Method and process for preparing MHP through laterite-nickel ore hydrometallurgy crystallization control
When preparing nickel cobalt manganese hydroxide (MHP), the number of nuclei and average particle size is determined based on the nucleation and growth reaction conditions, and the particle size distribution of agglomerated grains is predicted by using the Metropolis algorithm, the problem of the inability to predict the particle size distribution of MHP agglomerated grains in the prior art is solved, and the effect of narrower particle size distribution and higher performance of MHP products is achieved.
Patent Information
- Application Number
- CN202480002500.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-30
- Publication Date
- 2025-03-21
AI Technical Summary
The prior art cannot predict the agglomerated grain size distribution of nickel cobalt manganese hydroxide (MHP) before preparation, resulting in uncontrollable MHP performance.
The number of nuclei and average particle size is determined based on the nucleation reaction conditions and the primary growth reaction conditions, and the secondary agglomeration and growth process is simulated by the Metropolis algorithm to predict the particle size distribution of agglomerated grains.
The accurate prediction of the particle size distribution of agglomerated grains is improved, the reaction conditions are optimized, and the goal of narrower particle size distribution and higher performance of MHP products is achieved.
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Abstract
Description
Technical Field
[0001] The present application relates to the technical field of laterite nickel ore hydrometallurgy, and in particular to a method and process for preparing MHP by hydrometallurgical controlled crystallization of laterite nickel ore. Background Art
[0002] Nickel cobalt manganese hydroxide (MHP) is a nickel intermediate product made from laterite nickel ore through high-pressure acid leaching technology. Nickel cobalt manganese hydroxide can be used to produce nickel sulfate, refined nickel cobalt manganese hydroxide, nickel plates and other products, especially for the production of nickel sulfate, one of the main materials for the positive electrode of ternary batteries. In recent years, with the continuous development of industries such as electric vehicles, the market capacity of ternary batteries has continued to expand, which has also driven the market demand for nickel cobalt manganese hydroxide.
[0003] The preparation process of nickel cobalt manganese hydroxide is as follows: adding a precipitant to the liquid after iron and aluminum removal, and subjecting the nickel cobalt manganese hydroxide in the liquid after iron and aluminum removal to nucleation, primary grain growth, and secondary grain agglomeration and growth, finally obtaining nickel cobalt manganese hydroxide. The particle size distribution of the agglomerated grains obtained after the secondary grain agglomeration and growth of nickel cobalt manganese hydroxide has a great influence on the performance of nickel cobalt manganese hydroxide. The prior art determines the performance of the agglomerated particle size by evaluating the particle size distribution of the agglomerated particle size actually obtained, but cannot predict the particle size distribution of the agglomerated grains, that is, it is impossible to optimize the reaction conditions before preparation so that the particle size distribution meets the requirements, resulting in the technical problem that the performance of the prepared nickel cobalt manganese hydroxide is uncontrollable. In the actual production process, the ideal MHP product should have a narrow particle size distribution range and uniform morphology. Such a precipitated product has a high sedimentation rate, a fast filtration speed, and a low moisture content in the filter cake.
[0004] Therefore, there is an urgent need to provide a method and process for preparing MHP by hydrometallurgical controlled crystallization of laterite nickel ore, accurately predict the particle size distribution of agglomerated grains, so that the MHP product has a narrower particle size distribution, thereby improving the performance of the prepared nickel cobalt manganese hydroxide. Summary of the invention
[0005] In view of this, it is necessary to provide a method and process for preparing MHP by hydrometallurgical controlled crystallization of laterite nickel ore, so as to solve the technical problem that the particle size distribution of agglomerated grains cannot be predicted before preparation in the prior art, and therefore the reaction conditions cannot be optimized, resulting in uncontrollable performance of the prepared nickel cobalt manganese hydroxide.
[0006] On the one hand, in order to solve the above technical problems, the present application provides a method for preparing MHP by hydrometallurgical controlled crystallization of laterite nickel ore, comprising:
[0007] Determine the number of multiple crystal nuclei of the iron-aluminum-removed liquid after the nucleation reaction based on the nucleation reaction conditions;
[0008] Determining an average grain size of a plurality of crystal grains after the plurality of crystal nuclei have grown once based on a primary growth reaction condition;
[0009] The predicted particle size distribution of the agglomerated grains after the plurality of grains undergo secondary agglomeration and growth is determined based on the Metropolis algorithm, the number of crystal nuclei and the average particle size.
[0010] In a possible implementation, the nucleation reaction conditions include the pH and quality of the precipitant; then determining the number of multiple crystal nuclei of the iron-aluminum-removed liquid after the nucleation reaction based on the nucleation reaction conditions includes:
[0011] Determining the supersaturation of the primary nickel-cobalt-manganese hydroxide precipitation solution based on the pH and quality of the precipitant;
[0012] Determining the crystallization rate of the primary nickel-cobalt-manganese hydroxide precipitation solution based on the supersaturation and crystallization rate model;
[0013] The number of crystal nuclei of the plurality of crystal nuclei is determined based on the crystallization rate.
[0014] In a possible implementation, the crystallization rate model is:
[0015]
[0016] J0=A·ln S
[0017]
[0018] Where J is the crystallization rate, 1 / (m 3 ·s); J0 is the maximum crystallization rate, 1 / (m 3 ·s); γ is the surface energy of the hydroxide precipitate, J / m 2 ; is the partial molar volume of the hydroxide, mol / m 3 ;k B is the Boltzmann constant; R g is the ideal gas constant, J / (mol·K); T is the temperature, K; S is the supersaturation; A is the proportional constant; is the concentration of divalent ions in the liquid after iron and aluminum removal; c OH is the concentration of hydroxide ions; is the solubility product of the hydroxide precipitate; N A is Avogadro's constant; M 2+ Diffusion rate constant of metal ions in solution.
[0019] In a possible implementation, determining the average grain size of a plurality of crystal grains after the plurality of crystal nuclei have grown once based on a growth reaction condition includes:
[0020] Determining the concentration of hydroxide precipitation during the primary growth of the crystal nucleus based on the primary growth reaction conditions;
[0021] The average grain size of the plurality of grains is determined based on the hydroxide precipitate concentration, a grain growth partial differential equation, and boundary conditions.
[0022] In a possible implementation, the grain growth partial differential equation is:
[0023]
[0024] The boundary conditions are:
[0025]
[0026]
[0027] In the formula, is the concentration of hydroxide precipitate after one growth reaction condition; D is the diffusion rate constant of hydroxide precipitate in solution; r is the vector position, t is the time, c(r,t) is the component field variable; R is the maximum position of the vector field; is the concentration of hydroxide precipitate in the bulk phase of the solution.
[0028] In a possible implementation, determining the predicted particle size distribution of the agglomerated grains based on the Metropolis algorithm, the number of crystal nuclei and the average particle size includes:
[0029] Step 1, taking the number of crystal nuclei and the average particle size as the initial state;
[0030] Step 2: exchanging the liquid and grain positions in the nickel-cobalt-manganese hydroxide precipitation solution during the secondary agglomeration and growth;
[0031] Step 3, determining the total energy of the nickel-cobalt-manganese hydroxide precipitation solution after the positions of the liquid and the crystal grains are exchanged;
[0032] Step 4: determine the change trend of the total energy, and when the change trend is decreasing, accept the position change; when the change trend is increasing, accept the position change with a preset probability;
[0033] Step 5, return to step 2, and repeat steps 2 to 4 until the number of position changes reaches a preset number of iterations, and the last position of the liquid and the crystal is taken as the target position;
[0034] Step six: determining the predicted particle size distribution of the agglomerated grains based on the target position.
[0035] In a possible implementation, the total energy includes agglomeration energy and stirring energy.
[0036] In one possible implementation, the maximum distance between the liquid and the grain that exchange positions satisfies:
[0037]
[0038] In the formula, Δx max is the maximum distance; D p is the diffusion rate of the grain, m 2 / s; Δt is the time interval between two consecutive iterative calculations.
[0039] In a possible implementation, the method further includes:
[0040] When the predicted particle size distribution does not meet the desired particle size distribution, the nucleation reaction conditions and / or the primary growth reaction conditions are optimized until the predicted particle size distribution meets the desired particle size distribution.
[0041] On the other hand, the present application also provides a process for preparing MHP by hydrometallurgical controlled crystallization of laterite nickel ore, which is realized based on the method for preparing MHP by hydrometallurgical controlled crystallization of laterite nickel ore;
[0042] Wherein, the method for preparing MHP by hydrometallurgical controlled crystallization of laterite nickel ore is the method for preparing MHP by hydrometallurgical controlled crystallization of laterite nickel ore described in any one of the possible implementations described above.
[0043] The beneficial effects of the present application are as follows: the method for preparing MHP by hydrometallurgical controlled crystallization of laterite nickel ore provided in the present application first determines the number of multiple crystal nuclei after the iron and aluminum liquid undergoes a nucleation reaction based on the nucleation reaction conditions, and then determines the average particle size of multiple grains after the multiple crystal nuclei undergo a single growth based on the single growth reaction conditions. The number of crystal nuclei and the average particle size are used as prerequisite parameters for predicting the particle size distribution, which can improve the accuracy of the determined predicted particle size distribution.
[0044] Furthermore, since the secondary agglomeration and growth of grains are random, the present application determines the predicted particle size distribution based on the Metropolis algorithm, and utilizes its ability to simulate the characteristics of random sampling distribution to achieve the purpose of accurately describing the secondary agglomeration and growth process of grains, thereby further improving the accuracy of the predicted particle size distribution.
[0045] According to the predicted particle size distribution results, the present application adjusts the reaction conditions of the nucleation reaction and the primary growth reaction, controls the number of crystal nuclei and the average particle size, so as to obtain a high-performance MHP product with a better particle size distribution, which has a guiding role in the crystallization process of MHP. BRIEF DESCRIPTION OF THE DRAWINGS
[0046] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.
[0047] Figure 1 A schematic flow chart of an embodiment of a method for preparing MHP by hydrometallurgical controlled crystallization of laterite nickel ore provided in the present application;
[0048] Figure 2 For this application Figure 1 A schematic flow chart of an embodiment of S101;
[0049] Figure 3 For this application Figure 1 A schematic flow chart of an embodiment of S102;
[0050] Figure 4 For this application Figure 1 A schematic flow chart of an embodiment of S103;
[0051] Figure 5 A schematic diagram of the predicted particle size distribution corresponding to different pH values of the precipitant provided in this application;
[0052] Figure 6 This is a comparison chart before and after the particle size distribution optimization provided in this application. DETAILED DESCRIPTION
[0053] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative work are within the scope of protection of this application.
[0054] It should be understood that the schematic drawings are not drawn to scale. The flowcharts used in this application illustrate operations implemented according to some embodiments of the present application. It should be understood that the operations of the flowcharts may be implemented out of order, and steps without logical contextual relationships may be reversed in order or implemented simultaneously. In addition, those skilled in the art may add one or more other operations to the flowcharts, or may remove one or more operations from the flowcharts, under the guidance of the content of this application. Some of the block diagrams shown in the accompanying drawings are functional entities, and do not necessarily correspond to physically or logically independent entities. These functional entities may be implemented in software form, or implemented in one or more hardware modules or integrated circuits, or implemented in different networks and / or processor systems and / or microcontroller systems.
[0055] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.
[0056] The present application provides a method and process for preparing MHP by hydrometallurgical controlled crystallization of laterite nickel ore, which are respectively described below.
[0057] Figure 1 A schematic flow chart of an embodiment of a method for preparing MHP by hydrometallurgical controlled crystallization of laterite nickel ore provided in this application is as follows Figure 1 As shown, the method for preparing MHP by hydrometallurgical controlled crystallization of laterite nickel ore comprises:
[0058] S101, determining the number of multiple crystal nuclei of the iron-aluminum-removed liquid after the nucleation reaction based on the nucleation reaction conditions;
[0059] S102, determining an average grain size of a plurality of crystal grains after a plurality of crystal nuclei have grown once based on a primary growth reaction condition;
[0060] S103, determining the predicted particle size distribution of agglomerated grains after the plurality of grains undergo secondary agglomeration and growth based on the Metropolis algorithm, the number of crystal nuclei and the average particle size.
[0061] The iron-aluminium-removed liquid in step S101 is a solution obtained by high-pressure acid leaching and iron-aluminium-removal treatment of laterite nickel ore.
[0062] It should be noted that both the nucleation reaction and the primary growth reaction are performed by adding a precipitant to the solution, and the seed crystals in the solution undergo a precipitation reaction based on the added precipitant, thereby achieving nucleation and grain growth.
[0063] It should be understood that the precipitating agent is at least one of sodium hydroxide, lime milk, potassium hydroxide, calcium oxide, magnesium oxide and magnesium hydroxide.
[0064] Compared with the prior art, the method for preparing MHP by hydrometallurgical controlled crystallization of laterite nickel ore provided in the embodiment of the present application first determines the number of multiple crystal nuclei after the iron and aluminum liquid undergoes a nucleation reaction based on the nucleation reaction conditions, and then determines the average particle size of multiple grains after the multiple crystal nuclei grow once based on the primary growth reaction conditions. The number of crystal nuclei and the average particle size are used as prerequisite parameters for predicting the particle size distribution, which can improve the accuracy of the determined predicted particle size distribution.
[0065] Furthermore, since the secondary agglomeration and growth of grains are random, the present application determines the predicted particle size distribution based on the Metropolis algorithm, and utilizes its ability to simulate the characteristics of random sampling distribution to achieve the purpose of accurately describing the secondary agglomeration and growth process of grains, thereby further improving the accuracy of the predicted particle size distribution.
[0066] In some embodiments of the present application, the nucleation reaction conditions and the primary growth reaction conditions include at least one parameter affecting nucleation and primary growth, for example: including precipitant parameters, and / or, deironing aluminum liquid parameters, the precipitant parameters include the mass and pH of the precipitant, the deironing aluminum liquid parameters include the mass and concentration of the deironing aluminum liquid, etc.
[0067] In a specific embodiment of the present application, the nucleation reaction conditions include the pH and quality of the precipitant; Figure 2 As shown, step S101 includes:
[0068] S201, determining the supersaturation of a nickel-cobalt-manganese hydroxide precipitation solution based on the pH and quality of the precipitant;
[0069] S202, determining a crystallization rate of a nickel-cobalt-manganese hydroxide precipitation solution based on a supersaturation and crystallization rate model;
[0070] S203, determining the number of crystal nuclei of the plurality of crystal nuclei based on the crystallization rate.
[0071] The embodiments of the present application determine the crystallization rate through an effective and accurate crystallization rate model, accurately describe the crystallization mechanism, and improve the accuracy of the determined number of crystal nuclei.
[0072] The calculation formula of supersaturation S is:
[0073]
[0074] In the formula, is the concentration of divalent ions in the liquid after iron and aluminum removal; c OH is the concentration of hydroxide ions; is the solubility product of the hydroxide precipitate.
[0075] In a specific embodiment of the present application, the crystallization rate model is:
[0076]
[0077] J0=A·ln S
[0078]
[0079] Where J is the crystallization rate, 1 / (m 3 ·s); J0 is the maximum crystallization rate, 1 / (m 3 ·s); γ is the surface energy of the hydroxide precipitate, J / m 2 ; is the partial molar volume of the hydroxide, mol / m 3 ;k B is the Boltzmann constant; R g is the ideal gas constant, J / (mol·K); T is the temperature, K; N A is Avogadro's constant; M 2+ Diffusion rate constant of metal ions in solution.
[0080] It should be noted that step S203 specifically includes determining the number of crystal nuclei based on the crystallization rate, crystallization time and the volume of the liquid after iron and aluminum removal.
[0081] In some embodiments of the present application, Figure 3 As shown, step S102 includes:
[0082] S301, determining the hydroxide precipitation concentration during the primary growth process of the crystal nucleus based on the primary growth reaction conditions;
[0083] S302, determining an average grain size of the plurality of grains based on hydroxide precipitation concentration, a partial differential equation for grain growth, and boundary conditions.
[0084] The embodiment of the present application determines the influencing parameters of the primary growth reaction conditions on the primary growth process of the crystal nucleus, and then determines the average particle size of multiple grains generated after the primary growth reaction based on the influencing parameters, thereby ensuring the accuracy of the average particle size under the primary growth reaction conditions.
[0085] In a specific embodiment of the present application, the partial differential equation for grain growth is:
[0086]
[0087] The boundary conditions are:
[0088]
[0089] In the formula, is the concentration of hydroxide precipitate after one growth reaction condition; D is the diffusion rate constant of hydroxide precipitate in solution; r is the vector position, t is the time, c(r,t) is the component field variable; R is the maximum position of the vector field; is the concentration of hydroxide precipitate in the bulk phase of the solution.
[0090] Since the situation with the lowest global energy is regarded as the most stable situation for secondary agglomeration and growth, that is, the optimal possible particle size distribution, in some embodiments of the present application, Figure 4 As shown, step S103 includes:
[0091] S401, taking the number of crystal nuclei and the average particle size as the initial state;
[0092] S402, exchanging the liquid and grain positions in the nickel-cobalt-manganese hydroxide precipitation solution during secondary agglomeration and growth;
[0093] S403, determining the total energy of the nickel-cobalt-manganese hydroxide precipitation solution after the positions of the liquid and the crystal grains are exchanged;
[0094] S404, determining the change trend of the total energy, and accepting the position change when the change trend is decreasing, and accepting the position change with a preset probability when the change trend is increasing;
[0095] S405, returning to step S402, and repeatedly executing steps S402 to S404 until the number of position changes reaches a preset number of iterations, and taking the last position of the liquid and the crystal as the target position;
[0096] S406 , determining the predicted particle size distribution of the agglomerated grains based on the target position.
[0097] The embodiment of the present application is configured to change the acceptance position when the change trend is getting smaller, and to change the acceptance position with a preset probability when the change trend is getting larger, thereby ensuring that the particle size distribution prediction process will not fall into a local minimum, and further improving the accuracy of the predicted particle size distribution.
[0098] In some embodiments of the present application, the total energy is the energy between the solid and the liquid, and the energy between the solid and the liquid includes agglomeration energy and stirring energy. Specifically, the total energy is:
[0099]
[0100] E agglo =4π(R i (t)) 2 γ
[0101] E agi =-A f ·Ω
[0102] In the formula, ε sl is the total energy; E agglo E is the aggregation energy; agi is the stirring energy; R i (t) is the particle size of the secondary agglomerated particles at time t, m; γ is the surface energy density, mJ / m 2 ; A f is the proportional coefficient; Ω is the stirring speed, Hz.
[0103] It should be noted that the distance between the liquid and the crystal grains when they are exchanged in step S402 should not be too far, and the maximum distance between them satisfies:
[0104]
[0105] In the formula, Δx max is the maximum distance; D p is the diffusion rate of the grain, m 2 / s; Δt is the time interval between two consecutive iterative calculations.
[0106] The embodiment of the present application constrains the distance between the liquid and the grains when they exchange positions, so that the process is more consistent with the process of secondary agglomeration and growth of the grains, thereby further ensuring the accuracy of the predicted particle size distribution.
[0107] In order to achieve quality control of the finally obtained nickel cobalt manganese hydroxide product, in some embodiments of the present application, after step S103, the following steps are further included:
[0108] When the predicted particle size distribution does not meet the desired particle size distribution, the nucleation reaction conditions and / or the primary growth reaction conditions are optimized until the predicted particle size distribution meets the desired particle size distribution.
[0109] By optimizing the nucleation reaction conditions and / or the primary growth reaction conditions, the predicted particle size distribution can be achieved to meet the expected particle size distribution, thereby achieving control over the hydrometallurgical controlled crystallization of laterite nickel ore to prepare MHP and improving the quality of the obtained MHP product.
[0110] In a specific embodiment of the present application, Figure 5 is the predicted particle size distribution when the pH of the precipitant is 9.0 and 12.0, respectively. Figure 5 It can be seen that when the pH of the solution is higher during precipitation, the average particle size of the final product is smaller, which is more conducive to the subsequent filter press treatment. After adjusting the actual production process conditions according to the calculation results, the particle size distribution of the MHP product is obtained as follows: Figure 6 As shown. Figure 6It can be seen that after process optimization, the MHP particle size distribution curve becomes significantly narrower and the particle size becomes smaller overall, which is consistent with the calculation prediction results, verifying the feasibility of this method.
[0111] The embodiment of the present application also provides a process for preparing MHP by hydrometallurgical controlled crystallization of laterite nickel ore, which is realized based on the method for preparing MHP by hydrometallurgical controlled crystallization of laterite nickel ore;
[0112] The method for preparing MHP by controlled crystallization of laterite nickel ore by hydrometallurgy is the method for preparing MHP by controlled crystallization of laterite nickel ore in any one of the above embodiments.
[0113] Those skilled in the art will appreciate that all or part of the processes of the above-mentioned embodiments can be implemented by instructing related hardware (such as a processor, a controller, etc.) through a computer program, and the computer program can be stored in a computer-readable storage medium, wherein the computer-readable storage medium is a disk, an optical disk, a read-only storage memory, or a random access memory, etc.
[0114] The above is a detailed introduction to the method and process for preparing MHP by hydrometallurgical controlled crystallization of laterite nickel ore provided in the present application. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method of the present application and its core idea; at the same time, for those skilled in the art, according to the idea of the present application, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as limiting the present application.
Claims
1. A method for preparing MHP by hydrometallurgical controlled crystallization of laterite nickel ore, characterized in that: include: Determine the number of multiple crystal nuclei of the iron-aluminum-removed liquid after the nucleation reaction based on the nucleation reaction conditions; Determining an average grain size of a plurality of crystal grains after the plurality of crystal nuclei have grown once based on a primary growth reaction condition; The predicted particle size distribution of the agglomerated grains after the plurality of grains undergo secondary agglomeration and growth is determined based on the Metropolis algorithm, the number of crystal nuclei and the average particle size.
2. The method for preparing MHP by hydrometallurgical controlled crystallization of laterite nickel ore according to claim 1, characterized in that: The nucleation reaction conditions include the pH and quality of the precipitant; the method of determining the number of multiple crystal nuclei of the iron-aluminum-removed liquid after the nucleation reaction based on the nucleation reaction conditions includes: Determining the supersaturation of the primary nickel-cobalt-manganese hydroxide precipitation solution based on the pH and quality of the precipitant; Determining the crystallization rate of the primary nickel-cobalt-manganese hydroxide precipitation solution based on the supersaturation and crystallization rate model; The number of crystal nuclei of the plurality of crystal nuclei is determined based on the crystallization rate.
3. The method for preparing MHP by hydrometallurgical controlled crystallization of laterite nickel ore according to claim 2, characterized in that: The crystallization rate model is: J0=A·ln S Where J is the crystallization rate, 1 / (m 3 ·s); J0 is the maximum crystallization rate, 1 / (m 3 ·s); γ is the surface energy of the hydroxide precipitate, J / m 2 ; is the partial molar volume of the hydroxide, mol / m 3 ;k B is the Boltzmann constant; R g is the ideal gas constant, J / (mol·K); T is the temperature, K; S is the supersaturation; A is the proportional constant; is the concentration of divalent ions in the liquid after iron and aluminum removal; c OH is the concentration of hydroxide ions; is the solubility product of the hydroxide precipitate; N A is Avogadro's constant; M 2+ Diffusion rate constant of metal ions in solution.
4. The method for preparing MHP by hydrometallurgical controlled crystallization of laterite nickel ore according to claim 1, characterized in that: The step of determining the average grain size of a plurality of crystal grains after the plurality of crystal nuclei have grown once based on a growth reaction condition comprises: Determining the concentration of hydroxide precipitation during the primary growth of the crystal nucleus based on the primary growth reaction conditions; The average grain size of the plurality of grains is determined based on the hydroxide precipitate concentration, a grain growth partial differential equation, and boundary conditions.
5. The method for preparing MHP by hydrometallurgical controlled crystallization of laterite nickel ore according to claim 4, characterized in that: The partial differential equation for grain growth is: The boundary conditions are: In the formula, is the concentration of hydroxide precipitate after one growth reaction condition; D is the diffusion rate constant of hydroxide precipitate in solution; r is the vector position, t is the time, c(r,t) is the component field variable; R is the maximum position of the vector field; is the concentration of hydroxide precipitate in the bulk phase of the solution.
6. The method for preparing MHP by hydrometallurgical controlled crystallization of laterite nickel ore according to claim 1, characterized in that: The step of determining the predicted particle size distribution of the agglomerated grains based on the Metropolis algorithm, the number of crystal nuclei and the average particle size comprises: Step 1, taking the number of crystal nuclei and the average particle size as the initial state; Step 2: exchanging the liquid and grain positions in the nickel-cobalt-manganese hydroxide precipitation solution during the secondary agglomeration and growth; Step 3, determining the total energy of the nickel-cobalt-manganese hydroxide precipitation solution after the positions of the liquid and the crystal grains are exchanged; Step 4: determine the change trend of the total energy, and when the change trend is decreasing, accept the position change; when the change trend is increasing, accept the position change with a preset probability; Step 5, return to step 2, and repeat steps 2 to 4 until the number of position changes reaches a preset number of iterations, and the last position of the liquid and crystal is taken as the target position; Step six: determining the predicted particle size distribution of the agglomerated grains based on the target position.
7. The method for preparing MHP by hydrometallurgical controlled crystallization of laterite nickel ore according to claim 6, characterized in that: The total energy includes agglomeration energy and stirring energy.
8. The method for preparing MHP by hydrometallurgical controlled crystallization of laterite nickel ore according to claim 6, characterized in that: The maximum distance between the liquid and the grain that exchange positions satisfies: In the formula, Δx max is the maximum distance; D p is the diffusion rate of the grain, m 2 / s; Δt is the time interval between two consecutive iterative calculations.
9. The method for preparing MHP by hydrometallurgical controlled crystallization of laterite nickel ore according to claim 1, characterized in that: The method further comprises: When the predicted particle size distribution does not meet the desired particle size distribution, the nucleation reaction conditions and / or the primary growth reaction conditions are optimized until the predicted particle size distribution meets the desired particle size distribution.
10. A process for preparing MHP by hydrometallurgical controlled crystallization of laterite nickel ore, characterized in that: A method for preparing MHP based on hydrometallurgical controlled crystallization of laterite nickel ore is realized; Wherein, the method for preparing MHP by hydrometallurgical controlled crystallization of laterite nickel ore is the method for preparing MHP by hydrometallurgical controlled crystallization of laterite nickel ore according to any one of claims 1 to 9.