Method for improving particle size and morphology of neutralizer for laterite nickel ore hydrometallurgy

Abstract

The application provides a neutralizer particle size and morphology improvement method for laterite nickel ore hydrometallurgy, and is characterized in that, in the process of producing nickel-cobalt-manganese hydroxide by hydrometallurgy of laterite nickel ore, a neutralizer is used to sequentially perform one-stage iron and aluminum removal treatment and two-stage iron and aluminum removal treatment on a nickel-cobalt-manganese-containing liquid, wherein the mass ratio of the through-put of the neutralizer added to -200 mesh is in the range of 85% to 90%, and the sphericity coefficient of the solid particles in the neutralizer is not less than 0.6; the particle size and morphology of the neutralizer are improved respectively to be applied to the one-stage iron and aluminum removal treatment and the two-stage iron and aluminum removal treatment, so that the iron and aluminum removal rate in the one-stage iron and aluminum removal treatment and the two-stage iron and aluminum removal treatment is effectively improved, the surface roughness of the solid particles in the neutralizer is ensured to be low, the speed of the nickel-cobalt-manganese ions and the local alkali reaction to produce precipitation is reduced, the loss of nickel-cobalt-manganese is reduced, and the yield of the laterite nickel ore hydrometallurgy for producing nickel-cobalt-manganese hydroxide is further improved.

Description

Technical Field

[0001] This invention relates to the field of nickel-cobalt-manganese material production, and in particular to a method for improving the particle size and morphology of a neutralizing agent used in the hydrometallurgical process of laterite nickel ore. Background Technology

[0002] With the rapid development of the battery industry, the global demand for nickel, cobalt, and manganese has risen sharply, and the price of nickel, cobalt, and manganese has increased significantly. High-grade nickel, cobalt, and manganese resources are becoming increasingly depleted. People are focusing their attention on developing low-grade, complex-composition laterite nickel ore, and the process usually adopted is high-pressure acid leaching to produce nickel, cobalt, and manganese raw materials for ternary power batteries.

[0003] Currently, limestone powder is commonly used as a neutralizing agent in the iron and aluminum removal process of laterite nickel ore. To achieve the neutralization process, the particle size of limestone is typically controlled by a passing pass rate of -200 mesh. However, this method of controlling the particle size of limestone powder is relatively simple, resulting in a large number of over-ground fine particles and a small number of coarse particles. The gradation of limestone powder prepared using this single particle size control method is highly uncertain and greatly affected by the moisture content, origin, particle size, and hardness of the raw materials. This limestone powder has two disadvantages when added to laterite nickel ore hydrometallurgy for iron and aluminum removal due to its small sphericity coefficient: (1) The large number of fine particles (also known as over-ground particles) in the powder have a large surface area and react rapidly in the solution, which easily leads to local over-alkali formation, resulting in the precipitation of a large number of nickel, cobalt, and manganese ions and causing loss of nickel, cobalt, and manganese; (2) The small amount of large, un-ground limestone particles (also known as hard-to-grind particles) in the powder do not react sufficiently, and the reaction time is long, making it impossible to quickly and accurately control the pH value required for iron and aluminum removal, resulting in an unsatisfactory iron and aluminum removal rate. It may also form large CaSO4 crystals (particle size greater than 50 μm) in the iron and aluminum slag, such as Figure 1 As shown. In addition, the morphology of the neutralizing agent particles also affects the reaction rate. Data shows that neutralizing agent particles with low sphericity coefficients have rough surfaces, poor fluidity, and are more likely to aggregate in the solution, thus leading to localized over-alkaliness.

[0004] Therefore, there is an urgent need for a method to improve the particle size and morphology of neutralizing agents used in the hydrometallurgical process of laterite nickel ore in order to solve the above-mentioned technical problems. Summary of the Invention

[0005] The purpose of this invention is to provide a method for improving the particle size and morphology of neutralizing agents used in the hydrometallurgical process of laterite nickel ore, in order to address the technical problems of excessively low iron and aluminum removal rates and excessive nickel, cobalt and manganese metal loss rates in existing hydrometallurgical processes for producing nickel-cobalt-manganese hydroxide.

[0006] To solve the above-mentioned technical problems, the present invention provides a method for improving the particle size and morphology of neutralizing agent in hydrometallurgical process of laterite nickel ore. In the process flow of producing nickel cobalt manganese hydroxide by hydrometallurgical process of laterite nickel ore, a neutralizing agent is used to sequentially perform a first-stage iron and aluminum removal treatment and a second-stage iron and aluminum removal treatment on the nickel cobalt manganese-containing slurry.

[0007] The mass ratio of the neutralizing agent added to the -200 mesh passing amount ranges from 85% to 90%, and the sphericity coefficient of the solid particles in the neutralizing agent is not less than 0.6.

[0008] In the method for improving the particle size and morphology of neutralizing agent in hydrometallurgical processing of laterite nickel ore provided by the present invention, in the process flow of producing nickel-cobalt-manganese hydroxide by hydrometallurgical processing of laterite nickel ore, a neutralizing agent is used to perform a first-stage iron and aluminum removal treatment on the nickel-cobalt-manganese-containing slurry, and after solid-liquid separation, a first-stage iron and aluminum-containing slag and a first-stage iron and aluminum-removed slurry are obtained; a neutralizing agent is used to perform a second-stage iron and aluminum removal treatment on the first-stage iron and aluminum-removed slurry, and after solid-liquid separation, a second-stage iron and aluminum-containing slag and a second-stage iron and aluminum-removed slurry are obtained.

[0009] In the method for improving the particle size and morphology of neutralizing agent in hydrometallurgical processing of laterite nickel ore provided by the present invention, the neutralizing agent is selected from at least one of limestone, lime milk, magnesite slurry, magnesia powder slurry, magnesia minerals in laterite nickel ore, magnesium oxide, and sodium hydroxide.

[0010] In the method for improving the particle size and morphology of neutralizing agent for hydrometallurgical treatment of laterite nickel ore provided by the present invention, the neutralizing agent is prepared by the original ore material through a first-stage grinding process and a second-stage grinding process. The first-stage grinding process uses a vertical mill to grind the original ore material to obtain a first powder, and the second-stage grinding process uses a ball mill to ball mill and shape the first powder to obtain a second powder.

[0011] The sphericity coefficient of the second powder is greater than that of the first powder.

[0012] Preferably, in the method for improving the particle size and morphology of neutralizing agent for hydrometallurgical treatment of laterite nickel ore provided by the present invention, the mass ratio of the raw ore material after the first grinding process to the -200 mesh passing amount is 75%, and the mass ratio of the raw ore material after the second grinding process to the -200 mesh passing amount is 88%.

[0013] In the method for improving the particle size and morphology of neutralizing agent in hydrometallurgical lateritic nickel ore provided by the present invention, the particle size density distribution pattern of the solid particles in the neutralizing agent is a bimodal distribution pattern; wherein, the proportion of particle size density distribution with a particle size range of 1um to 10um is 2.5% to 4.5%, and the proportion of particle size density distribution with a particle size range of 10um to 20um is 2.5% to 2.8%.

[0014] In the method for improving the particle size and morphology of neutralizing agent for hydrometallurgical treatment of laterite nickel ore provided by the present invention, the pH range of the first-stage iron and aluminum removal solution is 3 to 4.2, and the pH range of the second-stage iron and aluminum removal solution is 4.5 to 5.5.

[0015] In the method for improving the particle size and morphology of neutralizing agent for hydrometallurgical treatment of laterite nickel ore provided by the present invention, the iron removal rate in the first-stage iron and aluminum removal process is greater than 88.46%, the aluminum removal rate in the first-stage iron and aluminum removal process is greater than 93.03%, the nickel precipitation rate in the first-stage iron and aluminum removal process is less than 4.36%, the cobalt precipitation rate in the first-stage iron and aluminum removal process is less than 4.47%, and the manganese precipitation rate in the first-stage iron and aluminum removal process is less than 5.74%.

[0016] In the method for improving the particle size and morphology of neutralizing agent for hydrometallurgical treatment of laterite nickel ore provided by the present invention, the iron removal rate in the two-stage iron and aluminum removal process is greater than 51.95%, the aluminum removal rate in the two-stage iron and aluminum removal process is greater than 99.03%, the nickel precipitation rate in the two-stage iron and aluminum removal process is less than 17.20%, the cobalt precipitation rate in the two-stage iron and aluminum removal process is less than 10.94%, and the manganese precipitation rate in the two-stage iron and aluminum removal process is less than 10.20%.

[0017] In the method for improving the particle size and morphology of neutralizing agents in hydrometallurgical processing of laterite nickel ore provided by the present invention, the method further includes the following step before performing a first-stage iron and aluminum removal treatment on the nickel-cobalt-manganese slurry using a neutralizing agent:

[0018] The laterite nickel ore was subjected to acid leaching to obtain a leaching slurry;

[0019] The leached slurry is subjected to cyclic leaching and pre-neutralization treatment to obtain a pre-neutralized slurry.

[0020] The pre-neutralized slurry was subjected to countercurrent washing, and after solid-liquid separation, leaching tailings and nickel-cobalt-manganese-containing slurry were obtained.

[0021] The beneficial effects of this invention are as follows: Unlike existing technologies, this invention provides a method for improving the particle size and morphology of a neutralizing agent used in the hydrometallurgical process of laterite nickel ore. In the process flow for producing nickel-cobalt-manganese hydroxide from laterite nickel ore hydrometallurgy, a neutralizing agent is used to sequentially perform a first-stage iron and aluminum removal treatment and a second-stage iron and aluminum removal treatment on the nickel-cobalt-manganese-containing slurry. The mass ratio of the neutralizing agent added to the -200 mesh filter is in the range of 85%–90%, and the sphericity coefficient of the solid particles in the neutralizing agent is not less than 0.6. The method for improving the particle size and morphology of a neutralizing agent used in the hydrometallurgical process of laterite nickel ore provided by this invention adjusts the particle size and morphology of the neutralizing agent and sequentially… This product is applied in both the first and second stages of iron and aluminum removal processes. The neutralizing agent is added at a mass ratio of 85% to 90% of the -200 mesh passing weight, ensuring relatively fine solid particles. This effectively improves the iron and aluminum removal rate in both stages. Simultaneously, the sphericity coefficient of the solid particles in the neutralizing agent is not less than 0.6, ensuring low surface roughness and reducing the rate at which nickel, cobalt, and manganese ions react with alkali to form precipitation. This reduces nickel, cobalt, and manganese loss and further improves the yield of nickel-cobalt-manganese hydroxide produced by hydrometallurgical processing of laterite nickel ore. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the X-ray energy dispersive spectroscopy layered image of iron-aluminum slag in the existing technology for improving the particle size and morphology of neutralizing agents used in the hydrometallurgical process of laterite nickel ore.

[0023] Figure 2 This is an electron microscope schematic diagram of the first neutralizing agent in the method for improving the particle size and morphology of neutralizing agents in hydrometallurgical processing of laterite nickel ore provided by the present invention.

[0024] Figure 3 This is an electron microscope schematic diagram of the second neutralizing agent in the method for improving the particle size and morphology of neutralizing agents in hydrometallurgical processing of laterite nickel ore provided by the present invention.

[0025] Figure 4 This is a schematic diagram of particle size distribution curves after two different grinding methods are used, as provided by the present invention. Detailed Implementation

[0026] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0027] This invention provides a method for improving the particle size and morphology of a neutralizing agent used in the hydrometallurgical process of laterite nickel ore. In the process of producing nickel-cobalt-manganese hydroxide by hydrometallurgical process of laterite nickel ore, a neutralizing agent is used to perform a first-stage iron and aluminum removal treatment on the nickel-cobalt-manganese-containing liquid. After solid-liquid separation, a first-stage iron-aluminum-containing slag and a first-stage iron and aluminum-removed liquid are obtained.

[0028] The mass ratio of the neutralizing agent added to the -200 mesh passing amount ranges from 85% to 90%, and the sphericity coefficient of the solid particles in the neutralizing agent is not less than 0.6.

[0029] Specifically, before the step of removing iron and aluminum from the nickel-cobalt-manganese slurry using a neutralizing agent, the following steps are also included:

[0030] The laterite nickel ore was subjected to acid leaching to obtain a leaching slurry;

[0031] The leached slurry is subjected to cyclic leaching and pre-neutralization treatment to obtain a pre-neutralized slurry.

[0032] The pre-neutralized slurry was countercurrently washed by CCD washing, and after solid-liquid separation, leaching tailings and nickel-cobalt-manganese slurry were obtained.

[0033] The CCD washing levels range from 4 to 7, and the washing ratio ranges from 2 to 7.

[0034] Furthermore, the laterite nickel ore is either limonite-type laterite nickel ore, residual laterite nickel ore, or a mixture of the two minerals. The leaching temperature is 80–300 °C, the leaching time is 0.5 h–5 h, and the final acidity value is controlled at 15 g / L–65 g / L.

[0035] Furthermore, the neutralizing agent used in the pre-neutralization treatment is selected from at least one of limestone, lime milk, magnesite slurry, magnesia slurry, laterite nickel ore magnesia, magnesium oxide, and sodium hydroxide, and the final pH value is controlled to be 1.0 to 2.0; sodium sulfate is also added in the pre-neutralization treatment to provide sodium ions to remove ferric iron.

[0036] In this embodiment of the invention, the sphericity coefficient of the solid particles in the neutralizing agent used in the pre-neutralization treatment is not less than 0.6; wherein, the neutralizing agent is prepared by the original ore material through a first-stage grinding process and a second-stage grinding process. The first-stage grinding process uses a vertical mill to grind the original ore material to obtain a first powder, and the second-stage grinding process uses a ball mill to ball mill and shape the first powder to obtain a second powder.

[0037] Specifically, the sphericity coefficient of the second powder is greater than that of the first powder, and the original ore material can be limestone ore.

[0038] In another embodiment of the invention, the neutralizing agent used in the pre-neutralization treatment can be a conventional neutralizing agent with a sphericity coefficient; this is because the pH value of the slurry after pre-neutralization is too low, and local over-alkaliness rarely occurs.

[0039] In this embodiment of the invention, a neutralizing agent is used to perform a first-stage iron and aluminum removal treatment on a nickel-cobalt-manganese slurry. After solid-liquid separation, a first-stage iron and aluminum slag and a first-stage iron and aluminum removal slurry are obtained.

[0040] The neutralizing agent used in the first-stage iron and aluminum removal treatment of nickel-cobalt-manganese slurry has a sphericity coefficient of not less than 0.6. The neutralizing agent is prepared from the raw ore material through a first-stage grinding process and a second-stage grinding process. The first-stage grinding process uses a vertical mill to grind the raw ore material to obtain a first powder, and the second-stage grinding process uses a ball mill to ball-mill and shape the first powder to obtain a second powder.

[0041] Specifically, the sphericity coefficient of the second powder is greater than that of the first powder, and the original ore material can be limestone ore.

[0042] Furthermore, the pH range of the iron and aluminum removal solution is 3 to 4.2.

[0043] In this embodiment of the invention, in the process of producing nickel-cobalt-manganese hydroxide by hydrometallurgical refining of laterite nickel ore, a neutralizing agent is used to perform a second-stage iron and aluminum removal treatment on the first-stage iron and aluminum removal liquid. After solid-liquid separation, a second-stage iron-aluminum slag and a second-stage iron and aluminum removal liquid are obtained.

[0044] Specifically, the neutralizing agent is selected from at least one of limestone, lime milk, magnesite slurry, magnesia slurry, laterite nickel ore, magnesium oxide, and sodium hydroxide.

[0045] Specifically, the neutralizing agent is prepared by first-stage grinding and second-stage grinding of the raw ore material. The first-stage grinding uses a vertical mill to grind the raw ore material to obtain the first powder, and the second-stage grinding uses a ball mill to ball mill and shape the first powder to obtain the second powder.

[0046] Specifically, the sphericity coefficient of the second powder is greater than that of the first powder, and the original ore material can be limestone ore.

[0047] Specifically, the pH range of the second-stage iron and aluminum removal solution is 4.5 to 5.5.

[0048] In this embodiment of the invention, the two-stage iron and aluminum removal liquid is subjected to deep impurity removal treatment and at least one stage of nickel-cobalt-manganese precipitation treatment, and nickel-cobalt-manganese hydroxide product is obtained after solid-liquid separation.

[0049] The neutralizing agent used in the deep impurity removal process is selected from at least one of limestone, lime slurry, magnesite slurry, magnesia slurry, laterite nickel ore magnesia, magnesium oxide, and sodium hydroxide; the final pH value is controlled to be 5.6–6.0. ​​The underflow after deep impurity removal is returned to be mixed with the leaching slurry for reaction, and the deep impurity removal removes iron ions and aluminum ions.

[0050] In this embodiment of the invention, the experimental results of using neutralizing agents of different particle sizes (the neutralizing agent was prepared separately using a vertical mill, with a single-peak particle size) to perform a first-stage iron and aluminum removal treatment on a nickel-cobalt-manganese slurry are shown in Table 1 below (experimental conditions: calcium carbonate was used as the neutralizing agent, the temperature during the first-stage iron and aluminum removal process was 60°C, and the final pH value of the first-stage iron and aluminum removal solution was 4):

[0051]

[0052] Table 1

[0053] As shown in Table 1, during the iron and aluminum removal process, the finer the calcium carbonate, the slower the loss of metals (nickel, cobalt, manganese) initially becomes, and then increases significantly at 90%, while the iron and aluminum removal effect is almost unaffected. Therefore, during the iron and aluminum removal process, the optimal fineness of the neutralizing agent for calcium carbonate is -200 mesh with a passing rate of 85%.

[0054] Specifically, the experimental results of using neutralizing agents of different particle sizes (the neutralizing agent was prepared separately using a vertical mill with a single-peak particle size) to perform two-stage iron and aluminum removal treatment on the first-stage iron and aluminum removal liquid are shown in Table 2 below: (Experimental conditions: calcium carbonate was used as the neutralizing agent, the temperature in the two-stage iron and aluminum removal process was 60°C, and the final pH value of the two-stage iron and aluminum removal liquid was 5).

[0055]

[0056] Table 2

[0057] As shown in Table 2, in the two-stage iron and aluminum removal process, the finer the calcium carbonate particle size, the iron removal rate initially increases and then decreases, and the aluminum removal rate also initially increases and then decreases, but the magnitude of the change is smaller compared to the iron removal rate. The nickel loss rate increases significantly at a particle size with a -200 mesh throughput of 95%. Therefore, the optimal fineness of calcium carbonate for the two-stage iron and aluminum removal process is selected as -200 mesh throughput of 90% (at this point, the iron and aluminum removal rates are relatively high, while the nickel, cobalt, and manganese precipitation rates are relatively low).

[0058] Therefore, based on Tables 1 and 2, it can be seen that using too coarse particles as the neutralizing agent may lead to insufficient reaction, resulting in a poorer effect in removing iron and aluminum; while using too fine particles may create localized over-alkaliness, leading to an excessive metal loss rate.

[0059] Specifically, the underlying reason for excessive alkalinity is that the neutralizing agent particles react rapidly with the acid. According to existing physicochemical theories, the rougher the particle surface, the easier it is for a chemical reaction to occur.

[0060] Furthermore, in order to ensure that the iron removal rate and aluminum removal rate are relatively high in the first-stage iron and aluminum removal process and the second-stage iron and aluminum removal process, and that the nickel precipitation rate, cobalt precipitation rate and manganese precipitation rate are relatively low, the present invention makes the mass ratio of the solid particles in the neutralizing agent to the amount passing through -200 mesh range 85% to 90%.

[0061] Furthermore, when the mass ratio of solid particles in the neutralizing agent to the -200 mesh passing amount is less than 85%, the iron removal rate and aluminum removal rate of the neutralizing agent when applied to the first iron and aluminum removal process are relatively low, while the nickel precipitation rate, cobalt precipitation rate and manganese precipitation rate are relatively high. In particular, when the mass ratio of solid particles in the neutralizing agent to the -200 mesh passing amount is less than 85%, the solid particles do not react sufficiently with iron ions and aluminum ions in the solution, resulting in an excessively low iron removal rate and aluminum removal rate.

[0062] Furthermore, when the mass ratio of solid particles in the neutralizing agent to the -200 mesh passing amount is greater than 90%, the iron removal rate and aluminum removal rate of the neutralizing agent when applied to the second-stage iron and aluminum removal process are relatively low, while the nickel precipitation rate, cobalt precipitation rate and manganese precipitation rate are relatively high. Among these, solid particles in the neutralizing agent with a mass ratio of -200 mesh passing amount greater than 90% may form local over-alkali, resulting in an excessive metal loss rate.

[0063] Therefore, when the mass ratio of solid particles in the neutralizer to the amount passing through a -200 mesh is 85% to 90%, the iron removal rate and aluminum removal rate are relatively high in the first-stage iron and aluminum removal process and the second-stage iron and aluminum removal process, while the nickel precipitation rate, cobalt precipitation rate and manganese precipitation rate are relatively low.

[0064] The technical solution of this application will now be described in conjunction with specific embodiments.

[0065] Example 1:

[0066] First, a limonite-type laterite nickel ore with a nickel content of 2 wt.% and an acid-to-ore ratio of 300 kg / t ore was selected. The leaching temperature was 250°C, and the leaching slurry was obtained after solid-liquid separation. Then, the leaching slurry was subjected to cyclic leaching and pre-neutralization treatment using a first neutralizing agent to obtain a pre-neutralized slurry with a final pH value controlled at 1.8. The first neutralizing agent used in the pre-neutralization treatment was limestone, which was prepared by grinding the limestone ore using a vertical mill.

[0067] Subsequently, the pre-neutralized slurry was countercurrently washed using CCD washing, and after solid-liquid separation, leaching tailings and nickel-cobalt-manganese-containing slurry were obtained; the CCD washing stage was 4 stages and the washing ratio was 2.

[0068] Subsequently, the pre-neutralized slurry was subjected to a first-stage iron and aluminum removal treatment using a first neutralizing agent. After solid-liquid separation, a first-stage iron and aluminum-containing slag and a first-stage iron and aluminum-removed liquid were obtained. The final pH value was controlled at 4, and the temperature of the first-stage iron and aluminum removal treatment was 60°C. Then, the first-stage iron and aluminum-removed liquid was subjected to a second-stage iron and aluminum removal treatment using the first neutralizing agent. After solid-liquid separation, a second-stage iron and aluminum-containing slag and a second-stage iron and aluminum-removed liquid were obtained. The final pH value was controlled at 5, and the temperature of the second-stage iron and aluminum removal treatment was 60°C. Subsequently, the second-stage iron and aluminum-removed liquid was subjected to deep impurity removal treatment and at least one stage of nickel-cobalt-manganese precipitation treatment. After solid-liquid separation, nickel-cobalt-manganese hydroxide product was obtained.

[0069] Specifically, the first neutralizing agent provided in this embodiment 1 is made by grinding limestone ore through a vertical mill. The mass ratio of the calcium carbonate ore material after grinding by the vertical mill to the -200 mesh passing amount is 85%, the sphericity is 0.47, and the particle size distribution is a unimodal distribution pattern.

[0070] Example 2:

[0071] Unlike Example 1, a second neutralizing agent was used to perform a first-stage iron and aluminum removal treatment on the pre-neutralized slurry. After solid-liquid separation, a first-stage iron and aluminum slag and a first-stage iron and aluminum removal liquid were obtained. The final pH value was controlled to be 4, and the temperature of the first-stage iron and aluminum removal treatment was 60°C.

[0072] Unlike Example 1, a second neutralizing agent was used to perform a second-stage iron and aluminum removal treatment on the first-stage iron and aluminum removal liquid. After solid-liquid separation, two-stage iron and aluminum-containing slag and a second-stage iron and aluminum removal liquid were obtained. The final pH value was controlled to be 5, and the temperature of the second-stage iron and aluminum removal treatment was 60°C.

[0073] The second neutralizing agent is made from limestone ore through a two-stage grinding process, using a vertical mill and a ball mill to grind the limestone ore.

[0074] Specifically, the limestone ore is first ground using a vertical mill so that the particle size of the solid particles in the second neutralizing agent is 75% of the -200 mesh passing through (according to the data in Tables 1 and 2, this setting can make the iron removal rate and aluminum removal rate relatively high in the first-stage iron and aluminum removal process and the second-stage iron and aluminum removal process, respectively, and the nickel precipitation rate, cobalt precipitation rate and manganese precipitation rate relatively low).

[0075] Specifically, a ball mill is used to grind the calcium carbonate solid particles with a -200 mesh throughput of 75% for a second time, so that the sphericity coefficient of the solid particles in the second neutralizing agent is 0.62 (at this time, the surface roughness of the second neutralizing agent is low, which slows down the reaction between the hydroxide ions generated by the hydrolysis of the second neutralizing agent and the nickel, cobalt and manganese ions, thereby reducing metal loss). At this time, the particle size of the solid particles in the second neutralizing agent is 88% with a -200 mesh throughput, and its particle size distribution is a bimodal distribution pattern.

[0076] Please see Figure 2 as well as Figure 3 , Figure 2 This is an electron microscope schematic diagram of the first neutralizing agent in the method for improving the particle size and morphology of neutralizing agents in hydrometallurgical processing of laterite nickel ore provided by the present invention. Figure 3 This is an electron microscope schematic diagram of the second neutralizing agent in the method for improving the particle size and morphology of neutralizing agents used in hydrometallurgical treatment of laterite nickel ore provided by the present invention.

[0077] Specifically, by Figure 2 It can be seen that vertical mills produce particles with greater roughness, and more often ellipsoidal, long rod-shaped, and polyhedral shapes; from Figure 3 It is known that the surface roughness of particles formed by ball milling is smaller and closer to that of spheres. This is because the ball mill contains multiple steel balls, and during the rotation of the ball mill, adjacent steel balls are squeezed against each other, resulting in a lower surface roughness of the solid particles and a shape closer to that of a sphere.

[0078] Specifically, the sphericity coefficient of powder prepared by vertical mill ranges from 0.3 to 0.5, while that of powder prepared by ball mill ranges from 0.45 to 0.7.

[0079] Please see Figure 4 , Figure 4 The diagram shows particle size distribution curves after two different grinding methods provided by this invention; where the horizontal axis represents particle size (unit μm), the vertical axis represents the proportion of particle size density distribution (unit %), and the neutralizing agent is calcium carbonate.

[0080] Depend on Figure 4 It can be seen that the particle size distribution of the first neutralizing agent is a single-peak distribution pattern (with only one peak in particle size distribution), and the particle size distribution percentage of solid particles with a diameter range of 1µm to 100µm is 0.5% to 2.5%; the particle size distribution of the second neutralizing agent is a double-peak distribution pattern (with two peaks in particle size distribution), and the particle size distribution percentage of solid particles with a diameter range of 1µm to 10µm is 2.5% to 4.5%, and the particle size distribution percentage of solid particles with a diameter range of 10µm to 20µm is 2.5% to 2.8%.

[0081] Specifically, in the particle size distribution diagram of the second neutralizing agent, there is one peak in the particle size range of 1µm to 10µm, and another peak in the particle size range of 10µm to 20µm. Therefore, the particle size distribution of the second neutralizing agent is more concentrated compared to that of the first neutralizing agent.

[0082] Specifically, the experimental results of using neutralizing agents of different particle sizes to perform a single-stage iron and aluminum removal process on nickel-cobalt-manganese slurry are shown in Table 3 below (experimental conditions: calcium carbonate was used as the neutralizing agent, the temperature during the single-stage iron and aluminum removal process was 60°C, and the final pH value of the single-stage iron and aluminum removal solution was 4):

[0083]

[0084] Table 3

[0085] As shown in Table 3, when using the second neutralizing agent for a single-stage iron and aluminum removal process compared to the first neutralizing agent, the iron removal rate and aluminum removal rate are relatively higher, and the nickel deposition rate, cobalt deposition rate and manganese deposition rate are relatively lower.

[0086] Specifically, the experimental results of using neutralizing agents of different particle sizes to perform two-stage iron and aluminum removal on the first-stage iron and aluminum removal solution are shown in Table 4 below: (Experimental conditions: calcium carbonate was used as the neutralizing agent, the temperature during the two-stage iron and aluminum removal process was 60°C, and the final pH value of the two-stage iron and aluminum removal solution was 5).

[0087]

[0088] Table 4

[0089] As shown in Table 4, when using the second neutralizing agent for two-stage iron and aluminum removal, compared with the first neutralizing agent, the iron removal rate and aluminum removal rate are relatively higher, and the nickel deposition rate, cobalt deposition rate and manganese deposition rate are relatively lower.

[0090] The reason why the second neutralizing agent has a relatively higher iron removal rate and aluminum removal rate, and a relatively lower nickel precipitation rate, cobalt precipitation rate, and manganese precipitation rate in the first-stage and second-stage iron and aluminum removal processes compared with the first neutralizing agent is mainly due to the following reasons:

[0091] The second neutralizing agent is first ground in a vertical mill and then in a ball mill, resulting in a more concentrated particle size distribution, better surface morphology, and finer particle size. On the one hand, the finer particle size of the second neutralizing agent improves the iron and aluminum removal rate during single-stage or two-stage iron and aluminum removal processes. On the other hand, the finer particle size allows for better fluidity in solution, reducing the likelihood of localized over-alkaliness. Furthermore, the second neutralizing agent has a higher sphericity coefficient, smoother particle surfaces, and greater fluidity, making it easier to disperse in solution and thus less likely to react chemically with nickel, cobalt, and manganese ions.

[0092] In summary, the neutralizing agent that has been ground in a vertical mill and then in a ball mill has a more concentrated particle size distribution, better surface morphology, and finer particle size compared to the neutralizing agent that has only been ground in a vertical mill. This can effectively improve the removal rate of iron and aluminum, while reducing metal loss caused by localized excessive alkalinity.

[0093] Compared to existing technologies, the method for improving the particle size and morphology of neutralizing agents used in the hydrometallurgical process of laterite nickel ore provided by this invention involves using a neutralizing agent to sequentially perform a first-stage iron and aluminum removal treatment and a second-stage iron and aluminum removal treatment on the nickel-cobalt-manganese-containing slurry in the hydrometallurgical process of laterite nickel ore. The mass ratio of the neutralizing agent added to the -200 mesh filter is 85%–90%, and the sphericity coefficient of the solid particles in the neutralizing agent is not less than 0.6. The method for improving the particle size and morphology of neutralizing agents used in the hydrometallurgical process of laterite nickel ore provided by this invention adjusts the particle size and morphology of the neutralizing agent and applies it sequentially to the first-stage iron and aluminum removal treatment. In the processing steps and the two-stage iron and aluminum removal process, the neutralizing agent is added at a mass ratio of 85% to 90% of the -200 mesh passing amount. This ensures relatively fine solid particles, effectively improving the iron and aluminum removal rate in both the first-stage and second-stage iron and aluminum removal processes. Simultaneously, the sphericity coefficient of the solid particles in the neutralizing agent is not less than 0.6, ensuring low surface roughness and reducing the rate at which nickel, cobalt, and manganese ions react with alkali to form precipitation. This reduces nickel, cobalt, and manganese loss and further improves the yield of nickel, cobalt, and manganese hydroxide produced by hydrometallurgical processing of laterite nickel ore.

[0094] It should be noted that all the above embodiments belong to the same inventive concept, and the descriptions of each embodiment have different focuses. Where the description in a particular embodiment is not detailed, please refer to the description in other embodiments.

[0095] The above embodiments merely illustrate implementation methods of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A method for improving the particle size and morphology of neutralizer for hydrometallurgy of laterite nickel ore, characterized in that, In a process flow of producing nickel cobalt manganese hydroxide by hydrometallurgy of laterite nickel ore, a neutralizing agent is used to sequentially perform one-stage iron and aluminum removal treatment and two-stage iron and aluminum removal treatment on a nickel cobalt manganese-containing solution; The mass ratio of the neutralizing agent added to the -200 mesh passing amount is 85% to 90%, the sphericity coefficient of the solid particles in the neutralizing agent is not less than 0.6, the particle size density distribution mode of the solid particles in the neutralizing agent is a bimodal distribution mode, and the particle size density distribution proportion of the particle size range of 1 um to 10 um in the neutralizing agent is 2.5% to 4.5%, and the particle size density distribution proportion of the particle size range of 10 um to 20 um is 2.5% to 2.8%.

2. The method for improving particle size and morphology of neutralizer for hydrometallurgy of nickel laterite according to claim 1, characterized in that, In the process flow of producing nickel cobalt manganese hydroxide by hydrometallurgy of laterite nickel ore, the neutralizing agent is used to perform one-stage iron and aluminum removal treatment on the nickel cobalt manganese-containing solution, and after solid-liquid separation, one-stage iron and aluminum-containing residue and one-stage iron and aluminum removal solution are obtained; the neutralizing agent is used to perform two-stage iron and aluminum removal treatment on the one-stage iron and aluminum removal solution, and after solid-liquid separation, two-stage iron and aluminum-containing residue and two-stage iron and aluminum removal solution are obtained.

3. The method for improving particle size and morphology of neutralizer for hydrometallurgy of nickel laterite according to claim 2, characterized in that, The material of the neutralizing agent is selected from at least one of limestone, lime milk, magnesite ore slurry, bauxite ore slurry, magnesium ore in laterite nickel ore, magnesium oxide, and sodium hydroxide.

4. The method for improving particle size and morphology of neutralizer for hydrometallurgy of nickel laterite according to claim 1, characterized in that, The neutralizing agent is prepared from raw ore materials through one-stage grinding treatment and two-stage grinding treatment, the one-stage grinding treatment is to grind the raw ore materials by using a vertical mill to obtain a first powder, and the two-stage grinding treatment is to perform ball milling and shaping treatment on the first powder by using a ball mill to obtain a second powder. The sphericity coefficient of the second powder is greater than that of the first powder.

5. The method for improving particle size and morphology of neutralizer for hydrometallurgy of nickel laterite according to claim 4, characterized in that, The mass ratio of the raw ore materials after the one-stage grinding treatment added to the -200 mesh passing amount is 75%, and the mass ratio of the raw ore materials after the two-stage grinding treatment added to the -200 mesh passing amount is 88%.

6. The method for improving particle size and morphology of neutralizer for hydrometallurgy of nickel laterite according to claim 2, characterized in that, The pH value of the one-stage iron and aluminum removal solution is 3 to 4.2, and the pH value of the two-stage iron and aluminum removal solution is 4.5 to 5.

5.

7. The method for improving particle size and morphology of neutralizer for hydrometallurgy of nickel laterite according to claim 1, characterized in that, The iron removal rate in the one-stage iron and aluminum removal treatment process is greater than 88.46%, the aluminum removal rate is greater than 93.03%, the nickel precipitation rate is less than 4.36%, the cobalt precipitation rate is less than 4.47%, and the manganese precipitation rate is less than 5.74%.

8. The method for improving particle size and morphology of neutralizer for hydrometallurgy of nickel laterite according to claim 2, characterized in that, The iron removal rate in the two-stage iron and aluminum removal treatment process is greater than 51.95%, the aluminum removal rate is greater than 99.03%, the nickel precipitation rate is less than 17.20%, the cobalt precipitation rate is less than 10.94%, and the manganese precipitation rate is less than 10.20%.

9. The method for improving particle size and morphology of neutralizer for hydrometallurgy of nickel laterite according to claim 1, characterized in that, Before the step of using the neutralizing agent to perform one-stage iron and aluminum removal treatment on the nickel cobalt manganese-containing solution, the following steps are further included: Performing acid leaching treatment on laterite nickel ore to obtain leaching slurry; Performing cyclic leaching and pre-neutralization treatment on the leaching slurry to obtain pre-neutralized slurry; The pre-neutralized slurry is countercurrently washed, and after solid-liquid separation, leaching tailings and the nickel-cobalt-manganese-containing solution are obtained.

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