Method for recycling high-pressure acid leaching residues of laterite-nickel ore through magnetization synergistic desulfurization

Abstract

The invention provides a magnetization synergistic desulfurization resource utilization method for laterite-nickel ore high-pressure acid leaching residues, and belongs to the technical field of mineral processing. According to the method, sulfur impurities in the laterite-nickel ore high-pressure acid leaching residues are effectively removed through pre-desulfurization treatment, iron minerals are reduced into magnetite through magnetizing roasting treatment, the subsequent magnetic separation process is more efficient, and the recovery rate of iron ore concentrate is greatly increased. According to the method, sulfur impurities in the acid leaching residues can be efficiently removed, meanwhile, the iron grade in the acid leaching residues is kept and improved, iron resources are efficiently recycled, and the problems that in a traditional process, due to the fact that the sulfur content is too high, treatment is difficult, resources are wasted, and the environment is polluted are solved. According to the method, on the basis of desulfurization, iron resources in the slag are recycled to the maximum extent, efficient utilization of iron and resourceful treatment of the acid leaching slag are achieved, an efficient and environment-friendly solution is provided for recycling of the iron resources, and remarkable economic benefits and environmental benefits are achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of mineral processing, and mainly relates to a resource utilization method of magnetization synergistic desulfurization of high-pressure acid leaching residue of laterite nickel ore. Background Art

[0002] Wet high-pressure acid leaching of laterite nickel ore is one of the main processes for extracting nickel resources in the nickel industry. Due to the complex ore properties of laterite nickel ore, it is difficult to effectively extract nickel from it by traditional metallurgical processes, and the wet high-pressure acid leaching process has become the preferred option. However, in this process, a large amount of by-products - high-pressure acid leaching slag of laterite nickel ore will be produced. As the main hazardous solid waste in the nickel industry, high-pressure acid leaching slag not only occupies a large amount of land resources, but also causes serious pollution to the environment. In addition, the acid leaching slag contains a large amount of iron resources, with an iron grade of up to 35%-40%, which is a potential high-value iron-containing resource. However, most of the current acid leaching slag is stored in the tailings reservoir in the form of solid waste for a long time, and has not been effectively utilized, resulting in a large amount of iron resources. Waste.

[0003] As the world's largest steel producer, China's steel industry has a huge demand for iron ore resources. Iron ore, as the basic raw material for steel production, is of irreplaceable importance. With the gradual depletion of domestic high-quality iron ore resources, the reserves of many easy-to-mine, high-grade iron ores are approaching their limits. The existing iron ore resources have fine ore distribution and complex associated components, making the development and utilization of iron ore more difficult. For this reason, China's steel industry's dependence on imported iron ore has increased year by year. This dependence not only brings hidden dangers to resource security, but also makes the domestic steel production cost affected by international market price fluctuations.

[0004] The resource utilization of iron-containing solid waste has become one of the effective ways to solve the problem of iron resource shortage. The iron grade in the acid leaching slag of laterite nickel ore is relatively high. If it can be recovered through a reasonable process, it can not only reduce the dependence on imported iron ore, but also effectively alleviate the pressure on domestic iron ore supply. However, the sulfur content in the high-pressure acid leaching slag of laterite nickel ore is relatively high, usually exceeding 2%, which makes it difficult for traditional mineral processing and roasting processes to directly treat the waste slag. The high sulfur content will cause sulfides generated during iron ore smelting to have an adverse effect on the quality of steel products and increase energy consumption during the smelting process. Therefore, how to effectively remove sulfur from the slag during the treatment process has become a key link in the recycling of iron resources. Summary of the invention

[0005] In view of the deficiencies of the prior art, the present invention provides a method for resource utilization of magnetized synergistic desulfurization of high-pressure acid leaching residue of laterite nickel ore, aiming to effectively solve the problem of high sulfur content in acid leaching residue restricting resource utilization. The process can efficiently remove sulfur impurities in acid leaching residue, while maintaining and improving the iron grade in acid leaching residue, so that iron resources can be efficiently recovered, overcoming the problems of processing difficulties, resource waste and environmental pollution caused by excessive sulfur content in traditional processes. On the basis of desulfurization, the present invention maximizes the recovery of iron resources in slag, realizes efficient utilization of iron and resource treatment of acid leaching residue, provides an efficient and environmentally friendly solution for the recovery of iron resources, and has significant economic and environmental benefits.

[0006] The technical solution adopted by the present invention to solve the technical problem is: a method for resource utilization of magnetization synergistic desulfurization of high-pressure acid leaching residue of laterite nickel ore, comprising the following steps:

[0007] (1) Using complex laterite nickel ore high pressure acid leaching residue as raw material, pre-treating the raw material to obtain a pre-desulfurized material; by controlling the heating temperature and time, the sulfur element in the slag is removed, the sulfur interference in the subsequent process is reduced, and the efficient recovery of iron resources is ensured;

[0008] (2) subjecting the pre-desulfurized material to magnetization roasting, which is divided into two stages: the first is a heating stage, in which the temperature is gradually increased to ensure that the material is evenly heated; the second is a roasting stage, in which a reduction reaction is carried out at a specific temperature to obtain a reduced material;

[0009] (3) subjecting the reduced material to a grinding process, wherein the particle size is controlled during the grinding process so that the material reaches an optimal beneficiation particle size standard;

[0010] (4) The ground material is subjected to magnetic separation, and the difference between magnetic minerals and non-magnetic minerals in the material is used to separate high-grade iron ore concentrate.

[0011] Furthermore, the iron content in the high-pressure acid leaching residue of laterite nickel ore in the step (1) is 46.2-54.7wt%, mainly in the form of hematite, and the main impurity components and their mass percentages are SiO24.12-5.43wt%, Al2O33.01-5.08wt% and Cr2O32.83-4.24wt%; the content of harmful element S is 2.09-2.95wt%, mainly in the form of sulfate; the impurity contents of NiO, TiO2 and MgO are all less than 1wt%.

[0012] Furthermore, the embedded particle size of the main minerals in the high-pressure acid leaching residue of laterite nickel ore in the step (2) is fine, the distribution rate of microparticle-level iron oxides with a particle size less than 0.010 mm is 70-80%, the distribution rate of microparticle-level aluminum potassium iron sulfate is as high as more than 95%, and the distribution rate of microparticle-level hematite / magnetite is 70-80%; the monomer dissociation degree of iron oxides is 80-90%, and the undissociated iron oxides are mostly associated with aluminum potassium iron sulfate.

[0013] Furthermore, the pretreatment process in step (1) is: heating the ore sample for pre-desulfurization treatment, the heating pre-desulfurization treatment temperature is 850-1000° C., and the heating pre-treatment roasting time is 10-15 minutes.

[0014] Furthermore, the heating stage in step (2) is heated to 800-1000°C, the reduction temperature of the calcination is 500-560°C, the reduction time is 8-16 min, the reducing gas is H2, the concentration is 30-50%, and the total gas flow rate is 500-700 mL·min -1 .

[0015] Furthermore, in the step (3), the grinding to a fineness of -15.7 μm accounts for no more than 90%.

[0016] Furthermore, in the magnetic separation in step (4), the magnetic field strength is 1600-1800 Oe.

[0017] Furthermore, the iron concentrate in step (4) has a TFe grade of 59.2-60.8%, an iron recovery rate of 89-91%, and an S content of 0.18-0.23wt%.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] The present invention effectively removes sulfur impurities in high-pressure acid leaching residue of laterite nickel ore through pre-desulfurization treatment. Compared with the prior art, the sulfur content is significantly reduced, avoiding the influence of sulfur on the subsequent iron resource recovery process, while avoiding the equipment corrosion and environmental pollution problems caused by sulfur residue in the traditional process. The present invention reduces iron minerals to magnetite through magnetization roasting treatment, making the subsequent magnetic separation process more efficient and greatly improving the recovery rate of iron concentrate. Compared with the traditional process, the present invention can recover iron resources to the maximum extent and reduce resource waste.

[0020] The present invention integrates pre-desulfurization, magnetization roasting and magnetic separation through a reasonably designed process flow, simplifies the processing steps, reduces energy consumption, and avoids the emission problem of high-temperature roasting tail gas, meeting the requirements of green production. In addition, the present invention can be applied to different types of laterite nickel ore acid leaching residues, especially in the treatment of complex slag materials, and has strong adaptability. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The process flow chart of an embodiment of the present invention. DETAILED DESCRIPTION

[0022] In order to further illustrate the technical means and effects of the present invention to achieve the expected effects, the present invention will be described in detail below in conjunction with the accompanying drawings and preferred embodiments of the specification. Obviously, the embodiments described are only some implementation cases of the present invention. The test methods described in the following embodiments are conventional methods unless otherwise specified; the reagents and materials, unless otherwise specified, can be obtained from commercial channels, and the steps described are not limitations on the reaction sequence. After understanding the inventive essence of the present invention, the steps can be adjusted. Therefore, it should be noted that the scope of protection of the present invention is not limited to the following specific embodiments, and the embodiments obtained in the art without significant creative improvements on the basis of the present invention belong to the protection scope of the present invention.

[0023] like Figure 1 As shown, the present invention provides a method for resource utilization of laterite nickel ore high pressure acid leaching residue by magnetization synergistic desulfurization, comprising the following steps:

[0024] (1) The main raw material is the complex laterite nickel ore high-pressure acid leaching residue, which has a high sulfur content and complex mineral composition. The iron in the laterite nickel ore acid leaching residue mainly exists in the form of hematite, with an iron content of 46.2-54.7wt%. The main impurities and mass percentages in the slag are SiO2 4.12-5.43wt%, Al2O3 3.01-5.08wt% and Cr2O32.83-4.24wt%, among which the harmful element sulfur content is relatively high, reaching 2.09-2.95wt%, mainly existing in the form of sulfate. In addition, the content of impurities NiO, TiO2 and MgO is less than 1%. The mineral embedding particle size of the acid leaching residue is fine, the distribution rate of micro-particle-level iron oxide with a particle size less than 0.010mm is 70-80%, the distribution rate of aluminum potassium iron sulfate is as high as more than 95%, the distribution rate of hematite / magnetite is 70-80%, and the monomer dissociation degree of iron oxide is 80-90%;

[0025] (2) The prepared laterite nickel ore acid leaching residue is heated for pre-desulfurization treatment. The heating temperature is set to 850-1000°C and the treatment time is 10-15 minutes. At this stage, sulfides such as sulfates are decomposed and removed, thereby reducing the sulfur impurity content in the acid leaching residue and reducing the adverse effects of sulfur on iron resource recovery during subsequent treatment. This pre-desulfurization treatment step can effectively improve the efficiency of the subsequent roasting reduction process;

[0026] (3) The pre-desulfurized material is subjected to magnetization roasting treatment. The magnetization roasting is divided into two stages: the first stage is the heating stage, by gradually raising the temperature to 800-1000°C, the material is evenly heated to promote the activation of iron minerals; the second stage is the roasting reduction stage, the roasting reduction temperature is 500-560°C, the reduction time is 8-16min, hydrogen (H2) is used as the reducing gas, the gas concentration is 30-50%, and the gas flow rate is controlled at 500-700mL / min. Under this temperature condition, iron oxides are reduced to magnetite;

[0027] (4) The reduced material after magnetization roasting is ground, and the grinding fineness is controlled at -15.7μm, accounting for 90%, to ensure that the material reaches the best beneficiation particle size. Magnetic separation is then carried out, and the magnetic field strength is set to 1600-1800Oe. The magnetic difference between magnetic minerals and non-magnetic minerals in the material is used to separate high-grade iron concentrate from impurities. After this process, the iron grade of the magnetic concentrate obtained reaches 59.2-60.8%, the iron recovery rate is 89-91%, and the sulfur content is further reduced to 0.18-0.23wt%.

[0028] Among them, hematite is easy to be over-reduced at high temperature, so the reaction temperature cannot be too high in the preheating stage and the reduction stage. Therefore, the reaction temperature needs to be controlled below 550°C and the reduction time is within 10 minutes. The main reaction of iron minerals in the acid leaching slag of laterite nickel ore during fluidized roasting is shown in the following formula:

[0029] 3Fe2O3+H2(g)=2Fe3O4+H2O(g)(1)

[0030] The present invention realizes the efficient recovery of iron resources and the effective removal of sulfur impurities in the high-pressure acid leaching residue of laterite nickel ore, and the content of sulfur impurities is reduced by more than 89%. The strong reduction characteristics and sustainable development characteristics of H2 are fully utilized, and H2 is used as a reducing agent for magnetic roasting. During the roasting process, the high-pressure acid leaching residue of laterite nickel ore is fully in contact with H2 in the fluidized reaction chamber, and the hematite is reduced to magnetite, with high reduction efficiency and low energy consumption. The method integrates pre-desulfurization, magnetic roasting and magnetic separation, simplifies the traditional multi-step complex processing flow, reduces energy consumption, and avoids the problem of tail gas emissions during high-temperature roasting, which meets the requirements of today's green production and environmental protection and has high economic benefits.

[0031] The specific parameters of each step are detailed in each embodiment.

[0032] Example 1

[0033] (1) In this example, high pressure acid leaching slag of laterite nickel ore was used, the TFe content was 52.0wt%, the sulfur content was 2.50wt%, the main iron mineral in the slag was hematite, and the main impurity components and mass percentages of the slag were SiO2 5.12%, Al2O3 4.03% and Cr2O3 3.17%, mainly in the form of sulfate; impurities included SiO2, Al2O3 and Cr2O3;

[0034] (2) The acid leaching residue is placed in a high-temperature furnace, the temperature is set to 850°C, and the heating time is 15 minutes. At this time, the sulfate undergoes thermal decomposition. Through this treatment step, the sulfur content is significantly reduced, reducing the interference of sulfur on the process in the subsequent treatment process.

[0035] (3) The pre-desulfurized material is subjected to magnetization roasting treatment, which is divided into two stages: the first stage is the heating stage, by gradually raising the temperature to 960°C, and the second stage is the roasting reduction stage, the roasting temperature is set to 530°C, the reducing atmosphere is 40% H2, the total gas flow is 600mL / min, and the roasting reduction time is set to 9 minutes. In this process, hematite is gradually reduced to magnetite, which improves the magnetic properties of the material;

[0036] (4) The calcined material was ground to a particle size of -15.7 μm, accounting for 80%. Then, magnetic separation was performed at a magnetic field strength of 1600 Oe to separate high-grade iron concentrate. Through this treatment, a magnetic separation concentrate with a TFe grade of 59.5 wt%, an iron recovery rate of 90.1%, and a sulfur content reduced to 0.22 wt% was finally obtained, and the sulfur removal rate reached 90.6%.

[0037] Example 2

[0038] The method is the same as in Example 1, except that:

[0039] (1) In this example, high-pressure acid leaching residue of laterite nickel ore was used, with a TFe content of 51.0wt%, a sulfur content of 2.70wt%, and hematite as the main iron mineral. The main impurity components and mass percentages of the slag were SiO2 4.88wt%, Al2O3 3.76wt% and Cr2O3 2.96wt%.

[0040] (2) The acid leaching residue was placed in a high-temperature furnace for pretreatment at a temperature of 950°C for 14 minutes, which significantly reduced the sulfur content in the residue.

[0041] (3) The material after pre-desulfurization treatment enters the roasting furnace for magnetization roasting. The magnetization roasting is divided into two stages: the first stage is the heating stage, by gradually raising the temperature to 930°C, and the second stage is the roasting reduction stage, the roasting temperature is set to 520°C, the reducing atmosphere is 40% H2, the total gas flow is 600mL / min, and the reduction time is 8 minutes. After roasting, the iron minerals are mainly converted into magnetite, which enhances the magnetism.

[0042] (4) The calcined material is ground, and the grinding fineness is controlled to -15.7μm, accounting for 70%. After grinding, the material is magnetically separated under a magnetic field of 1700Oe to separate high-purity iron concentrate. The TFe grade of the magnetic concentrate is 60.0wt%, the iron recovery rate is 89.5%, the sulfur content is 0.21wt%, and the sulfur removal rate is 92.2%.

[0043] Example 3

[0044] The method is the same as in Example 1, except that:

[0045] (1) In this example, high pressure acid leaching slag of laterite nickel ore was used, the TFe content was 46.2wt%, the sulfur content was 2.85wt%, the main iron mineral in the slag was hematite, and the main impurity components and mass percentages of the slag were SiO2 5.41wt%, Al2O3 4.97wt% and Cr2O3 2.99wt%; the impurities included SiO2, Al2O3 and Cr2O3;

[0046] (2) The acid leaching residue is placed in a high-temperature furnace, the temperature is set to 1000°C, and the heating time is 15 minutes. At this time, the sulfate decomposes into gas, and the sulfur impurities are discharged with the air flow, which reduces the sulfur content and improves the effect of the subsequent treatment process.

[0047] (3) The pre-desulfurized material is subjected to magnetization roasting, which is divided into two stages: the first stage is the heating stage, by gradually raising the temperature to 1000°C, and the second stage is the roasting reduction stage, the roasting temperature is set to 540°C, the reducing atmosphere is 40% H2, the total gas flow is 600mL / min, and the roasting reduction time is set to 10 minutes. In this process, hematite is effectively reduced to magnetite, which enhances the magnetic properties of the material and lays the foundation for subsequent magnetic separation.

[0048] (4) The calcined material was ground and the particle size was controlled at -15.7μm, accounting for 75%. Then, magnetic separation was carried out at a magnetic field strength of 1800Oe to separate high-grade iron concentrate. Finally, a magnetic separation concentrate with a TFe grade of 60.5wt%, an iron recovery rate of 90.3%, and a sulfur content reduced to 0.19wt%, was obtained, and the sulfur removal rate reached 93.3%.

[0049] The above technical scheme explains the technical idea of ​​the present invention, which cannot be used to limit the protection scope of the present invention. Any changes and modifications made to the above technical scheme based on the technical essence of the present invention without departing from the content of the technical scheme of the present invention shall fall within the protection scope of the technical scheme of the present invention.

[0050] Example 4

[0051] The method is the same as in Example 1, except that:

[0052] (1) In this example, high pressure acid leaching slag of laterite nickel ore was used, the TFe content was 54.7wt%, the sulfur content was 2.65wt%, the main iron mineral in the slag was hematite, and the main impurity components and mass percentages of the slag were SiO2 4.51wt%, Al2O3 4.33wt% and Cr2O3 4.01wt%; the impurities included SiO2, Al2O3 and Cr2O3;

[0053] (2) The acid leaching residue is placed in a high-temperature furnace, the temperature is set to 900°C, and the heating time is 15 minutes. Sulfate decomposes at this temperature, sulfur impurities are removed, and the sulfur content is effectively reduced, providing good conditions for subsequent roasting and magnetic separation processes.

[0054] (3) The pre-desulfurized material is subjected to magnetization roasting treatment, which is divided into two stages: the first stage is the heating stage, by gradually raising the temperature to 900°C, and the second stage is the roasting reduction stage, the roasting temperature is set to 530°C, the reducing atmosphere is 40% H2, the total gas flow rate is 600mL / min, and the roasting reduction time is 9 minutes. Under the roasting conditions, hematite is gradually reduced to magnetite, which improves the magnetic properties of the material.

[0055] (4) The calcined material was ground to a particle size of -15.7 μm, accounting for 85%. Then, magnetic separation was performed at a magnetic field strength of 1600 Oe to obtain a high-grade iron concentrate. After this treatment, a magnetic separation concentrate with a TFe grade of 59.8 wt%, an iron recovery rate of 89.8%, and a sulfur content reduced to 0.23 wt% was finally obtained, and the sulfur removal rate reached 91.5%.

[0056] Example 5

[0057] The method is the same as in Example 1, except that:

[0058] (1) In this example, high pressure acid leaching slag of laterite nickel ore was used, the TFe content was 50.5wt%, the sulfur content was 2.95wt%, the main iron mineral in the slag was hematite, and the main impurity components and mass percentages of the slag were SiO2 4.37wt%, Al2O3 3.91wt% and Cr2O3 2.87wt%; the impurities included SiO2, Al2O3 and Cr2O3;

[0059] (2) The acid leaching residue is placed in a high-temperature furnace, the temperature is set to 950°C, and the heating time is 15 minutes. Sulfate decomposes at this temperature, sulfur impurities are removed, and the sulfur content is effectively reduced, providing good conditions for subsequent roasting and magnetic separation processes.

[0060] (3) The pre-desulfurized material is subjected to magnetization roasting treatment, which is divided into two stages: the first stage is the heating stage, by gradually raising the temperature to 950°C, and the second stage is the roasting reduction stage, the roasting temperature is set to 510°C, the reducing atmosphere is 40% H2, the total gas flow is 600mL / min, and the roasting reduction time is 8 minutes. During the roasting process, hematite is gradually reduced to magnetite, which significantly improves the magnetic properties of the material and lays the foundation for the subsequent magnetic separation process.

[0061] (4) The calcined material was ground and the particle size was controlled at -15.7μm, accounting for 80%. Then, magnetic separation was carried out at a magnetic field strength of 1700Oe to separate high-grade iron concentrate. Finally, a magnetic separation concentrate with a TFe grade of 60.2wt%, an iron recovery rate of 90.5%, and a sulfur content reduced to 0.18wt%, was obtained, and the sulfur removal rate reached 92.6%.

[0062] Example 6

[0063] The method is the same as in Example 1, except that:

[0064] (1) In this example, high pressure acid leaching slag of laterite nickel ore was used, the TFe content was 49.6wt%, the sulfur content was 2.80wt%, the main iron mineral in the slag was hematite, and the main impurity components and mass percentages of the slag were SiO2 5.43wt%, Al2O3 3.01wt% and Cr2O3 4.05wt%; the impurities included SiO2, Al2O3 and Cr2O3;

[0065] (2) The acid leaching residue is placed in a high-temperature furnace, the temperature is set to 950°C, and the heating time is 15 minutes. Sulfate decomposes at this temperature, sulfur impurities are removed, and the sulfur content is effectively reduced, providing good conditions for subsequent roasting and magnetic separation processes.

[0066] (3) The pre-desulfurized material is subjected to magnetization roasting treatment, which is divided into two stages: the first stage is the heating stage, by gradually raising the temperature to 920°C, and the second stage is the roasting reduction stage, the roasting temperature is set to 550°C, the reducing atmosphere is 40% H2, the total gas flow is 600mL / min, and the roasting reduction time is 10 minutes. During the roasting process, hematite is reduced to magnetite, which enhances the magnetic properties of the material.

[0067] (4) The calcined material was ground to a particle size of -15.7 μm, accounting for 90%. Then, magnetic separation was performed at a magnetic field strength of 1800 Oe, and finally a magnetic concentrate with a TFe grade of 60.8 wt%, an iron recovery rate of 91.0%, a sulfur content reduced to 0.20 wt%, and a sulfur removal rate of 93.0% was obtained.

Claims

1. A method for resource utilization of high-pressure acid leaching residue of laterite nickel ore by magnetization synergistic desulfurization, characterized in that: The following steps are involved: (1) Using complex laterite nickel ore high pressure acid leaching residue as raw material, pre-treating the raw material to obtain a pre-desulfurized material; by controlling the heating temperature and time, the sulfur element in the slag is removed, the sulfur interference in the subsequent process is reduced, and the efficient recovery of iron resources is ensured; (2) subjecting the pre-desulfurized material to magnetization roasting, which is divided into two stages: the first is a heating stage, in which the temperature is gradually increased to ensure that the material is evenly heated; The second is the roasting stage, where a reduction reaction is carried out at a specific temperature to obtain a reduced material; (3) subjecting the reduced material to a grinding process, wherein the particle size is controlled during the grinding process so that the material reaches an optimal beneficiation particle size standard; (4) The ground material is subjected to magnetic separation, and the difference between magnetic minerals and non-magnetic minerals in the material is used to separate high-grade iron ore concentrate.

2. The method for resource utilization of high-pressure acid leaching residue of laterite nickel ore by magnetization synergistic desulfurization according to claim 1 is characterized in that: The iron content in the high-pressure acid leaching residue of laterite nickel ore in the step (1) is 46.2-54.7wt%, mainly in the form of hematite, and the main impurity components and their mass percentages are SiO24.12-5.43wt%, Al2O33.01-5.08wt% and Cr2O32.83-4.24wt%; the content of harmful element S is 2.09-2.95wt%, mainly in the form of sulfate; the impurity contents of NiO, TiO2 and MgO are all less than 1wt%.

3. The method for resource utilization of high-pressure acid leaching residue of laterite nickel ore by magnetization synergistic desulfurization according to claim 1, characterized in that: The embedded particle size of the main minerals in the high-pressure acid leaching residue of laterite nickel ore in the step (2) is fine, the distribution rate of micro-particle-level iron oxides with a particle size less than 0.010 mm is 70-80%, the distribution rate of micro-particle-level aluminum potassium iron sulfate is as high as more than 95%, and the distribution rate of micro-particle-level hematite / magnetite is 70-80%; the monomer dissociation degree of iron oxides is 80-90%, and the undissociated iron oxides are mostly associated with aluminum potassium iron sulfate.

4. The method for resource utilization of high-pressure acid leaching residue of laterite nickel ore by magnetization synergistic desulfurization according to claim 1, characterized in that: The pretreatment process in step (1) is: heating the ore sample for pre-desulfurization treatment, the heating pre-desulfurization treatment temperature is 850-1000° C., and the heating pre-treatment roasting time is 10-15 minutes.

5. The method for resource utilization of high-pressure acid leaching residue of laterite nickel ore by magnetization synergistic desulfurization according to claim 1, characterized in that: The heating stage in step (2) is heated to 800-1000°C, the reduction temperature of the calcination is 500-560°C, the reduction time is 8-16 min, the reduction gas is H2, the concentration is 30-50%, and the total gas flow rate is 500-700 mL·min -1 .

6. The method for resource utilization of high-pressure acid leaching residue of laterite nickel ore by magnetization synergistic desulfurization according to claim 1, characterized in that: In the step (3), the grinding to a fineness of -15.7 μm accounts for no more than 90%.

7. The method for resource utilization of high-pressure acid leaching residue of laterite nickel ore by magnetization synergistic desulfurization according to claim 1, characterized in that: In the magnetic separation of step (4), the magnetic field strength is 1600-1800 Oe.

8. The method for resource utilization of high-pressure acid leaching residue of laterite nickel ore by magnetization synergistic desulfurization according to claim 1, characterized in that: The iron concentrate described in step (4) has a TFe grade of 59.2-60.8%, an iron recovery rate of 89-91%, and an S content of 0.18-0.23wt%.

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