A method for oxidizing ferrous iron in cobalt-nickel ore smelting and a method for smelting cobalt-nickel ore

Abstract

The application discloses a method for oxidizing ferrous iron in cobalt-nickel ore smelting and a cobalt-nickel ore smelting method. The method for oxidizing ferrous iron in cobalt-nickel ore smelting comprises the following steps: adding alkali to copper-manganese liquid generated in cobalt-nickel ore smelting, removing copper and zinc to obtain a crude manganese sulfate solution containing manganese and calcium; then continuously adding alkali to the crude manganese sulfate solution, performing solid-liquid separation to obtain high-valence manganese residue; and finally adding the high-valence manganese residue into cobalt-nickel ore smelting leaching liquid to perform oxidation reaction, so that the oxidation of ferrous iron in the leaching liquid can be realized. The concentration of Fe 2+ in the leaching liquid treated by the method for oxidizing ferrous iron in cobalt-nickel ore smelting disclosed by the application is less than 20 mg / L, which meets the production requirements. The method disclosed by the application is simple in operation, convenient in production, can greatly improve the safety of production, and can reduce the production cost.

Description

Technical Field

[0001] This invention relates to the field of hydrometallurgy, specifically to a method for oxidizing ferrous iron in cobalt-nickel ore smelting and a method for smelting cobalt-nickel ore. Background Technology

[0002] In nickel-cobalt raw materials such as cobalt hydroxide, nickel hydroxide, and nickel-cobalt hydroxide, a large amount of iron is present. After leaching, the iron is converted into Fe. 2+ It exists in the form of Fe, which requires Fe to be... 2+ Oxidized to Fe 3+ Then, precipitation is carried out to remove the precipitate. This requires finding an oxidant that cannot oxidize cobalt and nickel to trivalent iron, but can oxidize iron to trivalent iron. In existing processes, hydrogen peroxide, sodium chlorate, or manganese dioxide are often used for oxidation. Hydrogen peroxide and sodium chlorate are both very effective, but both are hazardous chemicals and are subject to strict regulation. Manganese dioxide is very effective and is not a hazardous chemical, but it is expensive and has high usage costs. Summary of the Invention

[0003] To address the problems existing in the prior art, this invention provides a method for oxidizing ferrous iron in cobalt-nickel ore smelting and a smelting method for cobalt-nickel ore. The core idea of ​​the disclosed technical solution is that cobalt-nickel raw materials contain a large amount of manganese. The oxidant, prepared by utilizing the property of manganese hydroxide being readily oxidized in air, can oxidize ferrous iron. This method fully utilizes readily available elements to achieve oxidation, eliminating the use of hazardous chemicals at the source, significantly reducing costs, and preventing the introduction of impurities, thus achieving safe and low-cost production. Specifically, this invention includes the following:

[0004] A method for oxidizing ferrous iron in cobalt-nickel ore smelting involves adding alkali to the copper-manganese molten solution produced during cobalt-nickel ore smelting to remove copper and zinc, resulting in a crude manganese sulfate solution containing manganese and calcium. Then, alkali is added to the crude manganese sulfate solution to separate the solid and liquid phases, yielding high-valent manganese slag. Finally, the high-valent manganese slag is added to the cobalt-nickel ore smelting leachate for oxidation, thereby oxidizing the ferrous iron in the leachate.

[0005] Preferably, the specific method for obtaining the crude manganese sulfate solution containing manganese and calcium is as follows: add alkali to the copper-manganese solution to pH=6-6.5, carry out a precipitation reaction, and after the reaction is completed, filter to remove the precipitate containing copper and zinc to obtain the crude manganese sulfate solution containing manganese and calcium.

[0006] Preferably, the specific method for obtaining high-valence manganese slag is as follows: continue to add alkali to the crude manganese sulfate solution until the pH is 9-9.5, and at the same time, introduce air into the crude manganese sulfate solution to carry out an oxidation reaction. After the reaction is completed, filter to obtain high-valence manganese slag.

[0007] Preferably, the specific method for obtaining high-valence manganese slag is as follows: continue to add alkali to the crude manganese sulfate solution until the pH is 9-9.5, carry out the reaction, filter after the reaction is completed, and then place the obtained filter residue in an air atmosphere for oxidation to finally obtain high-valence manganese slag.

[0008] Preferably, the specific method for oxidizing ferrous iron in the leachate is as follows: ferrous iron to high-valent manganese slag is added to the leachate at a mass ratio of ferrous iron to high-valent manganese slag of 1:(2-4), and the pH is controlled at 1-1.5 and the temperature at 60-70℃ to carry out the oxidation reaction.

[0009] Preferably, the oxidation reaction time of the divalent iron and the high-valent manganese slag is 0.5-1h.

[0010] Preferably, the process further includes solid-liquid separation of the leachate after the oxidation reaction to obtain iron slag and supernatant, wherein the supernatant contains Fe 2+ The concentration is <20 mg / L.

[0011] A method for smelting cobalt-nickel ore, comprising oxidizing ferrous iron in the leaching solution using the method for oxidizing ferrous iron in cobalt-nickel ore smelting as described in this invention.

[0012] The beneficial effects of this invention are:

[0013] (1) The method for oxidizing ferrous iron in cobalt-nickel ore smelting disclosed in this invention involves adding alkali to the copper-manganese liquid produced in cobalt-nickel ore smelting and adjusting the pH to 6-6.5, which can remove 99% of the copper and zinc in the copper-manganese liquid and filter to obtain a crude manganese sulfate solution containing manganese and calcium.

[0014] (2) The method for oxidizing ferrous iron in cobalt-nickel ore smelting disclosed in this invention involves adding alkali to a crude manganese sulfate solution containing manganese and calcium to precipitate it until the pH reaches 9-9.5. Air is introduced during the alkali addition process, allowing for complete precipitation of manganese. The manganese hydroxide generated during precipitation is rapidly oxidized by air to a higher valence state of manganese. Filtration yields a high-valence manganese slag capable of oxidizing ferrous iron, while the calcium-containing wastewater is discharged into a water treatment plant. It should be noted that in the method disclosed in this invention, air can also be omitted during the preparation of the high-valence manganese slag. The filtered manganese hydroxide slag can be piled up in air for oxidation, where manganese hydroxide can also be rapidly oxidized.

[0015] The reaction equation for preparing high-valence manganese slag is:

[0016] Mn 2+ +2OH - =Mn(OH)2

[0017] 4Mn(OH)2 + O2 = 4MnO(OH) + 2H2O

[0018] Equation for the oxidation of ferrous iron by high-priced manganese slag:

[0019] MnO(OH) + Fe 2+ +3H + =Fe 3+ +Mn 2+ +2H2O

[0020] (3) In the leachate treated using the method for oxidizing ferrous iron in cobalt-nickel ore smelting disclosed in this invention, Fe 2+ The concentration is <20mg / L, which meets production requirements. The method disclosed in this invention is simple to operate, convenient to produce, and can significantly improve production safety and reduce production costs. Attached Figure Description

[0021] Figure 1 This is a process flow diagram of the cobalt-nickel ore smelting method disclosed in this invention. Detailed Implementation

[0022] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. The embodiments shown below do not limit the scope of the invention as described in the claims. Furthermore, the complete contents of the configurations illustrated in the following embodiments are not limited to those necessary for the solution of the invention as described in the claims.

[0023] A method for oxidizing ferrous iron in cobalt-nickel ore smelting includes the following steps:

[0024] (1) Add alkali to the copper-manganese liquid produced in the cobalt-nickel ore smelting process until the pH is 6-6.5 (e.g. 6.1, 6.2, 6.3, 6.4, etc.) to carry out the precipitation reaction. After the reaction is completed, filter to remove the precipitate containing copper and zinc to obtain a crude manganese sulfate solution containing manganese and calcium.

[0025] (2) Continue to add alkali to the crude manganese sulfate solution until the pH reaches 9-9.5 (e.g., 9.1, 9.2, 9.3, 9.4, etc.), and simultaneously introduce air into the crude manganese sulfate solution to carry out the oxidation reaction. After the reaction is completed, filter to obtain high-valence manganese slag; or continue to add alkali to the crude manganese sulfate solution until the pH reaches 9-9.5 (e.g., 9.1, 9.2, 9.3, 9.4, etc.), carry out the reaction, filter after the reaction is completed, and then place the obtained filter residue in an air atmosphere to oxidize, finally obtaining high-valence manganese slag;

[0026] (3) Add high-valent manganese slag to the leachate according to the mass ratio of ferrous iron to high-valent manganese slag of 1:(2-4) (e.g., 1:2, 1:2.2, 1:2.3, 1:2.5, 1:3, 1:3.5, 1:3.8, etc.), control the pH to 1-1.5 (e.g., 1.1, 1.2, 1.3, 1.4, etc.) and the temperature to 60-70℃ (e.g., 62℃, 64℃, 66℃, 68℃, 69℃, etc.), carry out the oxidation reaction, and the reaction time is 0.5-1h (e.g., 0.6h, 0.7h, 0.8h, 0.9h, etc.), so as to achieve the oxidation of ferrous iron in the leachate;

[0027] (4) The leachate after the oxidation reaction is separated into solid and liquid components to obtain iron slag and supernatant. The supernatant contains Fe. 2+ The concentration is <20 mg / L. It should be noted that the copper-manganese solution and leaching solution mentioned in the above method are both derived from the hydrometallurgical process of cobalt-nickel ore; for specific sources, please refer to the appendix. Figure 1 The process flow shown is as follows.

[0028] Reference Appendix Figure 1 A method for smelting cobalt-nickel ore, comprising oxidizing ferrous iron in the leaching solution using the method for oxidizing ferrous iron in cobalt-nickel ore smelting as described in this invention.

[0029] Example 1

[0030] A method for oxidizing ferrous iron in cobalt-nickel ore smelting includes the following steps:

[0031] (1) Add alkali to the copper-manganese liquid produced in the cobalt-nickel ore smelting until pH=6, carry out precipitation reaction, filter to remove the copper and zinc precipitate after the reaction is completed, and obtain crude manganese sulfate solution containing manganese and calcium.

[0032] (2) Add alkali to the crude manganese sulfate solution until pH=9, and at the same time, pass air into the crude manganese sulfate solution to carry out the oxidation reaction. After the reaction is completed, filter to obtain high-valence manganese slag.

[0033] (3) Add high-valent manganese slag to the leachate at a mass ratio of 1:2 for divalent iron to high-valent manganese slag, control pH=1 and temperature at 60℃, carry out oxidation reaction, and the reaction time is 0.5h to achieve oxidation of divalent iron in the leachate;

[0034] (4) The leachate after the oxidation reaction was separated into solid and liquid components to obtain iron slag and supernatant. Upon testing, the Fe content in the supernatant after treatment in this embodiment was found to be... 2+ The concentration was 15 mg / L.

[0035] Example 2

[0036] A method for oxidizing ferrous iron in cobalt-nickel ore smelting includes the following steps:

[0037] (1) Add alkali to the copper-manganese liquid produced in the cobalt-nickel ore smelting process until pH=6.5 to carry out precipitation reaction. After the reaction is completed, filter to remove the precipitate containing copper and zinc to obtain a crude manganese sulfate solution containing manganese and calcium.

[0038] (2) Add alkali to the crude manganese sulfate solution until pH = 9.5, carry out the reaction, filter after the reaction is completed, and then place the obtained filter residue in an air atmosphere to oxidize, and finally obtain high-valence manganese slag;

[0039] (3) Add high-valent manganese slag to the leachate at a mass ratio of 1:4 for divalent iron to high-valent manganese slag, control the pH to 1.5 and the temperature to 70℃, carry out the oxidation reaction, and the reaction time is 1h, so as to achieve the oxidation of divalent iron in the leachate.

[0040] (4) The leachate after the oxidation reaction was separated into solid and liquid components to obtain iron slag and supernatant. Upon testing, the Fe content in the supernatant after treatment in this embodiment was found to be... 2+ The concentration was 17 mg / L.

[0041] Example 3

[0042] A method for oxidizing ferrous iron in cobalt-nickel ore smelting includes the following steps:

[0043] (1) Add alkali to the copper-manganese liquid produced in the cobalt-nickel ore smelting process until pH=6.2 to carry out precipitation reaction. After the reaction is completed, filter to remove the precipitate containing copper and zinc to obtain a crude manganese sulfate solution containing manganese and calcium.

[0044] (2) Add alkali to the crude manganese sulfate solution until pH = 9.2, and at the same time, pass air into the crude manganese sulfate solution to carry out the oxidation reaction. After the reaction is completed, filter to obtain high-valence manganese slag.

[0045] (3) Add high-valent manganese slag to the leachate at a mass ratio of 1:3 for divalent iron to high-valent manganese slag, control the pH to 1.2 and the temperature to 63℃, carry out the oxidation reaction, and the reaction time is 0.7h to achieve the oxidation of divalent iron in the leachate;

[0046] (4) The leachate after the oxidation reaction was separated into solid and liquid components to obtain iron slag and supernatant. Upon testing, the Fe content in the supernatant after treatment in this embodiment was found to be... 2+ The concentration was 6 mg / L.

[0047] Example 4

[0048] A method for oxidizing ferrous iron in cobalt-nickel ore smelting includes the following steps:

[0049] (1) Add alkali to the copper-manganese liquid produced in the cobalt-nickel ore smelting process until pH=6.3 to carry out precipitation reaction. After the reaction is completed, filter to remove the precipitate containing copper and zinc to obtain a crude manganese sulfate solution containing manganese and calcium.

[0050] (2) Add alkali to the crude manganese sulfate solution until pH = 9.4, carry out the reaction, filter after the reaction is completed, and then place the obtained filter residue in an air atmosphere to oxidize, and finally obtain high-valence manganese slag;

[0051] (3) Add high-valent manganese slag to the leachate at a mass ratio of 1:2.8 for divalent iron to high-valent manganese slag, control the pH to 1.3 and the temperature to 68℃, carry out the oxidation reaction, and the reaction time is 0.8h to achieve the oxidation of divalent iron in the leachate;

[0052] (4) The leachate after the oxidation reaction was separated into solid and liquid components to obtain iron slag and supernatant. Upon testing, the Fe content in the supernatant after treatment in this embodiment was found to be... 2+ The concentration is 5 mg / L.

[0053] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for oxidizing ferrous iron in cobalt-nickel ore smelting, characterized in that, Includes the following steps: (1) Add alkali to the copper-manganese liquid produced in the cobalt-nickel ore smelting to pH=6-6.5 to carry out precipitation reaction. After the reaction is completed, filter to remove the copper and zinc precipitates to obtain a crude manganese sulfate solution containing manganese and calcium. (2) Add alkali to the crude manganese sulfate solution until pH=9-9.5, and at the same time pass air into the crude manganese sulfate solution to carry out the oxidation reaction, so that the manganese ions are precipitated as manganese hydroxide and then oxidized by air to manganese hydroxide MnO(OH). After the reaction is completed, filter to obtain high-valence manganese slag containing MnO(OH). (3) Add high-valent manganese slag to the cobalt-nickel ore smelting leaching solution according to the mass ratio of divalent iron to high-valent manganese slag of 1:(2-4), control the pH=1-1.5 and the temperature of 60-70℃, carry out the oxidation reaction, and the reaction time is 0.5-1h, so as to realize the oxidation of divalent iron in the leaching solution.

2. A method for oxidizing ferrous iron in cobalt-nickel ore smelting, characterized in that, Includes the following steps: (1) Add alkali to the copper-manganese liquid produced in the cobalt-nickel ore smelting to pH=6-6.5 to carry out precipitation reaction. After the reaction is completed, filter to remove the precipitate containing copper and zinc to obtain a crude manganese sulfate solution containing manganese and calcium. (2) Add alkali to the crude manganese sulfate solution until pH=9-9.5 to carry out the reaction. After the reaction is completed, filter to obtain manganese hydroxide slag. Then place the manganese hydroxide slag in the air atmosphere to oxidize manganese hydroxide to manganese hydroxide MnO(OH), and finally obtain high-valence manganese slag containing MnO(OH). (3) Add high-valent manganese slag to the cobalt-nickel ore smelting leaching solution according to the mass ratio of divalent iron to high-valent manganese slag of 1:(2-4), control the pH=1-1.5 and the temperature of 60-70℃, carry out the oxidation reaction, and the reaction time is 0.5-1h, so as to realize the oxidation of divalent iron in the leaching solution.

3. The method for oxidizing ferrous iron in cobalt-nickel ore smelting according to claim 1 or 2, characterized in that, It also includes solid-liquid separation of the leachate after oxidation reaction to obtain iron slag and supernatant, wherein the concentration of Fe²⁺ in the supernatant is <20 mg / L.

4. A method for smelting cobalt-nickel ore, characterized in that, The method for oxidizing ferrous iron in cobalt-nickel ore smelting according to any one of claims 1-3 is used to oxidize ferrous iron in the leachate.

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