Methods and applications for removing manganese from nickel-cobalt-manganese solutions

Abstract

This disclosure discloses a method for removing manganese from a nickel-cobalt-manganese solution and its application. By adjusting the nickel-cobalt-manganese solution to a slightly acidic state and oxidizing some of the manganese, the manganese is precipitated as manganese tetroxide. Sodium silicate is used as a dispersant to inhibit further agglomeration or growth of manganese tetroxide particles. Combined with flotation, the recovery efficiency and purity of manganese are improved, which is beneficial to the downstream utilization of the nickel-cobalt solution and the production of higher quality nickel-cobalt products.

Description

Technical Field

[0001] This disclosure relates to the field of hydrometallurgical technology, and more specifically, to a method for removing manganese from nickel-cobalt-manganese solutions and its application. Background Technology

[0002] Lateritic nickel ore, an oxide nickel ore, accounts for more than 65% of the total nickel reserves. Lateritic nickel ore can be divided into two main categories: limonite-type and ferromagnesian nickel ore-type. In existing production processes, the pressure leaching process for lateritic nickel ore directly precipitates nickel, cobalt, and manganese elements simultaneously as hydroxides. This results in nickel-cobalt hydroxide products with high manganese impurity content and low product quality.

[0003] With the rapid development of the new energy electric vehicle sector, the market demand for Ni, Co, and their derivatives, the main metallic elements in ternary batteries, is constantly expanding. Nickel-cobalt hydroxide, as an important intermediate in lithium nickel cobalt manganese oxide cathode materials, has its quality variations, such as impurity content, directly affecting the subsequent preparation process and production cost of ternary cathode materials.

[0004] In summary, exploring a new process for preparing nickel-cobalt hydroxide is of great significance for providing high-quality raw materials for the production of downstream ternary cathode materials.

[0005] In view of this, this disclosure is hereby made. Summary of the Invention

[0006] The purpose of this disclosure is to provide a method for removing manganese from nickel-cobalt-manganese solutions and its application, thereby reducing the manganese content in the solution and thus improving the purity of downstream nickel-cobalt hydroxide products.

[0007] This disclosure is implemented as follows:

[0008] In a first aspect, this disclosure provides a method for removing manganese from a nickel-cobalt-manganese solution, comprising:

[0009] An oxidant and sodium silicate are added to a nickel-cobalt-manganese-containing solution for flotation. During the flotation process, the pH of the solution is maintained at 6.0-7.0 to obtain manganese tetroxide-containing slag and a nickel-cobalt-containing solution.

[0010] In some embodiments, oxygen is used as an oxidant in the flotation step, and oxygen-containing gas is introduced into the nickel-cobalt-manganese-containing solution.

[0011] In some embodiments, the flow rate of oxygen introduced into the oxygen-containing gas is 0.05 m³ / s. 3 / h~0.1m 3 / h.

[0012] In some embodiments, during the flotation step, ammonia is used to adjust the pH of the nickel-cobalt-manganese-containing solution to 6.0-7.0.

[0013] In some embodiments, the concentration of the ammonia solution is 20wt%-25wt%.

[0014] In some embodiments, the molar ratio of the added sodium silicate to the molar ratio of the manganese element in the nickel-cobalt-manganese solution is 1:(19-21).

[0015] In some embodiments, the sodium silicate is mixed with the nickel-cobalt-manganese-containing solution in the form of an aqueous sodium silicate solution, wherein the mass fraction of sodium silicate in the aqueous sodium silicate solution is 2wt%-5wt%.

[0016] In some embodiments, the flotation is carried out in a self-priming flotation machine.

[0017] In some embodiments, the temperature of the flotation step is 45°C-55°C.

[0018] In some implementations, the flotation step takes 1.5h-2.5h.

[0019] In some embodiments, the nickel-cobalt-manganese solution contains nickel at a concentration of 4 g / L to 6 g / L, cobalt at a concentration of 0.3 g / L to 0.6 g / L, and manganese at a concentration of 4 g / L to 6 g / L.

[0020] Secondly, this disclosure provides a method for removing manganese from laterite nickel ore, comprising sequentially acid leaching and iron and aluminum removal of the laterite nickel ore to obtain a nickel-cobalt-manganese-containing solution, and then using the method described in any one of the foregoing embodiments to separate manganese from nickel and cobalt in the nickel-cobalt-manganese-containing solution.

[0021] In some embodiments, the acid leaching step includes: mixing lateritic nickel ore with acid for leaching, followed by filtration to obtain leaching residue and leaching stock solution.

[0022] In some embodiments, the acid leaching step is performed at a temperature of 200°C-250°C for 2 hours to 4 hours, and at a pressure of 2.0 MPa-2.5 MPa.

[0023] In some embodiments, in the acid leaching step, the acid is sulfuric acid with a concentration of 100g / L-150g / L, and the laterite nickel ore and acid are mixed at a solid-liquid ratio of (1:2.0-1:4.0) kg / L.

[0024] In some embodiments, in the iron and aluminum removal step, an oxidant is first added to the leaching solution, and then the pH is adjusted to 2.0-4.0 to remove iron. After solid-liquid separation, the pH of the liquid phase is adjusted to 4.0-6.0 to remove aluminum. After solid-liquid separation again, the liquid phase obtained is the nickel-cobalt-manganese solution.

[0025] In some embodiments, the oxidant is hydrogen peroxide.

[0026] In some embodiments, the volume of hydrogen peroxide added is 0.4%-0.6% of the volume of the original leaching solution.

[0027] In some embodiments, the temperature of the iron removal step is 90°C-95°C and the time is 50 min-70 min.

[0028] In some embodiments, the temperature of the aluminum removal step is 90°C-95°C and the time is 50 min-70 min.

[0029] In some embodiments, calcium hydroxide is used to adjust the pH in the iron and aluminum removal step.

[0030] Thirdly, this disclosure provides a method for producing nickel cobalt hydroxide by hydrometallurgical refining of laterite nickel ore, wherein the pH of the nickel cobalt-containing solution obtained by any of the preceding methods is adjusted to 7.0-9.0 to obtain nickel cobalt hydroxide precipitate.

[0031] In some embodiments, the pH of the nickel-cobalt-containing solution is adjusted to 7.0-9.0 and then kept at a temperature of 40℃-50℃ for 1.5h-2h to obtain nickel-cobalt hydroxide precipitate.

[0032] This disclosure has the following beneficial effects:

[0033] This invention discloses a method for separating manganese from nickel and cobalt in nickel-cobalt-manganese solutions and laterite nickel ore. By adjusting the nickel-cobalt-manganese solution to a slightly acidic state and oxidizing some of the manganese, it precipitates as manganese tetroxide (Mn3O4). Sodium silicate is used as a dispersant to inhibit further agglomeration or growth of Mn3O4 particles. This reduces nickel and cobalt inclusions and forms smaller Mn3O4 particles, facilitating better separation from the liquid phase via flotation. This improves manganese recovery efficiency and purity, reduces manganese content in the liquid phase, and ultimately benefits downstream utilization of the nickel-cobalt solution, resulting in higher-quality nickel-cobalt products. Furthermore, subsequent manganese removal from wastewater is eliminated, simplifying the process and reducing production costs. Attached Figure Description

[0034] To more clearly illustrate the technical solutions of the embodiments of this disclosure, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of this disclosure and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0035] Figure 1This is a flowchart of Embodiment 1 of this disclosure. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions in the embodiments of this disclosure will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0037] This disclosure provides a method for removing manganese from a nickel-cobalt-manganese solution, comprising:

[0038] An oxidant and sodium silicate are added to a nickel-cobalt-manganese-containing solution for flotation. During the flotation process, the pH of the solution is maintained at 6.0-7.0 to obtain manganese tetroxide-containing slag and a nickel-cobalt-containing solution.

[0039] This disclosure was developed in the context of the utilization of laterite nickel ore. The composition of the nickel-cobalt-manganese solution is related to the composition of the laterite nickel ore and its leaching method. However, under normal circumstances, as long as the solution contains nickel, cobalt and manganese elements, the manganese and nickel-cobalt in it can be separated using the method disclosed in this disclosure, including but not limited to its application in the metal recycling of waste batteries.

[0040] In existing technologies, manganese precipitation typically involves the hydrolysis of divalent manganese ions to Mn(OH)₂. Manganese hydroxide then reacts with slightly soluble oxygen in water to form basic manganese oxide (MnO(OH), with manganese ions in the trivalent state). Trivalent manganese ions readily undergo disproportionation reactions, ultimately transforming into +2 valent manganese ions and insoluble manganese dioxide (MnO₂). Therefore, the direct manganese precipitation process has low manganese ion precipitation efficiency, and complete precipitation of manganese ions cannot be achieved satisfactorily. In this embodiment, the main chemical equation for the reaction is 6Mn 2+ +O2+12OH - = 2Mn3O4↓+6H2O, in which divalent manganese ions in nickel-cobalt-manganese solutions are first partially oxidized to +3 valence and then precipitate. Compared with direct manganese precipitation, manganese ion precipitation is more efficient and more complete.

[0041] This embodiment adjusts the nickel-cobalt-manganese solution to a slightly acidic state and oxidizes some of the manganese, causing it to precipitate as manganese tetroxide (Mt. tetroxide). Sodium silicate is used as a dispersant to inhibit further agglomeration or growth of Mt. tetroxide particles. This reduces nickel-cobalt inclusions and creates smaller Mt. tetroxide particles, facilitating better separation from the liquid phase via flotation. This improves manganese recovery efficiency and purity, reduces manganese content in the liquid phase, and ultimately benefits downstream utilization of the nickel-cobalt solution, resulting in higher-quality nickel-cobalt products. Furthermore, subsequent manganese removal from wastewater is eliminated, simplifying the process and reducing production costs.

[0042] In some embodiments, oxygen is used as an oxidant in the flotation step, and oxygen-containing gas is introduced into the nickel-cobalt-manganese-containing solution.

[0043] The oxidant used in the flotation step can be hydrogen peroxide or other oxidants. However, in the context of flotation, since the system itself needs to be circulated with gas, oxygen is used to oxidize manganese, which is low-cost and widely available. The oxygen-containing gas can be air, pure oxygen, or other oxygen-containing gases.

[0044] In some embodiments, the flow rate of oxygen introduced into the oxygen-containing gas is 0.05 m³ / s. 3 / h~0.1m 3 / h, if there is too little oxygen, manganese cannot be completely precipitated in the form of manganese tetroxide, while excessive oxygen can also help flotation generate bubbles. Therefore, oxygen can usually be in excess, but too much gas will reduce flotation efficiency and increase energy consumption.

[0045] In some embodiments, during the flotation step, ammonia is used to adjust the pH of the nickel-cobalt-manganese-containing solution to 6.0-7.0. Specifically, the pH can be adjusted to any value among 6.0, 6.2, 6.4, 6.6, 6.8, 7.0, or 6.0-7.0. In this embodiment, using ammonia, which has relatively weak alkalinity, to adjust the solution pH can effectively improve the phenomenon of "local over-alkalinity," which helps to reduce the inclusion of impurities such as nickel and cobalt and improve the purity of manganese tetroxide.

[0046] In some embodiments, the concentration of the ammonia water is 20wt%-25wt%, specifically, it can be any value among 20wt%, 21wt%, 22wt%, 23wt%, 24wt%, 25wt%, or 20wt%-25wt%, using relatively concentrated ammonia water to reduce wastewater discharge.

[0047] In some embodiments, the molar ratio of the added sodium silicate to the molar ratio of the manganese element in the nickel-cobalt-manganese solution is 1:(19-21).

[0048] In some embodiments, the sodium silicate is mixed with the nickel-cobalt-manganese-containing solution in the form of an aqueous sodium silicate solution, wherein the mass fraction of sodium silicate in the aqueous sodium silicate solution is 2wt%-5wt%. The mixing of the sodium silicate aqueous solution and the nickel-cobalt-manganese-containing solution does not require a dissolution process, resulting in a faster mixing speed.

[0049] In some embodiments, the flotation is carried out in a self-priming flotation machine.

[0050] In some embodiments, the temperature of the flotation step is 45°C-55°C, specifically, it can be any value among 45°C, 50°C, 55°C or 45°C-55°C.

[0051] In some implementations, the flotation step takes 1.5h-2.5h, specifically, it can be any value among 1.5h, 2h, 2.5h, or 1.5h-2.5h.

[0052] In some embodiments, the nickel-cobalt-manganese-containing solution contains nickel at a concentration of 4 g / L-6 g / L, cobalt at a concentration of 0.3 g / L-0.6 g / L, and manganese at a concentration of 4 g / L-6 g / L. When the nickel-cobalt-manganese-containing solution originates from laterite nickel ore, the nickel concentration is approximately 4 g / L-6 g / L, the cobalt concentration is approximately 0.3 g / L-0.6 g / L, and the manganese concentration is approximately 4 g / L-6 g / L.

[0053] This disclosure provides a method for removing manganese from laterite nickel ore, comprising sequentially acid leaching and iron and aluminum removal of the laterite nickel ore to obtain a nickel-cobalt-manganese solution, and then using the method described in any one of the foregoing embodiments to separate manganese from nickel and cobalt in the nickel-cobalt-manganese solution.

[0054] In some embodiments, the acid leaching step includes: mixing lateritic nickel ore with acid for leaching, followed by filtration to obtain leaching residue and leaching stock solution.

[0055] In some embodiments, the temperature of the acid leaching step is 200℃-250℃, specifically, it can be any value among 200℃, 210℃, 220℃, 230℃, 240℃, 250℃ or 200℃-250℃; the time of the acid leaching step is 2h-4h, specifically, it can be any value among 2h, 2.5h, 3h, 3.5h, 4h or 2h-4h; the pressure of the acid leaching step is 2.0MPa-2.5MPa, specifically, it can be any value among 2.0MPa, 2.1MPa, 2.2MPa, 2.3MPa, 2.4MPa, 2.5MPa or 2.0-2.5MPa.

[0056] In some embodiments, in the acid leaching step, the acid is sulfuric acid with a concentration of 100 g / L to 150 g / L, specifically, it can be any value among 100 g / L, 110 g / L, 120 g / L, 130 g / L, 140 g / L, 150 g / L, or 100 g / L to 150 g / L; laterite nickel ore and acid are mixed at a solid-liquid ratio of (1:2.0-1:4.0) kg / L, specifically, it can be any value among 1:2.0 kg / L, 1:2.5 kg / L, 1:3.0 kg / L, 1:3.5 kg / L, 1:4.0 kg / L, or (1:2.0-1:4.0) kg / L.

[0057] In some embodiments, in the iron and aluminum removal step, an oxidant is first added to the leaching solution, and then the pH is adjusted to 2.0-4.0 to remove iron. Specifically, the pH can be any value among 2.0, 2.5, 3.0, 3.5, 4.0, or 2.0-4.0. After solid-liquid separation, the pH of the liquid phase is adjusted to 4.0-6.0 to remove aluminum. Specifically, the pH can be any value among 4.0, 4.5, 5.0, 5.5, 6.0, or 4.0-6.0. After solid-liquid separation again, the liquid phase obtained is the nickel-cobalt-manganese solution.

[0058] In some embodiments, the oxidant is hydrogen peroxide, which mainly oxidizes ferrous ions in the solution to ferric ions, while simultaneously reducing hydrogen peroxide to water, thus reducing the difficulty of wastewater treatment.

[0059] In some embodiments, the volume of hydrogen peroxide added is 0.4%-0.6% of the volume of the original leaching solution. Specifically, it can be any value among 0.4%, 0.5%, 0.6%, or 0.4%-0.6%, depending on the content of ferrous iron in the solution. It can be slightly overdone based on the theoretical dosage.

[0060] In some embodiments, the temperature of the iron removal step is 90℃-95℃, specifically, it can be any value among 90℃, 91℃, 92℃, 93℃, 94℃, 95℃ or 90℃-95℃; the time is 50min-70min, specifically, it can be any value among 50min, 55min, 60min, 65min, 70min or 50min-70min.

[0061] In some embodiments, the temperature of the aluminum removal step is 90℃-95℃, specifically, it can be any value among 90℃, 91℃, 92℃, 93℃, 94℃, 95℃ or 90℃-95℃; the time is 50min-70min, specifically, it can be any value among 50min, 55min, 60min, 65min, 70min or 50min-70min.

[0062] In some embodiments, calcium hydroxide is used to adjust the pH in the iron and aluminum removal step, which is low-cost and convenient.

[0063] Another embodiment of this disclosure provides a method for producing nickel-cobalt hydroxide by hydrometallurgical processing of laterite nickel ore. The pH of the nickel-cobalt-containing solution obtained by any of the preceding methods is adjusted to 7.0-9.0 to obtain nickel-cobalt hydroxide precipitate. Specifically, the pH can be any value among 7.0, 7.5, 8.0, 8.5, 9.0, or 7.0-9.0. In this embodiment, ammonia water can also be used to adjust the pH of the nickel-cobalt-containing solution, which can effectively improve the phenomenon of "local over-alkalinity," reduce impurities, improve the purity of the nickel-cobalt hydroxide product, and help reduce the production cost of downstream products.

[0064] In some embodiments, the pH of the nickel-cobalt containing solution is adjusted to 7.0-9.0, and then kept at a temperature of 40℃-50℃ for 1.5h-2h to obtain nickel-cobalt hydroxide precipitate. Specifically, the temperature for nickel-cobalt hydroxide precipitation is 40℃-50℃, and can be any value among 40℃, 42℃, 44℃, 46℃, 48℃, 50℃, or 40℃-50℃; the time is 1.5h-2h, and can be any value among 1.5h, 1.6h, 1.7h, 1.8h, 1.9h, 2h, or 1.5h-2h.

[0065] The features and performance of this disclosure will be further described in detail below with reference to embodiments.

[0066] Example 1:

[0067] This embodiment provides a method for producing nickel-cobalt hydroxide by hydrometallurgical refining of laterite nickel ore, such as... Figure 1 As shown, it includes:

[0068] (1) Limonite-type laterite nickel ore and sulfuric acid solution were added to a pressure reactor for pressure leaching. The sulfuric acid concentration was 130 g / L, the liquid-solid ratio was 3.0:1, the reaction temperature was 230℃, the pressure was 2.25 MPa, the leaching time was 3 h, and the leaching was filtered after precipitation to obtain pressure leaching solution 1 and iron-rich leaching residue.

[0069] (2) Add 30% hydrogen peroxide to the pressure leaching solution 1 of limonite-type laterite nickel ore and stir continuously to fully oxidize the ferrous ions in the solution to ferric ions. The volume of hydrogen peroxide to be added is 0.5% of the volume of the leaching solution 1 to obtain solution 2.

[0070] (3) Keep solution 2 at a constant temperature of 90℃, add 200g / L calcium hydroxide solution to adjust the pH to 3.0, precipitate and remove iron for 1h, and filter to obtain solution 3;

[0071] (4) Keep solution 3 at a constant temperature of 90℃, add 200g / L calcium hydroxide solution to adjust the pH to 5.0, carry out precipitation to remove aluminum for 1h, and filter to obtain solution 4;

[0072] (5) Solution 4 was placed in a self-priming flotation machine for aeration, oxidation, and stirring, wherein the oxygen flow rate in the oxygen-containing gas was 0.08 m³ / s. 3 / h, and keep the solution temperature at 50℃, add 25% ammonia water, adjust the solution pH to 6.7, add water glass solution of n(Mn):n(Na2SiO3)=20:1 in solution 4, in which the mass fraction of sodium silicate is 5wt%, carry out the oxidation precipitation reaction of manganese for 2h, and filter to obtain solution 5 and fine manganese slag;

[0073] (6) Add 25% ammonia water to solution 5, keep the solution temperature at 45℃, adjust the solution pH to 8.5, carry out the nickel-cobalt precipitation reaction for 2 hours, filter to obtain solution 6, wash the filter cake to obtain nickel-cobalt hydroxide product.

[0074] ICP element test

[0075] The original leaching solution 1 contained the following concentrations: Ni 5.17 g / L, Co 0.57 g / L, Mn 5.19 g / L, Fe 0.56 g / L, and Al 0.37 g / L.

[0076] The obtained nickel-cobalt hydroxide product contains: Ni 45.02%, Co 1.86%, Mn 0.0001%, Fe 0.01%, and Al 0.10%.

[0077] Solution 6 contains: Ni concentration 0.05 g / L, Co concentration 0.006 g / L, Mn concentration 0.0001 g / L, Fe concentration 0.006 g / L, and Al concentration 0.008 g / L.

[0078] Example 2:

[0079] This embodiment provides a method for producing nickel-cobalt hydroxide by hydrometallurgical refining of laterite nickel ore, including:

[0080] (1) Limonite-type laterite nickel ore and sulfuric acid solution were added to a pressure reactor for pressure leaching. The sulfuric acid concentration was 100 g / L, the liquid-solid ratio was 2.0:1, the reaction temperature was 200℃, the pressure was 2.0 MPa, the leaching time was 2 h, and the leaching was filtered after precipitation to obtain pressure leaching solution 1 and iron-rich leaching residue.

[0081] (2) Add 30% hydrogen peroxide to the pressure leaching solution 1 of limonite-type laterite nickel ore and stir continuously to fully oxidize the ferrous ions in the solution to ferric ions. The volume of hydrogen peroxide to be added is 0.4% of the volume of the leaching solution 1 to obtain solution 2.

[0082] (3) Keep solution 2 at a constant temperature of 95℃, add 200g / L calcium hydroxide solution to adjust the pH to 2.0, carry out precipitation to remove iron for 1h, and filter to obtain solution 3;

[0083] (4) Keep solution 3 at a constant temperature of 90℃, add 200g / L calcium hydroxide solution to adjust the pH to 4.0, precipitate and remove aluminum for 1h, and filter to obtain solution 4;

[0084] (5) Solution 4 was placed in a self-priming flotation machine for aeration, oxidation, and stirring, wherein the oxygen flow rate in the oxygen-containing gas was 0.08 m³ / s. 3 / h, and keep the solution temperature at 55℃, add 25% ammonia water, adjust the solution pH to 6, add water glass solution of n(Mn):n(Na2SiO3)=20:1 in solution 4, wherein the mass fraction of sodium silicate is 5wt%, carry out the oxidation precipitation reaction of manganese for 1.5h, and filter to obtain solution 5 and fine manganese slag;

[0085] (6) Add 25% ammonia water to solution 5, keep the solution temperature at 45℃, adjust the solution pH to 7, carry out the nickel-cobalt precipitation reaction for 2 hours, filter to obtain solution 6, wash the filter cake to obtain nickel-cobalt hydroxide product.

[0086] ICP element test

[0087] The original leaching solution 1 contained the following concentrations: Ni 4.42 g / L, Co 0.37 g / L, Mn 4.28 g / L, Fe 0.33 g / L, and Al 0.18 g / L.

[0088] The obtained nickel-cobalt hydroxide product contains: Ni 43.51%, Co 1.26%, Mn 0.0003%, Fe 0.005%, and Al 0.055%.

[0089] Solution 6 contains: Ni concentration 2.37 g / L, Co concentration 0.14 g / L, Mn concentration 0.0002 g / L, Fe concentration 0.005 g / L, and Al concentration 0.006 g / L.

[0090] Example 3:

[0091] This embodiment provides a method for producing nickel-cobalt hydroxide by hydrometallurgical refining of laterite nickel ore, including:

[0092] (1) Limonite-type laterite nickel ore and sulfuric acid solution were added to a pressure reactor for pressure leaching. The sulfuric acid concentration was 150 g / L, the liquid-solid ratio was 4.0:1, the reaction temperature was 250℃, the pressure was 2.50 MPa, the leaching time was 4 h, and the leaching was filtered after precipitation to obtain pressure leaching solution 1 and iron-rich leaching residue.

[0093] (2) Add 30% hydrogen peroxide to the pressure leaching solution 1 of limonite-type laterite nickel ore and stir continuously to fully oxidize the ferrous ions in the solution to ferric ions. The volume of hydrogen peroxide to be added is 0.6% of the volume of the leaching solution 1 to obtain solution 2.

[0094] (3) Keep solution 2 at a constant temperature of 90℃, add 200g / L calcium hydroxide solution to adjust the pH to 4.0, carry out precipitation to remove iron for 1h, and filter to obtain solution 3;

[0095] (4) Keep solution 3 at a constant temperature of 90℃, add 200g / L calcium hydroxide solution to adjust the pH to 6.0, precipitate and remove aluminum for 1h, and filter to obtain solution 4;

[0096] (5) Solution 4 was placed in a self-priming flotation machine for aeration, oxidation, and stirring, wherein the oxygen flow rate in the oxygen-containing gas was 0.08 m³ / s. 3 / h, and keep the solution temperature at 45℃, add 25% ammonia water, adjust the solution pH to 7, add water glass solution of n(Mn):n(Na2SiO3)=20:1 in solution 4, wherein the mass fraction of sodium silicate is 5wt%, carry out the oxidation precipitation reaction of manganese for 2.5h, and filter to obtain solution 5 and fine manganese slag;

[0097] (6) Add 25% ammonia water to solution 5, keep the solution temperature at 45℃, adjust the solution pH to 9, carry out the nickel-cobalt precipitation reaction for 2 hours, filter to obtain solution 6, wash the filter cake to obtain nickel-cobalt hydroxide product.

[0098] ICP element test

[0099] The original leaching solution 1 contained the following concentrations: Ni 5.36 g / L, Co 0.59 g / L, Mn 5.48 g / L, Fe 0.62 g / L, and Al 0.41 g / L.

[0100] The obtained nickel-cobalt hydroxide product contains: Ni 45.23%, Co 1.91%, Mn 0.0001%, Fe 0.008%, and Al 0.11%.

[0101] Solution 6 contains: Ni concentration 0.015 g / L, Co concentration 0.003 g / L, Mn concentration 0.0001 g / L, Fe concentration 0.002 g / L, and Al concentration 0.005 g / L.

[0102] Comparative Example 1:

[0103] This comparative example provides a method for producing nickel-cobalt hydroxide by hydrometallurgical refining of laterite nickel ore, including:

[0104] (1) Limonite-type laterite nickel ore and sulfuric acid solution were added to a pressure reactor for pressure leaching. The sulfuric acid concentration was 150 g / L, the liquid-solid ratio was 2.0:1, the reaction temperature was 250℃, the pressure was 2.50 MPa, the leaching time was 3 h, and the leaching was filtered after precipitation to obtain pressure leaching solution 1 and iron-rich leaching residue.

[0105] (2) Add 30% hydrogen peroxide to the pressure leaching solution 1 of limonite-type laterite nickel ore and stir continuously to fully oxidize the ferrous ions in the solution to ferric ions. The volume of hydrogen peroxide to be added is 0.5% of the volume of the leaching solution 1 to obtain solution 2.

[0106] (3) Keep solution 2 at a constant temperature of 90℃, add 200g / L calcium hydroxide solution to adjust the pH to 3.0, precipitate and remove iron for 1h, and filter to obtain solution 3;

[0107] (4) Keep solution 3 at a constant temperature of 90℃, add 200g / L calcium hydroxide solution to adjust the pH to 5.0, carry out precipitation to remove aluminum for 1h, and filter to obtain solution 4;

[0108] (5) Add 200 g / L sodium hydroxide solution to solution 4, keep the solution temperature at 45°C, adjust the solution pH to 8.5, carry out manganese-nickel-cobalt precipitation reaction for 2 h, filter to obtain solution 5, wash the filter cake to obtain nickel-cobalt hydroxide product.

[0109] ICP element test

[0110] The original leaching solution 1 contained the following concentrations: Ni 5.36 g / L, Co 0.59 g / L, Mn 5.48 g / L, Fe 0.62 g / L, and Al 0.41 g / L.

[0111] The obtained nickel-cobalt hydroxide product contains: Ni 41.31%, Co 1.58%, Mn 3.59%, Fe 0.02%, and Al 0.18%.

[0112] Solution 5 contains: Ni concentration 0.060 g / L, Co concentration 0.004 g / L, Mn concentration 2.32 g / L, Fe concentration 0.006 g / L, and Al concentration 0.004 g / L.

[0113] This comparative example is a conventional method for preparing nickel-cobalt hydroxide by pressure leaching of laterite nickel ore followed by nickel-cobalt-manganese co-precipitation. It does not include the pre-precipitation of manganese by oxidation and the use of ammonia as a pH adjuster as described in this application. The prepared nickel-cobalt hydroxide product has a high manganese content, and the impurity content in the product is slightly higher due to "local over-alkali". The nickel-cobalt hydroxide product produced by this process has a higher impurity content and a lower nickel-cobalt content than the example.

[0114] Comparative Example 2:

[0115] This comparative example provides a method for producing nickel-cobalt hydroxide by hydrometallurgical refining of laterite nickel ore, including:

[0116] (1) Limonite-type laterite nickel ore and sulfuric acid solution were added to a pressure reactor for pressure leaching. The sulfuric acid concentration was 100 g / L, the liquid-solid ratio was 4.0:1, the reaction temperature was 210℃, the pressure was 2.10 MPa, the leaching time was 3 h, and the leaching was filtered after precipitation to obtain pressure leaching solution 1 and iron-rich leaching residue.

[0117] (2)-(4) Same as in Example 1;

[0118] (5) Keep the solution temperature of solution 4 at 50℃, add 25% ammonia water to adjust the solution pH to 6.7, add water glass solution of n(Mn):n(Na2SiO3)=20:1 in solution 4, wherein the mass fraction of sodium silicate is 5wt%, carry out direct manganese precipitation reaction for 2h, and filter to obtain solution 5 and fine manganese slag.

[0119] (6) Same as Example 1.

[0120] ICP element test

[0121] The original leaching solution 1 contained the following concentrations: Ni 4.39 g / L, Co 0.35 g / L, Mn 4.09 g / L, Fe 0.41 g / L, and Al 0.28 g / L.

[0122] The obtained nickel-cobalt hydroxide product contains: Ni 43.88%, Co 1.63%, Mn 1.76%, Fe 0.02%, and Al 0.12%.

[0123] Solution 6 contains: Ni concentration 0.058 g / L, Co concentration 0.005 g / L, Mn concentration 2.27 g / L, Fe concentration 0.005 g / L, and Al concentration 0.006 g / L.

[0124] Comparative Example 3:

[0125] This comparative example provides a method for producing nickel-cobalt hydroxide by hydrometallurgical refining of laterite nickel ore, including:

[0126] (1)-(4) Same as Example 1;

[0127] (5) Solution 4 was placed in a self-priming flotation machine for aeration, oxidation, and stirring, wherein the oxygen flow rate in the oxygen-containing gas was 0.08 m³ / s. 3 / h, and keep the solution temperature at 50℃, add sodium hydroxide to adjust the solution pH to 6.7, add water glass solution of n(Mn):n(Na2SiO3)=20:1 in solution 4, in which the mass fraction of sodium silicate is 5wt%, carry out the oxidation precipitation reaction of manganese for 2h, and filter to obtain solution 5 and fine manganese slag;

[0128] (6) Same as Example 1.

[0129] ICP element test

[0130] The original leaching solution 1 contained the following concentrations: Ni 5.17 g / L, Co 0.57 g / L, Mn 5.19 g / L, Fe 0.56 g / L, and Al 0.37 g / L.

[0131] The obtained nickel-cobalt hydroxide product contains: Ni 44.96%, Co 1.80%, Mn 0.0001%, Fe 0.009%, and Al 0.09%.

[0132] Solution 6 contains: Ni concentration 0.04 g / L, Co concentration 0.005 g / L, Mn concentration 0.0001 g / L, Fe concentration 0.004 g / L, and Al concentration 0.006 g / L.

[0133] Comparative Example 4:

[0134] This comparative example provides a method for producing nickel-cobalt hydroxide by hydrometallurgical refining of laterite nickel ore, including:

[0135] (1)-(4) Same as Example 1;

[0136] (5) Solution 4 was placed in a self-priming flotation machine for aeration, oxidation, and stirring, wherein the oxygen flow rate in the oxygen-containing gas was 0.08 m³ / s. 3 / h, and keep the solution temperature at 50℃, add 25% ammonia water, adjust the solution pH to 6.7, carry out the oxidation precipitation reaction of manganese for 2h, and filter to obtain solution 5 and coarse manganese slag;

[0137] (6) Same as Example 1.

[0138] ICP element test

[0139] The original leaching solution 1 contained the following concentrations: Ni 5.17 g / L, Co 0.57 g / L, Mn 5.19 g / L, Fe 0.56 g / L, and Al 0.37 g / L.

[0140] The obtained nickel-cobalt hydroxide product contains: Ni 45.05%, Co 1.93%, Mn 0.0001%, Fe 0.011%, and Al 0.10%.

[0141] Solution 6 contains: Ni concentration 0.06 g / L, Co concentration 0.004 g / L, Mn concentration 0.0001 g / L, Fe concentration 0.005 g / L, and Al concentration 0.007 g / L.

[0142] Comparative Example 5:

[0143] This comparative example provides a method for producing nickel-cobalt hydroxide by hydrometallurgical refining of laterite nickel ore, including:

[0144] (1)-(4) Same as Example 1;

[0145] (5) Solution 4 was placed in a self-priming flotation machine for aeration, oxidation, and stirring, wherein the oxygen flow rate in the oxygen-containing gas was 0.08 m³ / s. 3 / h, and keep the solution temperature at 50℃, add 25% ammonia water to adjust the solution pH to 6.7, add sodium hexametaphosphate solution of n(Mn):n((NaPO3)6)=20:1 in solution 4, wherein the mass fraction of sodium hexametaphosphate is 5wt%, carry out the oxidation precipitation reaction for 2h, and filter to obtain solution 5 and fine manganese slag;

[0146] (6) Same as Example 1.

[0147] ICP element test

[0148] The original leaching solution 1 contained the following concentrations: Ni 5.17 g / L, Co 0.57 g / L, Mn 5.19 g / L, Fe 0.56 g / L, and Al 0.37 g / L.

[0149] The obtained nickel-cobalt hydroxide product contains: Ni 44.83%, Co 1.73%, Mn 0.0001%, Fe 0.009%, and Al 0.11%.

[0150] Solution 6 contains: Ni concentration 0.08 g / L, Co concentration 0.006 g / L, Mn concentration 0.0002 g / L, Fe concentration 0.007 g / L, and Al concentration 0.006 g / L.

[0151] Comparative Example 6:

[0152] This comparative example provides a method for producing nickel-cobalt hydroxide by hydrometallurgical refining of laterite nickel ore, including:

[0153] (1)-(4) Same as Example 1;

[0154] (5) Solution 4 was placed in a self-priming flotation machine for aeration, oxidation, and stirring, wherein the oxygen flow rate in the oxygen-containing gas was 0.08 m³ / s. 3 / h, and keep the solution temperature at 50℃, add 25% ammonia water, adjust the solution pH to 6.7, add water glass solution of n(Mn):n(Na2SiO3)=10:1 in solution 4, wherein the mass fraction of sodium silicate is 5wt%, carry out the oxidation precipitation reaction of manganese for 2h, and filter to obtain solution 5 and fine manganese slag;

[0155] (6) Same as Example 1.

[0156] ICP element test

[0157] The original leaching solution 1 contained the following concentrations: Ni 5.17 g / L, Co 0.57 g / L, Mn 5.19 g / L, Fe 0.56 g / L, and Al 0.37 g / L.

[0158] The obtained nickel-cobalt hydroxide product contains: Ni 42.34%, Co 1.17%, Mn 0.0008%, Fe 0.001%, and Al 0.09%.

[0159] Solution 6 contains: Ni concentration 0.18 g / L, Co concentration 0.013 g / L, Mn concentration 0.0008 g / L, Fe concentration 0.005 g / L, and Al concentration 0.006 g / L.

[0160] Comparative Example 7:

[0161] This comparative example provides a method for producing nickel-cobalt hydroxide by hydrometallurgical refining of laterite nickel ore, including:

[0162] (1)-(4) Same as Example 1;

[0163] (5) Solution 4 was placed in a self-priming flotation machine for aeration, oxidation, and stirring, wherein the oxygen flow rate in the oxygen-containing gas was 0.08 m³ / s. 3 / h, and keep the solution temperature at 50℃, add 25% ammonia water, adjust the solution pH to 6.7, add water glass solution of n(Mn):n(Na2SiO3)=30:1 in solution 4, in which the mass fraction of sodium silicate is 5wt%, carry out the oxidation precipitation reaction of manganese for 2h, and filter to obtain solution 5 and fine manganese slag;

[0164] (6) Same as Example 1.

[0165] ICP element test

[0166] The original leaching solution 1 contained the following concentrations: Ni 5.17 g / L, Co 0.57 g / L, Mn 5.19 g / L, Fe 0.56 g / L, and Al 0.37 g / L.

[0167] The obtained nickel-cobalt hydroxide product contains: Ni 43.77%, Co 1.62%, Mn 0.0004%, Fe 0.0012%, and Al 0.11%.

[0168] Solution 6 contains: Ni concentration 0.16 g / L, Co concentration 0.013 g / L, Mn concentration 0.0003 g / L, Fe concentration 0.005 g / L, and Al concentration 0.006 g / L.

[0169] Industrial applicability

[0170] This disclosure adjusts the nickel-cobalt-manganese solution to a slightly acidic state and oxidizes some of the manganese, causing it to precipitate as manganese tetroxide. Sodium silicate is used as a dispersant to inhibit further agglomeration or growth of the manganese tetroxide particles. This reduces the inclusion of nickel and cobalt elements and allows the smaller manganese tetroxide particles to be better separated from the liquid phase by flotation, thereby improving the recovery efficiency and purity of manganese, reducing the manganese content in the liquid phase, and facilitating downstream utilization of the nickel-cobalt solution to obtain higher-quality nickel-cobalt products. Furthermore, subsequent manganese removal from wastewater is unnecessary, simplifying the process, reducing production costs, and benefiting industrial applications.

Claims

1. A method for removing manganese from a nickel-cobalt-manganese-containing solution, characterized in that, include: An oxidant and sodium silicate are added to a nickel-cobalt-manganese-containing solution for flotation. During the flotation process, the pH of the solution is maintained at 6.0-7.0 to obtain manganese tetroxide-containing slag and a nickel-cobalt-containing solution. The molar ratio of the added sodium silicate to the molar ratio of manganese in the nickel-cobalt-manganese-containing solution is 1:(19-21). The temperature of the flotation process is 45℃-55℃. In the flotation step, oxygen is used as the oxidant, and oxygen-containing gas is introduced into the nickel-cobalt-manganese-containing solution at a flow rate of 0.05 m³ / s. 3 / h~0.1m 3 / h; The pH of the nickel-cobalt-manganese-containing solution was adjusted to 6.0-7.0 using ammonia.

2. The method for removing manganese from a nickel-cobalt-manganese solution according to claim 1, characterized in that, The concentration of the ammonia solution is 20wt%-25wt%.

3. The method for removing manganese from a nickel-cobalt-manganese solution according to claim 1, characterized in that, The sodium silicate is mixed with the nickel-cobalt-manganese-containing solution in the form of an aqueous sodium silicate solution, wherein the mass fraction of sodium silicate in the aqueous sodium silicate solution is 2wt%-5wt%.

4. The method for removing manganese from a nickel-cobalt-manganese solution according to claim 1, characterized in that, The flotation is carried out in a self-priming flotation machine.

5. The method for removing manganese from a nickel-cobalt-manganese solution according to claim 1, characterized in that, The flotation step takes 1.5-2.5 hours.

6. The method for removing manganese from a nickel-cobalt-manganese solution according to claim 1, characterized in that, In the nickel-cobalt-manganese solution, the concentration of nickel is 4 g / L-6 g / L, the concentration of cobalt is 0.3 g / L-0.6 g / L, and the concentration of manganese is 4 g / L-6 g / L.

7. A method for removing manganese from laterite nickel ore, characterized in that, The method involves sequentially acid leaching and iron and aluminum removal from laterite nickel ore to obtain a nickel-cobalt-manganese solution, and then removing manganese from the nickel-cobalt-manganese solution using the method described in any one of claims 1-6.

8. The method for removing manganese from laterite nickel ore according to claim 7, characterized in that, The acid leaching step includes: mixing laterite nickel ore with acid for leaching, followed by filtration to obtain leaching residue and leaching solution.

9. The method for removing manganese from laterite nickel ore according to claim 7, characterized in that, The acid leaching step is performed at a temperature of 200℃-250℃ for 2 hours to 4 hours, and at a pressure of 2.0 MPa-2.5 MPa.

10. The method for removing manganese from laterite nickel ore according to claim 7, characterized in that, In the acid leaching step, the acid is sulfuric acid with a concentration of 100g / L-150g / L, and the laterite nickel ore and acid are mixed at a solid-liquid ratio of (1:2.0-1:4.0) kg / L.

11. The method for removing manganese from laterite nickel ore according to claim 7, characterized in that, In the iron and aluminum removal step, an oxidant is first added to the leaching solution, and then the pH is adjusted to 2.0-4.0 to remove iron. After solid-liquid separation, the pH of the liquid phase is adjusted to 4.0-6.0 to remove aluminum. After solid-liquid separation again, the liquid phase obtained is the nickel-cobalt-manganese solution.

12. The method for removing manganese from laterite nickel ore according to claim 11, characterized in that, The oxidant is hydrogen peroxide.

13. The method for removing manganese from laterite nickel ore according to claim 12, characterized in that, The volume of hydrogen peroxide added is 0.4%-0.6% of the original leaching solution volume.

14. The method for removing manganese from laterite nickel ore according to claim 11, characterized in that, The iron removal step is performed at a temperature of 90℃-95℃ for 50min-70min.

15. The method for removing manganese from laterite nickel ore according to claim 11, characterized in that, The aluminum removal step is performed at a temperature of 90℃-95℃ for 50min-70min.

16. The method for removing manganese from laterite nickel ore according to claim 11, characterized in that, In the iron and aluminum removal step, calcium hydroxide is used to adjust the pH.

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