Method for selectively leaching nickel from nickel sulfide-containing material

Abstract

The invention provides a method for selectively leaching nickel from a nickel sulfide-containing material, which comprises the following steps: (1) mixing the nickel sulfide-containing material with a solid oxidant, and carrying out high-energy ball milling dry activation treatment to obtain an activated material; and (2) mixing the activated material with an acid solution, carrying out normal-pressure acid leaching treatment, and carrying out solid-liquid separation treatment to obtain a nickel-rich solution and leaching residues. According to the method, the nickel sulfide-containing material is activated by adopting a high-energy ball milling and oxidizing agent reinforced activation mode, so that nickel can be leached under normal-pressure acid leaching, the generation of waste gas is reduced, the leaching rate of nickel can also be improved, and the method has both economical efficiency and environmental protection property.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of hydrometallurgy, and relates to a method for selectively leaching nickel from a nickel sulfide-containing material. BACKGROUND

[0002] In modern industry, nickel is widely used in many fields such as stainless steel, batteries, alloys, etc. as a key non-ferrous metal. With the rapid development of the new energy industry, the demand for nickel continues to rise, making the technology for efficient extraction of nickel from various nickel-containing materials a research hotspot. Nickel sulfide-containing waste or minerals are one of the important sources of nickel, however, there are many challenges to achieve the selective leaching of nickel therein.

[0003] Traditionally, there are two types of processes for treating nickel sulfide ore, namely pyrometallurgical process and hydrometallurgical process. The pyrometallurgical process usually adopts sulfur-making smelting to smelt nickel in nickel sulfide ore into low-nickel sulfur, and then uses converter blowing to smelt into high-nickel matte, and finally produces nickel products through different refining methods. However, this method has extremely high energy consumption, and a large amount of sulfur dioxide gas will be generated during the smelting process, which will cause serious environmental pollution if not properly treated. For example, in the conventional pyrometallurgical process, about 10-15 gigajoules of energy are consumed to produce 1 ton of nickel, and several tons of sulfur dioxide are emitted.

[0004] The hydrometallurgical treatment method is relatively diverse, including high-pressure ammonia leaching method, high-pressure oxygen leaching method, sulfur acidizing roasting leaching method, oxidizing roasting reduction ammonia leaching method, and chlorination leaching method, etc. However, these methods also have their own disadvantages. For example, the high-pressure oxygen leaching method requires a reaction under harsh conditions of high temperature (200-250℃) and high pressure (3-5MPa), which has extremely high requirements for equipment, huge investment cost, and high maintenance and operation cost. At the same time, the reaction conditions of this method are difficult to control accurately, which can easily lead to unstable leaching rate of nickel and poor separation effect of associated elements.

[0005] CN107777734A proposes a method for preparing nickel sulfate from nickel sulfide ore, which improves the leaching rate of nickel by adding various chemical reagents. However, this method consumes a large amount of acid, and the large use of chemical reagents not only increases the production cost, but also makes the energy consumption of the reaction process too high. More seriously, the leaching residue contains a large amount of sulfide, which can cause great harm to the environment and human health if not properly treated.

[0006] CN104962733A discloses a method for leaching nickel from refractory nickel sulfide ore by microwave irradiation and pressure leaching. In the microwave irradiation process, a large amount of sulfur dioxide may be generated, causing environmental pollution, and the investment and operation cost of microwave equipment is high, which limits its large-scale application.

[0007] The method for leaching nickel from nickel sulfide ore in the above scheme is accompanied by the generation of a large amount of toxic gas, and the selectivity of nickel is low, therefore, developing a method capable of realizing high-efficiency selective leaching of nickel in nickel sulfide-containing materials, reducing acid consumption, reducing environmental pollution, and simplifying the process flow is of great significance for improving the utilization rate of nickel resources, reducing production costs, and promoting the sustainable development of the nickel industry. SUMMARY

[0008] The purpose of the present application is to provide a method for selectively leaching nickel from nickel sulfide-containing materials, which uses high-energy ball milling and oxidant strengthening activation to activate nickel sulfide-containing materials, so that nickel can be leached under normal pressure acid leaching. Not only can it significantly reduce acid consumption and avoid the generation of toxic gases, but it can also improve the leaching rate of nickel, and has both economic and environmental benefits.

[0009] To achieve this purpose, the present application uses the following technical solutions:

[0010] The present application provides a method for selectively leaching nickel from nickel sulfide-containing materials, which comprises the following steps:

[0011] (1) Mix the nickel sulfide-containing material with a solid oxidizing agent, and perform high-energy ball milling dry activation treatment to obtain an activated material;

[0012] (2) Mix the activated material with an acid solution and perform normal pressure acid leaching treatment, and then perform solid-liquid separation treatment to obtain a nickel-rich solution and a leaching residue.

[0013] The high-energy ball milling dry activation treatment of the present application is to use a high-energy ball mill to ball mill the mixture of the nickel sulfide-containing material and the solid oxidizing agent.

[0014] The mechanical force generated by the high-energy ball milling dry activation treatment of the present application destroys the crystal structure of nickel sulfide, causing lattice distortion and grain refinement of nickel sulfide, and forming a nanoscale mixed interface with the oxidizing agent, which significantly reduces the activation energy of the reaction, allowing the subsequent normal pressure acid leaching treatment to achieve the effect of high-pressure acid leaching treatment. The mechanical activation method of high-energy ball milling dry activation used in the present application generates lattice defects and active sites that promote the oxidation of nickel sulfide, reduce the amount of sulfuric acid used, and reduce costs, without the need for high-pressure equipment and with mild operating conditions.

[0015] Preferably, the nickel sulfide-containing material in step (1) comprises nickel sulfide ore and / or nickel sulfide waste.

[0016] Preferably, the median particle size D50 of the nickel sulfide-containing material is 1-100 μm, for example, 1 μm, 5 μm, 10 μm, 50 μm, or 100 μm, etc. The value range also applies to other values not listed.

[0017] Preferably, the solid oxidizing agent in step (1) comprises any one or a combination of at least two of ferric sulfate, tricobalt tetroxide or sodium chlorate, and typical but non-limiting combinations include a combination of ferric sulfate and tricobalt tetroxide, a combination of tricobalt tetroxide and sodium chlorate, or a combination of ferric sulfate and sodium chlorate, etc., and preferably ferric sulfate and tricobalt tetroxide.

[0018] Preferably, the mass ratio of ferric sulfate to tricobalt tetroxide is (1-3):1, such as 1:1, 1.5:1, 2:1, 2.5:1 or 3:1, etc., and not limited to the listed values, and other values not listed within the range are also applicable.

[0019] Preferably, the mass ratio of nickel sulfide in the nickel sulfide-containing material to the solid oxidizing agent in step (1) is 1:(0.1-0.5), such as 1:0.1, 1:0.2, 1:0.3, 1:0.4 or 1:0.5, etc., and not limited to the listed values, and other values not listed within the range are also applicable.

[0020] Preferably, the ball-to-material ratio in the high-energy ball milling dry activation treatment in step (1) is (10-20):1, such as 10:1, 12:1, 15:1, 18:1 or 20:1, etc., and not limited to the listed values, and other values not listed within the range are also applicable.

[0021] Preferably, the rotation speed in the high-energy ball milling dry activation treatment in step (1) is 300 rpm-800 rpm, such as 300 rpm, 400 rpm, 500 rpm, 600 rpm, 700 rpm or 800 rpm, etc., and not limited to the listed values, and other values not listed within the range are also applicable.

[0022] Preferably, the time in the high-energy ball milling dry activation treatment in step (1) is 1 h-5 h, such as 1 h, 2 h, 3 h, 4 h or 5 h, etc., and not limited to the listed values, and other values not listed within the range are also applicable.

[0023] Preferably, the median particle size D50 of the activated material in step (1) is 0.1-5 μm, such as 0.1 μm, 0.5 μm, 1 μm, 2 μm, 3 μm or 5 μm, etc.

[0024] Preferably, a dispersant is further added in the high-energy ball milling dry activation treatment in step (1).

[0025] The addition of a dispersant in the high-energy ball milling dry activation treatment can improve the ball milling efficiency and dispersibility of the nickel sulfide-containing material and the solid oxidizing agent, and the activation effect of the nickel sulfide-containing material is better.

[0026] Preferably, the dispersant comprises stearic acid and / or polyvinyl alcohol.

[0027] Preferably, the amount of the dispersant added is 0.5% to 2%, for example 0.5%, 0.8%, 1%, 1.5% or 2%, etc., not limited to the listed values, and other values not listed within the range of values are also applicable.

[0028] Preferably, the acid solution in step (2) comprises a sulfuric acid solution.

[0029] Preferably, the molar concentration of the sulfuric acid solution is 0.5 mol / L to 2 mol / L, for example 0.5 mol / L, 0.8 mol / L, 1 mol / L, 1.5 mol / L or 2 mol / L, etc., not limited to the listed values, and other values not listed within the range of values are also applicable.

[0030] Preferably, the mass-to-volume ratio of the activated material to the acid solution in step (2) is 50 g / L to 100 g / L, for example 50 g / L, 60 g / L, 70 g / L, 80 g / L, 90 g / L or 100 g / L, etc., not limited to the listed values, and other values not listed within the range of values are also applicable.

[0031] Preferably, the temperature of the atmospheric pressure acid leaching process in step (2) is 80℃ to 90℃, for example 80℃, 82℃, 85℃, 88℃ or 90℃, etc., not limited to the listed values, and other values not listed within the range of values are also applicable.

[0032] The hot solid-liquid separation process is required after the atmospheric pressure acid leaching process, and the solid-liquid separation process at a temperature above 60℃ can better separate leaching residues such as elemental sulfur and unreacted oxidizing agent from the nickel-rich solution, further improving the purity of the nickel-rich solution.

[0033] Compared with the prior art, the present application has the following beneficial effects:

[0034] (1) The present application activates the nickel sulfide-containing material by high-energy ball milling and oxidizing agent strengthening activation, so that the nickel can be leached under atmospheric pressure acid leaching. Not only can the acid consumption be significantly reduced, but also the leaching rate of nickel can be improved, and the Ni recovery rate is as high as 93.25%, which is both economical and environmentally friendly.

[0035] (2) The method of the present application can obtain a leaching solution with a nickel content of 5.29 g / L or more, a leaching residue with a nickel content of 0.7% or less, and a nickel recovery rate of 84.52% or more. DETAILED DESCRIPTION

[0036] The technical solutions of the present application are further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments are only used to help understand the present application and should not be regarded as specific limitations on the present application.

[0037] The composition of the nickel sulfide-containing material used in the examples and comparative examples of the present application is as follows:

[0038] The Ni content is 12.50%, the Co content is 0.25%, the Fe content is 35.80%, and the solid material is broken to form a solid material with a median particle size D50 of 45 μm.

[0039] Example 1

[0040] The present embodiment provides a method for selectively leaching nickel from a nickel sulfide-containing material, which comprises the following steps:

[0041] (1) The nickel sulfide-containing material is mixed with a solid oxidizing agent at a mass ratio of nickel sulfide to solid oxidizing agent of 1:0.3 to obtain a mixed material, the solid oxidizing agent is iron sulfate and tricobalt tetraoxide at a mass ratio of 2:1, the mixed material is mixed with zirconium beads at a ball-to-material ratio of 15:1 and placed in a high-energy ball mill, and high-energy ball milling dry activation treatment is performed at a speed of 500 rpm for 3 h, a stearic acid dispersant is added during the activation process, the addition amount of stearic acid is 1% of the mixed material, and an activated material with a median particle size D50 of 2 μm is obtained;

[0042] (2) The activated material is mixed with a sulfuric acid solution with a molar concentration of 1 mol / L at a mass-to-volume ratio of 50 g / L, and normal pressure acid leaching treatment is performed at 85°C, after the normal pressure acid leaching treatment, solid-liquid separation treatment is performed while maintaining the temperature of the material at 60-85°C to obtain a nickel-rich solution and a leaching residue.

[0043] Example 2

[0044] The present embodiment provides a method for selectively leaching nickel from a nickel sulfide-containing material, which comprises the following steps:

[0045] (1) The nickel sulfide-containing material is mixed with a solid oxidizing agent at a mass ratio of nickel sulfide to solid oxidizing agent of 1:0.1 to obtain a mixed material, the solid oxidizing agent is iron sulfate and tricobalt tetraoxide at a mass ratio of 1:1, the mixed material is mixed with zirconium beads at a ball-to-material ratio of 20:1 and placed in a high-energy ball mill, and high-energy ball milling dry activation treatment is performed at a speed of 300 rpm for 5 h, a stearic acid dispersant is added during the activation process, the addition amount of stearic acid is 0.5% of the mixed material, and an activated material with a median particle size D50 of 0.2 μm is obtained;

[0046] (2) The activated material is mixed with a sulfuric acid solution with a molar concentration of 0.5 mol / L at a mass-volume ratio of 50 g / L, and is subjected to atmospheric pressure acid leaching treatment at 80°C. After the atmospheric pressure acid leaching treatment, the temperature of the material is maintained at 60-80°C for solid-liquid separation treatment to obtain a nickel-rich solution and a leaching residue.

[0047] Example 3

[0048] The present embodiment provides a method for selectively leaching nickel from a nickel sulfide-containing material, which comprises the following steps:

[0049] (1) The nickel sulfide-containing material is mixed with a solid oxidizing agent at a mass ratio of nickel sulfide to solid oxidizing agent of 1:0.5 to obtain a mixture, the solid oxidizing agent is iron sulfate and tricobalt tetraoxide at a mass ratio of 3:1, the mixture is mixed with zirconium beads at a ball-material ratio of 10:1 and is placed in a high-energy ball mill, and is subjected to high-energy ball milling dry activation treatment at a speed of 800 rpm for 1 h, and a stearic acid dispersant is added during the activation process, the addition amount of stearic acid is 2% of the mixture, and an activated material with a median particle size D50 of 5 μm is obtained;

[0050] (2) The activated material is mixed with a sulfuric acid solution with a molar concentration of 2 mol / L at a mass-volume ratio of 50 g / L, and is subjected to atmospheric pressure acid leaching treatment at 90°C. After the atmospheric pressure acid leaching treatment, the temperature of the material is maintained at 60-90°C for solid-liquid separation treatment to obtain a nickel-rich solution and a leaching residue.

[0051] Example 4

[0052] The present embodiment is different from Example 1 only in that the nickel sulfide-containing material in step (1) is mixed with a solid oxidizing agent at a mass ratio of nickel sulfide to solid oxidizing agent of 1:0.05, and other conditions and parameters are completely the same as those in Example 1.

[0053] Example 5

[0054] The present embodiment is different from Example 1 only in that the nickel sulfide-containing material in step (1) is mixed with a solid oxidizing agent at a mass ratio of nickel sulfide to solid oxidizing agent of 1:0.8, and other conditions and parameters are completely the same as those in Example 1.

[0055] Example 6

[0056] The present embodiment is different from Example 1 only in that the mass ratio of iron sulfate to tricobalt tetraoxide in step (1) is 0.5:1, and other conditions and parameters are completely the same as those in Example 1.

[0057] Example 7

[0058] The embodiment is different from example 1 only in that the mass ratio of the ferric sulfate and the tricobalt tetraoxide in step (1) is 5:1, and other conditions and parameters are completely the same as those in example 1.

[0059] Comparative example 1

[0060] The comparative example is different from example 1 only in that the sulfur-containing nickel material is mixed with the hydrogen peroxide oxidant for oxidation in step (1), and other conditions and parameters are completely the same as those in example 1.

[0061] Performance test:

[0062] The nickel content in the nickel-rich solution and the leaching residue prepared in the examples and the comparative examples is detected, the nickel recovery rate is calculated, and the test results are shown in Table 1:

[0063] Table 1

[0064]

[0065] As can be seen from Table 1, according to examples 1-7, the nickel content in the leaching solution obtained by the method of the present application can reach 5.29 g / L or more, the nickel content in the leaching residue can reach 0.7% or less, and the nickel recovery rate can reach 84.52% or more.

[0066] As can be seen from the comparison between example 1 and examples 4-5, in the method for selectively leaching nickel from the sulfur-containing nickel-containing material according to the present application, the mass ratio of the sulfur-containing nickel in the sulfur-containing nickel-containing material to the solid oxidant will affect the leaching effect. If the mass ratio of the sulfur-containing nickel in the sulfur-containing nickel-containing material to the solid oxidant is controlled to be 1:(0.1-0.5), the leaching effect is better. If the amount of the solid oxidant is too high, it will cause waste of reagents. If the amount of the solid oxidant is too low, the sulfur-containing nickel cannot be completely oxidized to soluble Ni 2 +, resulting in a decrease in leaching rate and low leaching efficiency.

[0067] As can be seen from the comparison between example 1 and examples 6-7, in the method for selectively leaching nickel from the sulfur-containing nickel-containing material according to the present application, the composition of the solid oxidant will affect the leaching effect. If the mass ratio of ferric sulfate and tricobalt tetraoxide is (1-3):1, the leaching effect is better. If the proportion of ferric sulfate is too high, the excess Fe 3+ may hydrolyze and precipitate, which will wrap part of the nickel, resulting in a decrease in nickel recovery rate. If the proportion of tricobalt tetraoxide is too high, the introduction of excess cobalt ions will result in a decrease in the purity of the recovered nickel, and the cost of cobalt is high.

[0068] By comparing example 1 and comparative example 1, it can be seen that the mechanical force produced by the high-energy ball milling dry activation treatment in the application destroys the crystal structure of nickel sulfide, causes lattice distortion and grain refinement of nickel sulfide, and forms a nanoscale mixed interface with the oxidizing agent, thereby significantly reducing the reaction activation energy, achieving the effect of high-pressure acid leaching treatment in subsequent normal-pressure acid leaching treatment, and greatly reducing the cost while being simple to operate.

[0069] The applicant declares that the above is only a specific embodiment of the application, but the protection scope of the application is not limited thereto. It should be understood by those skilled in the art that any changes or replacements within the technical scope disclosed by the application can be easily thought of by any person skilled in the art, and all fall within the protection scope and disclosure scope of the application.

Claims

1. A method for selectively leaching nickel from a nickel sulfide-containing material, characterized in that: The method comprises the following steps: (1) mixing a nickel sulfide-containing material with a solid oxidant, and subjecting the mixture to a high-energy ball milling dry activation treatment to obtain an activated material; (2) The activated material is mixed with an acid solution and subjected to normal pressure acid leaching treatment, followed by solid-liquid separation to obtain a nickel-rich solution and leaching residue.

2. The method according to claim 1, wherein The nickel sulfide-containing material in step (1) includes nickel sulfide ore and / or nickel sulfide waste; Preferably, the median particle size D50 of the nickel sulfide material is 1 μm to 100 μm.

3. The method according to claim 1 or 2, wherein: The solid oxidant in step (1) comprises any one of ferric sulfate, cobalt trioxide or sodium chlorate or a combination of at least two thereof, preferably ferric sulfate and cobalt trioxide; Preferably, the mass ratio of the ferric sulfate to cobalt trioxide is (1-3):

1.

4. The method according to any one of claims 1 to 3, wherein The mass ratio of nickel sulfide to solid oxidant in the nickel sulfide-containing material in step (1) is 1:(0.1-0.5).

5. The method according to any one of claims 1 to 4, characterized in that The ball-to-material ratio of the high-energy ball milling dry activation treatment in step (1) is (10-20):1; Preferably, the rotation speed of the high-energy ball milling dry activation treatment in step (1) is 300 rpm to 800 rpm; Preferably, the high-energy ball milling dry activation treatment time in step (1) is 1 h to 5 h; Preferably, the median particle size D50 of the activated material in step (1) is 0.1 μm to 5 μm.

6. The method according to any one of claims 1 to 5, wherein: During the high-energy ball milling dry activation treatment in step (1), a dispersant is also added; Preferably, the dispersant comprises stearic acid and / or polyvinyl alcohol; Preferably, based on the total mass of the nickel sulfide-containing material and the solid oxidant being 100%, the added amount of the dispersant is 0.5% to 2%.

7. The method according to any one of claims 1 to 6, wherein: The acid solution in step (2) comprises a sulfuric acid solution; Preferably, the molar concentration of the sulfuric acid solution is 0.5 mol / L to 2 mol / L.

8. The method according to any one of claims 1 to 7, wherein: The mass volume ratio of the activated material to the acid solution in step (2) is 50 g / L to 100 g / L.

9. The method according to any one of claims 1 to 8, wherein The temperature of the normal pressure acid leaching treatment in step (2) is 80°C to 90°C.

10. The method according to any one of claims 1 to 9, wherein During the solid-liquid separation process in step (2), the temperature of the separated material is 60°C to 90°C.

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