A method for leaching nickel metal

Abstract

The present invention discloses a method for leaching nickel metal, which comprises the following steps: S1. After adding water to the nickel intermediate product for pulp making, adding a modified iron oxide nanomaterial and concentrated sulfuric acid to adjust the pH value to 0.5 - 1.0 and reacting to obtain a mixed solution 1; S2. Reacting the mixed solution 1 and hydrogen peroxide at a pH value between 1.5 - 2.5, heating and then filtering; S3. Adding water to the filtered leaching residue for pulp making, adding hydrogen peroxide for oxidation reaction, then adding concentrated sulfuric acid to adjust the pH value to 1.0 - 1.5 for acidification reaction and then filtering; The preparation raw materials of the modified iron oxide nanomaterial include iron oxide nanoparticles and dithiopropionic acid. The present invention provides a method for leaching nickel metal, which forms a complex with nickel and cobalt, thereby promoting the leaching of the metal.

Description

Technical Field

[0001] The present invention belongs to the technical field of metallurgy, and particularly relates to a method for leaching nickel metal. Background Art

[0002] At present, the new energy energy storage industry is in a stage of rapid development, and the consumption of batteries is increasing continuously, resulting in the generation of a large number of waste batteries. Therefore, the recycling of waste batteries has become a field of great concern, mainly for two reasons: First, recycling waste batteries can realize the reuse of heavy metal elements and achieve the purpose of recycling resources. Second, recycling old batteries can prevent their harm to the environment and human health.

[0003] In summary, it is urgent to propose a method for leaching nickel metal to improve the leaching rate of nickel metal. Summary of the Invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. For this purpose, the present invention proposes a method for leaching nickel metal to form a complex with nickel and cobalt, thereby promoting the leaching of metals.

[0005] According to the first aspect embodiment of the present invention, a method for leaching nickel metal is proposed, including the following steps:

[0006] S1. After adding water to the nickel intermediate product to make a slurry, then adding a modified iron oxide nanomaterial and concentrated sulfuric acid to adjust the pH value to 0.5 - 1.0 and reacting to obtain a mixed solution 1;

[0007] S2. Reacting the mixed solution 1 and hydrogen peroxide at a pH value between 1.5 - 2.5, heating and reacting, and then filtering;

[0008] S3. After adding water to the leaching residue obtained by filtration to make a slurry, adding hydrogen peroxide for reaction, then adding concentrated sulfuric acid to adjust the pH value to 1.0 - 1.5 for acidification reaction, and then filtering;

[0009] The preparation raw materials of the modified iron oxide nanomaterial include iron oxide nanoparticles and dithiopropionic acid.

[0010] According to the embodiment of the first aspect of the present invention, it has at least the following beneficial effects:

[0011] 1. In the present invention, the addition of concentrated sulfuric acid makes the reaction system in an acidic environment, which helps to promote the dissolution reaction of cobalt and nickel metals. After surface modification, iron oxide nanoparticles (Fe3O4) have good selective adsorption ability and high affinity for cobalt and nickel ions. At the same time, dithiopropionic acid ((DTPA)) is coated on the surface of the modified iron oxide nanoparticles. Multiple sulfur atoms of DTPA can provide coordination sites to form stable complexes with cobalt and nickel ions and increase the selective interaction with cobalt and nickel ions. Due to the selective interaction between DTPA and cobalt and nickel ions, the complexation ability with other metal ions is weak. By introducing functionalized nanomaterials (modified iron oxide nanomaterials), the interference reaction between other metal ions and iron oxide nanoparticles can be prevented, thus realizing the selective dissolution of cobalt and nickel ions. A large number of DTPA functional groups are introduced on the surface of DTPA-modified iron oxide, making the iron oxide have stronger chelating ability and being able to capture and enrich cobalt and nickel ions more effectively. Therefore, the selective dissolution ability of cobalt and nickel ions will be significantly improved; 2. The modified iron oxide nanomaterials can catalyze the decomposition of hydrogen peroxide to generate free radicals, which can further oxidize metals, thus reducing the usage amount of hydrogen peroxide.

[0012] 2. Maintain the pH value of the solution during the reaction. If the pH value is too low, the consumption of concentrated sulfuric acid will increase, raising the production cost. If the pH value is too high, a good acid dissolution effect cannot be achieved.

[0013] According to some embodiments of the present invention, in the step of adding water for pulp making in step S1, the liquid-solid ratio of the water to the nickel intermediate is 3.5 - 4.5:1.

[0014] According to some embodiments of the present invention, in step S2, the mass ratio of the hydrogen peroxide to the cobalt and nickel metals in the nickel intermediate is 0.6 - 0.8:1.

[0015] According to some embodiments of the present invention, in step S2, the temperature of the reaction is 80 - 90 °C.

[0016] According to some embodiments of the present invention, in step S2, the time for the heating reaction is 2 h.

[0017] According to some embodiments of the present invention, in step S2, the heating temperature of the reaction is 80 - 95 °C.

[0018] According to some embodiments of the present invention, in step S2, the mass ratio of the hydrogen peroxide to the metals in the nickel intermediate is 0.6 - 0.8:1.

[0019] According to some embodiments of the present invention, in step S2, the metals are cobalt and nickel.

[0020] According to some embodiments of the present invention, in the step of adding water for pulp making in step S3, the liquid-solid ratio of water to nickel intermediate product is 3.5 to 4.5:1.

[0021] According to some embodiments of the present invention, in step S3, the concentration of hydrogen peroxide is 25 to 30%.

[0022] According to some embodiments of the present invention, in step S3, the reaction time is 30 to 50 min

[0023] According to some embodiments of the present invention, in step S3, the temperature of the acidification reaction is 80 to 95 °C.

[0024] According to some embodiments of the present invention, in step S3, the time of the acidification reaction is 1.5 to 2.5 h.

[0025] According to some embodiments of the present invention, the concentration of the modified iron oxide nanomaterial is 0.5 to 1 mol / L.

[0026] According to some embodiments of the present invention, the preparation method of the modified iron oxide nanomaterial includes: dispersing iron oxide nanoparticles and then mixing and reacting with a solution of dithiopropionic acid, followed by impurity removal and drying.

[0027] According to some embodiments of the present invention, in the step of dispersing the iron oxide nanoparticles, the dispersion liquid is ethanol.

[0028] According to some embodiments of the present invention, the molar ratio of the iron oxide nanoparticles to the dithiopropionic acid is 1:1 to 3. Detailed Embodiments

[0029] To better illustrate the purpose, technical solution and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments. Those skilled in the art should understand that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0030] Unless otherwise specified, the test methods used in the examples are all conventional methods; the materials, reagents, etc. used, unless otherwise specified, can all be obtained from commercial channels.

[0031] Example 1

[0032] This example provides a method for leaching nickel metal, and the specific steps are as follows:

[0033] Prepare a modified iron oxide nanomaterial:

[0034] A1. Add iron oxide nanoparticles to ethanol and perform ultrasonic treatment to make them evenly dispersed;

[0035] A2. Add an appropriate amount of DTPA to water and stir to dissolve it;

[0036] A3. Slowly drop the DTPA suspension into the ethanol dispersion of iron oxide nanoparticles while mechanically stirring for 1 h. Control the reaction temperature at room temperature. After the reaction, collect the precipitated functionalized nanoparticles by centrifugation;

[0037] A4. Wash the collected nanoparticles with ethanol to remove residual substances such as unreacted DTPA. Finally, dry the nanomaterials in vacuo to obtain modified iron oxide nanomaterials.

[0038] Leaching of nickel metal:

[0039] Materials used: Cobalt content: 4.98%, Nickel content: 16.69%;

[0040] B1. Take 100 g of the material, add tap water to the nickel intermediate product according to the liquid-solid mass ratio of 3.5:1 to make a slurry, add the modified iron oxide nanomaterials with a concentration of 0.8 mol / L, add concentrated sulfuric acid to adjust the pH value to 1.0, then add 30% hydrogen peroxide (the mass of hydrogen peroxide is 0.5 times the total mass of the raw material cobalt and nickel metals), maintain the pH value between 1.0 and 1.5, heat to 85 °C and keep the reaction for 2 h, and filter to obtain a first-stage acid solution and a first-stage acid-insoluble residue;

[0041] B2. The first-stage acid-insoluble residue after filtration is slurried with tap water according to the liquid-solid mass ratio of 4:1, add 30% hydrogen peroxide (the mass of hydrogen peroxide is 1 times the total mass of the raw material cobalt and nickel metals), react for 30 min, then add concentrated sulfuric acid to adjust the pH value to 1.0 - 1.5, heat to 85 °C and keep the reaction for 2 h, and filter.

[0042] Detection results of the first-stage acid solution: Acid solution volume: 450 ml, Cobalt content: 1.75 g / L, Nickel content: 30.68 g / L, pH: 1.30;

[0043] Detection results of the first-stage acid-insoluble residue: Acid-insoluble residue mass: 28.70 g, Cobalt content: 0.55%, Nickel content: 1.63%;

[0044] Detection results of the second-stage acid-insoluble residue: Acid-insoluble residue mass: 4.41 g, Cobalt content: 0.10%, Nickel content: 0.19%.

[0045] Example 2

[0046] This example provides a method for leaching nickel metal, and the specific steps are as follows:

[0047] Preparation of modified iron oxide nanomaterials:

[0048] A1. Add iron oxide nanoparticles to ethanol and perform ultrasonic treatment to disperse them evenly.

[0049] A2. Add an appropriate amount of DTPA to water and stir to dissolve.

[0050] A3. Slowly drip the DTPA suspension into the ethanol dispersion of iron oxide nanoparticles while performing mechanical stirring for 1 h. Control the reaction temperature at room temperature. After the reaction, collect the precipitated functionalized nanoparticles by centrifugation.

[0051] A4. Wash the collected nanoparticles with ethanol to remove residual substances such as unreacted DTPA. Finally, dry the nanomaterials in vacuo to obtain modified iron oxide nanomaterials.

[0052] Leaching of nickel metal:

[0053] Materials used: Cobalt content: 4.98%, Nickel content: 16.69%.

[0054] B1. Take 100 g of the material, add tap water to the nickel intermediate product according to a liquid-solid mass ratio of 4:1 to make a slurry, add the modified iron oxide nanomaterials with a concentration of 0.8 mol / L, add concentrated sulfuric acid to adjust the pH value to 1.0, then add 30% hydrogen peroxide (the mass of hydrogen peroxide is 0.5 times the total mass of the raw material cobalt and nickel metals), maintain the pH value between 1.5 - 2.5, heat to 85 °C and hold for 2 h, and filter to obtain a first-stage acid solution and a first-stage acid-insoluble residue.

[0055] B2. Add tap water to the first-stage acid-insoluble residue after filtration according to a liquid-solid mass ratio of 4:1 to make a slurry, add 30% hydrogen peroxide (the mass of hydrogen peroxide is 1 times the total mass of the raw material cobalt and nickel metals), react for 30 min, then add concentrated sulfuric acid to adjust the pH value to 1.0 - 1.5, heat to 85 °C and hold for 2 h, and filter.

[0056] Test results of the first-stage acid solution: Acid solution volume: 340 ml, Cobalt content: 2.43 g / L, Nickel content: 50.26 g / L, pH: 1.53.

[0057] Test results of the first-stage acid-insoluble residue: Acid-insoluble residue mass: 29.03 g, Cobalt content: 0.69%, Nickel content: 1.87%.

[0058] Test results of the second-stage acid-insoluble residue: Acid-insoluble residue mass: 3.66 g, Cobalt content: 0.3%, Nickel content: 0.55%.

[0059] Example 3

[0060] This example provides a method for leaching nickel metal, and the specific steps are as follows:

[0061] Preparation of modified iron oxide nanomaterials:

[0062] A1. Add iron oxide nanoparticles to ethanol and perform ultrasonic treatment to disperse them evenly.

[0063] A2. Add an appropriate amount of DTPA to water and stir to dissolve it.

[0064] A3. Slowly drip the DTPA suspension into the ethanol dispersion of iron oxide nanoparticles while mechanically stirring for 1 h. Control the reaction temperature at room temperature. After the reaction, collect the precipitated functionalized nanoparticles by centrifugation.

[0065] A4. Wash the collected nanoparticles with ethanol to remove residual substances such as unreacted DTPA. Finally, dry the nanomaterials in vacuum to obtain modified iron oxide nanomaterials.

[0066] Leaching nickel metal:

[0067] Materials used: Cobalt content: 1.57%, nickel content: 16.55%.

[0068] B1. Take 400.15 g of materials, add tap water to the nickel intermediate product according to a liquid-solid mass ratio of 3.5:1 to make a slurry, add the modified iron oxide nanomaterials with a concentration of 0.8 mol / L, add concentrated sulfuric acid to adjust the pH value to 1.0, then add 30% hydrogen peroxide (the mass of hydrogen peroxide is 0.8 times the total mass of the raw material cobalt and nickel metals) while maintaining the pH value between 1.5 - 2.5, heat to 80 - 90 °C and hold for 2 h, then filter.

[0069] Detection results of the acid solution: Acid solution volume: 1920 ml, cobalt content: 4.02 g / L, nickel content: 33.00 g / L, pH: 2.09.

[0070] There is too little acid-soluble residue in this portion of the materials to be sent for inspection.

[0071] Comparative Example 1

[0072] This comparative example provides a method for leaching nickel metal. The difference between this comparative example and Example 1 is that it does not include the modified nanomaterials, and the other conditions are the same as those in Example 1.

[0073] Detection results of the first-stage acid solution: Acid solution volume: 450 ml, cobalt content: 0.65 g / L, nickel content: 20.32 g / L, pH: 1.50;

[0074] Detection results of the first-stage acid-soluble residue: Acid-soluble residue mass: 29.60 g, cobalt content: 0.21%, nickel content: 0.51%;

[0075] Detection results of the two-stage acid-soluble slag: mass of acid-soluble slag: 4.3 g, cobalt content: 0.05%, nickel content: 0.03%.

[0076] Comparative Example 2

[0077] This comparative example provides a method for leaching nickel metal. The difference between this comparative example and Example 1 is that acetylpyruvic acid is used to replace dithiopropionic acid in Example 1, and the remaining conditions are the same as those in Example 1.

[0078] Detection results of the first-stage acid solution: volume of acid solution: 450 ml, cobalt content: 0.82 g / L, nickel content: 26.32 g / L, pH: 1.50;

[0079] Detection results of the first-stage acid-soluble slag: mass of acid-soluble slag: 28 g, cobalt content: 0.41%, nickel content: 0.81%;

[0080] Detection results of the two-stage acid-soluble slag: mass of acid-soluble slag: 4.5 g, cobalt content: 0.06%, nickel content: 0.13%.

[0081] Comparative Example 3

[0082] This comparative example provides a method for leaching nickel metal. The difference between this comparative example and Example 1 is that the iron oxide nanoparticles are not modified with dithiopropionic acid, and the remaining conditions are the same as those in Example 1.

[0083] Detection results of the first-stage acid solution: volume of acid solution: 450 ml, cobalt content: 0.78 g / L, nickel content: 23.22 g / L, pH: 1.50;

[0084] Detection results of the first-stage acid-soluble slag: mass of acid-soluble slag: 26 g, cobalt content: 0.35%, nickel content: 0.66%;

[0085] Detection results of the two-stage acid-soluble slag: mass of acid-soluble slag: 4.0 g, cobalt content: 0.046%, nickel content: 0.10%.

[0086] In the present invention, by reacting iron oxide nanoparticles with DTPA and through washing and drying processes, a modified iron oxide nanomaterial is obtained, which helps improve the reaction efficiency and selectivity. Since the modified iron oxide nanomaterial has the ability to catalytically decompose hydrogen peroxide and can promote the dissolution of metals, it helps reduce the usage amount of hydrogen peroxide. In Comparative Example 1, the modified nanomaterial is not included, resulting in a decrease in leaching efficiency under the same usage of hydrogen peroxide. In Comparative Example 2, when acetylpyruvic acid is used to modify iron oxide nanoparticles instead of dithiopropionic acid, the coordination ability of acetylpyruvic acid may be inferior to that of dithiopropionic acid, leading to a decrease in the binding ability of the modified iron oxide nanomaterial with target metal ions, thus affecting the leaching efficiency. At the same time, the iron oxide nanomaterial modified with acetylpyruvic acid is unstable in the reaction system and prone to aggregation or precipitation, resulting in a reduction in the effective surface area and further affecting the leaching efficiency of metal ions. In Comparative Example 3, the chelating ability of iron oxide without DTPA modification is reduced, and it cannot capture and enrich cobalt and nickel ions more effectively. Therefore, the selective dissolution ability of cobalt and nickel ions will decrease.

[0087] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the protection scope of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A method for leaching nickel metal, characterized in that, It includes the following steps: S1. Take 400.15 g of materials, add tap water to the nickel intermediate product for pulp making according to the liquid-solid mass ratio of 3.5:1, add the modified iron oxide nanomaterial, the concentration of the modified iron oxide nanomaterial is 0.8 mol / L, add concentrated sulfuric acid to adjust the pH value to 1.0, then add 30% hydrogen peroxide, the mass of hydrogen peroxide is 0.8 times the total amount of raw material cobalt and nickel metals, and at the same time maintain the pH value between 1.5 - 2.5, heat to 80 - 90 °C for heat preservation reaction for 2 h, and filter; The preparation method of the modified iron oxide nanomaterial is as follows: A1. Add iron oxide nanoparticles to ethanol and perform ultrasonic treatment to make them disperse evenly; A2. Add an appropriate amount of dithiopropionic acid to water and stir to dissolve; A3. Slowly drop the dithiopropionic acid suspension into the ethanol dispersion of iron oxide nanoparticles, and at the same time perform mechanical stirring for 1 h, control the reaction temperature at room temperature, and collect the precipitated functionalized nanoparticles by centrifugation after the reaction; A4. Wash the collected nanoparticles with ethanol to remove the residual substances of unreacted dithiopropionic acid, and finally dry the ethanol-washed nanoparticles in vacuum to obtain the modified iron oxide nanomaterial.