferred to a sealed container and allowed to stand for 24 hours for vacuum degassing. The degassed casting solution was poured onto a clean glass plate, and the thickness was controlled to 400μm using a film scraper. The glass plate was then immediately immersed in a room temperature deionized water bath for 30 minutes to obtain a microporous polyacrylic acid resin membrane with a pore size of 0.5μm. The resin was then immersed in a 6.5% (w / w) solution of 3-aminopropyltriethoxysilane / toluene to solidify... The liquid-to-solid ratio was 1:10, and the mixture was refluxed at 80℃ for 6 hours under nitrogen protection. The reagents were removed by centrifugation at 8000 rpm for 10 minutes. The mixture was then washed three times alternately with toluene and ethanol, and dried under vacuum at 60℃ for 12 hours at a vacuum degree of 0.085 MPa to obtain the aminated resin. The aminated resin was then immersed in a 2.5% (w / w) glutaraldehyde aqueous solution at a solid-to-liquid ratio of 1:10 (pH 7.0). The solution was shaken at 40℃ for 4 hours, filtered, and the solid was washed twice with deionized water at 50℃. After drying for 12 hours, an aldehyde-activated resin was obtained. Then, L-histidine was dissolved in a phosphate buffer solution at pH 8.0 (0.1 M), and the aldehyde-activated resin was added. The molar ratio of histidine to aldehyde was 1.1:1. The solution was shaken at 50°C for 12 hours, then transferred to 0.1 M ethanolamine to block residual aldehyde groups for 2 hours. After removal, the solution was washed twice with deionized water and then dried at 40°C for 5 hours to obtain a histidine-modified resin. The histidine-modified resin was then immersed in a 0.05 M ZnSO4 aqueous solution. 2+The resin filter membrane was prepared by shaking at 25°C for 4 hours with histidine in a molar ratio of 1.75:1, washing four times with deionized water, and then drying at 30°C for 12 hours. The used resin filter membrane was then used with 0.5M... H2SO4 was used for desorption with 0.1M ascorbic acid. The adsorbent particles were prepared as follows: 10g of dimethylglyoxime and 9.8g of succinic anhydride were dissolved in 100mL of acetonitrile, 0.1g of DMAP catalyst was added, and the mixture was refluxed at 80℃ for 24h. The solvent was removed by rotary evaporation at 60℃, and the mixture was recrystallized from ethanol to obtain a dimethylglyoxime functionalized ligand. 0.16g of the dimethylglyoxime functionalized ligand, 0.20g of zirconium tetrachloride, 30ml of DMF, and 1ml of acetic acid were mixed and crystallized at 120℃ for 24h. The mixture was then washed three times with methanol and activated under vacuum at 150℃ for 12h at a vacuum degree of 0.085MPa to obtain MOFs with dimethylglyoxime groups, which were the adsorbent particles. The recovered adsorbent particles were desorbed using 0.1M EDTA-2Na.

[0039] (5) Take the recycled waste liquid and slowly add strong alkaline aqueous solution. The molar ratio of magnesium sulfate to strong alkali is 1:1. React at room temperature for 2.5 hours and the reaction temperature is 50℃. The source of the strong alkaline aqueous solution is: solid barium sulfate is washed twice with deionized water, dried at 100℃ for 2 hours, calcined to prepare barium oxide, and then mixed with deionized water. The solid-liquid mass ratio is 1:4 and the reaction time is 2 hours to form a strong alkaline aqueous solution, which is then recycled in the production process.

[0040] (6) After the reaction is completed, a vacuum filter is used to filter part of the slurry. The filtrate water is returned to step (2) for raw material slurrying or for the preparation of strong alkali solution. The filter residue and the remaining unfiltered mixed slurry are put into a high-pressure reactor. Then, CO2 gas is introduced into the reactor under stirring. The gas flow rate is 2L / min. The pressure inside the reactor is kept at 0.55MPa. The reaction is carried out for 2.5h at a temperature of 20℃ and a stirring speed of 300rpm. After the reaction is completed, solid-liquid separation is carried out. The solid is insoluble barium sulfate and the liquid phase is magnesium bicarbonate solution.

[0041] Example 3

[0042] (1) The laterite nickel ore was crushed to 80 mesh size, roasted at 720℃ for 2h to dehydrate, and then leached with 15wt% HF at a solid-liquid ratio of 1:3. The mixture was stirred at room temperature for 1h at a stirring speed of 60rpm. The solid was filtered and then dried at 50℃ for 6h to obtain pretreated ore. The pretreated ore was leached with concentrated sulfuric acid at a concentration of 300g / L at a solid-liquid ratio of 1:4. Then 0.5wt% H2O2 was added, and the mixture was stirred at 80℃ under normal pressure for 10h at a stirring speed of 60rpm. During the leaching process, the ore was first subjected to 4h of ultrasound at a power of 350W, and then subjected to 6h of high pressure at a pressure of 2.0MPa to obtain the leachate.

[0043] (2) Add CaCO3 to the leachate to neutralize to pH=4.0; filter to remove precipitate; use the magnesium bicarbonate regenerated in step (6) as saponifying agent to react with the blank organic phase P507 for saponification. The volume ratio of organic phase to water phase during saponification is 1:2, the concentration of blank organic phase is 20%, the saponification temperature is 30℃, and the saponification time is 10min. The CO2 generated by saponification is treated by a gas recovery device and then transported to step (6).

[0044] (3) After the saponification is completed, the organic phase and the filtered leachate are subjected to an extraction reaction; the extraction temperature is 40℃, the extraction stage is 10 stages, the volume ratio of organic phase to liquid is 1:1, and the blank organic phase after back-extraction is returned to step (2) to be saponified again.

[0045] (4) Take the magnesium sulfate waste liquid after extraction and filter it through a resin filter membrane at a flow rate of 5 BV / h; then add adsorption particles to the filtered waste liquid at a dosage of 5 g / L, stir for 40 min at a stirring speed of 120 rpm, and the remaining liquid after recovery is the recovered waste liquid; the reaction temperature throughout the process is 35℃; the preparation method of the resin filter membrane is as follows: add polyvinylpyrrolidone to N-methylpyrrolidone at a concentration of 10 wt%, stir magnetically for 3 h at a stirring speed of 60 rpm, and slowly add the fractional polymerase. Polyacrylic acid with a molecular weight of 25w and a concentration of 10wt% was stirred for 12 hours at a temperature controlled at 40℃. The solution was then transferred to a sealed container and allowed to stand for 24 hours for vacuum degassing. The degassed casting solution was poured onto a clean glass plate, and the thickness was controlled to 400μm using a film scraper. The glass plate was then immediately immersed in a room temperature deionized water bath for 30 minutes to obtain a microporous polyacrylic acid resin membrane with a pore size of 0.5μm. The resin was then immersed in an 8% (w / w) solution of 3-aminopropyltriethoxysilane / toluene for solid-liquid polymerization. The mixture was prepared by mixing a 1:10 ratio of solids and liquids in a nitrogen atmosphere and refluxing at 80°C for 6 hours. The reagents were removed by centrifugation at 8000 rpm for 10 minutes. The mixture was then washed three times alternately with toluene and ethanol, and finally dried under vacuum at 60°C for 12 hours at a vacuum degree of 0.085 MPa to obtain the aminated resin. The aminated resin was then immersed in a 2.5% (w / w) glutaraldehyde aqueous solution at a solid-liquid ratio of 1:10 (pH 7.0). The solution was shaken at 40°C for 4 hours, filtered, and the solid was washed twice with deionized water at 50°C. After drying for 12 hours, an aldehyde-activated resin was obtained. Then, L-histidine was dissolved in a phosphate buffer solution at pH 8.0 (0.1 M), and the aldehyde-activated resin was added to it. The molar ratio of histidine to aldehyde was 1.2:1. The solution was shaken at 50°C for 12 hours, then transferred to 0.1 M ethanolamine to block residual aldehyde groups for 2 hours. After removal, the solution was washed twice with deionized water and then dried at 40°C for 5 hours to obtain a histidine-modified resin. The histidine-modified resin was then immersed in a 0.05 M ZnSO4 aqueous solution. 2+The resin filter membrane was prepared by shaking at 25℃ for 4 hours with histidine in a molar ratio of 2.0:1, washing four times with deionized water, and then drying at 30℃ for 12 hours. The used resin filter membrane was desorbed using 0.5M H₂SO₄ and 0.1M ascorbic acid. The adsorbent particles were prepared by dissolving 10g of dimethylglyoxime and 9.8g of succinic anhydride in 100mL of acetonitrile, and adding 0.1g of... DMAP catalyst was refluxed at 80℃ for 24 h, solvent was removed by rotary evaporation at 60℃, and recrystallized from ethanol to obtain dimethylglyoxime functionalized ligands. 0.17 g of dimethylglyoxime functionalized ligands, 0.22 g of zirconium tetrachloride, 30 ml of DMF, and 1 ml of acetic acid were mixed and crystallized at 120℃ for 24 h. The mixture was then washed three times with methanol and activated under vacuum at 150℃ for 12 h at a vacuum degree of 0.085 MPa to obtain MOFs with dimethylglyoxime groups, which were used as adsorbent particles. The recovered adsorbent particles were desorbed using 0.1 M EDTA-2Na.

[0046] (5) Take the recycled waste liquid and slowly add strong alkaline aqueous solution. The molar ratio of magnesium sulfate to strong alkali is 1:1. React at room temperature for 3.5 hours and the reaction temperature is 60℃. The source of the strong alkaline aqueous solution is: solid barium sulfate is washed twice with deionized water, dried at 100℃ for 2 hours, calcined to prepare barium oxide, and then mixed with deionized water. The solid-liquid mass ratio is 1:5 and the reaction time is 2 hours to form a strong alkaline aqueous solution, which is then recycled in the production process.

[0047] (6) After the reaction is completed, a vacuum filter is used to filter part of the slurry. The filtrate water is returned to step (2) for raw material slurrying or for the preparation of strong alkali solution. The filter residue and the remaining unfiltered mixed slurry are put into a high-pressure reactor. Then, CO2 gas is introduced into the reactor under stirring. The gas flow rate is 3L / min. The pressure inside the reactor is kept at 0.6MPa. The reaction is carried out for 3.5h at a temperature of 35℃ and a stirring speed of 350rpm. After the reaction is completed, solid-liquid separation is carried out. The solid is insoluble barium sulfate and the liquid phase is magnesium bicarbonate solution.

[0048] Comparative Example 1

[0049] The difference between Comparative Example 1 and Example 2 lies in step (4). Step (4) is changed to: taking the magnesium sulfate waste liquid after extraction, filtering it through a resin filter membrane at a flow rate of 4 BV / h, and the remaining liquid after recovery is the recycled waste liquid; the reaction temperature throughout is 30℃; wherein, the resin filter membrane is prepared by: adding polyvinylpyrrolidone to N-methylpyrrolidone at a concentration of 7.5 wt%, stirring magnetically for 3 h at a stirring speed of 60 rpm, and slowly adding polyacrylic acid with a molecular weight of 25w. With a concentration of 10 wt%, stirring was continued for 12 hours at a temperature controlled at 40°C. The solution was then transferred to a sealed container and allowed to stand for 24 hours for vacuum degassing. The degassed casting solution was poured onto a clean glass plate, and the thickness was controlled to 400 μm using a film scraper. The glass plate was then immediately immersed in a room temperature deionized water bath for 30 minutes to obtain a microporous polyacrylic acid resin membrane with a pore size of 0.5 μm. The resin was then immersed in a 6.5% (w / w) solution of 3-aminopropyltriethoxysilane / toluene at a solid-liquid ratio of 1:10. Under nitrogen protection, the reaction was refluxed at 80℃ for 6 hours. The reagents were removed by centrifugation at 8000 rpm for 10 minutes. The mixture was then washed three times alternately with toluene and ethanol, and dried under vacuum at 60℃ for 12 hours at a vacuum degree of 0.085 MPa to obtain the aminated resin. The aminated resin was then immersed in a 2.5% (w / w) glutaraldehyde aqueous solution with a solid-liquid ratio of 1:10 and a pH of 7.0. The solution was shaken at 40℃ for 4 hours, filtered, and the solid was washed twice with deionized water and dried at 50℃ for 12 hours. After h, aldehyde-activated resin was obtained; then L-histidine was dissolved in phosphate buffer at pH 8.0, with an L-histidine concentration of 0.1 M, and aldehyde-activated resin was added to it, with a histidine:aldehyde molar ratio of 1.1:1. The mixture was shaken at 50 °C for 12 h, then transferred to 0.1 M ethanolamine to block residual aldehyde groups for 2 h. After removal, it was washed twice with deionized water and then dried at 40 °C for 5 h to obtain histidine-modified resin; the histidine-modified resin was then immersed in 0.05 M ZnSO4 aqueous solution, Zn 2+ The resin filter membrane was prepared by shaking at 25°C for 4 hours with histidine in a molar ratio of 1.75:1, washing four times with deionized water, and then drying at 30°C for 12 hours. The used resin filter membrane was desorbed with 0.5M H2SO4 and 0.1M ascorbic acid. The remaining steps were the same as in Example 2.

[0050] Comparative Example 2

[0051] The difference between Comparative Example 2 and Example 2 lies in step (4). Step (4) is changed to: taking the magnesium sulfate waste liquid after extraction, adding adsorbent particles to it at a rate of 3 g / L, stirring for 30 min at a stirring speed of 120 rpm, and reacting at a temperature of 30°C. The remaining liquid after recovery is the recovered waste liquid. The adsorbent particles are prepared by dissolving 10 g of dimethylglyoxime and 9.8 g of succinic anhydride in 100 mL of acetonitrile, adding 0.1 g of DMAP catalyst, refluxing at 80°C for 24 h, and removing by rotary evaporation at 60°C. The dimethylglyoxime functionalized ligand was prepared by recrystallization with ethanol as solvent. 0.16 g of the dimethylglyoxime functionalized ligand, 0.20 g of zirconium tetrachloride, 30 ml of DMF, and 1 ml of acetic acid were mixed and crystallized at 120 °C for 24 h. The mixture was then washed three times with methanol and activated under vacuum at 150 °C for 12 h at a vacuum degree of 0.085 MPa to obtain MOFs with dimethylglyoxime groups, which were then used as adsorbent particles. The recovered adsorbent particles were desorbed using 0.1 M EDTA-2Na. The remaining steps were the same as in Example 2.

[0052] Comparative Example 3

[0053] The difference between Comparative Example 3 and Example 2 is that step (4) is omitted, and step (5) is changed to: slowly adding the magnesium sulfate waste liquid after extraction to a strong alkaline aqueous solution, with a molar ratio of magnesium sulfate to strong alkali of 1:1, reacting at room temperature for 2.5 hours, and the reaction temperature is 50°C; the source of the strong alkaline aqueous solution is: solid barium sulfate salt is washed twice with deionized water, dried at 100°C for 2 hours, calcined to prepare barium oxide, and then mixed with deionized water to react, with a solid-liquid mass ratio of 1:4, and a reaction time of 2 hours to form a strong alkaline aqueous solution, which is then recycled in the production process; the remaining steps are the same as in Example 2.

[0054] Example of effect

[0055] The table below presents the performance analysis results of a nickel-cobalt hydrometallurgical recycling process using Examples 1 to 3 and Comparative Examples 1 to 3 of the present invention.

[0056] Table 1. Mass fraction of various metallic elements in laterite nickel ore

[0057] Fe (%) Mn(%) Si (%) Mg (%) Al(％) Cr(％) Ni (%) Co (%) Laterite nickel ore 16.84 0.34 8.79 12.62 1.23 1.18 1.57 0.024

[0058] Table 2 Recovery rates of various metal elements after one cycle of hydrometallurgical processing of laterite nickel ore

[0059] Mg (%) Ni (%) Co (%) Example 1 98.92 99.05 98.97 Example 2 99.25 99.14 99.20 Example 3 99.18 99.08 99.15 Comparative Example 1 98.10 97.35 97.42 Comparative Example 2 98.65 98.02 98.10 Comparative Example 3 95.83 92.76 93.15

[0060] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No markings in the claims should be construed as limiting the scope of the claims.

Claims

1. A nickel-cobalt hydrometallurgical cycle process, characterized in that, The process comprises the following steps: (1) pretreatment of laterite nickel ore, acid leaching; in the leaching process, first assisted by 2-4h ultrasonic, power is 250-350W, then assisted by 4-6h high pressure, pressure is 1.5-2.0MPam, to obtain leaching solution; (2) adding CaCO3 to the leaching solution and neutralizing to pH=4.0; removing the precipitate by filtration; using the regenerated magnesium bicarbonate in step (6) as saponification agent, reacting with blank organic phase for saponification, the CO2 generated by saponification is treated by gas recovery device and then delivered to step (6); (3) after saponification, the organic phase is reacted with the filtered leaching solution for extraction; extraction temperature is 40℃, extraction stage is 10 stages, the volume ratio of organic phase to leaching solution is 1:1, the blank organic phase after back extraction is returned to step (2) for saponification again; (4) Take the extracted magnesium sulfate waste liquid, filter it through a resin filter membrane at a flow rate of 3-5 BV / h; then add adsorption particles to the filtered waste liquid at a dosage of 1-5 g / L, stir for 20-40 min, and recover the remaining waste liquid; the preparation method of the resin filter membrane is as follows: polyvinylpyrrolidone is added to N-methylpyrrolidone at a concentration of 5-10 wt%, magnetically stirred for 3 h, slowly added with polyacrylic acid with a molecular weight of 25 w at a concentration of 10 wt%, and continuously stirred for 12 h at a temperature controlled at 40 DEG C; the solution is transferred to a sealed container, left to stand for 24 h for vacuum degassing, poured onto a clean glass plate after degassing, and the thickness is controlled at 400 mu m by a film scraper; then the glass plate is immediately immersed in a room temperature deionized water bath for 30 min to prepare a microporous polyacrylic acid resin membrane with a pore size of 0.5 mu m; the resin membrane is immersed in a 3-aminopropyltriethoxysilane / toluene solution with a mass fraction of 5-8% at a solid-liquid ratio of 1:10, protected by nitrogen gas, refluxed at 80 DEG C for 6 h, centrifugally separated to remove the reagent, then washed with toluene and ethanol alternately for 3 times, and vacuum dried at 60 DEG C for 12 h to prepare an aminated resin membrane; the aminated resin membrane is immersed in a glutaraldehyde aqueous solution with a mass fraction of 2.5% at a solid-liquid ratio of 1:10, the glutaraldehyde aqueous solution has a pH of 7.0, and oscillation is carried out at 40 DEG C for 4 h to prepare an aldehyde group activated resin membrane after filtration, washing and drying; then L-histidine is dissolved in a phosphate buffer with a pH of 8.0, and the concentration of L-histidine is 0.1 M; the aldehyde group activated resin membrane is added to the solution, and the molar ratio of histidine to aldehyde group is 1-1.2:1, oscillation is carried out at 50 DEG C for 12 h, then the residual aldehyde group is blocked with 0.1 M ethanolamine for 2 h, and the histidine modified resin membrane is prepared after filtration, washing and drying; the histidine modified resin membrane is immersed in a 0.05 M ZnSO4 aqueous solution, the molar ratio of Zn2+ to histidine is 1.5-2.0:1, oscillation is carried out at 25 DEG C for 4 h, and the resin filter membrane is prepared after filtration, washing and drying; the preparation method of the adsorption particles is as follows: 10 g of dimethylglyoxime and 9.8 g of succinic anhydride are dissolved in 100 mL of acetonitrile, 0.1 g of DMAP catalyst is added, refluxed at 80 DEG C for 24 h, the solvent is removed by rotary evaporation, and recrystallized with ethanol to prepare a dimethylglyoxime functionalized ligand; 0.15-0.17 g of dimethylglyoxime functionalized ligand, 0.18-0.22 g of zirconium tetrachloride, 30 ml of DMF and 1 ml of acetic acid are mixed, crystallized at 120 DEG C for 24 h, washed with methanol for 3 times, vacuum activated at 150 DEG C for 12 h to prepare MOF with dimethylglyoxime groups as adsorption particles; (5) The recovered waste liquid is slowly added to a strong alkali aqueous solution, the molar ratio of magnesium sulfate to strong alkali is 1:1, and the reaction is carried out at room temperature for 1.5-3.5 h at a reaction temperature of 40-60 DEG C; (6) After the reaction is completed, part of the slurry is filtered by a vacuum filter, and the filtered water phase is returned to the pretreatment section of step (1) or is prepared into a strong alkaline aqueous solution; the filter residue and the remaining unfiltered mixed slurry are put into a high-pressure reaction kettle, then CO2 gas is introduced into the kettle under stirring, and after the reaction is completed, solid-liquid separation is performed, the solid is an insoluble barium sulfate salt, and the liquid water phase is a magnesium bicarbonate solution.

2. A nickel-cobalt hydrometallurgical cycle process according to claim 1, characterized in that, The pretreatment in step (1) is as follows: the laterite nickel ore is crushed to 80 mesh, is dehydrated by roasting at 680-720 DEG C for 2 h, is then immersed and washed with 15wt% HF, the solid-liquid ratio is 1:3, stirring is performed at room temperature for 1 h, and the pretreated ore is obtained by filtration and drying; acid leaching of the laterite nickel ore is as follows: the ore is immersed with concentrated sulfuric acid with a concentration of 200-300 g / L, the solid-liquid ratio is 1:4, 0.5wt% H2O2 is further added, and stirring is performed at 80 DEG C under normal pressure for 6-10 h.

3. The nickel-cobalt hydrometallurgical cycle process according to claim 1, characterized in that, In step (2), the volume ratio of the organic phase to the aqueous phase during saponification is 1:2, the blank organic phase is P204 or P507, the concentration of the blank organic phase is 20%, the saponification temperature is 30 DEG C, and the saponification time is 10 min.

4. The nickel-cobalt hydrometallurgical cycle process according to claim 1, characterized in that, The resin filter membrane used in step (4) can be desorbed by 0.5M H2SO4 and 0.1M ascorbic acid.

5. The nickel-cobalt hydrometallurgical cycle process according to claim 1, characterized in that, The recovered adsorption particles are desorbed by 0.1M EDTA-2Na.

6. The nickel-cobalt hydrometallurgical cycle process according to claim 1, characterized in that, In step (4), the whole reaction temperature is 25-35 DEG C.

7. The nickel-cobalt hydrometallurgical cycle process according to claim 1, characterized in that, In step (5), the strong alkaline aqueous solution is obtained as follows: the solid barium sulfate salt is washed with deionized water for 2 times, is dried by drying at 100 DEG C for 2 h, is prepared into barium oxide by high-temperature calcination, and then is mixed with deionized water to react, the solid-liquid mass ratio is 1:3-5, the reaction time is 2 h, a strong alkaline aqueous solution is formed, and is recycled in the production link.

8. The nickel-cobalt hydrometallurgical cycle process according to claim 1, characterized in that, In step (6), the gas flow is 1-3 L / min when CO2 gas is introduced, the kettle pressure is maintained at 0.5-0.6 MPa, the reaction time is 1.5-3.5 h, the temperature is 5-35 DEG C, and the stirring speed is 250-350 rpm.