Optimization method and application of O / A ratio in nickel-cobalt (manganese) ion extraction of laterite-nickel ore

Abstract

The invention discloses a method for optimizing the O / A ratio in nickel-cobalt (manganese) extraction through laterite-nickel ore ions and application. The optimization method comprises the following steps: obtaining feed liquid parameters of feed liquid to be extracted, parameters of an extraction agent and a target extraction rate of manganese; constructing a theoretical O / A ratio model, and determining a theoretical O / A ratio based on the material liquid parameters, the parameters of the extraction agent, the target extraction rate of manganese and the theoretical O / A ratio model; and constructing a limiting condition, and determining an optimal O / A ratio based on the theoretical O / A ratio and the limiting condition. On the basis of combining theories and production practices, a corresponding theoretical model is established according to the selection of the O / A ratio of the extraction section in the nickel-cobalt (manganese) co-extraction process based on different extraction agents and the problem of how to avoid the generation of the extraction third phase, and the optimal O / A ratio is determined on the basis of the theoretical model, so that the aim of extracting the third phase in the nickel-cobalt (manganese) co-extraction process is fulfilled. And finally, the nickel-cobalt (manganese) mixed solution obtained by co-extraction under the optimal O / A ratio condition is used for preparing a nickel-cobalt (manganese) precursor and a ternary positive electrode material.

Description

Technical Field

[0001] The present application relates to the technical field of hydrometallurgy, and in particular to a method and application for optimizing the O / A ratio in nickel-cobalt (manganese) extraction from laterite nickel ore. Background Art

[0002] At present, the process of preparing battery-grade nickel, cobalt and manganese crystals from laterite nickel ore hydrometallurgy generally adopts the process of high-pressure leaching - multi-stage neutralization and iron and aluminum removal - multi-stage precipitation of MHP - leaching and impurity removal - P204 impurity extraction - P507 cobalt extraction - P507 magnesium extraction - P507 enrichment of nickel, cobalt and manganese respectively. In order to simplify the above cumbersome process, the nickel-cobalt (manganese) co-extraction process was developed in the context of the rapid rise of ternary new energy materials, that is, nickel, cobalt and manganese are extracted simultaneously from the nickel-cobalt-manganese mixed solution, thereby quickly separating nickel, cobalt and manganese from other impurity ions.

[0003] In the nickel-cobalt (manganese) co-extraction process of laterite nickel ore, the O / A ratio of the extraction section (i.e., the volume ratio of the extraction organic phase to the aqueous phase) directly affects the extraction efficiency, selectivity and recovery rate of metal ions. The selection of the O / A ratio is crucial to optimizing the entire extraction process. Specifically, a higher O / A ratio will increase the extraction efficiency of metal ions. As the O / A ratio increases, the increase in recovery rate will gradually decrease until it reaches a stable state. However, an excessively high O / A ratio will not only reduce the extraction selectivity of the extractant for the target metal, but will also cause the appearance of a third phase in the extraction tank, hindering the extraction process. At present, whether it is the industrialized nickel-cobalt (manganese) co-extraction agent or the newly developed co-extraction agent, it can be roughly divided into two categories. One is the co-extraction agent whose pH of the aqueous phase decreases after the extraction reaction, that is, the equilibrium pH is less than the initial pH, such as HBL110, HBL116 and other composite component extractants; the other is the extractant whose pH of the aqueous phase increases after the extraction reaction, that is, the equilibrium pH is greater than the initial pH, such as Versatic 10, DY319, etc. This type of extractant generally has a high loading capacity and is acid-resistant, but the increase in pH of the aqueous phase after the extraction reaction will often cause the third phase to appear in the continuous extraction tank extraction section, which affects the phase separation process during extraction. At the same time, the third phase will block the extraction tank and make the extraction process unable to continue. The fundamental reason for the generation of the third phase and how to solve the problem of the third phase of extraction by optimizing the O / A ratio are challenges faced by the extraction industry.

[0004] In actual operation, the O / A ratio needs to be adjusted according to specific circumstances. At present, the nickel-cobalt (manganese) co-extraction process often selects a fixed O / A ratio according to the ion composition and content of different nickel-cobalt (manganese) mixed solutions, or adjusts it only by human judgment. However, in the hydrometallurgical process of laterite nickel ore, the composition and content of the nickel-cobalt (manganese) mixed solution obtained through different processes are different, resulting in an O / A ratio that is too high or too low during actual operation, causing unnecessary cost increases or reduced production efficiency. Summary of the invention

[0005] The purpose of this application is to overcome the above-mentioned technical deficiencies, propose a method and application for optimizing the O / A ratio in nickel-cobalt (manganese) extraction from laterite nickel ore ions, and solve the technical problems in the prior art of using a fixed O / A ratio or adjusting it only by human judgment, resulting in unnecessary cost increases or reduced production efficiency.

[0006] In a first aspect, the present application provides a method for optimizing the O / A ratio in nickel-cobalt (manganese) extraction from laterite nickel ore, comprising the following steps: Obtaining the parameters of the feed liquid to be extracted, the parameters of the extractant and the target extraction rate of manganese; A theoretical O / A ratio model is constructed to determine the theoretical O / A ratio based on the feed and liquid parameters, the parameters of the extractant, the target extraction rate of manganese and the theoretical O / A ratio model; Construct constraints and determine the optimal O / A ratio based on the theoretical O / A ratio and the constraints; where: The feed liquid parameters include the composition of the feed liquid to be extracted and the pH of the feed liquid to be extracted; The parameters of the extractant include the type of the extractant, the acid value of the extractant, the dilution rate of the extractant and the saponification rate of the extractant.

[0007] In a second aspect, the present application provides the application of the above-mentioned method for optimizing the O / A ratio in the extraction of nickel, cobalt (manganese) from laterite nickel ore ions in the preparation of a nickel, cobalt (manganese) precursor.

[0008] In a third aspect, the present application provides the application of the above-mentioned method for optimizing the O / A ratio in the extraction of nickel, cobalt (manganese) from laterite nickel ore ions in the preparation of nickel-cobalt (manganese) ternary positive electrode materials.

[0009] Compared with the prior art, the beneficial effects of this application include: Based on the combination of theory and production practice, this application establishes a corresponding theoretical model for the selection of O / A ratio in the extraction section of nickel-cobalt (manganese) co-extraction process based on different extractants and how to avoid the generation of the third phase of extraction. Based on this theoretical model, the optimal O / A ratio of the extraction section in the nickel-cobalt (manganese) extraction process of laterite nickel ore ions is determined, and finally the nickel-cobalt (manganese) mixed solution obtained by co-extraction under the optimal O / A ratio is used to prepare nickel-cobalt (manganese) precursors and ternary positive electrode materials. The method proposed in this application can also be extended to the application fields of other extractants. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a process flow chart of an embodiment of a method for optimizing the O / A ratio in nickel-cobalt (manganese) extraction from laterite nickel ore provided in the present application; Figure 2 This is a graph showing the relationship between the maximum threshold of raffinate pH and manganese concentration. DETAILED DESCRIPTION

[0011] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0012] In a first aspect, the present application provides a method for optimizing the O / A ratio in nickel-cobalt (manganese) extraction from laterite nickel ore, comprising the following steps: S1. Obtaining the parameters of the feed liquid to be extracted, the parameters of the extractant and the target extraction rate of manganese; the feed liquid parameters include the composition of the feed liquid to be extracted and the pH of the feed liquid to be extracted, and the parameters of the extractant include the type of the extractant, the acid value of the extractant, the dilution rate of the extractant and the saponification rate of the extractant; S2. constructing a theoretical O / A ratio model, and determining the theoretical O / A ratio based on the feed liquid parameters, the parameters of the extractant, the target extraction rate of manganese and the theoretical O / A ratio model; S3. Construct constraint conditions and determine the optimal O / A ratio based on the theoretical O / A ratio and the constraint conditions.

[0013] In the present embodiment, in step S1, the feed liquid to be extracted comes from the laterite nickel ore hydrometallurgical process, and the present application does not impose too many restrictions on its specific source and composition, and those skilled in the art can choose according to the actual situation. For example, the feed liquid to be extracted can be a liquid after iron and aluminum removal or a P204 stripping solution. In some specific embodiments of the present application, the liquid after iron and aluminum removal I is obtained by filtering the laterite nickel ore leachate after multiple stages of iron and aluminum removal; the liquid after iron and aluminum removal II is obtained by leaching, neutralizing and removing impurities from the MHP filter cake obtained by multi-stage precipitation of MHP after the liquid after iron and aluminum removal I; the P204 stripping solution is obtained by extracting the liquid after iron and aluminum removal II with P204.

[0014] In this embodiment, in step S1, the extractant includes one of the first type of extractant or the second type of extractant; wherein the first type of extractant is an extractant whose aqueous phase pH decreases after the extraction reaction, that is, the equilibrium pH is less than the initial pH; the second type of extractant is an extractant whose aqueous phase pH increases after the extraction reaction, that is, the equilibrium pH is greater than the initial pH. The present application does not limit the specific types of the first type of extractant and the second type of extractant, and those skilled in the art can choose according to actual conditions. In some specific embodiments of the present application, the first type of extractant can be HBL110, HBL116, etc., and the second type of extractant can be Versatic10, DY319, etc.

[0015] In this embodiment, in step S1, the target extraction rate of manganese is selected according to the following principle: if the extracting liquid contains calcium, the target extraction rate of manganese needs to be appropriately reduced. The reason is that generally speaking, the extraction rates of calcium and magnesium by the extractant are lower than those of nickel, cobalt (manganese), and calcium is more difficult to elute relative to magnesium. If a large amount of calcium is extracted, a large amount of nickel, cobalt (manganese) will be lost in the washing section to elute calcium. In addition, if the elution rate of calcium in the washing section is not enough, calcium sulfate will be continuously enriched in the stripping solution, affecting the quality of the nickel, cobalt (manganese) product finally obtained.

[0016] Specifically, in the extractable liquid, if the Mn / Ca mass ratio is less than 10, the target extraction rate of manganese η is less than 40%; if 10≤Mn / Ca mass ratio<200, the target extraction rate of manganese η should satisfy: 100%>η≥40%; if the Mn / Ca mass ratio is ≥200, the target extraction rate of manganese η=100%.

[0017] In this embodiment, in step S2, the calculation formula of the theoretical O / A ratio model is: (1) Where i is the metal element whose metal ion extraction rate of the extractant in the extraction liquid is greater than or equal to the manganese extraction rate; γ is the excess coefficient of the extracted organic phase. For the first type of extractant, γ is 1.4, and for the second type of extractant, γ is 1.3; C i is the molar concentration of a single metal ion in the extract; X i is the valence state of a single metal ion in the extract; η i is the extraction rate of the extractant for a single metal ion, and the extraction rate η of the metal element whose metal ion extraction rate in the extraction liquid is greater than the manganese extraction rate is 100%; A is the acid value of the extractant; D is the dilution rate of the extractant; S is the saponification rate of the extractant.

[0018] In this embodiment, in step S3, the step of determining the optimal O / A ratio based on the theoretical O / A ratio and the constraint condition includes: If the extractant is a first type extractant, the theoretical O / A ratio is the optimal O / A ratio; or, If the extractant is a second-class extractant and the Mn / Ca in the extractant is ≥ 200, the theoretical O / A ratio is the optimal O / A ratio; or, If the extractant is a second-class extractant and the Mn / Ca ratio in the extractant is less than 200, the optimal O / A ratio is determined according to the following steps: S31, based on the theoretical O / A ratio, obtain the actual pH of the first raffinate and the Mn content of the first raffinate 2+ concentration; S32, constructing a maximum threshold model for the pH of the raffinate, based on the Mn 2+The maximum threshold value of the raffinate pH is determined by the concentration of and the maximum threshold value model of the raffinate pH; S33. Determine the optimal O / A ratio based on the actual pH of the first raffinate and the highest threshold of the pH of the raffinate.

[0019] In this embodiment, for the first type of extractant with a reduced pH of the raffinate, since the equilibrium pH is less than the initial pH, the calculated theoretical O / A ratio can be directly used as the optimal O / A ratio for the extraction section; for the extraction system in which the extractant is the second type of extractant and the Mn / Ca in the feed liquid to be extracted is ≥200, since the calcium ion content in the feed liquid to be extracted is extremely low, all manganese is extracted in the extraction section so that there is no manganese or there is basically little manganese in the raffinate after extraction, so that manganese basically does not have the problem of hydrolyzing in the extraction section to produce a third phase, so the calculated theoretical O / A ratio can be directly used as the optimal O / A ratio for the extraction section; for the extraction system in which the extractant is the second type of extractant and the Mn / Ca in the feed liquid to be extracted is less than 200, since the equilibrium pH is greater than the initial pH, after the theoretical O / A ratio is calculated, in order to avoid the generation of the third phase in the extraction section and ensure the normal progress of the nickel-cobalt (manganese) co-extraction process, it is also necessary to determine the optimal O / A ratio based on the actual pH of the first raffinate and the highest threshold of the raffinate pH.

[0020] More specifically, the actual pH of the first raffinate and the Mn content of the first raffinate are obtained based on the theoretical O / A ratio. 2+ The step of obtaining the actual pH value of the first raffinate and the Mn content of the first raffinate after running the co-extraction process according to the feed liquid parameters, the extractant parameters, the theoretical O / A ratio and the actual production conditions. 2+ The actual production conditions include: extraction temperature, extraction time, and extraction stage.

[0021] More specifically, the calculation formula of the highest threshold model of the raffinate pH is: (2) Where, pH max is the highest threshold of the raffinate pH, K sp [Mn(OH)2] is a constant related to temperature and pressure. It is 4×10 -14 ; C(Mn 2+ ) is Mn in the raffinate 2+ The molar concentration of Mn 2+ It can be gradually oxidized in the air, which accelerates its hydrolysis.

[0022] More specifically, the step of determining the optimal O / A ratio based on the actual pH of the first raffinate and the highest threshold of the pH of the raffinate includes: If the actual pH of the first raffinate is less than the highest threshold of the raffinate pH, the theoretical O / A ratio is the optimal O / A ratio; or, If the actual pH of the first raffinate is greater than the maximum threshold of the raffinate pH, the O / A ratio is reduced based on the theoretical O / A ratio until the corresponding raffinate pH is less than the maximum threshold of the raffinate pH, and the O / A ratio at this time is used as the optimal O / A ratio.

[0023] Specifically, in the co-extraction process, the pH of the raffinate is determined by the K sp In order to avoid the formation of the third phase of the extraction, the pH of the raffinate must be less than the highest threshold of the raffinate pH determined by the raffinate pH threshold model.

[0024] In some preferred embodiments of the present application, for the second type of extractant, the minimum threshold of the pH of the raffinate is 5.5. If the pH of the raffinate is too low, the extraction rate of nickel, cobalt (manganese) in the extraction stage will be reduced.

[0025] In this embodiment, the extractant is a first-class extractant, the acid value of the extractant is 1-3 mol / L, the dilution rate is 30-60%, the saponification rate is 35-60%, the extraction level is 6-10, the extraction temperature is room temperature, the extraction time is 6-10 min, and the pH of the liquid to be extracted is 4-6. Within the above parameter range, nickel, cobalt and manganese can be efficiently extracted to improve production efficiency.

[0026] In this embodiment, the extractant is a second-class extractant, the acid value of the extractant is 1-3 mol / L, the dilution rate is 25-50%, the saponification rate is 20-50%, the extraction level is 6-10, the extraction temperature is room temperature, the extraction time is 6-10 min, and the pH of the liquid to be extracted is 1.5-4. For the second-class extractant, since the pH of the raffinate is related to the properties of the extractant itself, the saponification rate of the extractant, the pH of the liquid to be extracted and the extraction level, in order to avoid the generation of the third phase of extraction, these process factors should be well coordinated with each other. Within the above parameter range, it is possible to avoid the pH of the liquid to be extracted, the saponification rate is too high, and the extraction level is too high, resulting in the pH of the raffinate being too high. At the same time, it is possible to avoid the pH of the liquid to be extracted, the saponification rate and the extraction level being too low, resulting in a low extraction rate.

[0027] It should be emphasized that this application establishes a theoretical model for the selection of the O / A ratio in the extraction section of the nickel-cobalt (manganese) co-extraction process and how to avoid the generation of the third phase of extraction by optimizing the O / A ratio, when other factors (such as the acid value of the extractant, saponification rate, dilution rate, extraction stage, extraction temperature, pH value of the extracted liquid, etc.) are set relatively reasonably, and uses the methods involved in the model to guide the co-extraction process.

[0028] In practical applications, after the optimal O / A ratio is determined, the amount of extractant to be added to the extracting liquid can be dynamically adjusted in real time according to the optimal O / A ratio.

[0029] In a second aspect, the present application provides the application of the above-mentioned method for optimizing the O / A ratio in the extraction of nickel, cobalt (manganese) from laterite nickel ore ions in the preparation of a nickel, cobalt (manganese) precursor.

[0030] In this implementation, the above-mentioned applications include: T1. Determine the optimal O / A ratio according to the method for optimizing the O / A ratio in nickel-cobalt (manganese) extraction from laterite nickel ore provided in the first aspect of the present application; T2, co-extracting based on feed liquid parameters, extractant parameters and optimal O / A ratio to obtain a second raffinate; T3. Prepare the second raffinate into a nickel-cobalt (manganese) precursor.

[0031] In this embodiment, in step T3, the raffinate can be selectively treated for impurities according to the composition and content of the second raffinate. The present application does not limit the method of impurity removal, and those skilled in the art can choose according to actual conditions. For example, P204 can be used for impurity removal.

[0032] In some specific embodiments of the present invention, the high-purity nickel-cobalt (manganese) mixed solution obtained by co-extraction of iron-aluminum-removed liquid I and iron-aluminum-removed liquid II with nickel-cobalt (manganese) is purified by a P204 impurity removal line to obtain a battery-grade nickel-cobalt (manganese) mixed solution; the high-purity nickel-cobalt (manganese) mixed solution obtained by co-extraction of nickel-cobalt (manganese) with P204 stripping liquid is a battery-grade nickel-cobalt (manganese) mixed solution.

[0033] In this embodiment, in step T3, nickel, cobalt, manganese or other doping elements can be selectively added for compounding according to the composition and content of the second raffinate and the composition and content of the target nickel-cobalt (manganese) precursor, and directly used to prepare the nickel-cobalt (manganese) precursor.

[0034] In a third aspect, the present application provides the application of the above-mentioned method for optimizing the O / A ratio in the extraction of nickel, cobalt (manganese) from laterite nickel ore ions in the preparation of nickel-cobalt (manganese) ternary positive electrode materials.

[0035] The method for optimizing the O / A ratio in nickel-cobalt (manganese) extracted from laterite nickel ore ions provided in the present application can obtain the optimal O / A ratio of the extraction section, and then the nickel-cobalt (manganese) is co-extracted by combining the optimal O / A ratio with other parameters to obtain a raffinate containing nickel-cobalt (manganese), and the raffinate containing nickel-cobalt (manganese) is used to prepare a nickel-cobalt (manganese) precursor through optional impurity removal and compounding steps, and finally the nickel-cobalt (manganese) precursor is prepared into a nickel-cobalt (manganese) ternary positive electrode material.

[0036] In the following examples and comparative examples of this application, the DY319 and HBL110 nickel-cobalt (manganese) co-extraction extractants currently used in the industry are used as extractants, and the nickel-cobalt (manganese) mixed solution obtained from different process sections of laterite nickel ore hydrometallurgy is used as the feed solution to be extracted, and the optimization of the O / A ratio in the extraction section of the nickel-cobalt (manganese) co-extraction process is guided and explained. Among them, the source of the feed solution to be extracted and the extraction steps are as follows: (1) removing iron and aluminum from the laterite nickel ore leaching solution in multiple stages, and obtaining the iron and aluminum-removed solution I by filter pressing; (2) The iron and aluminum removal liquid I is subjected to multi-stage MHP precipitation, and the MHP filter cake is obtained by filter pressing, and the MHP filter cake is sequentially subjected to leaching, neutralization and impurity removal to obtain the iron and aluminum removal liquid II; (3) Extracting the iron and aluminum-removed liquid II with P204 to obtain P204 stripping liquid; (4) co-extracting nickel, cobalt (manganese) from one or more of the iron and aluminum removal liquid I, the iron and aluminum removal liquid II, and the P204 stripping liquid to obtain a loaded organic phase and a raffinate; (5) The loaded organic phase is acid-washed, and the washing liquid is recycled to the extraction section, followed by stripping to obtain a high-purity nickel-cobalt (manganese) mixed solution.

[0037] In the examples of the present application, Example 1 is used to illustrate the relationship between the maximum threshold of the pH of the raffinate and the manganese concentration and the influence of the pH of the raffinate on the formation of the third phase in the continuous extraction process. Examples 2-5 are combined with specific nickel-cobalt (manganese) co-extraction steps to further verify the above method.

[0038] Example 1 When the pH of the raffinate is greater than the maximum threshold, a third phase is formed. When the pH of the raffinate is less than the maximum threshold, no third phase is formed. According to the maximum threshold model of the pH of the raffinate proposed in this application, it can be inferred that after the co-extraction is completed, the maximum threshold of the pH of the raffinate is related to the Mn content in the raffinate. 2+ The molar concentration of Mn in different raffinates satisfies a certain relationship. 2+ Substituting the molar concentrations of into formula (2), we can obtain the relationship between the maximum threshold of the raffinate pH and the manganese concentration.

[0039] See also Figure 2 ,pass Figure 2 It can be seen that with the increase of manganese concentration, the maximum threshold of raffinate pH gradually decreases.

[0040] Example 2 Table 1 Composition of liquid I after multi-stage iron and aluminum removal (g / L)

[0041] (1) Preparation of DY319 extraction organic phase: The selected diluent is sulfonated kerosene, the saponifying agent is liquid alkali, the dilution rate D of the DY319 extraction organic phase is 50%, the saponification rate S is 35%, and the acid value A of DY319 is 3 mol / L.

[0042] (2) Nickel-cobalt (manganese) co-extraction: The selectivity of DY319 for the elements listed in Table 1 is Cu>Zn>Fe>Al>Ni>Co>Mn>Ca>Mg. Therefore, the mass concentrations of Cu, Zn, Fe, Al, Ni, Co and Mn are converted into molar concentrations and substituted into formula (1) for calculation. The extraction rate η of manganese in the extraction section is calculated as 30%. Substitute each parameter into formula (1) to calculate the O / A ratio:

[0043] That is: O / A=0.35.

[0044] The extraction temperature was taken as room temperature, the extraction stage was 7, the extraction time was 8 min, and after running the co-extraction process according to the O / A ratio, it was found that a third phase was produced in the extraction section. At this time, the pH of the raffinate was 6.82, and the mass concentration of Mn in the raffinate was 1.52 g / L.

[0045] The mass concentration of Mn in the above raffinate is converted into molar concentration and substituted into formula (2) to calculate the pH range of the raffinate when the third phase is not generated:

[0046] That is: pH <6.30.

[0047] The experiment found that when the O / A ratio was adjusted to 0.30, the pH of the raffinate was stable at 6.01, less than 6.30. Figure 2 It can be seen that the raffinate pH of 6.01 at this time is also lower than the corresponding maximum threshold of the raffinate pH. At the same time, when the O / A ratio is 0.30, it is found that the third phase is not produced in the extraction section of the co-extraction process. At this time, the nickel extraction rate is 92%.

[0048] (3) Washing: The extracted organic phase was washed with 0.12 mol / L sulfuric acid, and the washing water was circulated to the extraction section. The O / A ratio during washing was 10:1, the number of washing stages was 6, and the reaction time was 12 min.

[0049] (4) Stripping: The organic phase was stripped with 2.75 mol / L sulfuric acid. The O / A ratio was 20:1, the stripping stage was 8, and the reaction time was 14 min. The composition of the obtained nickel-cobalt (manganese) mixed salt solution was: Table 2 Composition of co-extracted nickel-cobalt (manganese) mixed salt solution (g / L)

[0050] (5) P204 purification line: The nickel-cobalt (manganese) mixed salt solution is purified by the P204 purification line to obtain a battery-grade nickel-cobalt (manganese) mixed salt solution that meets the requirements for the preparation of ternary materials.

[0051] Example 3 Different from Example 1, the O / A ratio of the extraction section of the co-extraction process was reduced to 0.21, and the pH of the raffinate was 5.5. Although the generation of the third phase of extraction was suppressed, the nickel extraction rate dropped to 76%, which significantly reduced the utilization efficiency and production efficiency of the extractant and increased the production cost. It can be seen that the O / A ratio should not be too large or too small.

[0052] Example 4 Table 3 P204 stripping solution composition (g / L)

[0053] Since there are only a very small amount of Ca and Mg impurities in the P204 stripping solution, and the Mn / Ca mass ratio is ≥200, the manganese extraction rate is 100%; at the same time, since DY319 has excellent selectivity for nickel and cobalt in the calcium-magnesium system, all manganese is extracted in the extraction section, so that there is no manganese or very little manganese in the residual solution after extraction, so that manganese basically does not have the problem of hydrolysis in the extraction section to produce a third phase. The O / A ratio is directly calculated according to formula (1), and the co-extraction steps are as follows: (1) Preparation of DY319 extraction organic phase: The selected diluent is sulfonated kerosene, the saponifying agent is liquid alkali, the dilution rate D of the DY319 extraction organic phase is 50%, the saponification rate S is 45%, and the acid value A of DY319 is 3 mol / L.

[0054] (2) Nickel-cobalt (manganese) co-extraction: The mass concentrations of Ni, Co and Mn are converted into molar concentrations and then substituted into formula (1) for calculation, where the extraction rate η of manganese in the extraction section is calculated as 100%. Substitute each parameter into formula (1) to calculate the O / A ratio:

[0055] That is: O / A≈7.78.

[0056] The extraction temperature was set to room temperature, the number of extraction stages was set to 8, and the extraction time was set to 7 min. After running the co-extraction process according to the O / A ratio, it was found that no third phase was produced in the extraction section, and the pH of the raffinate was 7.09. The experiment found that the nickel extraction rate was 99%, so the O / A ratio was set reasonably.

[0057] (3) Washing: The extracted organic phase was washed with 0.15 mol / L sulfuric acid, and the washing water was circulated to the extraction section. The O / A ratio during washing was 15:1, the number of washing stages was 6, and the reaction time was 10 min.

[0058] (4) Stripping: The organic phase was stripped with 2.75 mol / L sulfuric acid. The O / A ratio was 20:1, the stripping stage was 8, and the reaction time was 12 min. The composition of the obtained nickel-cobalt (manganese) mixed salt solution was: Table 4 Composition of co-extracted nickel-cobalt (manganese) mixed salt solution (g / L)

[0059] This solution fully meets the requirements for the preparation of ternary materials and can be compounded to prepare high-nickel NCM ternary precursors.

[0060] Example 5 HBL110 was used to co-extract the liquid I after multi-stage iron and aluminum removal. The composition of the liquid I after multi-stage iron and aluminum removal was consistent with that in Example 2, and the pH was adjusted to 5. After extraction with the HBL110 extractant, the pH of the raffinate decreased relative to the initial pH of the extract. Therefore, no third phase would appear in the extraction section. The co-extraction steps are as follows: (1) Preparation of HBL110 extraction organic phase: The selected diluent is sulfonated kerosene, the saponifying agent is liquid alkali, the dilution rate D of the HBL110 extraction organic phase is 50%, the saponification rate S is 45%, and the acid value A of HBL110 is 1 mol / L.

[0061] (2) Nickel-cobalt (manganese) co-extraction: The selectivity of HBL110 for the elements listed in Table 1 is Cu>Ni>Co>Zn>Mn>Fe, Al, Ca, Mg. Therefore, the mass concentrations of Cu, Ni, Co, Zn and Mn are converted into molar concentrations and then substituted into formula (1) for calculation. Since there are many impurities in the extracted water phase, the extraction rate η of manganese in the extraction section is calculated as 30%. Substitute each parameter into formula (1) to calculate the O / A ratio:

[0062] That is: O / A≈0.88.

[0063] The extraction temperature was set to room temperature, the number of extraction stages was set to 8, and the extraction time was set to 9 min. After running the co-extraction process according to the O / A ratio, it was found that no third phase was produced in the extraction section, and the pH of the raffinate was 4.5. The experiment found that in the extraction section, the nickel extraction rate was 97% and the cobalt extraction rate was 91%, so the O / A ratio was set reasonably.

[0064] (3) Washing: The extracted organic phase was washed with 0.12 mol / L sulfuric acid, and the washing water was circulated to the extraction section. The O / A ratio during washing was 15:1, the number of washing stages was 5, and the reaction time was 12 min.

[0065] (4) Stripping: The extracted organic phase was stripped with 2.5 mol / L sulfuric acid. The O / A ratio during stripping was 20:1, the stripping stage was 8, and the reaction time was 15 min. The composition of the obtained nickel-cobalt (manganese) mixed salt solution was: Table 5 Composition of co-extracted nickel-cobalt (manganese) mixed salt solution (g / L)

[0066] (5) P204 purification line: The impurity elements Cu, Zn, Fe, Al and Ca in the above-mentioned nickel-cobalt (manganese) mixed salt solution are removed by the P204 purification line to obtain a battery-grade nickel-cobalt (manganese) mixed salt solution that meets the requirements for the preparation of ternary materials.

[0067] The specific implementation methods of the present application described above do not constitute a limitation on the protection scope of the present application. Any other corresponding changes and modifications made according to the technical concept of the present application should be included in the protection scope of the claims of the present application.

Claims

1. A method for optimizing the O / A ratio in nickel-cobalt (manganese) extraction from laterite nickel ore, characterized in that: The following steps are involved: Obtaining the parameters of the feed liquid to be extracted, the parameters of the extractant and the target extraction rate of manganese; Constructing a theoretical O / A ratio model, and determining the theoretical O / A ratio based on the feed liquid parameters, the extractant parameters, the target extraction rate of manganese and the theoretical O / A ratio model; Constructing a constraint condition, and determining an optimal O / A ratio based on the theoretical O / A ratio and the constraint condition; wherein, The feed liquid parameters include the composition of the feed liquid to be extracted and the pH of the feed liquid to be extracted; The parameters of the extractant include the type of the extractant, the acid value of the extractant, the dilution rate of the extractant and the saponification rate of the extractant.

2. The method for optimizing the O / A ratio in nickel-cobalt (manganese) extraction from laterite nickel ore according to claim 1, characterized in that: In the extractable liquid, if the Mn / Ca mass ratio is less than 10, the target extraction rate of manganese is less than 40%; if 10≤Mn / Ca mass ratio<200, the target extraction rate of manganese should satisfy: 100%>η≥40%; if Mn / Ca mass ratio is ≥200, the target extraction rate of manganese=100%.

3. The method for optimizing the O / A ratio in the extraction of nickel, cobalt (manganese) from laterite nickel ore according to claim 1, characterized in that: The calculation formula of the theoretical O / A ratio model is: （1） Wherein, i is the metal element whose metal ion extraction rate of the extractant in the extracting liquid is greater than or equal to the manganese extraction rate; γ is the excess coefficient of the extracted organic phase, and for the first type of extractant whose pH of the aqueous phase decreases after the extraction reaction, γ is 1.4, and for the second type of extractant whose pH of the aqueous phase increases after the extraction reaction, γ is 1.3; C i is the molar concentration of a single metal ion in the liquid to be extracted; i is the valence state of a single metal ion in the liquid to be extracted; η i is the extraction rate of the extractant for a single metal ion, and the extraction rate η of the metal element whose metal ion extraction rate in the extractant is greater than the manganese extraction rate is 100%; A is the acid value of the extractant; D is the dilution rate of the extractant; and S is the saponification rate of the extractant.

4. The method for optimizing the O / A ratio in nickel-cobalt (manganese) extraction from laterite nickel ore according to claim 3, characterized in that: The step of determining the optimal O / A ratio based on the theoretical O / A ratio and the limiting condition comprises: If the extractant is a first type of extractant, the theoretical O / A ratio is the optimal O / A ratio; or, If the extractant is a second type of extractant and Mn / Ca in the extractant is ≥ 200, the theoretical O / A ratio is the optimal O / A ratio; or, If the extractant is a second type of extractant and the Mn / Ca in the extractant is less than 200, the optimal O / A ratio is determined according to the following steps: Based on the theoretical O / A ratio, the actual pH of the first raffinate and the Mn content of the first raffinate are obtained. 2+ concentration; The highest threshold model of the raffinate pH is constructed based on the Mn 2+ The maximum threshold value of the raffinate pH is determined by the concentration of and the maximum threshold value model of the raffinate pH; An optimal O / A ratio is determined based on the actual pH of the first raffinate and a highest threshold of the raffinate pH.

5. The method for optimizing the O / A ratio in nickel-cobalt (manganese) extraction from laterite nickel ore according to claim 4, characterized in that: The actual pH of the first raffinate and the Mn content of the first raffinate obtained based on the theoretical O / A ratio 2+ The steps of the concentration include: According to the feed liquid parameters, extractant parameters, theoretical O / A ratio and actual production conditions, the actual pH of the first raffinate and the Mn content of the first raffinate were obtained by running the co-extraction process. 2+ concentration.

6. The method for optimizing the O / A ratio in the extraction of nickel, cobalt (manganese) from laterite nickel ore according to claim 4, characterized in that: The calculation formula of the highest threshold model of the raffinate pH is: （2） Where, pH max is the highest threshold of the raffinate pH, K sp [Mn(OH)2] is a constant related to temperature and pressure; C(Mn 2+ ) is Mn in the raffinate 2+ The molar concentration of .

7. The method for optimizing the O / A ratio in nickel-cobalt (manganese) extraction from laterite nickel ore according to claim 4, characterized in that: The step of determining the optimal O / A ratio based on the actual pH of the first raffinate and the highest threshold of the pH of the raffinate comprises: If the actual pH of the first raffinate is less than the highest threshold of the raffinate pH, the theoretical O / A ratio is the optimal O / A ratio; or, If the actual pH of the first raffinate is greater than the maximum threshold of the raffinate pH, the O / A ratio is reduced based on the theoretical O / A ratio until the corresponding raffinate pH is less than the maximum threshold of the raffinate pH, and the O / A ratio at this time is used as the optimal O / A ratio.

8. The method for optimizing the O / A ratio in the extraction of nickel, cobalt (manganese) from laterite nickel ore according to claim 1, characterized in that: The extractant is a first-class extractant, the acid value of the extractant is 1-3 mol / L, the dilution rate is 30-60%, the saponification rate is 35-60%, the extraction level is 6-10, the extraction temperature is room temperature, the extraction time is 6-10 min, and the pH of the liquid to be extracted is 4-6; or, The extractant is a second-class extractant, the acid value of the extractant is 1-3 mol / L, the dilution rate is 25-50%, the saponification rate is 20-50%, the extraction level is 6-10, the extraction temperature is room temperature, the extraction time is 6-10 min, and the pH of the liquid to be extracted is 1.5-4.

9. Use of the method for optimizing the O / A ratio in the extraction of nickel, cobalt (manganese) from laterite nickel ore ions as claimed in claim 1 in the preparation of nickel, cobalt (manganese) precursors.

10. Use of the method for optimizing the O / A ratio in nickel-cobalt (manganese) extraction from laterite nickel ore as claimed in claim 1 in the preparation of nickel-cobalt (manganese) ternary positive electrode materials.

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