Method for preparing nickel-cobalt-manganese raw material with ion co-balance in hydrometallurgy of laterite-nickel ore
By establishing a model relating the theoretical pH of the reaction endpoint solution to the target precipitation rate of the target metal in the hydrometallurgical process of laterite nickel ore, the problem of unstable product quality in the existing technology of MHP was solved, and more intuitive and controllable reaction process management was achieved, thereby improving product quality and production efficiency.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2024-09-30
- Publication Date
- 2026-04-02
AI Technical Summary
In existing hydrometallurgical processes for laterite nickel ore, the reliance on empirical assessments of the reaction extent leads to inconsistent MHP product quality, as it is impossible to accurately determine the amount of precipitant added and the degree of reaction.
A first theoretical relationship model is established between the theoretical pH of the reaction endpoint solution and the target precipitation rate of the target metal. The theoretical pH of the reaction endpoint solution is directly obtained through the initial solution parameters and the target precipitation rate of the target metal, and the reaction is stopped by combining the actual pH.
It simplifies the assessment of reaction degree, improves the quality consistency of MHP products and the controllability of the production process, and reduces the cost of subsequent refining stages.
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Figure CN2024122777_02042026_PF_FP_ABST
Abstract
Description
Preparation method of ion co-balance nickel-cobalt-manganese raw material in laterite nickel ore hydrometallurgy TECHNICAL FIELD
[0001] The present application relates to the technical field of hydrometallurgy, and particularly relates to a preparation method of ion co-balance nickel-cobalt-manganese raw material in laterite nickel ore hydrometallurgy. BACKGROUND
[0002] Under the background of the new energy era, laterite nickel ore is a key nickel resource that has attracted much attention. Compared with pyrometallurgical technology, hydrometallurgical technology of laterite nickel ore has obvious advantages in energy consumption, raw material adaptability, cost and environmental protection. In the field of hydrometallurgy, the design of the whole process of hydrometallurgical technology is closely related to the balance of various ions. The whole process of hydrometallurgical technology based on laterite nickel ore involves high-pressure leaching, cyclic leaching and neutralization, iron and aluminum removal, MHP (nickel-cobalt hydroxide) precipitation and other process sections. How to design, evaluate and optimize the process conditions of each process section depends on the balance of various ions in the aqueous solution.
[0003] At present, the quality of MHP products prepared by the hydrometallurgical process of laterite nickel ore is uneven. As a process section for producing products in the whole process of hydrometallurgical technology of laterite nickel ore, the precipitation of MHP is crucial to the product. In the process of MHP precipitation of laterite nickel ore, the type of precipitant, the amount of precipitant added and the reaction degree have a decisive influence on the quality of MHP. In actual industrial production, the amount of precipitant added and the reaction degree are generally evaluated artificially by experience. However, if the composition of nickel-cobalt solution changes, the amount of precipitant added and the reaction degree cannot be accurately judged, which ultimately affects the quality of MHP products.
[0004] SUMMARY
[0005] The present application aims to overcome the above technical deficiencies and provides a preparation method of ion co-balance nickel-cobalt-manganese raw material in laterite nickel ore hydrometallurgy, which solves the technical problem that the reaction degree is generally evaluated artificially by experience in the prior art, resulting in uneven quality of MHP products.
[0006] The present application provides a preparation method of ion co-balance nickel-cobalt-manganese raw material in laterite nickel ore hydrometallurgy, which comprises the following steps:
[0007] Obtaining initial solution parameters, actual pH of reaction end solution and target precipitation rate of target metal;
[0008] Constructing a first theoretical relationship model of theoretical pH of reaction end solution and target precipitation rate of target metal, and obtaining the theoretical pH of reaction end solution based on the initial solution parameters and the first theoretical relationship model;
[0009] whether to stop the reaction based on the theoretical pH of the reaction end point solution and the actual pH of the reaction end point solution.
[0010] Compared with the prior art, the beneficial effects of the present application include:
[0011] The present application establishes a first theoretical relationship model of the theoretical pH of the reaction end point solution and the target precipitation rate of the target metal from the perspective of ion balance, guiding the MHP process. Through the method of the present application, the theoretical pH of the reaction end point solution can be directly obtained based on the initial solution parameters and the target precipitation rate of the target metal, so as to determine whether to stop the reaction through the theoretical pH of the reaction end point solution and the actual pH of the reaction end point solution; at the same time, the testing method of the actual pH of the reaction end point solution is simpler and more intuitive compared with the testing method of the metal concentration in the reaction end point solution, and it is easier to directly determine the reaction degree through pH, so as to control the reaction process. BRIEF DESCRIPTION OF DRAWINGS
[0012] Fig. 1 is a process flow diagram of an embodiment of the method for preparing nickel-cobalt-manganese raw materials in ion co-balance in the hydrometallurgy of laterite nickel ore provided by the present application;
[0013] Fig. 2 is a relationship diagram of the target precipitation rates of nickel, cobalt, manganese and magnesium and the theoretical pH of the reaction end point solution based on the first theoretical relationship model established in Example 1 of the present application. DETAILED DESCRIPTION
[0014] In order to make the purpose, technical scheme and advantages of the present application more clear and explicit, 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.
[0015] Referring to Fig. 1, the present application provides a method for preparing nickel-cobalt-manganese raw materials in ion co-balance in the hydrometallurgy of laterite nickel ore, comprising the following steps:
[0016] S1, obtaining initial solution parameters, actual pH of the reaction end point solution and target precipitation rate of the target metal; wherein the initial solution parameters include the composition and volume of the initial solution;
[0017] S2, constructing a first theoretical relationship model of the theoretical pH of the reaction end point solution and the target precipitation rate of the target metal, and obtaining the theoretical pH of the reaction end point solution based on the initial solution parameters and the first theoretical relationship model;
[0018] S3, determining whether to stop the reaction based on the theoretical pH of the reaction end point solution and the actual pH of the reaction end point solution.
[0019] The present application establishes a first theoretical relationship model of the theoretical pH of the reaction end-point solution and the target precipitation rate of the target metal from the perspective of ion balance, which guides the MHP precipitation process. Through the method of the present application, the theoretical pH of the reaction end-point solution can be directly obtained based on the initial solution parameters and the target precipitation rate of the target metal, so as to determine whether to stop the reaction through the theoretical pH of the reaction end-point solution and the actual pH of the reaction end-point solution; at the same time, the testing method of the actual pH of the reaction end-point solution is simpler and more intuitive compared with the testing method of the metal concentration in the reaction end-point solution, and it is easier to directly determine the reaction degree through pH in order to control the reaction process.
[0020] The present application does not limit the source of the initial solution, and those skilled in the art can select according to the actual situation. In some specific embodiments of the present application, the initial solution is a solution after removing iron and aluminum from laterite nickel ore, which is prepared into MHP slurry by reacting with a precipitant.
[0021] Since the key target metal element recovered by the hydrometallurgical process of laterite nickel ore is nickel, and the precipitation rate of nickel is determined, the precipitation rates of cobalt and manganese and the composition of MHP are basically determined. Therefore, in some specific embodiments of the present application, the target metal is nickel.
[0022] The present application does not limit the type of precipitant, and those skilled in the art can select according to the actual situation. In some specific embodiments of the present application, the precipitant can be sodium hydroxide solution and / or magnesium oxide slurry, etc.
[0023] In this embodiment, the actual pH of the reaction end-point solution is obtained by detecting the filtrate obtained by solid-liquid separation of the slurry after the initial solution reacts with the precipitant. The present application does not limit the method of solid-liquid separation, and those skilled in the art can select according to the actual situation. For example, the method of filtration can be used for solid-liquid separation.
[0024] In some specific embodiments of the present application, the reaction end-point solution is obtained as follows:
[0025] Mixing and reacting the initial solution with the precipitant to obtain MHP slurry;
[0026] Concentrating the MHP slurry to obtain MHP thickener underflow;
[0027] Filtering the MHP thickener underflow to obtain MHP filter cake and filtrate, and the obtained filtrate is the reaction end-point solution.
[0028] Further, washing the MHP filter cake with water to obtain wash water, and detecting the filtrate and the wash water to calculate the actual precipitation rate.
[0029] In this embodiment, in step S2, the calculation formula corresponding to the first theoretical relationship model is as follows:
[0030] In the formula, K sp is the solubility product constant, K w is the ion product of water, C i is the mass concentration of the target metal in the initial feed liquid, A is the relative atomic mass of the target metal, R is the target precipitation rate of the target metal, pH is the theoretical pH of the reaction end-point feed liquid, and X is the chemical valence of the target metal.
[0031] Specifically, in step S2, the step of constructing the first theoretical relationship model of the theoretical pH of the reaction end-point feed liquid and the target precipitation rate of the target metal includes:
[0032] S21, constructing a solubility product constant model and a water ion product constant model;
[0033] The solubility product constant model is constructed based on the hydrolysis equilibrium reaction equation of the target metal, and the hydrolysis equilibrium reaction equation of the target metal is:
[0034] In the formula, X is the chemical valence of the target metal.
[0035] The solubility product constant (K sp ), abbreviated as the solubility product, represents the product of the powers of the concentrations of various ions when precipitation reaches a precipitation-dissolution equilibrium state in a solution. The concentration of the target metal in the reaction end-point feed liquid and the solubility product constant (K sp ) when it reaches the precipitation-dissolution equilibrium satisfy the following solubility product constant model:
[0036] In the formula, A is the relative atomic mass of the target metal, C f is the mass concentration of the target metal in the reaction end-point feed liquid, C f (OH - ) is the molar concentration of OH - ions in the reaction end-point feed liquid, K sp is only related to temperature or pressure, and when the atmospheric pressure and temperature are 25°C, the K sp of Ni(OH)2 is 5.92×10 -16 , the K sp of Co(OH)2 is 1.6×10 -15 , the K sp of Mn(OH)2 is 4×10 -14 , and the K sp of Mg(OH)2 is 5.61×10 -12 .
[0037] The water ion product constant, abbreviated as the water ion product, represents the concentration of the ionization products H + and OH- The product of concentrations, the OH- concentration in the feed solution at the reaction endpoint. - The ion concentration and the theoretical pH of the feed solution at the reaction endpoint satisfy the following water ion product constant model:
[0038] K w =10 -pH ×C f (OH - (3)
[0039] In the formula, the ion product of water, K w It depends only on temperature or pressure. At normal pressure and a temperature of 25°C, K w Take 1×10 -14 pH is the theoretical pH of the feed solution at the reaction endpoint.
[0040] S22. Construct a theoretical model relating the precipitation rate of the target metal to the initial feed parameters and the feed parameters at the reaction endpoint;
[0041] The theoretical relationship between the precipitation rate of the target metal and the initial and final feed parameters is represented by the following formula:
[0042] In the formula, R is the target precipitation rate of the target metal; C i and C f V represents the mass concentration of the target metal before and after the metal hydrolysis reaction (i.e., the mass concentration of the target metal in the initial feed solution and the mass concentration of the target metal in the feed solution at the end of the reaction, respectively); i and V f V represents the volume of the solution before and after the hydrolysis reaction (i.e., the initial volume of the feed solution and the final volume of the feed solution, respectively). Since the volume of the precipitant added during the MHP precipitation process is relatively small compared to the initial volume of the feed solution, V can be considered as... i ≈V f .
[0043] S23. Based on the solubility product constant model, the ion product constant model of water, and the theoretical relationship model between the precipitation rate of the target metal and the initial feed parameters and the feed parameters at the reaction endpoint, a first theoretical relationship model between the theoretical pH of the feed at the reaction endpoint and the target precipitation rate of the target metal is constructed.
[0044] Specifically, step S23 includes: combining (2), (3) and (4) to form the first theoretical relationship model between the theoretical pH of the final solution and the target precipitation rate of the target metal.
[0045] In this embodiment, before step S2, the method further includes: constructing a second theoretical relationship model between the amount of precipitant and the target precipitation rate of the target metal, and obtaining the amount of precipitant based on the initial liquid parameters and the second theoretical relationship model.
[0046] Specifically, the calculation formula corresponding to the second theoretical relationship model is as follows:
[0047] In the formula, m is the amount of precipitant; C Ni , C Co are the mass concentrations of nickel ions and cobalt ions in the initial feed liquid, respectively; R is the target precipitation rate of the target metal; B is the molecular weight of the precipitant; P is the mass concentration of the precipitant; and η is the amount-of-precipitant coefficient fitted according to the test results.
[0048] More specifically, the precipitant is sodium hydroxide solution, and the amount-of-precipitant coefficient η is 2.08; or, the precipitant is magnesium oxide slurry, and the amount-of-precipitant coefficient η is 0.95.
[0049] In the method of the present application, a second theoretical relationship model of the amount of precipitant and the target precipitation rate of the target metal is also established to guide the MHP process. Through the method of the present application, the amount of precipitant can be directly obtained based on the initial feed liquid parameters and the target precipitation rate of the target metal.
[0050] In the present embodiment, in step S3, the step of determining whether to stop the reaction based on the theoretical pH of the reaction-end feed liquid and the actual pH of the reaction-end feed liquid includes: when the ratio of the actual pH of the reaction-end feed liquid to the theoretical pH of the reaction-end feed liquid is 99-101%, the reaction is stopped.
[0051] In the method of the present application, when the ratio of the actual pH of the reaction-end feed liquid to the theoretical pH of the reaction-end feed liquid is <99, i.e., the reaction has not reached the target reaction degree, the reaction is continued until the ratio of the actual pH of the reaction-end feed liquid to the theoretical pH of the reaction-end feed liquid is 99-101%, and then the reaction is stopped.
[0052] The present application takes the currently industrialized precipitant sodium hydroxide solution and magnesium oxide slurry as an example, establishes a first theoretical relationship model of the theoretical pH of the reaction end liquid and the target precipitation rate of the target metal and a second theoretical relationship model of the amount of precipitant and the target precipitation rate of the target metal in the MHP process from the perspective of ion balance, and guides the MHP process. The inventors find that when the precipitant is sodium hydroxide solution, the conditions for the theory to be established are that the target precipitation rate of nickel is less than or equal to 93%, the mass concentration of the sodium hydroxide solution is 5-15%, the reaction time is 0.5h≤t≤3h, and the reaction temperature is 55℃≤T≤70℃; when the precipitant is magnesium oxide slurry, the conditions for the theory to be established are that the target precipitation rate of nickel is less than or equal to 98%, the mass concentration of the magnesium oxide slurry is 3-15%, the reaction time is 4h≤t≤8h, and the reaction temperature is 55℃≤T≤70℃. The method proposed in the present application is established within the above range. In addition, the current MHP is generally divided into two stages. In order to ensure the delivery quality of the MHP product and reduce the cost of the subsequent extraction stage, the first stage of the MHP is the product stage, and the precipitation rate of nickel is generally less than or equal to 85%. At the same time, in actual production, the precipitation rate of nickel in the MHP product stage is generally about 80%, so the method of the present application is sufficient to guide actual production.
[0053] In the examples and comparative examples of the present application, Example 1 is used to illustrate the relationship between the theoretical pH of the reaction end liquid and the target precipitation rate of the target metal, and Examples 2-5 and Comparative Examples 1-3 further verify the above method in combination with specific MHP processes.
[0054] In order to avoid repetition, the composition of the nickel-cobalt solution used in each of the examples and comparative examples of the present application is shown in Table 1.
[0055] Table 1 Composition of the nickel-cobalt solution for preparing MHP after removing iron and aluminum from the laterite nickel ore (g / L)
[0056] Example 1
[0057] According to the first theoretical model proposed in the present application, it can be inferred that the theoretical pH of the reaction end liquid after the MHP reaction is independent of the type of precipitant, and is related to the target precipitation rate of the target metal, and the target precipitation rate of the target metal and the theoretical pH of the reaction end liquid both satisfy the relationship of formula (1).
[0058] Taking nickel as an example, when the target precipitation rate of nickel is 80%, 90% and 95%, the theoretical pH of the reaction end liquid can be calculated by bringing each parameter into formula (1). Further, taking the target precipitation rate of nickel as 80% as an example, the relationship between the target precipitation rate of nickel and the theoretical pH of the reaction end liquid is as follows:
[0059] The end point pH = 7.35. In formula (1), K w is 1 x 10 -14 , K sp is 5.92 x 10 -16 .
[0060] Similarly, when the target precipitation rate of nickel is 90% and 95% in turn, the theoretical pH of the reaction end point solution is 7.50 and 7.65 respectively.
[0061] The equilibrium constants K sp (K sp of the hydrolysis precipitation reactions of the valuable metal ions nickel, cobalt, manganese and magnesium in the nickel-cobalt solution are 5.92 x 10 -16 , 1.6 x 10 -15 , 4 x 10 -14 , 5.61 x 10 -12 respectively.
[0062] Referring to FIG. 2, it can be seen from FIG. 2 that the hydrolysis sequence of nickel, cobalt, manganese and magnesium is nickel > cobalt > manganese > magnesium, and under the same pH condition, magnesium basically does not hydrolyze when the theoretical pH of the reaction end point solution is less than 8, and manganese has little effect on the hydrolysis of nickel and cobalt. Therefore, the amount of alkali used in the MHP preparation process can be calculated according to the concentration of nickel and cobalt in the nickel-cobalt solution, which is the theoretical basis for constructing the second theoretical model.
[0063] The nickel recovery is the main purpose of the hydrometallurgy of laterite nickel ore, followed by cobalt. Therefore, the first theoretical model and the second theoretical model proposed in the present application are verified from the actual precipitation rate of nickel and the actual reaction end point pH.
[0064] Example 2
[0065] (1) 48% liquid alkali is mixed with industrial water to obtain an alkali solution with a mass concentration of 5%;
[0066] (2) the MHP slurry is obtained by mixing the iron and aluminum removed laterite nickel ore solution with the alkali solution for precipitation reaction, the reaction temperature is 65°C, and the reaction time is 2h. In this process, the target precipitation rate of nickel needs to be controlled at 80%, and the amount m of 48% liquid alkali added is obtained by bringing the mass concentrations of nickel and cobalt in Table 1 into formula (5):
[0067] That is, the mass m of 48% liquid alkali added per liter of nickel-cobalt solution is 9.16g. In formula (5), the molecular weight of sodium hydroxide is 40g / mol, and η is 2.08.
[0068] (3) The MHP slurry is thickened to obtain MHP thickened underflow;
[0069] (4) The thickened underflow is filtered to obtain MHP filter cake and filtrate. After the filtrate is sampled and detected, it is found that the actual pH of the reaction end liquor is 7.38, which is basically consistent with the theoretical pH of the reaction end liquor. In addition, the MHP filter cake is washed with industrial water to obtain washing water, and the filtrate and washing water are sampled and detected to calculate that the actual precipitation rate of nickel is 80.79%, which is also very close to the target precipitation rate of nickel, verifying the rationality of the method.
[0070] (5) Part of the thickened underflow is returned to the MHP precipitation process as a seed.
[0071] Example 3
[0072] Different from Example 2: 48% liquid caustic is mixed with industrial water to obtain an alkali solution with a mass fraction of 10% for the precipitation reaction, and the actual precipitation rate of nickel is calculated to be 79.16%, and the actual pH of the reaction end liquor is 7.31. Since the increase in the concentration of liquid caustic will cause local over-alkalization, the precipitation rate of nickel will decrease slightly. However, within the concentration range of the alkali solution commonly used in production as specified in the present application, the relationship between the amount of sodium hydroxide and the precipitation rate of nickel proposed in the present application is applicable.
[0073] Example 4
[0074] Different from Example 2: the target precipitation rate of nickel is 90%.
[0075] The calculation shows that the amount m of 48% liquid caustic added is:
[0076] That is, the mass m of 48% liquid caustic added per liter of nickel-cobalt solution is 10.31 g.
[0077] After the filtrate is sampled and detected, it is found that the actual pH of the reaction end liquor is 7.45, and the actual precipitation rate of nickel is calculated to be 88.25%. It can be found that there is a difference of 1.75% between the actual precipitation rate and the target precipitation rate, but it has little effect on the quality of the MHP product. However, as the target precipitation rate of nickel increases, the actual precipitation rate of nickel will deviate more from the target precipitation rate under the calculated amount of sodium hydroxide. It is found that the relationship between the amount of sodium hydroxide and the precipitation rate of nickel proposed in the present application is used as much as possible when the target precipitation rate of nickel is ≤93%.
[0078] Example 5
[0079] The composition of the nickel-cobalt solution is the same as that of Example 2, and different from Example 2 is that magnesium oxide is used as a precipitant.
[0080] (1) 93% magnesium oxide is mixed with industrial water to obtain a 5% alkali slurry;
[0081] (2) The MHP slurry is obtained by mixing the liquid after removing iron and aluminum from the laterite nickel ore with the alkali slurry and performing a precipitation reaction, the reaction temperature is 65°C, and the reaction time is 5 h. If the target precipitation rate of nickel needs to be controlled to be 80% in this process section, the mass concentration of nickel and cobalt in Table 1 is brought into formula (5), and the addition amount m of 93% magnesium oxide is:
[0082] That is, the addition mass m of 93% magnesium oxide per liter of nickel-cobalt solution is 2.17 g. In formula (5), the molecular weight of magnesium oxide is 40.3 g / mol, and η is 0.95.
[0083] (3) The MHP slurry is subjected to thickening treatment to obtain MHP thickening underflow;
[0084] (4) The thickening underflow is filtered to obtain an MHP filter cake and a filtrate, and the filtrate is found to have an actual pH of 7.40 at the reaction end point, which is very close to the theoretical pH of the reaction end point liquid. In addition, the MHP is washed with industrial water to obtain washing water, and the filtrate and the washing water are detected to calculate that the actual precipitation rate of nickel is 80.88%, which is also very close to the target precipitation rate of nickel, indicating that the method of the present application can also be well applied to the system using magnesium oxide as a precipitant.
[0085] Example 6
[0086] Different from Example 5, the target precipitation rate of nickel is 95%. Calculation shows that the addition amount m of 93% magnesium oxide is:
[0087] That is, the addition mass m of 93% magnesium oxide per liter of nickel-cobalt solution is 2.58 g. It is found through detection that the actual precipitation rate of nickel is 95.45%, and the actual pH of the reaction end point liquid is 7.70.
[0088] Comparative Example 1
[0089] Different from Example 2, the MHP precipitation reaction time is 0.2 h, and other reaction conditions are the same.
[0090] It is found through detection that the actual pH of the reaction end point liquid is 7.48, and the actual precipitation rate of nickel is calculated to be 83.61%. It can be found that the actual reaction end point pH = 7.48 and the theoretical end point pH calculated by formula (1) is 7.35, which has a large difference. At the same time, although nickel is more prone to hydrolysis than cobalt and manganese, and the precipitation rate of nickel is higher when the reaction time is 0.2 h, the MHP slurry has a small particle size and is difficult to filter press due to the short reaction time.
[0091] Comparative Example 2
[0092] Different from Example 2: MHP precipitation reaction time is 4h, other reaction conditions are the same.
[0093] It is found by detection that the actual pH of the reaction end liquid is 7.26 (theoretical reaction end pH = 7.35), and the actual precipitation rate of nickel is only 75.25%. Therefore, the reaction time should not be too long when using sodium hydroxide as the precipitant, and too long reaction time will promote the oxidation and hydrolysis of manganese, thereby leading to the decrease of nickel precipitation rate.
[0094] Comparative Example 3
[0095] Different from Example 5: MHP precipitation reaction time is 1.5h, other reaction conditions are the same.
[0096] It is found by detection that the actual pH of the reaction end liquid is 7.24 (theoretical reaction end pH = 7.35), and the nickel precipitation rate is only 73.46%. Therefore, the reaction time is too short when using magnesium oxide as the precipitant, which will lead to low nickel precipitation rate.
[0097] Comparative Example 4
[0098] Different from Example 5: MHP precipitation reaction time is 9h, other reaction conditions are the same.
[0099] It is found by detection that the actual pH of the reaction end liquid is 7.43 (theoretical reaction end pH = 7.35), and the nickel precipitation rate is 82.93%. When using magnesium oxide as the precipitant, the reaction time is too long, which will increase the nickel precipitation rate, but the cobalt precipitation rate will decrease to 66.83%. In order to reduce transportation cost, the reaction time should be appropriate.
[0100] The specific implementation of the application described above does not constitute a limitation on the scope of protection of the application. Any various other corresponding changes and modifications made according to the technical concept of the application should be included in the protection scope of the claims of the application.
Claims
1. A process for the preparation of a raw material for the ion co- equilibrium of nickel, cobalt and manganese in hydrometallurgy of laterites, characterized in that, The method comprises the following steps: obtaining initial feed liquid parameters, actual pH of reaction end feed liquid, and target precipitation rate of target metal; constructing a first theoretical relationship model of theoretical pH of reaction end feed liquid and target precipitation rate of target metal, and obtaining theoretical pH of reaction end feed liquid based on the initial feed liquid parameters and the first theoretical relationship model; judging whether to stop the reaction based on the theoretical pH of reaction end feed liquid and the actual pH of reaction end feed liquid.
2. The method for preparing raw material of nickel-cobalt-manganese according to ion co- balance in hydrometallurgy of nickel laterite according to claim 1, characterized in that, The initial feed liquid parameters are obtained by detecting the liquid after removing iron and aluminum from laterite nickel ore; and the actual pH of reaction end feed liquid is obtained by detecting filtrate obtained by solid-liquid separation of slurry after the initial feed liquid is reacted with a precipitant.
3. The method for preparing raw material of nickel, cobalt and manganese according to ion co-balance in hydrometallurgy of nickel laterite according to claim 1, characterized in that, The calculation formula corresponding to the first theoretical relationship model is as follows: wherein K sp is the solubility product constant, K w is the ion product of water, C i is the mass concentration of the target metal in the initial feed solution, A is the relative atomic mass of the target metal, R is the target precipitation rate of the target metal, pH is the theoretical pH of the feed solution at the end of the reaction, and X is the chemical valence of the target metal.
4. The method for preparing raw material of nickel, cobalt and manganese according to ion co-balance in hydrometallurgy of nickel laterite according to claim 1, characterized in that, The step of constructing the first theoretical relationship model of theoretical pH of reaction end feed liquid and target precipitation rate of target metal comprises: constructing a solubility product constant model and a water ion product constant model; constructing a theoretical relationship model of precipitation rate of target metal and initial feed liquid parameters and reaction end feed liquid parameters; constructing the first theoretical relationship model of theoretical pH of reaction end feed liquid and target precipitation rate of target metal based on the solubility product constant model, the water ion product constant model, and the theoretical relationship model of precipitation rate of target metal and initial feed liquid parameters and reaction end feed liquid parameters. The calculation formula corresponding to the ion product constant model is as follows:
5. The method for preparing raw material of nickel, cobalt and manganese according to ion co-balance in hydrometallurgy of nickel laterite according to claim 4, characterized in that, The solubility product constant model corresponds to the calculation formula as follows: wherein A is the relative atomic mass of the target metal, C f is the mass concentration of the target metal in the feed solution at the end of the reaction, C f (OH - ) is the molar concentration of OH - ions in the feed solution at the end of the reaction; In the formula, pH is the theoretical pH of reaction end feed liquid. K w = 10 -pH x C f (OH - ) (3) Before constructing the first theoretical relationship model of theoretical pH of reaction end feed liquid and target precipitation rate of target metal, the method further comprises: The calculation formula corresponding to the theoretical relation model of the precipitation rate of the target metal and the initial feed liquid parameters and the reaction end point feed liquid parameters is: wherein R is the target precipitation rate of the target metal; C i and C f are the mass concentration of the target metal in the initial feed solution and the mass concentration of the target metal in the feed solution at the end of the reaction, respectively; V i and V f are the volume of the initial feed solution and the volume of the feed solution at the end of the reaction, respectively, V i ≈ V f .
6. The method for preparing raw material of nickel, cobalt and manganese according to ion co-balance in hydrometallurgy of nickel laterite according to claim 1, characterized in that, constructing a second theoretical relationship model of precipitant dosage and target precipitation rate of target metal, and obtaining precipitant dosage based on the initial feed liquid parameters and the second theoretical relationship model. η is a precipitant dosage coefficient fitted according to test results.
7. The method for preparing raw material of nickel-cobalt-manganese according to ion co- balance in hydrometallurgy of nickel laterite according to claim 6, characterized in that, The calculation formula corresponding to the second theoretical relationship model is as follows: wherein m is the amount of precipitant; C Ni , C Co are the mass concentrations of nickel ions and cobalt ions in the initial feed liquid, respectively; R is the target precipitation rate of the target metal; B is the molecular weight of the precipitant; and P is the mass concentration of the precipitant. The target metal is nickel, the precipitant is sodium hydroxide solution, and the precipitant dosage coefficient is 2.08; or, the target metal is nickel, the precipitant is magnesium oxide slurry, and the precipitant dosage coefficient is 0.
95.
8. The method for preparing raw material of nickel, cobalt and manganese according to ion co-balance in hydrometallurgy of nickel laterite according to claim 7, characterized in that, The target metal is nickel, the precipitant is sodium hydroxide solution, the target precipitation rate of target metal is ≤93%, the mass concentration of sodium hydroxide solution is 5-15%, the reaction time is 0.5h≤t≤3h, and the reaction temperature is 55℃≤T≤70℃; or, 9. The method for preparing raw material of nickel, cobalt and manganese according to ion co-balance in hydrometallurgy of nickel laterite according to claim 1, characterized in that, The target metal is nickel, the precipitant is magnesium oxide slurry, the target precipitation rate of target metal is ≤98%, the mass concentration of magnesium oxide slurry is 3-15%, the reaction time is 4h≤t≤8h, and the reaction temperature is 55℃≤T≤70℃. The step of judging whether to stop the reaction based on the theoretical pH of reaction end feed liquid and the actual pH of reaction end feed liquid comprises: if the ratio of the actual pH of reaction end feed liquid to the theoretical pH of reaction end feed liquid is 99-101%, the reaction is stopped.
10. The method for preparing raw material of nickel, cobalt and manganese according to ion co-balance in hydrometallurgy of nickel laterite according to claim 1, characterized in that,