A method for preparing ternary cathode materials from a nickel-cobalt-manganese-containing ammoniacal solution

Abstract

This invention provides a method for preparing ternary cathode materials from an ammoniacal solution containing nickel, cobalt, and manganese, comprising: Step S1, directly evaporating ammonia from the ammoniacal solution containing nickel, cobalt, and manganese to obtain a nickel-cobalt-manganese enrichment; the ammonia gas generated during the evaporation process and the residual liquid after condensation and absorption, and then being prepared for recycling ammonia leaching; Step S2, mixing the nickel-cobalt-manganese enrichment from Step S1 with a small amount of nickel / cobalt / manganese source and lithium source at a specific molar ratio to control the composition; the mixture after composition control is calcined to prepare the ternary cathode material. This invention avoids the complex separation of nickel, cobalt, and manganese in the solution and the product preparation process, achieving a short-process synergistic recovery of nickel, cobalt, and manganese from the ammoniacal solution and preparing ternary cathode materials. Furthermore, the prepared ternary cathode material is free of sulfur impurities, has higher quality, and the process is simple and generates no waste liquid.

Description

Technical Field

[0001] This invention relates to the field of resource recycling and processing technology, and in particular to a method for preparing ternary cathode materials from a nickel-cobalt-manganese-containing ammoniacal solution. Background Technology

[0002] Nickel, cobalt, and manganese are all important strategic energy metals. In recent years, the rapid development of the new energy vehicle industry has led to an explosive growth in the demand for nickel, cobalt, and manganese resources. To maintain industrial stability and ensure resource supply security, it is crucial to extract and recover nickel, cobalt, and manganese from primary and secondary resources in a low-carbon and efficient manner.

[0003] Ammonia leaching is favored due to its high selectivity for transition metals. In nickel-cobalt-manganese resources, only nickel, cobalt, and manganese form complexes with ammonia (Me(NH3)) during the ammonia leaching process. i z+ When the leaching solution is relatively pure, subsequent purification and product preparation steps can be greatly reduced. For example, the reduction roasting-ammonia leaching and direct ammonia leaching processes for laterite nickel ore and degraded ternary cathode materials have been extensively studied. However, for ammonia solutions containing nickel, cobalt, and manganese after ammonia leaching, it is also extremely important to find a short-process and efficient way to recover nickel, cobalt, and manganese from them.

[0004] Ternary cathode materials are one of the most important applications of nickel, cobalt, and manganese. The traditional method for preparing ternary cathode materials involves co-precipitating sulfate followed by calcination with a lithium source. However, the cathode materials prepared by this method inevitably contain sulfate ions, which can easily lead to excessive sulfur content in the product. If ternary cathode materials are prepared directly from an ammoniacal solution containing nickel, cobalt, and manganese, not only can a short-process recovery of nickel, cobalt, and manganese be achieved, but the problem of sulfur impurities in the final product can also be avoided from the source.

[0005] Chinese patent CN 115571925 A describes a method for preparing ternary precursors by co-precipitating ammonia leaching solutions containing nickel, cobalt, and manganese from waste batteries using caustic alkali and controlling the pH to 10-12. While this method achieves the recovery of nickel, cobalt, and manganese and the preparation of precursors, the recovery process consumes alkali, and the resulting co-precipitated solution is high-sodium wastewater. Existing technologies for recovering nickel, cobalt, and manganese from ammonia solutions and preparing cathode materials suffer from significant problems such as long process flows and the generation of saline wastewater. Therefore, there is an urgent need to develop a low-carbon, sustainable new technology for the co-recovery of nickel, cobalt, and manganese from ammonia solutions and the preparation of ternary materials. Summary of the Invention

[0006] To address the prominent problems of existing technologies in recovering nickel, cobalt, and manganese from ammoniacal solutions and preparing cathode materials, such as long process flow, generation of saline wastewater, and sulfur impurities in the products, this invention provides a new method. This method achieves synergistic and efficient recovery of nickel, cobalt, and manganese from ammoniacal solutions and prepares ternary cathode materials. The recovery process realizes the recycling of ammonia, generates no waste liquid, and compared with the traditional sulfate coprecipitation process, the prepared ternary cathode material does not contain sulfur impurities.

[0007] A method for preparing ternary cathode materials from a nickel-cobalt-manganese ammoniacal solution includes:

[0008] Step S1: Directly evaporate ammonia from an ammonia solution containing nickel, cobalt, and manganese to obtain a nickel, cobalt, and manganese enrichment. The ammonia gas generated during the evaporation process and the residual liquid from ammonia evaporation are condensed, absorbed, and then mixed with the residual liquid from ammonia evaporation and used for circulating ammonia leaching (i.e., ammonia gas is absorbed into ammonia water, mixed with the residual liquid from ammonia evaporation, and then mixed with the liquid for circulating ammonia leaching).

[0009] Step S2: Mix the nickel-cobalt-manganese enrichment from step S1 with a small amount of nickel / cobalt / manganese source and lithium source in a certain molar ratio to adjust the composition. The mixture after composition adjustment can be calcined to prepare ternary cathode material.

[0010] Optionally, in step S1, the ammonia solution refers to the ammonia solution generated when a primary or secondary resource containing nickel, cobalt, and manganese reacts with an ammonia-ammonium salt mixed solution. The primary or secondary resource containing nickel, cobalt, and manganese includes, but is not limited to, laterite nickel ore, waste ternary batteries, or nickel, cobalt, and manganese enrichment produced during the smelting process. The ammonium salt is one or more of ammonium carbonate and ammonium bicarbonate.

[0011] If ammonium sulfate is used as the ammonium salt, some sulfate ions will enter the nickel-cobalt-manganese enrichment, ultimately resulting in excessive sulfur content in the prepared nickel-cobalt-manganese cathode material, which reduces battery performance and lifespan.

[0012] Optionally, in step S1, the concentration of nickel in the ammonia solution is ≥1.0 g / L, the concentration of cobalt is ≥1.0 g / L, and the concentration of manganese is ≥0.5 g / L. If the concentrations of nickel, cobalt, and manganese in the ammonia solution do not meet the requirements, their precipitation rate will decrease during the ammonia stripping process.

[0013] Optionally, in step S1, the ammonia stripping process can be carried out under normal or negative pressure. The ammonia stripping temperature under negative pressure is ≥80℃, and the ammonia stripping temperature under normal pressure is ≥110℃. The evaporation volume is not less than 30% of the initial solution volume. If the ammonia stripping temperature or evaporation volume does not meet the requirements, the precipitation rate of nickel, cobalt, and manganese will decrease.

[0014] Optionally, in step S2, the nickel / cobalt / manganese source in the composition control process is selected from one or more of carbonates, oxalates, and oxides, and the lithium source is selected from one or more of lithium hydroxide and lithium carbonate.

[0015] Optionally, in step S2, the molar ratio of nickel, cobalt, and manganese during the composition adjustment process can be selected, but is not limited to, one of 8:1:1, 5:2:3, 1:1:1, or 6:2:2, and the common molar ratio of lithium to nickel, cobalt, and manganese (i.e., lithium:(nickel+cobalt+manganese)) is (1.03~1.05):1. Selecting a molar ratio close to the element content in the nickel-cobalt-manganese enrichment can reduce the amount of corresponding nickel-cobalt-manganese source used.

[0016] Optionally, in step S2, the roasting process adopts two-stage roasting, with the first stage roasting temperature at 400℃~600℃ and the roasting time at 2h~5h, and the second stage roasting temperature at 800℃~900℃ and the roasting time at 10h~12h.

[0017] The beneficial effects of the technical solution provided by this invention include at least the following:

[0018] In this invention, nickel, cobalt, and manganese are first recovered through ammonia stripping, and ammonia and the residual liquid from ammonia stripping are recycled. Nickel, cobalt, and manganese precipitate together and are uniformly mixed in the ammonia stripping product. Based on the nickel, cobalt, and manganese content in the concentrate, a molar ratio close to the component content is selected, and the ammonia stripping product is mixed with a small amount of nickel / cobalt / manganese source and lithium source in the corresponding molar ratio to control the composition. After simple calcination, a ternary cathode material can be prepared.

[0019] This invention features a simple process, short flow, and high metal recovery rate. The ammonia stripping process requires no pH control or addition of other reagents, and the volatilized ammonia and residual liquid can be treated and returned to the ammonia leaching process, achieving synergistic recovery of nickel, cobalt, and manganese while avoiding wastewater generation. The ammonia stripping product, combined with a small amount of mixed nickel, cobalt, and manganese sources and lithium sources, can be mixed and then simply calcined to prepare ternary cathode materials, avoiding the problem of sulfur impurities in the cathode material at the source. This invention connects the downstream of the nickel, cobalt, and manganese recovery process with the battery manufacturing process, achieving efficient and short-process recovery of nickel, cobalt, and manganese from ammoniacal solutions and preparing ternary cathode materials, providing technical support for the recovery and reuse of nickel, cobalt, and manganese resources. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a process flow diagram of the present invention. Detailed Implementation

[0022] The technical solution of this invention is described below.

[0023] In embodiments of the present invention, words such as "exemplarily," "for example," etc., are used to indicate that something is an example, illustration, or description. Any embodiment or design described as "exemplary" in the present invention should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of the word "exemplary" is intended to present the concept in a concrete manner. Furthermore, in embodiments of the present invention, the meaning expressed by "and / or" can be both, or either one.

[0024] In this embodiment of the invention, sometimes a subscript such as W1 may be mistakenly written as a non-subscript form such as W1. When the difference is not emphasized, the meaning they express is the same.

[0025] To make the technical problems, technical solutions and advantages of the present invention clearer, a detailed description will be given below in conjunction with the accompanying drawings and specific embodiments.

[0026] Example 1

[0027] For the ammonia solution (Ni: 15.5 g / L, Co: 2.0 g / L, Mn: 0.5 g / L) generated during the stepwise ammonia leaching of the water-leached residue from waste nickel-cobalt-manganese ternary batteries after reduction roasting and water leaching with an ammonia-ammonium carbonate mixed solution, 1 L of the ammonia solution was placed under normal pressure for direct ammonia stripping. The ammonia stripping temperature was controlled at 130℃, and the evaporation volume was 30% of the initial solution volume. The precipitation rates of nickel, cobalt, and manganese reached 93.25%, 94.68%, and 98.75%, respectively. The molar ratio of nickel:cobalt:manganese in the nickel-cobalt-manganese enrichment obtained by ammonia stripping was 24.63:3.21:2.74. The composition of the ammonia precipitate was controlled by mixing it with a small amount of nickel carbonate, manganese tetroxide, and lithium carbonate in a nickel:cobalt:manganese molar ratio of 8:1:1 and a lithium:(nickel+cobalt+manganese) molar ratio of 1.03:1. The mixture was then calcined at 400℃ for 5 hours and at 800℃ for 12 hours to prepare the 811 type ternary cathode material.

[0028] Example 2

[0029] For the ammonia solution (Ni: 1 g / L, Co: 2.0 g / L, Mn: 0.5 g / L) generated during the stepwise ammonia leaching of the water-leached residue from waste nickel-cobalt-manganese ternary batteries after reduction roasting and water leaching with an ammonia-ammonium bicarbonate mixed solution, 1 L of the ammonia solution was placed under normal pressure for direct ammonia stripping. The ammonia stripping temperature was controlled at 110℃, and the evaporation volume was 50% of the initial solution volume. The precipitation rates of nickel, cobalt, and manganese reached 89.74%, 90.32%, and 95.36%, respectively. The molar ratio of nickel:cobalt:manganese in the nickel-cobalt-manganese enrichment obtained by ammonia stripping was 2:3:1. The ammonia precipitate was mixed with a small amount of nickel carbonate, manganese oxalate, and lithium hydroxide in a nickel:cobalt:manganese molar ratio of 1:1:1 and a lithium:(nickel+cobalt+manganese) molar ratio of 1.05:1 and ball-milled to adjust the composition. The mixture was then calcined at 600℃ for 2 hours and at 900℃ for 10 hours to prepare the 111 type ternary cathode material.

[0030] Example 3

[0031] For the ammonia solution (Ni: 2.5 g / L, Co: 1.0 g / L, Mn: 1.6 g / L) generated during the stepwise ammonia leaching of nickel-cobalt-manganese concentrate from laterite nickel ore acid leaching with an ammonia-ammonium bicarbonate mixed solution, 1 L of the ammonia solution was subjected to negative pressure ammonia stripping. The negative pressure inside the device was maintained at -0.25 MPa using a vacuum pump, the ammonia stripping temperature was controlled at 80℃, and the evaporation volume was 40% of the initial solution volume. The precipitation rates of nickel, cobalt, and manganese reached 91.43%, 95.96%, and 98.34%, respectively. The molar ratio of nickel:cobalt:manganese in the nickel-cobalt-manganese concentrate obtained by ammonia stripping was 13.16:5.14:8.02. The ammonia precipitate was mixed with a small amount of nickel carbonate, cobalt oxalate, and lithium carbonate in a nickel:cobalt:manganese molar ratio of 5:2:3 and a lithium:(nickel+cobalt+manganese) molar ratio of 1.03:1 and ball-milled to adjust the composition. The mixture was then calcined at 400℃ for 5 hours and at 800℃ for 12 hours to prepare the 523 type ternary cathode material.

[0032] Example 4

[0033] For the ammonia solution (Ni: 18.46 g / L, Co: 5.78 g / L, Mn: 6.35 g / L) generated during the stepwise ammonia leaching of the water-leached residue from waste nickel-cobalt-manganese ternary batteries after reduction roasting and water leaching with an ammonia-ammonium carbonate mixed solution, 1 L of the ammonia solution was subjected to negative pressure ammonia stripping. The vacuum pump was used to extract the ammonia solution at a negative pressure of -0.20 MPa, the ammonia stripping temperature was controlled at 100℃, and the evaporation volume was 50% of the initial solution volume. The precipitation rates of nickel, cobalt, and manganese reached 95.26%, 96.81%, and 98.63%, respectively. The molar ratio of nickel:cobalt:manganese in the nickel-cobalt-manganese enrichment obtained by ammonia stripping was 3.01:0.95:1.14. The composition of the ammonia precipitate was controlled by mixing it with a small amount of cobalt tetroxide, manganese tetroxide and lithium hydroxide according to the molar ratio of nickel:cobalt:manganese of 5:2:3 and the molar ratio of lithium:(nickel+cobalt+manganese) of 1.04:1. The mixture was then calcined at 500℃ for 2 hours and at 850℃ for 10 hours to prepare the 523 type ternary cathode material.

[0034] Comparative Example 1

[0035] The ammonia solution in Example 1 was subjected to ammonia stripping at atmospheric pressure. When the stripping temperature was controlled at 100°C and the evaporation volume was 40% of the initial volume, the precipitation rates of nickel, cobalt, and manganese were 40.57%, 30.45%, and 80.89%, respectively. It can be seen that when the stripping temperature is below 110°C, the precipitation rates of nickel, cobalt, and manganese will decrease.

[0036] Comparative Example 2

[0037] The ammonia solution in Example 3 was subjected to negative pressure ammonia removal. The vacuum pump was used to extract the ammonia at a negative pressure of -0.25 MPa, and the ammonia removal temperature was controlled at 90°C. When the evaporation volume was 20% of the initial volume, the precipitation rates of nickel, cobalt, and manganese were 80.73%, 83.57%, and 88.46%, respectively. This shows that when the evaporation volume is less than 30% of the initial solution volume, the precipitation rates of nickel, cobalt, and manganese will decrease.

[0038] Comparative Example 3

[0039] The ammonia solution from Example 3 was diluted to nickel, cobalt, and manganese concentrations of 0.625 g / L, 0.25 g / L, and 0.4 g / L, respectively. One L of the diluted ammonia solution was then subjected to negative pressure ammonia evaporation. The vacuum pump maintained a negative pressure of -0.25 MPa, the ammonia evaporation temperature was controlled at 80°C, and the evaporation volume was 40% of the initial solution volume. The precipitation rates of nickel, cobalt, and manganese reached 32.61%, 26.45%, and 56.37%, respectively. This demonstrates that when the concentrations of nickel, cobalt, and manganese in the solution are at lower levels, their precipitation rates are significantly reduced.

[0040] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for producing a ternary cathode material from a nickel-cobalt-manganese-containing ammoniacal solution, characterized in that, The application relates to a preparation method of a ternary positive electrode material, and belongs to the field of material preparation. The method comprises the following steps: S1, directly evaporating ammonia from an ammonia solution containing nickel, cobalt and manganese to obtain a nickel-cobalt-manganese enrichment, and ammonia gas generated in the evaporation process is absorbed and mixed with the evaporation residue to prepare a solution for recycling ammonia leaching; the ammonia solution contains nickel with a concentration of greater than or equal to 1.0 g / L, cobalt with a concentration of greater than or equal to 1.0 g / L and manganese with a concentration of greater than or equal to 0.5 g / L; the ammonia evaporation process adopts normal pressure or negative pressure evaporation, the negative pressure evaporation temperature is greater than or equal to 80 DEG C, the normal pressure evaporation temperature is greater than or equal to 110 DEG C, and the evaporation volume is not less than 30% of the initial volume of the solution; S2, the nickel-cobalt-manganese enrichment in the step S1 is mixed with a small amount of nickel / cobalt / manganese source and lithium source to regulate the composition, and the mixture after the composition regulation is calcined to prepare the ternary positive electrode material. In the step S1, the ammonia solution refers to an ammonia solution generated when primary or secondary resources containing nickel, cobalt and manganese are mixed with an ammonia water-ammonium salt solution, wherein the ammonium salt is at least one of ammonium carbonate and ammonium bicarbonate.

2. The method of claim 1, wherein, In the step S2, the nickel / cobalt / manganese source in the composition regulation process is selected from one or more of carbonates, oxalates and oxides of nickel, cobalt and manganese, and the lithium source is selected from at least one of lithium hydroxide and lithium carbonate.

3. The method of claim 1, wherein, In the step S2, the molar ratio of nickel, cobalt and manganese in the composition regulation process is selected from one of 8:1:1, 5:2:3, 1:1:1 and 6:2:2, and the molar ratio of Li:(Ni+Co+Mn) is 1.03-1.05:

1.

4. The method of claim 1, wherein, In the step S2, the calcination process adopts two-stage calcination, the first-stage calcination temperature is 400 DEG C-600 DEG C, the calcination time is 2h-5h, the second-stage calcination temperature is 800 DEG C-900 DEG C, and the calcination time is 10h-12h.

5. The method of claim 1, wherein, ​

Images