Method for preparing ternary positive electrode material from nickel-cobalt-manganese-containing ammoniacal solution

Abstract

The invention provides a method for preparing a ternary positive electrode material from an ammoniacal solution containing nickel, cobalt and manganese, which comprises the following steps of: S1, directly distilling ammonia in the ammoniacal solution containing nickel, cobalt and manganese to obtain a nickel, cobalt and manganese enriched product, and respectively condensing, absorbing and preparing ammonia gas and ammonia distillation residual liquid generated in the evaporation process to be used for circulating ammonia leaching; and step S2, mixing the nickel-cobalt-manganese enriched product in the step S1 with a small amount of nickel / cobalt / manganese source and lithium source according to a specific molar ratio to carry out composition regulation and control, and roasting the mixture after composition regulation and control to prepare the ternary positive electrode material. According to the method, a complex nickel-cobalt-manganese separation and product preparation process in the solution is avoided, short-process collaborative recovery of nickel-cobalt-manganese in the ammoniacal solution is realized, the ternary positive electrode material is prepared, the prepared ternary positive electrode material does not contain sulfur impurities, the quality is higher, the process is simple, and no waste liquid is generated.

Description

Technical Field

[0001] The invention relates to the technical field of resource recovery and treatment, and in particular to a method for preparing a ternary positive electrode material from an ammonia solution containing nickel, cobalt and manganese. Background Art

[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. In order to maintain industrial stability and ensure the security of resource supply, it is critical to extract and recover nickel, cobalt and manganese from primary and secondary resources containing nickel, cobalt and manganese in a low-carbon and efficient manner.

[0003] Ammonia leaching is favored due to its high selectivity for transition metals. In the ammonia leaching process, only nickel, cobalt and manganese form complexes with ammonia (Me(NH3) i z+ ) and enter the solution. The relatively pure leachate can greatly reduce the subsequent purification and product preparation steps. For example, the reduction roasting-ammonia leaching and direct ammonia leaching processes of laterite nickel ore and failed ternary positive electrode materials have been widely studied. However, for the ammonia solution containing nickel, cobalt and manganese after ammonia leaching, how to efficiently recover the nickel, cobalt and manganese in a short process is also extremely important.

[0004] Ternary cathode material is one of the most important uses of nickel, cobalt and manganese. The traditional method of preparing ternary cathode material is to co-precipitate sulfate and then mix it with lithium source for roasting. However, the cathode material prepared by this method inevitably contains sulfate, which easily leads to excessive sulfur content in the product. If the ternary cathode material is directly prepared from the ammonia solution containing nickel, cobalt and manganese, not only can the short process of nickel, cobalt and manganese be recovered, but also the problem of sulfur impurities in the final product can be avoided from the source.

[0005] Chinese patent CN 115571925 A adds caustic soda to the ammonia leaching solution of waste batteries containing nickel, cobalt and manganese and controls the pH to 10-12 to prepare a ternary precursor by coprecipitation. Although this method achieves the recovery of nickel, cobalt and manganese and the preparation of precursors, the recovery process consumes alkali, and the solution after coprecipitation is sodium-containing high-salt wastewater. The existing technology for recovering nickel, cobalt and manganese from ammonia solutions and preparing positive electrode materials has prominent problems such as long process flow and generation of salt-containing wastewater. Overall, it is urgent to develop a low-carbon, sustainable new technology for the coordinated recovery of nickel, cobalt and manganese from ammonia solutions and the preparation of ternary materials. Summary of the invention

[0006] In view of the prominent problems in the prior art of recovering nickel, cobalt and manganese from ammoniacal solution and preparing positive electrode materials, such as long process, generation of salt-containing wastewater, and sulfur impurities in products, the present invention provides a new method, which can achieve the coordinated and efficient recovery of nickel, cobalt and manganese in ammoniacal solution and prepare a ternary positive electrode material. The recovery process realizes the circulation of ammonia without generating waste liquid, and compared with the traditional sulfate co-precipitation process, the prepared ternary positive electrode material does not contain sulfur impurities.

[0007] A method for preparing a ternary positive electrode material from an ammoniacal solution containing nickel, cobalt and manganese, comprising:

[0008] Step S1, directly evaporating ammonia from an ammonia solution containing nickel, cobalt and manganese to obtain a nickel, cobalt and manganese enriched product, and the ammonia gas and ammonia evaporation residual liquid generated in the evaporation process can be used for circulating ammonia leaching after being condensed, absorbed and prepared with liquid (that is, the ammonia gas is absorbed into ammonia water, mixed with the ammonia evaporation residual liquid, and used for circulating ammonia leaching after being prepared with liquid);

[0009] Step S2, mixing the nickel-cobalt-manganese concentrate in step S1 with a small amount of nickel / cobalt / manganese source and lithium source in a certain molar ratio to adjust the composition, and the mixture after the composition adjustment can be calcined to prepare a ternary positive electrode material.

[0010] Optionally, in step S1, the ammoniacal solution refers to an ammoniacal solution generated when a primary or secondary resource containing nickel, cobalt and manganese reacts with an ammonia-ammonium salt mixed solution, wherein 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 enriched products produced during a smelting process, and the ammonium salt is one or more of ammonium carbonate and ammonium bicarbonate.

[0011] If ammonium sulfate is used as the ammonium salt, part of the sulfate ions will enter the nickel-cobalt-manganese concentrate, eventually leading to an excessively high sulfur content in the prepared nickel-cobalt-manganese positive electrode material, thereby reducing battery performance and life.

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

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

[0014] Optionally, in step S2, the nickel / cobalt / manganese source in the composition regulation 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 in the composition control process can be selected but 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 concentrate can reduce the amount of the corresponding nickel-cobalt-manganese source.

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

[0017] The beneficial effects brought about by the technical solution provided by the present invention include at least:

[0018] In the present invention, the nickel, cobalt and manganese are firstly recovered by ammonia evaporation, and ammonia and ammonia evaporation residual liquid are circulated. Nickel, cobalt and manganese are precipitated in a coordinated manner and uniformly mixed in the ammonia evaporation product. According to the nickel, cobalt and manganese content in the enrichment, a molar ratio close to the component content is selected, and the ammonia evaporation product is mixed with a small amount of nickel / cobalt / manganese source and lithium source according to the corresponding molar ratio for composition control, and a ternary positive electrode material can be prepared by simple roasting.

[0019] The process of the present invention is simple, the flow is short, and the metal recovery rate is high. The ammonia evaporation process does not require the control of the solution pH and the addition of other reagents, and the volatilized ammonia and the residual ammonia evaporation liquid can be returned to the ammonia leaching process after treatment, thereby realizing the coordinated recovery of nickel, cobalt and manganese while avoiding the generation of wastewater. The ammonia evaporation product is mixed with a small amount of nickel, cobalt, manganese source and lithium source for composition adjustment and simple roasting to prepare a ternary positive electrode material, avoiding the problem of sulfur impurities in the positive electrode material at the source. The invention connects the back end of the nickel, cobalt and manganese recovery process with the battery preparation process, realizes the efficient and short-process recovery of nickel, cobalt and manganese in ammonia solution and prepares ternary positive electrode materials, providing technical support for the recovery and reuse of nickel, cobalt and manganese resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0021] Figure 1 It is a process flow chart of the present invention. DETAILED DESCRIPTION

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

[0023] In the embodiments of the present invention, words such as "exemplarily" and "for example" are used to indicate examples, illustrations or explanations. Any embodiment or design described as "example" in the present invention should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of the word "example" is intended to present the concept in a specific way. In addition, in the embodiments of the present invention, the meaning expressed by "and / or" can be both, or it can be either of the two.

[0024] In the embodiments of the present invention, sometimes a subscript such as W1 may be mistakenly written as a non-subscript such as W1. When the difference is not emphasized, the meanings to be expressed are consistent.

[0025] In order to make the technical problems, technical solutions and advantages to be solved by the present invention more clear, a detailed description will be given below with reference to the accompanying drawings and specific embodiments.

[0026] Example 1

[0027] For the ammonia solution (Ni: 15.5g / L, Co: 2.0g / L, Mn: 0.5g / L) generated by the water-leached residue of the waste nickel-cobalt-manganese ternary battery after reduction roasting and water leaching in steps with ammonia water-ammonium carbonate mixed solution, 1L of ammonia solution was directly evaporated at normal pressure, the ammonia evaporation temperature was controlled at 130℃, the evaporation volume was 30% of the initial solution volume, and 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 evaporation was 24.63:3.21:2.74. The evaporated ammonia precipitate is mixed with a small amount of nickel carbonate, manganese tetraoxide and lithium carbonate at a molar ratio of nickel:cobalt:manganese of 8:1:1 and a molar ratio of lithium:(nickel+cobalt+manganese) of 1.03:1, and ball-milled to adjust the composition. The adjusted mixture is then calcined at 400°C for 5h and at 800°C for 12h to prepare a 811 type ternary positive electrode material.

[0028] Example 2

[0029] For the ammonia solution (Ni: 1g / L, Co: 2.0g / L, Mn: 0.5g / L) generated by the step-by-step ammonia leaching of the water-leached residue of the waste nickel-cobalt-manganese ternary battery with ammonia water-ammonium bicarbonate mixed solution, 1L of the ammonia solution was directly evaporated at normal pressure, the ammonia evaporation temperature was controlled at 110℃, the evaporation volume was 50% of the initial solution volume, and 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 evaporation is 2:3:1. The evaporated ammonia precipitate is mixed with a small amount of nickel carbonate, manganese oxalate and lithium hydroxide at a molar ratio of nickel:cobalt:manganese of 1:1:1 and a molar ratio of lithium:(nickel+cobalt+manganese) of 1.05:1 and ball-milled to adjust the composition. The adjusted mixture is then calcined at 600°C for 2h and at 900°C for 10h to prepare a 111-type ternary positive electrode material.

[0030] Example 3

[0031] For the ammonia solution (Ni: 2.5g / L, Co: 1.0g / L, Mn: 1.6g / L) generated by the step-by-step ammonia leaching of the nickel-cobalt-manganese enriched product produced by the laterite nickel ore acid leaching process with ammonia water-ammonium bicarbonate mixed solution, 1L of the ammonia solution was subjected to negative pressure ammonia evaporation, the negative pressure in the vacuum pump extraction device was -0.25MPa, the ammonia evaporation temperature was controlled at 80℃, the evaporation volume was 40% of the initial solution volume, and 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 enriched product obtained by ammonia evaporation was 13.16:5.14:8.02. The evaporated ammonia precipitate is mixed with a small amount of nickel carbonate, cobalt oxalate and lithium carbonate at a molar ratio of nickel:cobalt:manganese of 5:2:3 and a molar ratio of lithium:(nickel + cobalt + manganese) of 1.03:1 and ball-milled to adjust the composition. The adjusted mixture is then calcined at 400°C for 5h and at 800°C for 12h to prepare a 523 type ternary positive electrode material.

[0032] Example 4

[0033] For the ammonia solution (Ni: 18.46g / L, Co: 5.78g / L, Mn: 6.35g / L) generated by the water leaching residue of the waste nickel-cobalt-manganese ternary battery after reduction roasting and water leaching in steps with ammonia water-ammonium carbonate mixed solution, 1L of ammonia solution was subjected to negative pressure ammonia evaporation, and the negative pressure in the vacuum pump extraction device was -0.20MPa, the ammonia evaporation 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 enriched product obtained by ammonia evaporation was 3.01:0.95:1.14. The evaporated ammonia precipitate is mixed with a small amount of cobalt tetraoxide, manganese tetraoxide and lithium hydroxide in a molar ratio of nickel:cobalt:manganese of 5:2:3 and a molar ratio of lithium:(nickel+cobalt+manganese) of 1.04:1, and ball-milled to adjust the composition. The adjusted mixture is then calcined at 500°C for 2h and at 850°C for 10h to prepare a 523-type ternary positive electrode material.

[0034] Comparative Example 1

[0035] The ammonia solution in Example 1 was subjected to atmospheric pressure ammonia evaporation. When the ammonia evaporation temperature was controlled to be 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 ammonia evaporation temperature is lower than 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 evaporation, and the negative pressure in the vacuum pump extraction device was -0.25 MPa, the ammonia evaporation temperature was controlled to be 90°C, and 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. It can be seen 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 in 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. 1 L of the diluted ammonia solution was subjected to negative pressure ammonia evaporation. The negative pressure in the vacuum pump extraction device was -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 were 32.61%, 26.45%, and 56.37%, respectively. It can be seen that when the concentrations of nickel, cobalt, and manganese in the solution are at a low level, their precipitation rates will be significantly reduced.

[0040] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A method for preparing a ternary positive electrode material from an ammonia solution containing nickel, cobalt and manganese, characterized in that: include: Step S1, directly evaporating ammonia from an ammonia solution containing nickel, cobalt and manganese to obtain a nickel, cobalt and manganese enriched product, and the ammonia gas generated in the evaporation process is absorbed and mixed with the residual ammonia evaporation liquid for circulating ammonia leaching; Step S2, mixing the nickel-cobalt-manganese enriched product in step S1 with a small amount of nickel / cobalt / manganese source and lithium source to adjust the composition, and calcining the mixture after the composition adjustment to prepare a ternary positive electrode material.

2. The method according to claim 1, characterized in that: In step S1, the ammonia solution refers to an ammonia solution generated when primary or secondary resources containing nickel, cobalt and manganese react with an ammonia water-ammonium salt mixed solution, wherein the ammonium salt is at least one of ammonium carbonate and ammonium bicarbonate.

3. The method according to claim 1, characterized in that In step S1, the nickel concentration in the ammonia solution is ≥1.0 g / L, the cobalt concentration is ≥1.0 g / L, and the manganese concentration is ≥0.5 g / L.

4. The method according to claim 1, characterized in that In step S1, the ammonia evaporation process adopts normal pressure or negative pressure ammonia evaporation, the negative pressure ammonia evaporation temperature is ≥80°C, the normal pressure ammonia evaporation temperature is ≥110°C, and the evaporation volume is not less than 30% of the initial volume of the solution.

5. The method according to claim 1, characterized in that In step S2, the nickel / cobalt / manganese source in the composition control process is selected from one or more of the carbonates, oxalates and oxides of nickel / cobalt / manganese, and the lithium source is selected from at least one of lithium hydroxide and lithium carbonate.

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

1.

7. The method according to claim 1, characterized in that In step S2, the roasting process adopts two-stage roasting, the first stage roasting temperature is 400℃~600℃, the roasting time is 2h~5h, and the second stage roasting temperature is 800℃~900℃, and the roasting time is 10h~12h.

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