Optimization method for o / a ratio during ion extraction of nickel and cobalt (manganese) from laterite nickel ore and use of optimization method

Abstract

The present application discloses an optimization method for the O / A ratio during the ion extraction of nickel and cobalt (manganese) from laterite nickel ore and a use of the optimization method. The optimization method comprises the following steps: acquiring liquid parameters of a liquid to be extracted, parameters of an extractant, and a target extraction rate of manganese; constructing a theoretical O / A ratio model, and determining a theoretical O / A ratio on the basis of the liquid parameters, the parameters of the extractant, the target extraction rate of manganese, and the theoretical O / A ratio model; and constructing limiting conditions, and determining an optimal O / A ratio on the basis of the theoretical O / A ratio and the limiting conditions. On the basis of the combination of theory and production practice, the present application establishes a corresponding theoretical model for the selection of the O / A ratio in an extraction section in a nickel-cobalt (manganese) co-extraction process based on different extractants and the problem of how to avoid the generation of a third phase during extraction, determines an optimal O / A ratio on the basis of the theoretical model, and finally uses a nickel-cobalt (manganese) mixed solution resulting from co-extraction under the condition of the optimal O / A ratio to prepare a nickel-cobalt (manganese) precursor and a ternary positive electrode material.

Description

Optimization method and application of O / A ratio in ion extraction of nickel, cobalt (manganese) from laterite nickel ore TECHNICAL FIELD

[0001] The present application relates to the technical field of hydrometallurgy, in particular to an optimization method and application of O / A ratio in ion extraction of nickel, cobalt (manganese) from laterite nickel ore. BACKGROUND

[0002] At present, for the process of preparing battery-grade nickel, cobalt and manganese crystals from laterite nickel ore by hydrometallurgy, a process of high-pressure leaching-multi-stage neutralization to remove iron and aluminum-multi-stage MHP to precipitate-multiple stages of impurity removal by leaching-P204 impurity removal-P507 cobalt extraction-P507 magnesium extraction-P507 nickel, cobalt and manganese enrichment is generally adopted. In order to simplify the above-mentioned complicated process, under the background of the rapid rise of ternary new energy materials, a nickel, cobalt (manganese) co-extraction process has been developed, that is, nickel, cobalt (manganese) is extracted from a mixed solution of nickel, cobalt and manganese, so as to quickly separate nickel, cobalt (manganese) from other impurity ions.

[0003] In the process of co-extraction of nickel, cobalt (manganese) from laterite nickel ore, the O / A ratio (i.e. the volume ratio of organic phase to aqueous phase) in the extraction stage directly affects the extraction efficiency, selectivity and recovery rate of metal ions. The selection of O / A ratio is crucial for optimizing the entire extraction process. Specifically, a higher O / A ratio will improve the extraction efficiency of metal ions. With the increase of O / A ratio, the improvement amplitude of recovery rate will gradually decrease until a stable state is reached. However, too high O / A ratio will not only reduce the extraction selectivity of the extractant for the target metal, but also cause the appearance of a third phase in the extraction tank, which hinders the progress of the extraction process. At present, whether it is an industrialized nickel, cobalt (manganese) co-extraction extractant or a newly developed co-extraction extractant, it can be generally divided into two categories. One is the co-extraction extractant whose aqueous phase pH decreases after 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 aqueous phase pH increases after extraction reaction, that is, the equilibrium pH is greater than the initial pH, such as Versatic 10, DY319 and others. This kind of extractant generally has high loading capacity and acid resistance, but the increase of aqueous phase pH after extraction reaction will cause the appearance of a third phase in the extraction stage of continuous extraction tank, which affects the phase separation process during extraction, and the third phase will block the extraction tank, making the extraction process unable to continue. The essential reason for the generation of the third phase and how to solve the problem of the generation of the third phase by optimizing 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 conditions. 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 artificial judgment. However, in the hydrometallurgical process of laterite nickel ore, the composition and content of nickel-cobalt (manganese) mixed solution obtained after different processes are different, resulting in too high or too low O / A ratio in actual operation, causing unnecessary cost increase or production efficiency reduction.

[0005] SUMMARY

[0006] The purpose of the present application is to overcome the above technical deficiencies, and to provide an O / A ratio optimization method for ion extraction of nickel-cobalt (manganese) from laterite nickel ore and its application, to solve the technical problems of unnecessary cost increase or production efficiency reduction caused by using a fixed O / A ratio or adjusting it only by artificial judgment in the prior art.

[0007] In a first aspect, the present application provides an O / A ratio optimization method for ion extraction of nickel-cobalt (manganese) from laterite nickel ore, comprising the following steps:

[0008] Obtaining the parameters of the to-be-extracted solution, the parameters of the extractant, and the target extraction rate of manganese;

[0009] Constructing a theoretical O / A ratio model, determining the theoretical O / A ratio based on the parameters of the solution, the parameters of the extractant, the target extraction rate of manganese, and the theoretical O / A ratio model;

[0010] Constructing a constraint condition, determining the optimal O / A ratio based on the theoretical O / A ratio and the constraint condition; wherein,

[0011] The parameters of the solution include the composition of the to-be-extracted solution and the pH of the to-be-extracted solution;

[0012] 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.

[0013] In a second aspect, the present application provides the application of the above-mentioned O / A ratio optimization method for ion extraction of nickel-cobalt (manganese) from laterite nickel ore in the preparation of nickel-cobalt (manganese) precursors.

[0014] In a third aspect, the present application provides the application of the above-mentioned O / A ratio optimization method for ion extraction of nickel-cobalt (manganese) from laterite nickel ore in the preparation of nickel-cobalt (manganese) ternary positive electrode materials.

[0015] Compared with the prior art, the present application has the following advantages:

[0016] The present application is based on the combination of theory and production practice, aiming at the selection of O / A ratio in the extraction section of the nickel-cobalt (manganese) co-extraction process based on different extractants and how to avoid the generation of the third phase in extraction, establishes the corresponding theoretical model, and determines the optimal O / A ratio in the extraction section of the ion extraction of nickel-cobalt (manganese) from laterite nickel ore based on the theoretical model. Finally, the mixed solution of nickel-cobalt (manganese) co-extracted under the optimal O / A ratio is used to prepare nickel-cobalt (manganese) precursors and ternary positive electrode materials. The method proposed in the present application can also be extended to other application fields of extractants. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 is a process flow diagram of an embodiment of the method for optimizing O / A ratio in ion extraction of nickel-cobalt (manganese) from laterite nickel ore provided by the present application;

[0018] Figure 2 is a graph of the relationship between the highest threshold value of raffinate pH and manganese concentration. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical scheme and advantages of the present application clearer, the present application will be further described in detail below in combination with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the present application and do not limit the present application.

[0020] In a first aspect, the present application provides a method for optimizing O / A ratio in ion extraction of nickel-cobalt (manganese) from laterite nickel ore, comprising the following steps:

[0021] S1, obtaining the parameters of the extraction feed liquid, the parameters of the extractant and the target extraction rate of manganese; the parameters of the extraction feed liquid include the composition of the extraction feed liquid and the pH of the extraction feed liquid, 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;

[0022] S2, constructing a theoretical O / A ratio model, determining the theoretical O / A ratio based on the parameters of the extraction feed liquid, the parameters of the extractant, the target extraction rate of manganese and the theoretical O / A ratio model;

[0023] S3, constructing a constraint condition, determining the optimal O / A ratio based on the theoretical O / A ratio and the constraint condition.

[0024] In the embodiment, in step S1, the to-be-extracted feed liquid comes from a laterite nickel ore hydrometallurgy process, and the specific source and composition of the to-be-extracted feed liquid are not limited in the application, and a person skilled in the art can select according to the actual situation. For example, the to-be-extracted feed liquid can be a post-iron-removal and post-aluminum-removal solution or a P204 back-extraction solution. In some specific embodiments of the application, the post-iron-removal and post-aluminum-removal solution I is obtained by filtering a multi-stage post-iron-removal and post-aluminum-removal solution of a laterite nickel ore leaching solution; the post-iron-removal and post-aluminum-removal solution II is obtained by leaching and neutralizing impurities from a MHP filter cake obtained by multi-stage MHP precipitation of the post-iron-removal and post-aluminum-removal solution I; and the P204 back-extraction solution is obtained by P204 impurity extraction of the post-iron-removal and post-aluminum-removal solution II.

[0025] In the embodiment, in step S1, the extractant includes one of a first type of extractant or a second type of extractant; wherein the first type of extractant is an extractant whose pH of the aqueous phase decreases after the extraction reaction, that is, the equilibrium pH < the initial pH; and the second type of extractant is an extractant whose pH of the aqueous phase increases after the extraction reaction, that is, the equilibrium pH > the initial pH. The specific types of the first type of extractant and the second type of extractant are not limited in the application, and a person skilled in the art can select according to the actual situation. In some specific embodiments of the application, the first type of extractant can be HBL110, HBL116, etc., and the second type of extractant can be Versatic 10, DY319, etc.

[0026] In the embodiment, in step S1, the selection principle of the target extraction rate of manganese is as follows: if the to-be-extracted feed liquid contains calcium, the target extraction rate of manganese needs to be appropriately reduced, and the reason is that: generally, the extraction rates of calcium and magnesium by the extractant are lower than those of nickel and cobalt (manganese), and calcium is more difficult to elute than magnesium. If a large amount of calcium is extracted, a large amount of nickel and cobalt (manganese) will be lost in the washing section in order to elute calcium. In addition, if the elution rate of calcium in the washing section is not enough, calcium sulfate will continuously enrich in the back-extraction solution, affecting the quality of the final nickel and cobalt (manganese) products.

[0027] Specifically, in the to-be-extracted feed liquid, if the mass ratio of Mn / Ca < 10, the target extraction rate of manganese η < 40%; if 10 ≤ the mass ratio of Mn / Ca < 200, the target extraction rate of manganese η should satisfy: 100% > η ≥ 40%; and if the mass ratio of Mn / Ca ≥ 200, the target extraction rate of manganese η = 100%.

[0028] In the embodiment, in step S2, the calculation formula of the theoretical O / A ratio model is:

[0029] In the formula, i is a metal element in the to-be-extracted feed liquid whose extraction rate by the extractant is ≥ the extraction rate of manganese; γ is the excess coefficient of the extraction organic phase, and γ is 1.4 for the first type of extractant and γ is 1.3 for the second type of extractant; C i is the molar concentration of a single metal ion in the to-be-extracted feed liquid; Xi η is the valence of the single metal ion in the feed solution to be extracted; i η is the extraction rate of the extractant for the single metal ion, and the extraction rate of the metal element with an extraction rate of the extractant for the metal ion in the feed solution to be extracted is greater than the extraction rate of manganese; 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.

[0030] 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 comprises:

[0031] If the extractant is the first type of extractant, the theoretical O / A ratio is the optimal O / A ratio; or,

[0032] If the extractant is the second type of extractant and Mn / Ca in the feed solution to be extracted is greater than or equal to 200, the theoretical O / A ratio is the optimal O / A ratio; or,

[0033] If the extractant is the second type of extractant and Mn / Ca in the feed solution to be extracted is less than 200, the optimal O / A ratio is determined according to the following steps:

[0034] S31, obtaining the actual pH of the first raffinate and the concentration of Mn 2+ in the first raffinate based on the theoretical O / A ratio;

[0035] S32, constructing a highest threshold model of raffinate pH, determining the highest threshold of raffinate pH based on the concentration of Mn 2+ in the first raffinate and the highest threshold model of raffinate pH;

[0036] S33, determining the optimal O / A ratio based on the actual pH of the first raffinate and the highest threshold of raffinate pH.

[0037] In this embodiment, for the first type of extractant with a reduced raffinate pH, 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 Mn / Ca in the feed solution to be extracted is greater than or equal to 200, since the content of calcium ions in the feed solution to be extracted is extremely low, all manganese is extracted in the extraction section, so that there is no or almost no manganese in the raffinate after extraction, thus the problem of the generation of the third phase due to the hydrolysis of manganese in the extraction section is basically eliminated, and therefore 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 Mn / Ca in the feed solution 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 operation of the nickel-cobalt (manganese) co-extraction process, the optimal O / A ratio also needs to be determined according to the actual pH of the first raffinate and the highest threshold of raffinate pH.

[0038] More specifically, the step of obtaining the actual pH of the first raffinate and the concentration of Mn 2+ in the first raffinate based on the theoretical O / A ratio comprises: obtaining the actual pH of the first raffinate and the concentration of Mn 2+ in the first raffinate after the co-extraction process is operated according to the parameters of the feed liquid, the parameters of the extractant, the theoretical O / A ratio and the actual production conditions. The actual production conditions comprise: extraction temperature, extraction time and extraction stages.

[0039] More specifically, the calculation formula of the upper threshold value model of the raffinate pH is:

[0040] In the formula, pH max is the upper threshold value of the raffinate pH, K sp [Mn(OH)2] is a constant related to temperature and pressure, which is 4×10 -14 under normal pressure and normal temperature; C(Mn 2+ ) is the molar concentration of Mn 2+ in the raffinate; and the coefficient 1.3 is related to the gradual oxidation of Mn 2+ in air to accelerate its hydrolysis.

[0041] More specifically, the step of determining the optimal O / A ratio based on the actual pH of the first raffinate and the upper threshold value of the raffinate pH comprises:

[0042] If the actual pH of the first raffinate is less than the upper threshold value of the raffinate pH, the theoretical O / A ratio is the optimal O / A ratio; or,

[0043] If the actual pH of the first raffinate is greater than the upper threshold value 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 upper threshold value of the raffinate pH, and the O / A ratio at this time is taken as the optimal O / A ratio.

[0044] Specifically, in the co-extraction process, the raffinate pH is determined according to the K sp [Mn(OH)2] of the Mn hydrolysis reaction. In order to avoid the generation of the third phase in the extraction, the raffinate pH must be less than the upper threshold value of the raffinate pH determined according to the raffinate pH threshold value model.

[0045] In some preferred embodiments of the present application, the lower threshold value of the raffinate pH is 5.5 for the second type of extractant. If the raffinate pH is too small, the extraction rate of nickel, cobalt (manganese) in the extraction section will be reduced.

[0046] In the embodiment, the extractant is the first type of 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 stage is 6-10 stages, the extraction temperature is room temperature, the extraction time is 6-10 min, and the pH of the to-be-extracted feed liquid is 4-6. Within the above parameter range, the co-extraction of nickel, cobalt and manganese can be efficiently carried out, and the production efficiency is improved.

[0047] In the embodiment, the extractant is the second type of 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 stage is 6-10 stages, the extraction temperature is room temperature, the extraction time is 6-10 min, and the pH of the to-be-extracted feed liquid is 1.5-4. For the second type of extractant, the pH of the raffinate, the nature of the extractant itself, the saponification rate of the extractant, the pH of the to-be-extracted feed liquid, and the extraction stage are all related. In order to avoid the generation of the third phase in extraction, these process factors should be well coordinated. Within the above parameter range, the pH of the to-be-extracted feed liquid, the saponification rate, and the extraction stage can be avoided to be too high, which leads to the pH of the raffinate being too high. At the same time, the pH of the to-be-extracted feed liquid, the saponification rate, and the extraction stage can be avoided to be too low, which leads to a low extraction rate.

[0048] It should be emphasized that the present application is a theoretical model established for the selection of the O / A ratio in the co-extraction process of nickel and cobalt (manganese) and how to avoid the generation of the third phase in extraction by optimizing the O / A ratio under the condition that other factors (such as the acid value, saponification rate, dilution rate, extraction stage, extraction temperature, and pH of the to-be-extracted feed liquid of the extractant) are relatively reasonable, and the method involved in the model is used to guide the co-extraction process.

[0049] In actual application, after the optimal O / A ratio is determined, the amount of extractant to be added to the to-be-extracted feed liquid can be dynamically adjusted in real time according to the optimal O / A ratio.

[0050] In a second aspect, the present application provides the application of the above-mentioned method for optimizing the O / A ratio in the ion extraction of nickel and cobalt (manganese) from laterite nickel ore in the preparation of nickel and cobalt (manganese) precursors.

[0051] In the embodiment, the above-mentioned application includes:

[0052] T1, determining the optimal O / A ratio according to the method for optimizing the O / A ratio in the ion extraction of nickel and cobalt (manganese) from laterite nickel ore provided in the first aspect of the present application;

[0053] T2, co-extracting based on the parameters of the feed liquid, the parameters of the extractant, and the optimal O / A ratio to obtain a second raffinate;

[0054] T3, preparing the second raffinate into nickel and cobalt (manganese) precursors.

[0055] In the embodiment, in step T3, the second raffinate is selectively subjected to impurity removal treatment according to the composition and content of the second raffinate. The application does not limit the impurity removal method, and those skilled in the art can select according to the actual situation. For example, P204 impurity removal can be used.

[0056] In some specific embodiments of the application, the high-purity nickel-cobalt (manganese) mixed solution obtained by nickel-cobalt (manganese) co-extraction from the iron and aluminum removal solution I and the iron and aluminum removal solution II is purified by P204 impurity removal line to obtain a battery-grade nickel-cobalt (manganese) mixed solution; the high-purity nickel-cobalt (manganese) mixed solution obtained by nickel-cobalt (manganese) co-extraction from the P204 back-extraction solution is a battery-grade nickel-cobalt (manganese) mixed solution.

[0057] In the embodiment, in step T3, according to the composition and content of the second raffinate and the composition and content of the target nickel-cobalt (manganese) precursor, nickel, cobalt, manganese or other doping elements can be selectively added for compounding, which is directly used for preparing the nickel-cobalt (manganese) precursor.

[0058] In a third aspect, the application provides the use of the above-mentioned method for optimizing the O / A ratio in the ion extraction of nickel-cobalt (manganese) from laterite nickel ore in the preparation of nickel-cobalt (manganese) ternary positive electrode materials.

[0059] The method for optimizing the O / A ratio in the ion extraction of nickel-cobalt (manganese) from laterite nickel ore provided by the application can obtain the optimal O / A ratio in the extraction section. Then, the optimal O / A ratio is used in combination with other parameters for co-extraction of nickel-cobalt (manganese) to obtain a raffinate containing nickel-cobalt (manganese). The raffinate containing nickel-cobalt (manganese) is subjected to optional impurity removal and compounding processes for preparing a nickel-cobalt (manganese) precursor. Finally, the nickel-cobalt (manganese) precursor is prepared into a nickel-cobalt (manganese) ternary positive electrode material.

[0060] In the following examples and comparative examples of the application, DY319 and HBL110 nickel-cobalt (manganese) co-extraction extractants currently used in the industry are used as extractants, and nickel-cobalt (manganese) mixed solutions obtained from different process sections of laterite nickel ore hydrometallurgy are used as the extractable feed liquid. The optimization of the O / A ratio in the extraction section of the nickel-cobalt (manganese) co-extraction process is described. The source of the extractable feed liquid and the extraction steps are as follows:

[0061] (1) The laterite nickel ore leaching solution is subjected to multi-stage iron and aluminum removal, and the iron and aluminum removal solution I is obtained by pressure filtration;

[0062] (2) The iron and aluminum removal solution I is subjected to multi-stage MHP precipitation, and the MHP filter cake is obtained by pressure filtration. The MHP filter cake is sequentially subjected to leaching and impurity removal by neutralization to obtain the iron and aluminum removal solution II;

[0063] (3) The iron and aluminum removal solution II is subjected to P204 impurity removal to obtain the P204 back-extraction solution;

[0064] (4) one or more of the iron and aluminum removal post-liquor I, iron and aluminum removal post-liquor II, and P204 stripping liquor is subjected to nickel-cobalt (manganese) co-extraction to obtain a loaded organic phase and a raffinate;

[0065] (5) the loaded organic phase is subjected to acid washing, and the washing liquor is recycled to the extraction section, followed by stripping to obtain a high-purity nickel-cobalt (manganese) mixed liquor.

[0066] In the embodiments of the present application, Example 1 is used to illustrate the relationship between the highest threshold value of the raffinate pH and the manganese concentration and the influence of the raffinate pH on the formation of the third phase in the continuous extraction process, and Examples 2-5 further verify the above method in combination with a specific nickel-cobalt (manganese) co-extraction process.

[0067] Example 1

[0068] The third phase is formed when the raffinate pH is greater than the highest threshold value, and no third phase is formed when the raffinate pH is less than the highest threshold value. According to the highest threshold value model of the raffinate pH proposed in the present application, it can be inferred that, after the co-extraction is completed, the highest threshold value of the raffinate pH and the molar concentration of Mn 2+ in the raffinate satisfy a certain relationship. By bringing the molar concentration of Mn 2+ in different raffinates into equation (2), a relationship diagram of the highest threshold value of the raffinate pH and the manganese concentration can be obtained.

[0069] Please refer to FIG. 2, which shows that, with the increase of the manganese concentration, the highest threshold value of the raffinate pH gradually decreases.

[0070] Example 2

[0071] Table 1 Composition of the multi-stage iron and aluminum removal post-liquor I (g / L)

[0072] (1) Preparation of DY319 extraction organic phase: the selected diluent is sulfonated kerosene, the saponification agent is liquid caustic, 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.

[0073] (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, so the mass concentration of Cu, Zn, Fe, Al, Ni, Co and Mn is converted into molar concentration and then brought into equation (1) for calculation, wherein the extraction rate η of manganese in the extraction section is brought into the calculation according to 30%. The O / A ratio is calculated by bringing the parameters into equation (1):

[0074] That is, O / A = 0.35.

[0075] The co-extraction process was run according to the O / A ratio, and it was found that the third phase was generated in the extraction section when the extraction temperature was room temperature, the extraction stage was 7 stages, and the extraction time was 8 min. 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.

[0076] The mass concentration of Mn in the above-mentioned raffinate was converted into molar concentration and brought into formula (2) to calculate the pH range of the raffinate when the third phase was not generated:

[0077] That is, pH < 6.30.

[0078] It was found through experiments that when the O / A ratio was adjusted to 0.30, the pH of the raffinate was stable at 6.01, which was less than 6.30. It can be seen from Figure 2 that the pH of the raffinate 6.01 is also less than the highest threshold value of the corresponding raffinate pH. At the same time, it was found that the third phase was not generated in the extraction section of the co-extraction process when the O / A ratio was 0.30. At this time, the extraction rate of nickel was 92%.

[0079] (3) Washing: The organic phase of extraction was washed with 0.12 mol / L sulfuric acid, and the washing water was recycled to the extraction section. The O / A ratio was 10:1 during washing, the washing stage was 6 stages, and the reaction time was 12 min.

[0080] (4) Stripping: The organic phase of extraction was stripped with 2.75 mol / L sulfuric acid. The O / A ratio was 20:1 during stripping, the stripping stage was 8 stages, and the reaction time was 14 min. The composition of the obtained nickel-cobalt(manganese) mixed salt solution was:

[0081] Table 2 Composition of the co-extracted nickel-cobalt(manganese) mixed salt solution (g / L)

[0082] (5) P204 purification line: The above-mentioned nickel-cobalt(manganese) mixed salt solution was purified by a P204 purification line to obtain a battery-grade nickel-cobalt(manganese) mixed salt solution that met the requirements of ternary material preparation.

[0083] Example 3

[0084] Different from Example 1, the O / A ratio of the extraction section of the co-extraction process was reduced to 0.21. At this time, the pH of the raffinate was 5.5, although the generation of the third phase in extraction was inhibited, but the nickel extraction rate decreased to 76%, which significantly reduced the utilization efficiency of the extractant and the production efficiency, and increased the production cost. It can be seen that the O / A ratio should not be too large or too small.

[0085] Example 4

[0086] Table 3 Composition of P204 stripping solution (g / L)

[0087] Since the impurities in the P204 stripping solution are only a small amount of Ca and Mg, the mass ratio of Mn / Ca is ≥200, so the extraction rate of manganese is 100%; at the same time, since DY319 has excellent selectivity for nickel and cobalt in the calcium and magnesium system, the extraction of manganese in the extraction section makes the raffinate after extraction have no or very little manganese, so that the problem of hydrolysis of manganese to produce a third phase in the extraction section does not exist. The O / A ratio is calculated according to formula (1) as follows:

[0088] (1) Preparation of DY319 extraction organic phase: the selected diluent is sulfonated kerosene, the saponifier is liquid caustic, 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.

[0089] (2) Nickel-cobalt (manganese) co-extraction: after the mass concentration of Ni, Co and Mn is converted into molar concentration, it is brought into formula (1) for calculation, wherein the extraction rate η of manganese in the extraction section is brought into the calculation according to 100%. The O / A ratio is calculated by bringing the parameters into formula (1):

[0090] That is, O / A ≈ 7.78.

[0091] The extraction temperature is taken as room temperature, the extraction stage is 8 stages, the extraction time is 7 min, and after the co-extraction process is run according to the O / A ratio, it is found that there is no third phase in the extraction section, and the raffinate pH is 7.09. It is found that the nickel extraction rate is 99%, so the O / A ratio is reasonable.

[0092] (3) Washing: 0.15 mol / L sulfuric acid is used to wash the extraction organic phase, and the wash water is recycled to the extraction section. The O / A ratio during washing is 15:1, the washing stage is 6 stages, and the reaction time is 10 min.

[0093] (4) Stripping: 2.75 mol / L sulfuric acid is used to strip the extraction organic phase. The O / A ratio during stripping is 20:1, the stripping stage is 8 stages, and the reaction time is 12 min. The composition of the nickel-cobalt (manganese) mixed salt solution obtained is:

[0094] Table 4 Composition of nickel-cobalt (manganese) mixed salt solution after co-extraction (g / L)

[0095] The solution completely meets the needs of the preparation of ternary materials and can be compounded to prepare high-nickel NCM ternary precursors.

[0096] Example 5

[0097] The multi-stage iron-removed aluminum solution I is treated by co-extraction using HBL110. The composition of the multi-stage iron-removed aluminum solution I is the same as that in Example 2, and the pH is adjusted to 5. After extraction by the HBL110 extractant, the pH of the raffinate solution decreases relative to the initial pH of the to-be-extracted solution. Therefore, the third phase does not appear in the extraction stage. The co-extraction steps are as follows:

[0098] (1) Preparation of HBL110 extraction organic phase: the selected diluent is sulfonated kerosene, the saponifier is liquid caustic, 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.

[0099] (2) Nickel-cobalt (manganese) co-extraction: the selectivity of HBL110 to the elements listed in Table 1 is Cu > Ni > Co > Zn > Mn > Fe, Al, Ca, Mg, so the mass concentrations of Cu, Ni, Co, Zn and Mn are converted into molar concentrations and brought into formula (1) for calculation. Since there are many impurities in the to-be-extracted aqueous phase, the extraction rate η of manganese in the extraction stage is taken as 30% for calculation. The O / A ratio is calculated by bringing the parameters into formula (1):

[0100] That is, O / A ≈ 0.88.

[0101] The extraction temperature is taken as room temperature, the extraction stage is 8, and the extraction time is 9 min. After running the co-extraction process according to the O / A ratio, it is found that there is no third phase in the extraction stage, and the pH of the raffinate solution is 4.5. It is found that in the extraction stage, the nickel extraction rate is 97%, and the cobalt extraction rate is 91%. Therefore, the O / A ratio is reasonable.

[0102] (3) Washing: the extraction organic phase is washed with 0.12 mol / L sulfuric acid, and the wash water is recycled to the extraction stage. The O / A ratio during washing is 15:1, the washing stage is 5, and the reaction time is 12 min.

[0103] (4) Stripping: the extraction organic phase is stripped with 2.5 mol / L sulfuric acid. The O / A ratio during stripping is 20:1, the stripping stage is 8, and the reaction time is 15 min. The composition of the obtained nickel-cobalt (manganese) mixed salt solution is:

[0104] Table 5 Composition of the nickel-cobalt (manganese) mixed salt solution after co-extraction (g / L)

[0105] (5) P204 purification line: the Cu, Zn, Fe, Al and Ca impurities in the above nickel-cobalt (manganese) mixed salt solution are removed using the P204 purification line, and a battery-grade nickel-cobalt (manganese) mixed salt solution that meets the requirements for the preparation of ternary materials is obtained.

[0106] The specific implementation of the present application described above does not constitute a limitation on the protection scope of the present application. Any various other corresponding changes and modifications made according to the technical concept of the present application shall be included in the protection scope of the claims of the present application.

Claims

1. A method for optimizing the O / A ratio in the ion-extraction of nickel-cobalt (manganese) from laterite nickel ores, characterized in that, The method comprises the following steps: obtaining the parameters of the to-be-extracted feed liquid, the parameters of the extractant, and the target extraction rate of manganese; constructing a theoretical O / A ratio model, determining a theoretical O / A ratio based on the parameters of the feed liquid, the parameters of the extractant, the target extraction rate of manganese, and the theoretical O / A ratio model; constructing a restriction condition, and determining an optimal O / A ratio based on the theoretical O / A ratio and the restriction condition; wherein the parameters of the feed liquid include the composition of the to-be-extracted feed liquid and the pH of the to-be-extracted feed liquid; 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 the ion-extraction of nickel and cobalt (manganese) from laterite nickel ores according to claim 1, characterized in that, If the mass ratio of Mn / Ca in the to-be-extracted feed liquid is less than 10, the target extraction rate of manganese is less than 40%; if the mass ratio of Mn / Ca is 10 to less than 200, the target extraction rate of manganese should satisfy: 100%>η≥40%; if the mass ratio of Mn / Ca is greater than or equal to 200, the target extraction rate of manganese is 100%. The step of determining the optimal O / A ratio based on the theoretical O / A ratio and the restriction condition comprises:

3. The method for optimizing the O / A ratio in the ion-extraction of nickel and cobalt (manganese) from laterites according to claim 1, characterized in that, The theoretical O / A ratio model is calculated by the formula: In the formula, i is a metal element whose extraction rate of metal ions in the to-be-extracted feed liquid by the extractant is greater than the extraction rate of manganese; γ is an excess coefficient of the extraction organic phase, and for a first type of extractant whose pH of the aqueous phase decreases after the extraction reaction, γ is taken as 1.4, and for a second type of extractant whose pH of the aqueous phase increases after the extraction reaction, γ is taken as 1.3; C i is the molar concentration of the single metal ion in the to-be-extracted feed liquid; X i is the valence of the single metal ion in the to-be-extracted feed liquid; η i is the extraction rate of the extractant to the single metal ion, and the extraction rate of the extractant to the metal element whose extraction rate of metal ions in the to-be-extracted feed liquid is greater than the extraction rate of manganese is all 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 the ion-extraction of nickel and cobalt (manganese) from laterites according to claim 3, characterized in that, 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 the mass ratio of Mn / Ca in the to-be-extracted feed liquid is greater than or equal to 200, the theoretical O / A ratio is the optimal O / A ratio; or, if the extractant is a second type of extractant and the mass ratio of Mn / Ca in the to-be-extracted feed liquid is less than 200, the optimal O / A ratio is determined according to the following steps: determining the optimal O / A ratio based on the actual pH of the first raffinate and the highest threshold value of the raffinate pH. Based on the theoretical O / A ratio, an actual pH of the first raffinate and a concentration of Mn in the first raffinate are obtained 2+ ; constructing a maximum threshold model for the pH of the raffinate, determining a maximum threshold value for the pH of the raffinate based on the concentration of Mn in the first raffinate and the maximum threshold model for the pH of the raffinate 2+ ; The step of determining the optimal O / A ratio based on the actual pH of the first raffinate and the highest threshold value of the raffinate pH comprises:

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

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

7. The method for optimizing the O / A ratio in the ion-extraction of nickel and cobalt (manganese) from laterites according to claim 4, characterized in that, if the actual pH of the first raffinate is less than the highest threshold value 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 highest threshold value 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 highest threshold value of the raffinate pH, and the O / A ratio at this time is taken as the optimal O / A ratio. The extractant is a first type of 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 stage is 6-10 stages, the extraction temperature is room temperature, the extraction time is 6-10 min, and the pH of the to-be-extracted feed liquid is 4-6; or, 8. The method for optimizing O / A ratio in ion exchange of nickel-cobalt (manganese) from laterite nickel ore according to claim 1, characterized in that, The extractant is a second type of 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 stage is 6-10 stages, the extraction temperature is room temperature, the extraction time is 6-10 min, and the pH of the to-be-extracted feed liquid is 1.5-4.

9. The use of the method for optimizing the O / A ratio in the ion extraction of nickel and cobalt (manganese) from laterite nickel ore according to claim 1 in the preparation of nickel and cobalt (manganese) precursors.

10. The use of the method for optimizing the O / A ratio in the ion extraction of nickel and cobalt (manganese) from laterite nickel ore according to claim 1 in the preparation of nickel and cobalt (manganese) ternary positive electrode materials. ​

Images