Treatment method and treatment system for nickel-containing minerals

Abstract

The invention discloses a treatment method and system for nickel-containing minerals, and the treatment method comprises the following steps: a pre-reduction process: carrying out pre-reduction treatment on the nickel-containing minerals in the presence of an auxiliary agent and a reducing agent so as to reduce at least part of nickel in an oxidation state to obtain pre-reduced calcine; the sulfuration process comprises the step of carrying out sulfuration treatment on the pre-reduced calcine, so that at least part of metal state nickel / oxidation state nickel in the pre-reduced calcine is converted into nickel sulfide, and sulfuration calcine is obtained; the magnetic separation process comprises the step of carrying out magnetic separation treatment on the vulcanized calcine to obtain magnetic separation concentrate and magnetic separation tailings; and the flotation procedure comprises the step that flotation treatment is conducted on the magnetic separation tailings, and nickel-containing flotation concentrate is obtained. According to the treatment method, the metallization rate and the vulcanization rate of nickel can be controlled, the recovery cost of nickel is reduced, and the recovery efficiency and the recovery rate of nickel are improved.

Description

Technical Field

[0001] This application belongs to the field of nickel-bearing mineral processing technology, and particularly relates to a method and system for processing nickel-bearing minerals. Background Technology

[0002] Nickel-bearing minerals, as the main carriers of global nickel resources, are widely distributed. However, due to their complex mineral composition and large fluctuations in nickel grade (commonly ranging from 0.8% to 2.5%), they face bottlenecks in beneficiation and smelting technology adaptability. Furthermore, nickel in these deposits often exists isomorphously in the layered structure of limonite (FeO(OH)·nH2O) or nickel-silica ore, making it difficult for existing physical beneficiation methods to directly and efficiently enrich nickel components. Flotation methods suffer from high costs and low recovery efficiency and rates. Summary of the Invention

[0003] This application provides a method and system for processing nickel-containing minerals. The processing method of this application can control the metallization rate of nickel, reduce the cost of nickel recycling, and improve the efficiency and recovery rate of nickel recycling.

[0004] In a first aspect, embodiments of this application provide a method for processing nickel-containing minerals, the method comprising: a pre-reduction step, wherein the pre-reduction step includes pre-reducing the nickel-containing minerals in the presence of an additive and a reducing agent to reduce at least a portion of the oxidized nickel to obtain pre-reduced roasted ore; a sulfidation step, wherein the sulfidation step includes sulfidating the pre-reduced roasted ore to convert at least a portion of the metallic nickel / oxidized nickel in the pre-reduced roasted ore into nickel sulfides to obtain sulfided roasted ore; a magnetic separation step, wherein the magnetic separation step includes magnetic separation of the sulfided roasted ore to obtain magnetic concentrate and magnetic tailings; and a flotation step, wherein the flotation step includes flotation of the magnetic tailings to obtain nickel-containing flotation concentrate.

[0005] According to the embodiments of this application, the nickel-containing mineral processing method of this application can control the metallization rate and sulfidation rate of nickel through the pre-reduction process and the sulfidation process, thereby improving the efficiency of the magnetic separation process and recovering most of the minerals at low cost. Combined with the flotation process, the nickel recovery rate can be further improved.

[0006] In some alternative embodiments, the pre-reduction process may also satisfy one or more of the following conditions: (1) the mass ratio of reducing agent to nickel-containing mineral is 0.03:1 to 0.1:1; (2) the auxiliary agent is one or more of calcium chloride, sodium carbonate, sodium sulfate, calcium sulfate and calcium fluoride.

[0007] In some alternative embodiments, the pre-reduction process may also satisfy one or more of the following conditions: (1) the mass ratio of sodium carbonate to nickel-containing minerals is 1:10 to 3:20; (2) the mass ratio of sodium sulfate to nickel-containing minerals is 0 to 0.15:1; (3) the mass ratio of calcium sulfate to nickel-containing minerals is 0.05:1 to 0.2:1; (4) the mass ratio of calcium fluoride to nickel-containing minerals is 0.06:1 to 0.1:1; (5) the mass ratio of calcium chloride to nickel-containing minerals is 0 to 0.15:1.

[0008] In some alternative embodiments, the vulcanization process includes: adding a vulcanizing agent to the pre-reduced calcined sand for a first vulcanization to obtain primary calcined sand; mixing the primary calcined sand, the vulcanizing agent, and the reducing agent and then performing a second vulcanization, followed by cooling to obtain vulcanized calcined sand.

[0009] In some alternative embodiments, the sulfidation process may also satisfy one or more of the following conditions: (1) the temperature of the primary calcination is 600°C to 900°C; (2) the secondary sulfidation is carried out in a preheating container, the preheating temperature of which is greater than the temperature of the primary calcination; (3) the primary calcination, sulfidizing agent and reducing agent are added and mixed alternately; (4) the metallization rate of Ni in the sulfidated calcination is 45% to 95%, and the sulfidation rate of Ni is 5% to 30%.

[0010] In the above optional embodiments, the sulfidation process of this application can promote the directional combination of sulfur and nickel, while reducing sulfur volatilization loss, further increasing the nickel recovery rate by 5% to 8%, and can grow the nickel sulfide grains to 10 μm to 50 μm, greatly improving the subsequent flotation efficiency.

[0011] In some alternative embodiments, the vulcanization process may also satisfy one or more of the following conditions: (1) in the step of adding a vulcanizing agent to the pre-reduced calcined sand for the first vulcanization, the mass ratio of the vulcanizing agent to the pre-reduced calcined sand is 1:10 to 1:20; (2) in the step of mixing the primary calcined sand, the vulcanizing agent and the reducing agent for the second vulcanization, the mass ratio of the vulcanizing agent to the primary calcined sand is 0.05:1 to 0.1:1; (3) the preheating temperature of the preheating container is 700℃ to 1000℃; (4) cooling to obtain vulcanized calcined sand includes: cooling at 50℃ / h to 150℃ / h to 100℃ to 400℃ and then water quenching to obtain vulcanized calcined sand, or air cooling to room temperature to obtain vulcanized calcined sand.

[0012] In some optional embodiments, the magnetic separation process includes: grinding the sulfide roasted sand to obtain refined roasted sand, wherein optionally, the volume of particles that can pass through a 200-mesh sieve in the refined roasted sand accounts for 70% to 85% of the total volume of the refined roasted sand; subjecting the refined roasted sand to slurry treatment to obtain slurry roasted sand, wherein optionally, the solid content of the slurry roasted sand is 30% to 35%; and subjecting the slurry roasted sand to magnetic separation treatment to obtain magnetic concentrate and magnetic tailings, wherein optionally, the nickel grade of the magnetic concentrate is 9% to 12%, and the magnetic field strength of the magnetic separation treatment is 2000T to 3000T.

[0013] In some optional embodiments, the flotation process includes: adding a pH adjuster, dispersant, collector, frother, and depressant to the magnetic separation tailings and then performing roughing treatment to obtain rough concentrate and rough tailings; adding a collector to the rough tailings and then performing scavenging treatment to obtain scavenging concentrate and scavenging tailings; adding a collector, frother, and depressant to the rough concentrate and performing a primary cleaning treatment to obtain a primary clean concentrate and primary clean tailings; adjusting the pH of the primary clean concentrate to 9-10 and then performing a secondary cleaning treatment to obtain a secondary clean concentrate and secondary clean tailings; and dewatering the secondary clean concentrate to obtain nickel sulfide concentrate with a nickel grade ≥6%.

[0014] In some alternative embodiments, the flotation process satisfies one or more of the following conditions: (1) the scavenging concentrate is returned to the roughing process; (2) the primary cleaning tailings are returned to the roughing process; (3) the ratio of the amount of collector added in the roughing process, the amount of collector added in the scavenging process, and the amount of collector added in the primary cleaning process is (5-10):1:(1-2); (4) in the step of adding pH adjuster, dispersant, collector, frother, and depressant to the magnetic separation tailings and then performing roughing treatment, the amount of dispersant added is 100g / t to 300g / t; (5) the dispersant is sodium hexametaphosphate and / or sodium silicate; (6) the pH adjuster is sodium carbonate; (7) after adding pH adjuster, dispersant, collector, frother, and depressant to the magnetic separation tailings, the flotation process is performed... In the roughing process, the amount of collector added is 150g / t to 250g / t. Optionally, the collector is added to the magnetic separation tailings in two separate additions. (8) In the roughing process after adding pH adjuster, dispersant, collector, frother and inhibitor to the magnetic separation tailings, the amount of frother added is 20g / t to 40g / t to control the bubble size to 0.5mm to 1.5mm. (9) The frother is methyl isobutyl methanol or pine oil. (10) In the roughing process after adding pH adjuster, dispersant, collector, frother and inhibitor to the magnetic separation tailings, the amount of inhibitor added is 50g / t to 150g / t. (11) The inhibitor includes carboxymethyl cellulose and / or dextrin. (12) The secondary cleaning tailings are subjected to a primary cleaning process.

[0015] Secondly, embodiments of this application provide a processing system for nickel-containing minerals. This processing system processes nickel-containing minerals using the processing method of the first aspect. The processing system includes: a roasting and sulfidation unit, comprising a roasting component and a heat preservation component connected in sequence, the roasting component and the heat preservation component being used to perform pre-reduction treatment and sulfidation treatment on the nickel-containing minerals to obtain sulfided roasted sand; a magnetic separation unit, the magnetic separation unit being used to perform magnetic separation treatment on the sulfided roasted sand, the inlet of the magnetic separation unit being connected to the outlet of the heat preservation component; and a flotation unit, the flotation unit being used to perform flotation treatment on the magnetic separation tailings, the inlet of the flotation unit being connected to the magnetic separation tailings outlet of the magnetic separation unit.

[0016] According to the embodiments of this application, the processing system of this application adopts dynamic sulfidation at the rotary kiln outlet and makes efficient use of the preheating of the rotary kiln, further shortening the sulfidation time, while reducing the energy consumption of the additional heating stage in the traditional process, and reducing the loss of sulfiding agent during the heating process, saving energy and improving the nickel sulfidation rate.

[0017] In some alternative embodiments, the processing system satisfies one or more of the following conditions: (1) the roasting component is a rotary kiln, and a sulfiding agent inlet is provided in the rotary kiln at a distance of 1m to 5m from the discharge port; (2) the insulation component is an insulated steel ladle; (3) the magnetic separation unit includes a grinding component, a magnetic separation slurry preparation component, and a magnetic separation component, the discharge port of the insulation component is connected to the inlet of the grinding component, the discharge port of the grinding component is connected to the inlet of the magnetic separation slurry preparation component, the discharge port of the magnetic separation slurry preparation component is connected to the inlet of the magnetic separation component, and the magnetic separation tailings discharge port of the magnetic separation component is connected to the inlet of the flotation unit; (4) the flotation unit includes a flotation slurry preparation component, a roughing flotation component, a scavenging flotation component, a primary cleaning component, a secondary cleaning component, and an automatic reagent addition component, the magnetic separation tailings discharge port of the magnetic separation unit is connected to the inlet of the flotation slurry preparation component, and the flotation slurry preparation component is connected to the inlet of the flotation slurry preparation component. The discharge port of the slurry assembly is connected to the feed port of the roughing flotation assembly. The roughing tailings discharge port of the roughing flotation assembly is connected to the feed port of the scavenging flotation assembly. The scavenging concentrate discharge port of the scavenging flotation assembly is connected to the feed port of the roughing flotation assembly. The roughing concentrate discharge port of the roughing flotation assembly is connected to the feed port of the primary cleaning assembly. The primary cleaning tailings discharge port of the primary cleaning assembly is connected to the feed port of the roughing flotation assembly. The primary cleaning concentrate discharge port of the primary cleaning assembly is connected to the feed port of the secondary cleaning assembly. The secondary cleaning tailings discharge port of the secondary cleaning assembly is connected to the feed port of the primary cleaning assembly. The secondary cleaning concentrate discharge port of the secondary cleaning assembly is connected to the downstream processing system. The automatic reagent addition assembly is connected to the reagent feed ports of the flotation slurry conditioning assembly, the roughing flotation assembly, the scavenging flotation assembly, the primary cleaning assembly, and the secondary cleaning assembly, respectively. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic flowchart illustrating a method for processing nickel-containing minerals according to an embodiment of this application.

[0020] Figure 2 This is a schematic flowchart of the vulcanization process according to an embodiment of this application.

[0021] Figure 3 This is a schematic flowchart of a magnetic separation process according to an embodiment of this application.

[0022] Figure 4 This is a schematic flowchart of a flotation process according to an embodiment of this application.

[0023] Figure 5 This is a process flow diagram of laterite nickel ore processing in one embodiment of this application. Detailed Implementation

[0024] The features and exemplary embodiments of various aspects of this application will now be described in detail. Numerous specific details are set forth in the following detailed description in order to provide a comprehensive understanding of this application. However, it will be apparent to those skilled in the art that this application can be implemented without some of these specific details. The following description of embodiments is merely intended to provide a better understanding of this application by illustrating examples thereof.

[0025] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The embodiments will now be described in detail with reference to the accompanying drawings.

[0026] Furthermore, the term "and / or" in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0027] It should be understood that in the embodiments of this application, "B corresponding to A" means that B is associated with A, and B can be determined based on A. However, it should also be understood that determining B based on A does not mean that B is determined solely based on A; B can also be determined based on A and / or other information.

[0028] In this application, the particle size -XX mesh refers to the particle size that can pass through a XX mesh sieve. For example, -200 mesh particles refer to particles that can pass through a 200 mesh sieve. As another example, "crushing and grinding sulfide roasted sand to -200 mesh 85%" means that after crushing and grinding the sulfide roasted sand, the volume of particles that can pass through a 200 mesh sieve accounts for 85% of the total volume.

[0029] Nickel-bearing minerals, such as laterite nickel ore, have complex mineral compositions and fluctuate greatly in nickel grade (commonly 0.8% to 2.5%). In these deposits, nickel is mostly present in the layered structure of limonite (FeO(OH)·nH2O) or siliceous magnesium nickel ore, which makes it difficult for traditional physical beneficiation methods to directly and efficiently enrich nickel components, resulting in a bottleneck of poor adaptability to beneficiation and smelting technologies.

[0030] In related technologies, the production process of nickel-bearing minerals has significant limitations:

[0031] 1. The pyrometallurgical RKEF process requires high temperature (>1500℃) to reduce iron-nickel oxides and generate high iron content nickel-iron alloys. However, the power consumption per ton of nickel is as high as 3000-4000 kWh, and the economics of low-grade ore (Ni<1.5%) are greatly reduced. The OESBF oxygen-enriched side-blowing process has limitations in adaptability to raw materials and poor adaptability to high magnesium ores. More flux additives are needed to adjust the slag shape and slag formation, which increases the smelting cost.

[0032] 2. Although hydrometallurgy (HPAL, reduction roasting-ammonia leaching) can process low-grade ores, it faces challenges such as difficulty in controlling corrosion in high-pressure reactors, high purification costs of multi-metal synergistic leachate (accounting for 30% to 40% of the total investment), and the risk of stockpiling large amounts of acidic tailings.

[0033] 3. For the beneficiation process of laterite nickel ore, the relevant flotation methods have inherent defects: For the oxidized nickel in laterite nickel ore, conventional processes use reagent sulfidation (such as adding sodium sulfide) to induce surface sulfidation reaction, forming metastable NiS. x Thin film. However, because the sulfidation reaction does not penetrate the bulk phase of the mineral particles (diffusion depth < 200 nm), the product is amorphous or microcrystalline (XRD peak half-width > 2θ), forming a micron-scale encapsulation structure with gangue minerals such as hematite and quartz (SEM-EDS observation interface transition layer thickness 1–3 μm). This "surface pseudo-sulfidation" necessitates ultrafine grinding (P... 80 The surface sulfide layer is designed to expose the sulfide interface (<15μm), but over-grinding leads to sludge covering (sludge formation rate >30% for -5μm), resulting in an actual nickel recovery rate of less than 60%. In addition, the surface sulfide layer is prone to desorption in alkaline slurry (Zeta potential tests show that the stability of the sulfide film decreases by 50% when pH>8), further restricting the improvement of concentrate grade.

[0034] To address the aforementioned issues, this application provides a method and system for processing nickel-containing minerals, thereby reducing nickel recovery costs and improving nickel recovery efficiency and recovery rate.

[0035] The following section will first introduce the processing method for nickel-bearing minerals provided in the embodiments of this application.

[0036] Processing methods for nickel-bearing minerals

[0037] See Figure 1 As shown in the embodiment of this application, a method for processing nickel-containing minerals includes steps S100 to S400.

[0038] S100, Pre-reduction process, which includes pre-reduction treatment of nickel-containing minerals in the presence of additives and reducing agents, so as to reduce at least part of the oxidized nickel to obtain pre-reduced roasted sand.

[0039] S200, Sulfurization process, which includes sulfurizing the pre-reduced calcined sand to convert at least a portion of the metallic nickel / oxidized nickel in the pre-reduced calcined sand into nickel sulfides, thereby obtaining sulfided calcined sand.

[0040] S300, magnetic separation process, which includes magnetic separation of sulfide roasted sand to obtain magnetic concentrate and magnetic tailings.

[0041] S400, flotation process, which includes flotation treatment of magnetic separation tailings to obtain nickel-containing flotation concentrate.

[0042] According to the embodiments of this application, the method for processing nickel-bearing minerals controls the metallization and sulfidation rates of nickel through a pre-reduction process and a sulfidation process, thereby improving the efficiency of the magnetic separation process and recovering most of the minerals at low cost. Combining this with a flotation process can further improve the nickel recovery rate. This solves the problem of limited raw material adaptability in traditional pyrometallurgical smelting of nickel-bearing minerals, allowing for the selection of concentrates of different grades according to requirements, providing stable high-grade raw materials for subsequent processing.

[0043] The following reactions may occur during the pre-reduction process in the embodiments of this application:

[0044] NiO+C=Ni+CO(g); C+CO2(g)=2CO(g);

[0045] 3Fe2O3+C=2Fe3O4+CO(g); NiO+CO(g)=Ni+CO2(g);

[0046] Fe3O4+C=3FeO+CO(g); CoO+CO(g)=Co+CO2(g);

[0047] FeO+C=Fe+CO(g); 3Fe2O3+CO(g)=3FeO+CO2(g);

[0048] CoO+C=Co+CO(g); Fe3O4+CO(g)=3FeO+CO2(g);

[0049] 2C+O2(g)=2CO(g); 1 / 4Fe3O4+CO(g)=3 / 4Fe+CO2(g);

[0050] FeO + CO(g) = Fe + CO2(g).

[0051] The following reactions may occur during the vulcanization process in the embodiments of this application:

[0052] 2Fe + S2(g) = 2FeS;

[0053] 3Ni + S2(g) = Ni3S2;

[0054] 2Ni + S2(g) = 2NiS;

[0055] 9 / 4Co + S2(g) = 1 / 4Co9S8;

[0056] 2Co + S2(g) = 2CoS;

[0057] 12NiO+7S2(g)=4Ni3S2+6SO2(g);

[0058] 4NiO + 3S2(g) = 4NiS + 2SO2(g);

[0059] 36CoO+25S2(g)=4Co9S8+18SO2(g);

[0060] 4CoO + 3S2(g) = 4CoS + 2SO2(g);

[0061] 12Fe2O3+S2(g)=8Fe3O4+2SO2(g);

[0062] 4FeO + 3S2(g) = 4FeS + 2SO2(g).

[0063] It should be noted that in the above reaction equation, "(g)" indicates that the reactants / products exist in gaseous form.

[0064] In some embodiments, in step S100, the mass ratio of the reducing agent to the nickel-containing mineral in the pre-reduction process is 0.03:1 to 0.1:1. For example, the mass ratio of the reducing agent to the nickel-containing mineral can be 0.03:1, 0.04:1, 0.05:1, 0.06:1, 0.07:1, 0.08:1, 0.09:1, 0.1:1, or any range of the above values.

[0065] As an example, the amount of reducing agent can be selected according to the specific composition of the nickel-containing mineral. During the production process, the material can be quantitatively fed through weighing belts in different silos and then transported to the rotary kiln for feeding after the batching is completed.

[0066] In some embodiments, in step S100, the auxiliary agent in the pre-reduction process is one or more of calcium chloride, sodium carbonate, sodium sulfate, calcium sulfate, and calcium fluoride.

[0067] In some embodiments, in step S100, the pre-reduction process further satisfies one or more of the following conditions:

[0068] (1) The mass ratio of sodium carbonate to nickel-containing minerals is 0.1:1 to 0.15:1. For example, the mass ratio of sodium carbonate to nickel-containing minerals can be 0.1:1, 0.11:1, 0.12:1, 0.13:1, 0.14:1, 0.15:1, or any of the above values.

[0069] (2) The mass ratio of sodium sulfate to nickel-containing minerals is 0 to 0.15:1. For example, the mass ratio of sodium sulfate to nickel-containing minerals can be 0, 0.01:1, 0.02:1, 0.03:1, 0.04:1, 0.05:1, 0.06:1, 0.07:1, 0.08:1, 0.09:1, 0.1:1, 0.11:1, 0.12:1, 0.13:1, 0.14:1, 0.15:1, or any range of the above values.

[0070] (3) The mass ratio of calcium sulfate to nickel-containing minerals is 0.05:1 to 0.2:1. For example, the mass ratio of calcium sulfate to nickel-containing minerals can be 0.05:1, 0.08:1, 0.1:1, 0.12:1, 0.15:1, 0.18:1, 0.2:1, or any of the above values.

[0071] (4) The mass ratio of calcium fluoride to nickel-containing minerals is 0.06:1 to 0.1:1. For example, the mass ratio of calcium fluoride to nickel-containing minerals can be 0.06:1, 0.07:1, 0.08:1, 0.09:1, 0.1:1, or any of the above values.

[0072] (5) The mass ratio of calcium chloride to nickel-containing minerals is 0 to 0.15:1. For example, the mass ratio of calcium chloride to nickel-containing minerals can be 0, 0.01:1, 0.02:1, 0.03:1, 0.04:1, 0.05:1, 0.06:1, 0.07:1, 0.08:1, 0.09:1, 0.1:1, 0.11:1, 0.12:1, 0.13:1, 0.14:1, 0.15:1, or any range of the above values.

[0073] In some embodiments, see Figure 2 As shown, step S200 includes steps S210 to S220.

[0074] S210, a sulfiding agent is added to the pre-reduced calcined sand for the first sulfidation to obtain primary calcined sand.

[0075] S220 involves mixing primary calcined sand, vulcanizing agent, and reducing agent, followed by a second vulcanization process, and then cooling to obtain vulcanized calcined sand.

[0076] By adding a sulfiding agent to the pre-reduced calcined sand, the sulfiding agent and the pre-reduced calcined sand can be fully contacted, and the first sulfidation can be completed at a high temperature. Secondary sulfidation of the calcined sand mixed with the sulfiding agent and reducing agent can promote the sulfidation reaction, reduce sulfiding agent loss, control the sulfidation rate, increase grain size, and improve the efficiency of subsequent magnetic separation and flotation.

[0077] It is understandable that the vulcanizing agents in steps S210 and S220 can be the same or different.

[0078] In some embodiments, the sulfiding agent is one or more of sulfur, pyrite, and gypsum products produced by flue gas desulfurization in a smelting system. It is understood that the sulfiding agent can also be other sulfur-containing substances that can participate in the sulfidation reaction.

[0079] In some embodiments, the temperature of the primary calcination in step S210 is 600°C to 900°C. For example, the temperature of the primary calcination can be 600°C, 620°C, 650°C, 680°C, 700°C, 720°C, 750°C, 780°C, 800°C, 820°C, 850°C, 880°C, 900°C, or any range of the above values.

[0080] In some embodiments, the mass ratio of the vulcanizing agent to the pre-reduced calcined sand in step S210 is 1:10 to 1:20. For example, the mass ratio of the vulcanizing agent to the pre-reduced calcined sand can be 1:10, 1:12, 1:15, 1:18, 1:20, or any range of the above values.

[0081] In some embodiments, the mass ratio of the vulcanizing agent to the primary calcined sand in step S220 is 1:10 to 1:20. For example, the mass ratio of the vulcanizing agent to the primary calcined sand can be 1:10, 1:12, 1:15, 1:18, 1:20, or any range of the above values.

[0082] In some embodiments, in step S220, the second vulcanization is carried out in a closed preheating container, the preheating temperature of which is greater than the temperature of the first calcination.

[0083] In some embodiments, in step S220, the metallization rate of Ni in the sulfided calcined ore is 45% to 95%, and the sulfidation rate of Ni is 5% to 30%.

[0084] In some embodiments, in step S220, the primary calcined sand, vulcanizing agent, and reducing agent are added and mixed alternately. Exemplarily, the alternating addition and mixing includes adding the primary calcined sand, vulcanizing agent, and reducing agent in sequence and alternately, so that the primary calcined sand, vulcanizing agent, and reducing agent can be distributed alternately, thereby achieving a more uniform mixture, which is beneficial for creating a suitable reducing vulcanization atmosphere.

[0085] In some embodiments, the process of mixing the primary calcined sand, vulcanizing agent and reducing agent in step S220 includes: adding the vulcanizing agent and reducing agent to the preheating container by means of a feeding pipe or injection during the process of the primary calcined sand falling into the preheating container, so that the primary calcined sand, vulcanizing agent and reducing agent are distributed in layers in the preheating container.

[0086] In some embodiments, the preheating temperature of the preheating container in step S220 is 700°C to 1000°C. For example, the preheating temperature of the preheating container can be 700°C, 720°C, 750°C, 780°C, 800°C, 820°C, 850°C, 880°C, 900°C, 920°C, 950°C, 980°C, 1000°C, or any range of the above values.

[0087] In some embodiments, step S220 includes: placing the primary calcined ore, vulcanizing agent, and reducing agent in a sealed preheating container, and cooling it along with the sealed preheating container at a rate of 10°C / h to 150°C / h to below 100°C to obtain vulcanized calcined ore. Exemplarily, the temperature can be cooled to 90°C, 70°C, 50°C, or room temperature, and the cooling process can involve placing the preheating container in a natural environment for natural cooling. It is understood that during the cooling process in the sealed preheating container, the primary calcined ore undergoes vulcanization and reduction reactions with the vulcanizing agent and reducing agent.

[0088] It should be noted that the cooling rate in this application may be non-uniform. For example, in a natural cooling process, the preheated container temperature is high in the early stages, resulting in a large temperature difference with the environment and a faster cooling rate. In the later stages, the temperature difference decreases, and the cooling rate slows down. The cooling rate in this application generally refers to the average cooling rate throughout the entire cooling process, that is, the ratio between the temperature difference before and after cooling and the time of the cooling process.

[0089] In some embodiments, step S220 includes: placing the primary calcined slag, vulcanizing agent, and reducing agent in a sealed preheating container, and cooling them in the sealed preheating container at a rate of 10°C / h to 150°C / h to 100°C to 400°C, followed by water quenching to obtain vulcanized calcined slag. Exemplarily, the slag can be cooled to 350°C, 300°C, 250°C, 200°C, 150°C, 100°C, 100°C to 300°C, 100°C to 250°C, or 100°C to 200°C before water quenching.

[0090] By placing the calcined sand, sulfiding agent, and reducing agent in a sealed, preheated container and slowly cooling them, the directional bonding of sulfur and nickel can be promoted, while reducing sulfur volatilization loss, allowing nickel sulfide grains to grow to 10μm–50μm. Slowly cooling to 100℃–400℃, especially below 300℃, can effectively reduce the sudden cooling cracking of the nickel sulfide phase caused by direct water quenching, improving flotation efficiency and increasing nickel recovery. Choosing to first slowly cool to a suitable preset temperature and then combine it with water quenching can improve efficiency while ensuring the efficiency of subsequent flotation.

[0091] In some embodiments, see Figure 3 As shown, step S300 includes steps S310 to S330.

[0092] S310 is used to grind sulfide calcined sand to obtain refined calcined sand.

[0093] S320 is obtained by slurry preparation of refined calcined sand.

[0094] S330 is used to perform magnetic separation on slurry roasted sand to obtain magnetic concentrate and magnetic tailings.

[0095] In some embodiments, in step S310, the volume of particles in the refined calcined sand that can pass through a 200-mesh sieve accounts for 70% to 85% of the total volume of the refined calcined sand. For example, the volume of particles smaller than 200 mesh in the refined calcined sand can account for 70%, 71%, 72%, 73%, 74%, 75%, 76%, 77%, 78%, 79%, 80%, 81%, 82%, 83%, 84%, 85%, or any of the above-mentioned values ​​in the total volume of the refined calcined sand.

[0096] In some embodiments, the solid content of the slurry-prepared roasted sand in step S320 is 30% to 35%. For example, the solid content of the slurry-prepared roasted sand can be 30%, 31%, 32%, 33%, 34%, 35%, or any of the above values.

[0097] Controlling the grinding process to ensure that particles smaller than 200 mesh account for 70%–85% of the refined roasted sand allows for the full dissociation of metallic nickel minerals and nickel sulfide minerals (such as Ni3S2, NiS, FeS, etc.) from the gangue. Combined with adjusting the solid content of the slurry roasted sand to 30%–35%, the efficiency of subsequent magnetic separation-flotation can be improved.

[0098] In some embodiments, the nickel grade of the magnetic concentrate in step S330 is 9% to 12%, and the magnetic field strength for magnetic separation is 2000T to 3000T. For example, the nickel grade of the magnetic concentrate can be 9%, 10%, 11%, 12%, or any other range of the above values. The magnetic field strength for magnetic separation can be 2000T, 2200T, 2500T, 2800T, 3000T, or any range of the above values.

[0099] In some embodiments, see Figure 4 As shown, step S400 includes steps S410 to S440.

[0100] S410 involves adding pH adjuster, dispersant, collector, frother, and inhibitor to the magnetic separation tailings and then performing roughing treatment to obtain roughing concentrate and roughing tailings.

[0101] S420 involves adding a collector to the roughing tailings and then performing scavenging treatment to obtain scavenged concentrate and scavenged tailings.

[0102] S430 involves adding collectors, frothers, and depressants to the roughing concentrate for a primary cleaning process, resulting in a primary cleaned concentrate and a primary cleaned tailings.

[0103] S440, after adjusting the pH of the primary concentrate to 9-10, undergoes secondary cleaning to obtain secondary concentrate and secondary tailings. The secondary concentrate is then dehydrated to obtain nickel sulfide concentrate with a nickel grade ≥6%. Optionally, the secondary concentrate can be dehydrated to obtain nickel sulfide concentrate with a nickel grade ≥6.5%.

[0104] In some embodiments, the pH adjuster in step S410 is sodium carbonate (Na2CO3), and the pulp pH is 10.5-11. A suitable roughing system can suppress the flotation of iron minerals (such as FeS) and enhance the selectivity of nickel sulfides. It should be noted that the above pulp is a pulp formed by mixing magnetic separation tailings, pH adjuster, dispersant, collector, frother, and inhibitor.

[0105] In some embodiments, the amount of dispersant added in step S410 is 100 g / t to 300 g / t, for example, it can be 100 g / t, 120 g / t, 150 g / t, 180 g / t, 200 g / t, 220 g / t, 250 g / t, 280 g / t, 300 g / t, or any range of the above values. Optionally, the dispersant is sodium hexametaphosphate and / or sodium silicate. A suitable dispersant is beneficial for further reducing fine mud agglomeration and reducing interference with the flotation process.

[0106] In some embodiments, the amount of collector added in step S410 is 150 g / t to 250 g / t, for example, it can be 150 g / t, 180 g / t, 200 g / t, 220 g / t, 250 g / t, or any range of the above values. Optionally, the collector is one or more of butyl xanthate, isobutyl xanthate, pentyl xanthate, or butylammonium black powder.

[0107] In some embodiments, the collector in step S410 is added to the magnetic separation tailings in two parts. The ratio of the mass of the first collector added to the mass of the second collector added is 1.4 to 1.6:1. For example, it can be 1.4:1, 1.45:1, 1.5:1, 1.55:1, 1.6:1, or any range of the above values, so that the collector preferentially adsorbs the nickel sulfide surface. As an example, the collector can be added to the slurry preparation tank and the flotation cell respectively.

[0108] In some embodiments, the amount of foaming agent added in step S410 is 20 g / t to 40 g / t, for example, it can be 20 g / t, 22 g / t, 25 g / t, 28 g / t, 30 g / t, 32 g / t, 35 g / t, 38 g / t, 40 g / t, or any of the above values, to control the bubble size to be 0.5 mm to 1.5 mm. As an example, the foaming agent can be methyl isobutyl methanol (MIBC) or pine oil (2# oil).

[0109] In some embodiments, the amount of inhibitor added in step S410 is 50 g / t to 150 g / t, for example, it can be 50 g / t, 80 g / t, 100 g / t, 120 g / t, 150 g / t, or any range of the above values.

[0110] In some embodiments, the inhibitor in step S410 includes carboxymethyl cellulose and / or dextrin.

[0111] As an example, the inhibitor may include carboxymethyl cellulose and dextrin, wherein the amount of carboxymethyl cellulose added is 50 g / t to 100 g / t, for example, 50 g / t, 60 g / t, 70 g / t, 80 g / t, 90 g / t, 100 g / t, or any combination of the above values; when the iron sulfide content is high, 20 g / t to 50 g / t of dextrin may be added simultaneously, for example, 20 g / t, 25 g / t, 30 g / t, 35 g / t, 40 g / t, 45 g / t, 50 g / t, or any combination of the above values. Using the above-mentioned amounts of carboxymethyl cellulose and dextrin can effectively inhibit gangue minerals such as SiO2 while further inhibiting the flotation of FeS.

[0112] In some embodiments, the amount of collector added in step S420 is 30 g / t to 50 g / t, for example, it can be 30 g / t, 40 g / t, 50 g / t, or any range of the above values.

[0113] In some embodiments, the method further includes returning the scavenging concentrate from step S420 to the roughing process. It is understood that the method for returning the scavenging concentrate to the roughing process can be the same as that for magnetic separation tailings or can be adjusted according to the specific parameters of the scavenging concentrate. As an example, the scavenging concentrate and magnetic separation tailings can be roughed together.

[0114] In some embodiments, the primary refined tailings from step S430 are further returned to the roughing process. It is understood that the method for roughing the primary refined tailings can be the same as that for magnetic separation tailings or adjusted according to the specific parameters of the primary refined tailings. As an example, the primary refined tailings and magnetic separation tailings can be roughed together.

[0115] In some embodiments, the amount of collector added in step S430 is 20 g / t to 40 g / t, for example, it can be 20 g / t, 25 g / t, 30 g / t, 35 g / t, 40 g / t, or any range of the above values.

[0116] In some embodiments, the amount of foaming agent added in step S430 is 5g / t-10g / t, for example, it can be 5g / t, 6g / t, 7g / t, 8g / t, 9g / t, 10g / t, or any range of the above values.

[0117] In some embodiments, the amount of inhibitor added in step S430 is 20 g / t to 50 g / t, for example, it can be 20 g / t, 25 g / t, 30 g / t, 35 g / t, 40 g / t, 45 g / t, 50 g / t, or any range of the above values.

[0118] It should be noted that the selection of the collector, foaming agent, and inhibitor in step S430 can be the same as or different from that in step S410. It is understood that the collector, foaming agent, and inhibitor can be selected based on the specific circumstances.

[0119] In some embodiments, the secondary tailings from step S440 are further subjected to a primary refining process. As an example, the secondary tailings and the roughing concentrate can be subjected to a primary refining process together.

[0120] In some embodiments, the mass ratio of the collector added in steps S410, S420, and S430 is (5-10):1:(1-2). For example, it can be 5:1:1, 5:1:1.5, 5:1:2, 8:1:1, 8:1:1.5, 8:1:2, 10:1:1, 10:1:1.5, 10:1:2, or any range of the above values.

[0121] As an example, roughing can be performed in a roughing flotation unit, where the aeration rate is controlled at 0.8 m³. 3 / (m 2 ·min)~1.2m 3 / (m 2 •min), with the frothing time maintained at 4min–6min. The target nickel grade of the roughing concentrate is 4%–5%, with a recovery rate ≥75%. The roughing tailings are treated by scavenging (with the addition of 30g / t–50g / t of collector), and the aeration rate is increased to 1.5m. 3 / (m 2 ·min)~2.0m 3 / (m 2 (·min), recover residual nickel minerals, return scavenging concentrate to roughing treatment, and discharge scavenging tailings. The roughing concentrate enters the primary cleaning unit, where 20g / t~40g / t collector and 5g / t~10g / t frother are added, and the aeration rate is reduced to 0.5m. 3 / (m 2 ·min)~0.8m 3 / (m 2The skimming time is extended to 3-4 minutes, increasing the nickel grade of the concentrate to 6%-7%. The tailings are then roughed. Lime / sodium carbonate is added to further adjust the pH of the primary concentrate to 9.0-10.0 to reduce reagent interference, resulting in a secondary concentrate and tailings. The nickel grade of the secondary concentrate is increased to 8%-10%, and the tailings are then subjected to primary cleaning. The secondary concentrate is dewatered and conveyed. Both the magnetic concentrate and the secondary concentrate enter a high-efficiency thickener, increasing the underflow concentration to 50%-55%. Further dewatering is performed using a ceramic filter or filter press, with the filter cake moisture content ≤15%, yielding a nickel sulfide concentrate with a nickel grade ≥8%. The dewatered concentrate can then proceed to subsequent processing steps.

[0122] In some embodiments, the process further includes smelting the nickel sulfide concentrate to obtain low-grade nickel matte. For example, an electric furnace or an oxygen-enriched side-blown furnace can be used for smelting to obtain a low-grade nickel matte product with a nickel content of 20% to 30%.

[0123] In some embodiments, the nickel-containing minerals used in this application may be pretreated nickel-containing minerals. The processing method of this application may further include a raw material processing step, which includes: screening, crushing, and drying the nickel-containing minerals to obtain pretreated nickel-containing minerals. The crushed wet nickel-containing minerals are then fed into a drying kiln for drying and roasting to obtain the pretreated nickel-containing minerals.

[0124] Screening and crushing can obtain mineral particles that meet the particle size requirements for entering the drying kiln, thereby reducing blockages and material jams during the transfer process, improving transfer efficiency, and the fine particles are more conducive to subsequent drying and reduction sulfidation.

[0125] In some embodiments, the flue gas generated during the smelting of nickel sulfide concentrate is used to dry the nickel-containing minerals. When the high-temperature flue gas generated during smelting is used as a heat source, efficient heat recovery and utilization can be achieved. Simultaneously, the flue gas passing through the drying kiln can be collected and then fed into a desulfurization system, where it is absorbed and desulfurized with lime before being discharged into the atmosphere. The resulting dust can be returned to the system for batching or directly injected into the side-blown furnace during the smelting process to improve utilization. The gypsum obtained from desulfurization can be used as a sulfiding agent after pressure filtration, dehydration, and drying. The moisture content of the pretreated nickel-containing minerals is reduced from 30%-50% to 20%-22%, which can further reduce the load on the roasting rotary kiln and reduce mineral adhesion during transport.

[0126] Processing system for nickel-bearing minerals

[0127] This application provides a processing system for nickel-containing minerals, the processing system comprising:

[0128] The roasting and sulfidation unit includes a roasting component and a heat preservation component connected in sequence. The roasting component and the heat preservation component are used to pre-reduc and sulfidate nickel-containing minerals to obtain sulfided roasted sand.

[0129] The magnetic separation unit is used to perform magnetic separation treatment on the sulfided calcined sand. The feed port of the magnetic separation unit is connected to the discharge port of the insulation component.

[0130] And, a flotation unit, which is used to perform flotation treatment on magnetic separation tailings, wherein the feed inlet of the flotation unit is connected to the magnetic separation tailings outlet of the magnetic separation unit.

[0131] The nickel-containing mineral processing system provided in this application embodiment can be used to perform the above-described nickel-containing mineral processing method. By setting up a roasting component and a heat preservation component, pre-reduction, first sulfidation, and second sulfidation can be achieved in the roasting component and the heat preservation component, controlling the metallization rate and sulfidation rate of nickel in the roasted ore. Combined with the subsequently connected magnetic separation unit and flotation unit, the efficiency of magnetic separation and flotation is improved, thereby increasing the nickel yield.

[0132] In some embodiments, the calcination assembly is a rotary kiln.

[0133] As an example, the pre-reduction process can be carried out in a rotary kiln. The rotary kiln has three temperature zones: a low-temperature zone (200-400℃), a medium-temperature zone (400℃-800℃), and a high-temperature zone (800℃-1200℃). The nickel-containing minerals can pass through the rotary kiln for 2-3 hours, with a flue gas outlet temperature of 200℃-300℃ and a rotary kiln discharge temperature of 600℃-900℃. A 100mm grid is installed at the rotary kiln outlet to screen out large pieces of material and kiln lining formed during the roasting process, and transport them back for crushing. After crushing, the material is returned to the feeding process.

[0134] In this application, the heat insulation component is a component that provides a high-temperature and sealed environment for the vulcanization reaction. The reaction raw materials can undergo reduction and vulcanization reactions in the heat insulation component and then slowly cool down with the heat insulation component.

[0135] In some embodiments, the insulation component is an insulated steel ladle.

[0136] It should be noted that the connection in this application can be a direct connection or an indirect connection through other components or systems, as long as the corresponding material flow can be realized. The specific connection method is not limited here. For example, the connection between the feed inlet of the magnetic separation unit and the discharge outlet of the insulation component can be achieved through a hanging component, a rotating bracket, and a belt conveyor. The insulation component is transferred to the rotating bracket above the belt conveyor through the hanging component and rotates on the rotating bracket, pouring the sulfide calcined sand into the feed end of the belt conveyor, and then conveyed by the belt conveyor to the feed inlet of the magnetic separation unit.

[0137] In some embodiments, a vulcanizing agent inlet is provided inside the rotary kiln at a distance of 1m to 5m from the discharge port.

[0138] As an example, the specific feeding method can be selected based on the specific choice of vulcanizing agent.

[0139] In some embodiments, the nickel-containing mineral processing system further includes a sulfiding agent injection assembly, with the sulfiding agent inlet connected to the assembly. The sulfiding agent injection assembly also includes an inert gas source for supplying inert gas. Sulfur can be ground into powder and mixed with pulverized coal before being injected into the nickel-containing mineral through the sulfiding agent inlet via the sulfiding agent injection assembly. The gas used for conveying and injecting the sulfur powder is an inert gas such as nitrogen or argon to reduce oxidation losses. After contact with the nickel-containing mineral, the sulfur powder and the sulfiding agent continuously tumble and mix under the action of the rotary kiln, completing the first sulfidation at high temperature. Alternatively, sulfur can be prepared as liquid sulfur and injected into the nickel-containing mineral through the sulfiding agent inlet using the sulfiding agent injection assembly. The liquid sulfur is pumped out under pressure, and a rapid sulfidation reaction occurs upon contact with the pre-reduced calcined sand, yielding primary calcined sand. Alternatively, sulfiding agents can be directly added to the calcined sand through the sulfiding agent injection component at the sulfiding agent inlet. The sulfiding agent can be one or more of the following: industrial sulfur (S>99%), pyrite, desulfurized gypsum produced in the sulfur-containing flue gas desulfurization process. After the sulfiding agent and nickel-containing minerals come into contact, they are continuously tumbled and mixed under the action of the rotary kiln, and the sulfidation reaction is completed at high temperature to obtain primary calcined sand.

[0140] According to the embodiments of this application, the processing system of this application adopts dynamic sulfidation at the rotary kiln outlet and makes efficient use of the preheating of the rotary kiln, shortening the sulfidation time by more than 50%, while avoiding the energy consumption of the additional heating stage in the traditional process, and avoiding the loss of sulfiding agent during the heating process, saving energy consumption by 20%-30%, and increasing the nickel sulfidation rate to 5%-30%.

[0141] In some embodiments, the magnetic separation unit includes a grinding assembly, a magnetic slurry preparation assembly, and a magnetic separation assembly. The outlet of the heat preservation assembly is connected to the inlet of the grinding assembly, the outlet of the grinding assembly is connected to the inlet of the magnetic slurry preparation assembly, the outlet of the magnetic slurry preparation assembly is connected to the inlet of the magnetic separation assembly, and the tailings outlet of the magnetic separation assembly is connected to the inlet of the flotation unit. It should be noted that the grinding assembly, slurry preparation assembly, and magnetic separation assembly in this application can all be commonly used components in magnetic separation processes. For example, the grinding assembly may include a ball mill and a hydrocyclone for closed-circuit grinding, the slurry preparation assembly may include a slurry preparation tank, and the magnetic separation assembly may include a magnetic separator.

[0142] In some embodiments, the flotation unit includes a flotation slurry conditioning component, a roughing flotation component, a scavenging flotation component, a primary cleaning component, a secondary cleaning component, and an automatic reagent addition component. The magnetic tailings outlet of the magnetic separation unit is connected to the feed inlet of the flotation slurry conditioning component, the outlet of the flotation slurry conditioning component is connected to the feed inlet of the roughing flotation component, the roughing tailings outlet of the roughing flotation component is connected to the feed inlet of the scavenging flotation component, the scavenging concentrate outlet of the scavenging flotation component is connected to the feed inlet of the roughing flotation component, and the roughing concentrate outlet of the roughing flotation component is connected to... The feed inlet of the primary cleaning unit and the tailings outlet of the primary cleaning unit are connected to the feed inlet of the roughing flotation unit. The primary concentrate outlet of the primary cleaning unit is connected to the feed inlet of the secondary cleaning unit. The tailings outlet of the secondary cleaning unit is connected to the feed inlet of the primary cleaning unit. The secondary concentrate outlet of the secondary cleaning unit is connected to the downstream processing system. The automatic reagent addition unit is connected to the reagent inlets of the flotation pulp conditioning unit, roughing flotation unit, scavenging flotation unit, primary cleaning unit, and secondary cleaning unit, respectively. It is understood that the flotation pulp conditioning unit, roughing flotation unit, scavenging flotation unit, primary cleaning unit, secondary cleaning unit, and automatic reagent addition unit in this application can all be commonly used flotation components. For example, the flotation pulp conditioning unit is a pulp conditioning tank, and the roughing flotation unit, scavenging flotation unit, primary cleaning unit, and secondary cleaning unit can be flotation machines of the same or different models, specifically selected according to the actual situation of the nickel-containing minerals.

[0143] As an example, the method disclosed in this application can be combined with the system disclosed in this application to process nickel-bearing minerals. Taking laterite nickel ore as an example, for instance... Figure 5 As shown, the processing procedure can be as follows:

[0144] Large pieces of lateritic nickel ore are screened out through a 200mm screen. The screened ore is then subjected to coarse and fine crushing and returned to the feedstock. The screened wet lateritic nickel ore is dried in a drying kiln. The heat source for the drying kiln is one or more of the following: sensible heat from the flue gas of the smelting furnace, exothermic heat from the combustion of pulverized coal in the fluidized bed furnace, and exothermic heat from the combustion of pulverized coal in the burner. After drying, the moisture content of the lateritic nickel ore is reduced to 20%-25%, removing the free water. The dried ore is then screened again, and a reducing agent is added to complete the batching. The batched mixture is then fed into a rotary kiln.

[0145] The mixed materials enter a rotary kiln for pre-reduction roasting. The materials sequentially pass through a low-temperature zone, a medium-temperature zone, and a high-temperature zone to complete the roasting process. During the heating and roasting process, the bound water in the laterite nickel ore is removed, and the main pre-reduction reaction is completed in the high-temperature zone. The heat source used in the rotary kiln is one or more of the following: sensible heat from the flue gas of the smelting furnace, exothermic heat from the combustion of pulverized coal in the fluidized bed furnace, and exothermic heat from the combustion of pulverized coal in the burner. The material and flue gas flow in a counter-current direction. The roasted ore reaches a temperature of 600℃-900℃ in the high-temperature zone, completing the metal pre-reduction reaction and obtaining pre-reduced roasted ore, which meets the high-temperature conditions required for the sulfidation reaction.

[0146] Sulfidating agents are added to the pre-reduced calcined sand at high temperatures using various feeding methods. The sulfidating agents come into contact with the pre-reduced calcined sand before the kiln head outlet of the rotary kiln and continue to mix under the action of the rotary kiln movement. A sulfidation reaction occurs under high temperature conditions, and the reduced elemental metal / metal oxide is sulfided into metal sulfides. A grid is set at the discharge port of the rotary kiln to screen out large pieces of material and return them to the raw material process for crushing, and then return them to the feeding process. The primary calcined sand after discharge enters a preheated insulated steel ladle for heat preservation treatment. During the feeding process of the steel ladle, sulfidating agents and reducing agents are added to further improve the reduction rate and sulfidation rate. A strong reducing atmosphere is formed by the sealed heat preservation treatment to further promote the reduction sulfidation reaction. The material in the insulated steel ladle is cooled to 100℃-400℃ and then water-quenched, or directly cooled to room temperature to obtain sulfidized calcined sand.

[0147] Sulfide roasted sand is refined by closed-circuit grinding with ball mill and hydrocyclone group, and then magnetically separated to obtain magnetic concentrate and magnetic tailings. The magnetic field strength of the magnetic separation process is 2000T to 3000T.

[0148] pH adjuster, dispersant, collector, frother, and depressant are added to the magnetic separation tailings slurry. The slurry is then pumped into a roughing flotation machine, where air is introduced to form bubbles. Hydrophobic minerals adhere to the bubbles and float to the surface. A rotating scraper removes the foam layer containing the target minerals, yielding the roughing concentrate. The slurry not scraped off is used as roughing tailings, some of which is discharged directly or enters the next stage of flotation. The roughing concentrate is sent to a cleaning flotation machine, where reagents are added as needed to further separate gangue minerals and improve the concentrate grade. The cleaning operation is repeated 1-3 times according to the grade requirements to obtain nickel sulfide concentrate that meets the requirements. The roughing tailings enter a scavenging flotation machine, where a small amount of reagents is added to recover the remaining target minerals and reduce the tailings grade. The scavenging concentrate is returned to the roughing process. The magnetic separation concentrate and nickel sulfide flotation concentrate are further dehydrated using a thickener and filter press or drying equipment.

[0149] The nickel sulfide concentrate obtained after flotation is processed in the smelting process. Nickel and cobalt metals can be enriched by smelting in a submerged arc furnace or an oxygen-enriched side-blown furnace to obtain low-grade nickel matte. Then, the low-grade nickel matte is further oxidized and de-ironized in a converter or side-blown furnace to obtain high-grade nickel matte.

[0150] Example

[0151] The following embodiments describe the disclosure of this application in more detail. These embodiments are merely illustrative, as various modifications and variations will be apparent to those skilled in the art within the scope of the disclosure of this application. Unless otherwise stated, all components, percentages, and ratios reported in the following embodiments are based on weight, and all reagents used in the embodiments are commercially available or synthesized by conventional methods and can be used directly without further processing, and the instruments used in the embodiments are commercially available.

[0152] Example 1

[0153] The main components of the laterite nickel ore provided in this embodiment are: Ni: 1.15wt%, Co: 0.12wt%, Fe: 40.29wt%, Mg: 1.35wt%, Mn: 0.85wt%, Al: 2.78wt%, and Ca: 1.97wt%.

[0154] Raw material processing steps: After screening and crushing, the above-mentioned wet laterite nickel ore raw material with a particle size of <200mm is dried in a drying kiln. In this embodiment, a rotary kiln is selected as the drying kiln. A fluidized bed furnace is used as the drying heat source. The hot air temperature generated by the fluidized bed furnace is about 800℃, and the air direction and material flow direction are the same. The moisture content of the wet laterite nickel ore is about 38%. The drying time is 50 minutes. The outlet temperature of the dried ore is about 90℃, and the moisture content of the dried ore is 20%. The dust-laden flue gas at the outlet of the drying kiln is discharged after being collected by a bag filter. The collected dust can be used to return the raw material and mix with the wet ore to reduce the moisture content, or it can be directly injected into a side-blown furnace for use. The dried ore is stored in the batching station.

[0155] Further processing of the dried ore, including:

[0156] S100 involves mixing and batching the reducing agent (anthracite), auxiliary agents (calcium chloride, sodium sulfate, calcium fluoride), and dry ore. The mass ratio of the reducing agent to the dry ore is 1:20, the mass ratio of the auxiliary agent (calcium chloride) to the dry ore is 1:10, the mass ratio of the auxiliary agent (sodium sulfate) to the dry ore is 1:10, and the mass ratio of the auxiliary agent (calcium fluoride) to the dry ore is 1:6. The mixture after batching is fed into a rotary kiln for pre-reduction roasting. The heat source used in the rotary kiln is side-blown flue gas. The material passes through the low-temperature section (200℃-400℃), the medium-temperature section (400℃-800℃), and the high-temperature section (800℃-1200℃) in sequence for 2 hours. The roasted ore after reduction roasting reaches the highest temperature of 800℃ in the high-temperature section.

[0157] In S210, sulfur is added to the high-temperature calcined sand via a sulfurizing agent injection component at a distance of 5m from the kiln opening. The mass ratio of sulfur to calcined sand is 5:100. The sulfurizing agent and the high-temperature calcined sand come into contact and mix at high temperature, undergoing a sulfurization reaction. The sulfurization reaction continues during the remaining discharge time until the material is discharged. A 100mm grid is installed below the rotary kiln discharge port to screen out large pieces of kiln skin and lumps, which are then returned to the raw material process for crushing. The calcined sand that passes through the screen is the primary calcined sand.

[0158] S220 involves adding primary calcined sand into an insulated steel ladle below the rotary kiln. The insulated steel ladle is preheated to 900℃ to ensure the insulation effect after the primary calcined sand enters the ladle. During the process of adding the primary calcined sand into the insulated steel ladle, sulfur and anthracite are simultaneously added to the primary calcined sand in the insulated steel ladle through a feeding pipe. The mass ratio of sulfur to primary calcined sand is 5:100, and the mass ratio of anthracite to primary calcined sand is 1:100. The primary calcined sand, sulfiding agent, and reducing agent are layered and covered inside the insulated steel ladle. After the insulated steel ladle is filled, it is sealed to maintain a strong reducing atmosphere inside, allowing the reduction and sulfidation reactions to proceed fully. The material is allowed to cool naturally in the insulated steel ladle for 24 hours until the temperature drops to room temperature, resulting in sulfided calcined sand.

[0159] S300 first crushes and grinds sulfide roasted sand to -200 mesh (85%), then adjusts the slurry to a solid content of 35%, and after hydrocyclone classification, it enters a magnetic separator with a magnetic field strength of 2000T-3000T to obtain magnetic tailings and magnetic concentrate with a nickel grade of approximately 11.2%.

[0160] In S400, the magnetic separation tailings slurry enters the slurry conditioning and mixing tank. Sodium carbonate is added to adjust the slurry pH to 11.0 to inhibit pyrite activation, and 130 g / t of sodium hexametaphosphate is added to disperse the slime. In the roughing stage, butyl xanthate (180 g / t) and butylammonium black (80 g / t) are used as collectors to enhance the hydrophobicity of nickel sulfide. The collectors are added in two batches (60% to the slurry conditioning tank and 40% to the flotation tank), and MIBC frother (35 g / t) is used to form a stable froth layer. The slurry is then pumped into the roughing flotation machine, and air is introduced to form bubbles. Hydrophobic minerals adhere to the bubbles and float to the surface. A rotating scraper scrapes off the froth layer containing the target minerals. The roughing concentrate is obtained by scraping the bubbles. The roughing tailings are scavenged and 40 g / t of butyl xanthate is added to recover residual nickel minerals. The rougher concentrate undergoes a primary cleaning process, with the addition of 30 g / t butyl xanthate and 10 g / t MIBC frother, along with the introduction of 150 g / t water glass to suppress silicate gangue. This primary cleaning process yields a primary cleaned concentrate and primary cleaned tailings. Sodium carbonate is added to the primary cleaned concentrate to adjust the pH to 12, followed by a secondary cleaning process for further purification, yielding a secondary cleaned concentrate and secondary cleaned tailings. After drying the nickel in the secondary cleaned concentrate, the grade of the resulting nickel sulfide concentrate is increased to 6.1%, with a comprehensive nickel recovery rate of 90.1%.

[0161] After the concentrate is dried and dehydrated, it is fed into a side-blown furnace with auxiliary materials such as batching, flux, and granular coal for smelting to obtain a low-grade nickel matte product with Ni: 21.4wt%, Co: 0.55wt%, Fe: 45.5wt%, and S: 26.5wt%. Then, it is oxidized and smelted in a side-blown furnace to remove iron and obtain a high-grade nickel matte product with Ni: 65.3wt%, Co: 0.51wt%, Fe: 6.94wt%, and S: 17.2wt%.

[0162] Example 2

[0163] The main components of the laterite nickel ore provided in this embodiment are: Ni: 1.28wt%, Co: 0.04wt%, Fe: 18.37wt%, Mg: 10.20wt%, Si: 15.48wt%, Al: 2.63wt%, and Ca: 0.46wt%.

[0164] Raw material processing: The above-mentioned wet laterite nickel ore raw material is screened and crushed to a particle size of <200mm, and then fed into a drying kiln for drying. The drying kiln uses a fluidized bed furnace as the drying heat source. The hot air temperature generated by the fluidized bed furnace is 700℃, and the air direction is the same as the material flow direction. The moisture content of the wet laterite nickel ore is about 40%. The time to pass through the drying kiln is 50 minutes. The temperature of the dried ore after drying is 70℃, and the moisture content of the dried ore is 21%. The dust-laden flue gas at the outlet of the drying kiln is discharged after being collected by a bag filter. The collected dust is returned to the raw material and mixed with the wet ore to reduce the moisture content. The dried ore is then stored in the batching station.

[0165] Further processing of the dried ore, including:

[0166] S100 involves mixing anthracite as a reducing agent, sodium sulfate as an additive, and dry ore. The mass ratio of reducing agent to dry ore is 1:25, and the mass ratio of additive to dry ore is 1:10. The mixture is then fed into a rotary kiln for pre-reduction roasting. The heat source for the rotary kiln is side-blown flue gas. The material passes through a low-temperature section, a medium-temperature section, and a high-temperature section in sequence, with a passage time of 2 hours. The roasted ore reaches a maximum temperature of 750℃ in the high-temperature section, thus obtaining pre-reduced roasted ore.

[0167] In S210, sulfur is injected into the pre-reduced calcined ore into the rotary kiln via a sulfurizing agent injection assembly at a distance of 5m from the kiln opening. The mass ratio of sulfur to dry ore is 6:100. The sulfurizing agent and pre-reduced calcined ore come into contact and mix at high temperature, undergoing a sulfurization reaction. The sulfurization reaction continues during the remaining discharge time until the ore is discharged. A 100mm grid is installed below the rotary kiln discharge port to screen out large pieces of kiln skin and agglomerates, which are then returned to the raw material process for crushing. The calcined ore that passes through the screen is the primary calcined ore.

[0168] In S220, primary calcined sand is added to the insulated steel ladle below the rotary kiln. The preheating temperature of the insulated steel ladle is 900℃ to ensure the insulation effect after the primary calcined sand enters the insulated steel ladle. During the process of the primary calcined sand entering the insulated steel ladle, sulfur and anthracite are simultaneously added to the primary calcined sand in the insulated steel ladle through the feeding pipe. The mass ratio of sulfur to primary calcined sand is 6:100, and the mass ratio of anthracite to primary calcined sand is 1:50. The primary calcined sand, sulfiding agent, and reducing agent are layered and covered in the insulated steel ladle. After the feeding is completed, the insulated steel ladle is sealed and covered to keep the ladle warm and maintain a strong reducing atmosphere inside, so that the reduction and sulfidation reactions can be fully carried out. After 8 hours of natural cooling, the temperature of the calcined sand in the ladle drops to room temperature, resulting in sulfided calcined sand.

[0169] S300, sulfide roasted ore can have its grade improved through conventional magnetic separation-flotation process for sulfide nickel ore. The ore is first crushed and ground to -200 mesh (75%), and the slurry is adjusted to have a solid content of 35%. After hydrocyclone classification, it enters a magnetic separator with a magnetic field strength of 2000T-3000T to obtain magnetic concentrate and magnetic tailings slurry with a nickel grade of 10.3%.

[0170] In S400, the magnetic separation tailings slurry enters the mixing tank, where sodium carbonate is added to adjust the slurry pH to 10.5 to inhibit pyrite activation, and 100g / t of sodium hexametaphosphate is added to disperse the slime. In the roughing stage, pentyl xanthate (160g / t) is used as the collector to enhance the hydrophobicity of nickel sulfide. The collector is added in two batches (60% to the mixing tank and 40% to the flotation tank), and combined with No. 2 oil frother (30g / t) to form a stable foam layer. The slurry is then pumped into the roughing flotation machine, where air is introduced to form bubbles. Hydrophobic minerals adhere to the bubbles and float to the surface. A rotating scraper scrapes off the foam layer enriched with the target minerals, and the scraping process yields the roughing concentrate. The roughing tailings are scavenged and supplemented with 30g / t of pentyl xanthate to recover residual nickel minerals. The rougher concentrate undergoes a primary cleaning process, with the addition of 30 g / t of pentyl xanthate and 80 g / t of MIBC frother, along with 120 g / t of water glass to suppress silicate gangue. This primary cleaning process yields a primary cleaned concentrate and primary cleaned tailings. The primary cleaned concentrate undergoes a secondary cleaning process for further purification, yielding a secondary cleaned concentrate and secondary cleaned tailings. After drying, the nickel in the secondary cleaned concentrate is converted to nickel sulfide concentrate with a grade increased to 6.5%, and the overall nickel recovery rate reaches 87%.

[0171] Example 3

[0172] The main components of the laterite nickel ore provided in this embodiment are: Ni: 1.0 wt%, Co: 0.04 wt%, Fe: 35.12 wt%, Mg: 6.19 wt%, Si: 10.39 wt%, Al: 2.63 wt%, and Ca: 0.46 wt%.

[0173] The above-mentioned wet laterite nickel ore raw material, after screening and crushing, has a particle size of <200mm and is fed into a drying kiln for drying. The drying kiln uses a fluidized bed furnace as the drying heat source. The hot air temperature generated by the fluidized bed furnace is 600℃, and the air direction is the same as the material flow direction. The moisture content of the wet laterite nickel ore is about 41%. The time to pass through the drying kiln is 50 minutes. The temperature of the dried ore after drying is 70℃, and the moisture content of the dried ore is 22%. The dust-laden flue gas at the outlet of the drying kiln is discharged after being collected by a bag filter. The collected flue gas is transported to a side-blown furnace for direct injection and utilization. The dried ore is stored.

[0174] Further processing of the dried ore, including:

[0175] S100, the reducing agent anthracite, the auxiliary agent sodium sulfate and the above-mentioned dried ore are mixed and batched. The mass ratio of reducing agent to dry ore is 9:200 and the mass ratio of auxiliary agent to dry ore is 1:10. The mixture after batching is fed into a rotary kiln for pre-reduction roasting. The heat source used in the rotary kiln is side-blown flue gas. The material passes through the low temperature section, the medium temperature section and the high temperature section in sequence. The passage time is 2 hours. The roasted ore after reduction roasting reaches the highest temperature of 800℃ in the high temperature section, and the pre-reduced roasted ore is obtained.

[0176] In S210, sulfur is added to the pre-reduced calcined sand via a sulfurizing agent injection assembly at a distance of 5m from the kiln opening. The mass ratio of sulfur to calcined sand is 5:100. The sulfurizing agent and pre-reduced calcined sand come into contact and mix at high temperature, undergoing a sulfurization reaction. The sulfurization reaction continues during the remaining discharge time until the material is discharged. A 100mm grid is installed below the rotary kiln discharge port to screen out large pieces of kiln skin and agglomerates, which are then returned to the raw material process for crushing. The calcined sand that passes through the screen is the primary calcined sand.

[0177] S220 involves adding primary calcined sand into an insulated steel ladle below the rotary kiln. The preheating temperature of the insulated steel ladle is 900℃ to ensure the insulation effect after the calcined sand enters the ladle. During the process of adding the primary calcined sand into the insulated steel ladle, sulfur and anthracite are simultaneously added to the primary calcined sand in the insulated steel ladle through a feeding pipe. The mass ratio of sulfur to primary calcined sand is 5:100, and the mass ratio of anthracite to primary calcined sand is 3:200. The primary calcined sand, sulfiding agent, and reducing agent are layered and covered inside the insulated steel ladle. After the insulated steel ladle is filled, it is covered to keep it warm and maintain a strong reducing atmosphere inside, allowing the reduction and sulfidation reactions to proceed fully. After about 5 hours of natural cooling to a temperature of 300℃, the calcined sand is obtained by water quenching.

[0178] S300, the above-mentioned sulfide roasted sand is crushed and ground to -200 mesh (70%), the slurry is adjusted to a solid content of 35%, and after hydrocyclone classification, it enters a magnetic separator for magnetic separation with a magnetic field strength of 2000T-3000T, to obtain magnetic concentrate and magnetic tailings slurry with a nickel grade of 9.5%.

[0179] In S400, the magnetic separation tailings slurry enters the mixing tank, where sodium carbonate is added to adjust the slurry pH to 10.0 to inhibit pyrite activation, and 120 g / t of sodium hexametaphosphate is added to disperse the slime. In the roughing stage, isobutyl xanthate (150 g / t) is used as the collector to enhance the hydrophobicity of nickel sulfide. The collector is added in two batches (60% to the mixing tank and 40% to the flotation tank), and combined with No. 2 oil frother (25 g / t) to form a stable foam layer. The slurry is then pumped into the roughing flotation machine, where air is introduced to form bubbles. Hydrophobic minerals adhere to the bubbles and float to the surface. A rotating scraper scrapes off the foam layer enriched with the target minerals, and the scraping process yields the roughing concentrate. The roughing tailings are scavenged and supplemented with 20 g / t of isobutyl xanthate to recover residual nickel minerals. The roughing concentrate undergoes a primary cleaning process, with the addition of 30 g / t of isobutyl xanthate and 5 g / t of No. 2 oil frother, along with 120 g / t of water glass to suppress silicate gangue. This primary cleaning process yields a primary cleaned concentrate and primary cleaned tailings. The primary cleaned concentrate undergoes a secondary cleaning process for further purification, yielding a secondary cleaned concentrate and secondary cleaned tailings. After drying, the nickel in the secondary cleaned concentrate is converted to nickel sulfide concentrate with a grade increased to 6.3%, and the overall nickel recovery rate reaches 85%.

[0180] Example 4

[0181] The process is essentially the same as in Example 1, with the main difference being that no anthracite is added in step S220. The nickel grade of the magnetic separation concentrate is approximately 9.1%, and after drying the secondary separation concentrate, the nickel sulfide concentrate obtained has a nickel grade of 5.4%, with a comprehensive nickel recovery rate of 81.2%.

[0182] Comparative Example 1

[0183] The process is basically the same as in Example 1, except that the sulfide roasted sand is first ground to -200 mesh (85%) and then floated according to the flotation process parameters of Example 1. The flotation tailings are then magnetically separated according to the magnetic separation process of Example 1.

[0184] The final flotation yielded a nickel grade of 6.8% in the nickel sulfide concentrate and approximately 5.3% in the magnetic concentrate, resulting in an overall nickel yield of approximately 79.4%.

[0185] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for processing nickel-bearing minerals, characterized in that, The processing method includes: The pre-reduction process includes pre-reducing nickel-containing minerals in the presence of additives and reducing agents to reduce at least some of the oxidized nickel, thereby obtaining pre-reduced roasted ore; The sulfidation process includes sulfidation treatment of the pre-reduced calcined sand to convert at least a portion of the metallic nickel / oxidized nickel in the pre-reduced calcined sand into nickel sulfides, thereby obtaining sulfided calcined sand. The magnetic separation process includes magnetic separation treatment of the sulfide roasted sand to obtain magnetic concentrate and magnetic tailings; The flotation process includes flotation treatment of the magnetic separation tailings to obtain nickel-containing flotation concentrate.

2. The processing method according to claim 1, characterized in that, The pre-reduction process also meets one or more of the following conditions: (1) The mass ratio of the reducing agent to the nickel-containing mineral is 0.03:1 to 0.1:1; (2) The auxiliary agent is one or more of calcium chloride, sodium carbonate, sodium sulfate, calcium sulfate and calcium fluoride.

3. The processing method according to claim 2, characterized in that, The pre-reduction process also meets one or more of the following conditions: (1) The mass ratio of sodium carbonate to nickel-containing mineral is 0.1:1 to 0.15:1; (2) The mass ratio of the sodium sulfate to the nickel-containing mineral is 0 to 0.15:1; (3) The mass ratio of the calcium sulfate to the nickel-containing mineral is 0.05:1 to 0.2:1; (4) The mass ratio of the calcium fluoride to the nickel-containing mineral is 0.06:1 to 0.1:1; (5) The mass ratio of the calcium chloride to the nickel-containing mineral is 0 to 0.15:

1.

4. The processing method according to claim 1, characterized in that, The vulcanization process includes: A sulfiding agent is added to the pre-reduced calcined sand for the first sulfidation to obtain primary calcined sand; The primary calcined sand, vulcanizing agent, and reducing agent are mixed and then subjected to a second vulcanization, followed by cooling to obtain the vulcanized calcined sand.

5. The processing method according to claim 4, characterized in that, The vulcanization process also meets one or more of the following conditions: (1) The temperature of the first calcination is 600℃~900℃; (2) The second vulcanization is carried out in a preheating container, and the preheating temperature of the preheating container is greater than the temperature of the first calcination. (3) The primary roasting sand, vulcanizing agent and reducing agent are added and mixed alternately; (4) The nickel metallization rate in the sulfided calcined sand is 45% to 95%, and the nickel sulfidation rate is 5% to 30%.

6. The processing method according to claim 5, characterized in that, The vulcanization process also meets one or more of the following conditions: (1) In the step of adding a sulfiding agent to the pre-reduced calcined sand for the first sulfidation, the mass ratio of the sulfiding agent to the pre-reduced calcined sand is 1:10 to 1:

20. (2) In the step of mixing the primary calcined sand, the sulfiding agent and the reducing agent and then performing a second sulfidation, the mass ratio of the sulfiding agent to the primary calcined sand is 1:10 to 1:

20. (3) The preheating temperature of the preheating container is 700℃~1000℃; (4) The cooling process to obtain the sulfided calcined sand includes: cooling at 50℃ / h to 150℃ / h to 100℃ to 400℃ and then water quenching to obtain the sulfided calcined sand, or air cooling to room temperature to obtain the sulfided calcined sand.

7. The processing method according to claim 1, characterized in that, The magnetic separation process includes: The sulfide calcined ... The refined calcined sand is subjected to slurry preparation to obtain slurry-prepared calcined sand. Optionally, the solid content of the slurry-prepared calcined sand is 30% to 35%. The prepared roasted slurry is subjected to magnetic separation to obtain magnetic concentrate and magnetic tailings. Optionally, the nickel grade of the magnetic concentrate is 9% to 12%, and the magnetic field strength of the magnetic separation is 2000T to 3000T.

8. The processing method according to claim 1, characterized in that, The flotation process includes: After adding pH adjuster, dispersant, collector, frother and inhibitor to the magnetic separation tailings, roughing treatment is carried out to obtain roughing concentrate and roughing tailings; Collector is added to the roughing tailings and then scavenging is performed to obtain scavenging concentrate and scavenging tailings; Collector, frother and depressant are added to the rough concentrate for a first cleaning treatment to obtain a first-clean concentrate and a first-clean tailings. After adjusting the pH of the primary concentrate to 9-10, a secondary concentrate is obtained to produce a secondary concentrate and secondary tailings. The secondary concentrate is then dehydrated to obtain nickel sulfide concentrate with a nickel grade of ≥6%.

9. The processing method according to claim 8, characterized in that, The processing method also satisfies one or more of the following conditions: (1) The scavenged concentrate is returned to the roughing process; (2) The tailings from the first fine selection are returned to the roughing process; (3) The ratio of the amount of collector added in the coarse selection process, the amount of collector added in the scavenging process, and the amount of collector added in the primary fine selection process is (5-10):1:(1-2); (4) In the step of adding pH adjuster, dispersant, collector, frother and inhibitor to the magnetic separation tailings and then performing roughing treatment, the amount of dispersant added is 100g / t to 300g / t. (5) The dispersant is sodium hexametaphosphate and / or sodium silicate; (6) The pH adjuster is sodium carbonate; (7) In the step of adding pH adjuster, dispersant, collector, frother and inhibitor to the magnetic separation tailings and then performing roughing treatment, the amount of collector added is 150g / t to 250g / t. Optionally, the collector is added to the magnetic separation tailings in two parts. (8) In the step of adding pH adjuster, dispersant, collector, frother and inhibitor to the magnetic separation tailings and then performing roughing treatment, the amount of frother added is 20g / t to 40g / t to control the bubble size to be 0.5mm to 1.5mm. (9) The foaming agent is methyl isobutyl methanol or pine oil; (10) In the step of adding pH adjuster, dispersant, collector, frother and inhibitor to the magnetic separation tailings and then performing roughing treatment, the amount of inhibitor added is 50g / t to 150g / t. (11) The inhibitors include carboxymethyl cellulose and / or dextrin; (12) Perform a first-stage refining process on the secondary refined tailings.

10. A processing system for nickel-bearing minerals, characterized in that, The processing system can execute the processing method as described in any one of claims 1 to 9; The processing system includes: The roasting and sulfidation unit includes a roasting component and a heat preservation component connected in sequence. The roasting component and the heat preservation component are used to perform pre-reduction treatment and sulfidation treatment on the nickel-containing mineral to obtain sulfided roasted sand. A magnetic separation unit is used to perform magnetic separation treatment on the sulfide calcined sand, and the inlet of the magnetic separation unit is connected to the outlet of the heat preservation component. And a flotation unit for flotating magnetic separation tailings, wherein the feed inlet of the flotation unit is connected to the magnetic separation tailings outlet of the magnetic separation unit.

11. The processing system according to claim 10, characterized in that, The processing system also satisfies one or more of the following conditions: (1) The calcination component is a rotary kiln, and a vulcanizing agent inlet is provided in the rotary kiln at a distance of 1m to 5m from the discharge port. (2) The insulation component is an insulated steel ladle; (3) The magnetic separation unit includes a grinding component, a magnetic separation slurry preparation component and a magnetic separation component. The outlet of the heat preservation component is connected to the inlet of the grinding component. The outlet of the grinding component is connected to the inlet of the magnetic separation slurry preparation component. The outlet of the magnetic separation slurry preparation component is connected to the inlet of the magnetic separation component. The magnetic tailings outlet of the magnetic separation component is connected to the inlet of the flotation unit. (4) The flotation unit includes a flotation pulp conditioning component, a rougher flotation component, a scavenger flotation component, a primary cleaning component, a secondary cleaning component, and an automatic reagent addition component. The magnetic tailings outlet of the magnetic separation unit is connected to the feed inlet of the flotation pulp conditioning component, the discharge outlet of the flotation pulp conditioning component is connected to the feed inlet of the rougher flotation component, the rougher tailings outlet of the rougher flotation component is connected to the feed inlet of the scavenger flotation component, the scavenger concentrate outlet of the scavenger flotation component is connected to the feed inlet of the rougher flotation component, and the rougher concentrate outlet of the rougher flotation component is connected to the primary cleaning component. The feed inlet of the component is connected to the feed inlet of the rougher flotation component, the feed outlet of the primary cleaning component is connected to the feed inlet of the secondary cleaning component, the feed outlet of the secondary cleaning component is connected to the feed inlet of the primary cleaning component, the feed outlet of the secondary cleaning component is connected to the feed inlet of the primary cleaning component, and the feed outlet of the secondary cleaning component is connected to the subsequent processing system. The automatic reagent addition component is connected to the reagent feed inlets of the flotation pulp conditioning component, the rougher flotation component, the scavenger flotation component, the primary cleaning component, and the secondary cleaning component, respectively.

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