Method for comprehensively utilizing sulfur-cobalt concentrate

Abstract

The invention belongs to the field of comprehensive utilization of non-ferrous metal resources, and particularly discloses a method for comprehensively utilizing cobalt-sulfur concentrate, which comprises the following steps of: aiming at the cobalt-sulfur concentrate which is a byproduct comprehensively utilized by vanadium titano-magnetite, mixing ferrous sulfate according to a specific proportion, performing microwave drying and grinding, and performing two-stage fluidized bed roasting to obtain the cobalt-sulfur concentrate. The cobalt calcine is subjected to ore dressing and cobalt concentrate enrichment through jigging reselection and low intensity magnetic separation, the cobalt concentrate is subjected to pressure leaching to efficiently separate iron and cobalt, cobalt, nickel and copper are recycled from cobalt leaching liquid in a wet extraction metallurgy mode, and cobalt leaching residues are subjected to tempering, drying and magnetic separation to prepare fine iron powder. According to the process, the resource utilization rate of iron, sulfur and cobalt is increased, comprehensive energy consumption is low, economic and environmental benefits are achieved, and a new path is provided for comprehensive utilization of vanadium titano-magnetite associated cobalt resources.

Description

Technical Field

[0001] The present application relates to the field of comprehensive utilization of nonferrous metal resources, and specifically to a method for comprehensive utilization of sulfur-cobalt concentrate. Background Art

[0002] Sulfur-cobalt concentrate is the main product of vanadium-titanium magnetite sulfur beneficiation operations, and ferrous sulfate is a by-product of titanium dioxide production. Both have high sulfur and iron grades and have good synergistic potential for comprehensive utilization.

[0003] In the past, most domestic and foreign methods used to treat sulfur-cobalt concentrates, including sulfuric acid roasting-leaching-purification-cobalt-nickel separation hydrometallurgical processes. However, these processes are complex, have long cycles, are highly polluting, and have low resource recovery rates. Currently, most sulfur-cobalt concentrates are treated using oxidation roasting as the initial treatment. For example, Yang Shaoli's team invented a method for comprehensively recovering cobalt, nickel, copper, and iron resources from sulfur-cobalt concentrates, and a method for treating sulfur-cobalt concentrates. These methods do not utilize the sulfur-cobalt concentrates and the by-product ferrous sulfate. Instead, the sulfur-cobalt concentrates are directly subjected to oxidation roasting, and the oxidized roasted materials are then mixed with reducing agents, binders, and the like, pressure-formed and reduced. Finally, alloyed iron powder and cobalt-nickel-copper pig iron are obtained through fine grinding and magnetic separation or electric furnace smelting, respectively. Li Junhan's team studied a method for converting sulfur-cobalt concentrates into metallized pellets, and the specific steps are similar to those of Professor Yang Shaoli's team. However, current research on sulfide-cobalt concentrate has not made reasonable use of ferrous sulfate heptahydrate to cooperate with sulfide-cobalt concentrate for resource recovery and utilization. The operation is relatively complicated and energy-consuming, which increases the utilization cost of sulfide-cobalt concentrate. At the same time, the products obtained are mostly alloys, the extraction efficiency of iron powder is not high, and the quality of iron powder is also low.

[0004] Therefore, there is an urgent need for a method to utilize sulphur-cobalt concentrate and ferrous sulfate for synergistic processing, introduce an off-site treatment method to enhance separation and sorting, and achieve efficient recovery of copper, sulphur and iron, as well as comprehensive resource utilization. At the same time, a comprehensive sulphur-cobalt concentrate utilization solution with advantages such as a short process, energy conservation and emission reduction is also needed. Summary of the Invention

[0005] The purpose of this application is to provide a solution for the comprehensive utilization of sulphur-cobalt concentrate with the advantages of short process, energy saving and emission reduction, and good connection with existing process equipment.

[0006] In order to achieve the above technical objectives, the following technical solutions are proposed: A method for comprehensive utilization of sulphur-cobalt concentrate comprises the following steps: S1: mixing the sulfide cobalt concentrate and ferrous sulfate heptahydrate, and then performing microwave drying to obtain a microwave-dried powder; S2: Two-stage boiling roasting and desulfurization: the microwave-dried powder is put into a boiling furnace for two-stage roasting, which includes a first stage roasting and a second stage roasting to obtain a two-stage boiling cobalt roasted sand; S3: Cobalt roasted sand beneficiation and enrichment: After the second-stage boiling furnace roasting and desulfurization are completed, the cobalt-containing roasted sand from the second-stage boiling furnace is immediately subjected to a combined beneficiation process of jigging gravity separation and weak magnetic separation to obtain enriched nickel-cobalt ore; S4: Separation of iron and cobalt from cobalt concentrate by pressure leaching: The enriched cobalt concentrate is ball-milled into a slurry and then put into a pressure leaching process to obtain cobalt leaching residue; S5: Tempering, drying and magnetic separation of cobalt leaching residue: The cobalt leaching residue is dehydrated and screened, and then a neutralizing agent is added to obtain tempered cobalt leaching residue. The tempered cobalt leaching residue is dried to obtain dried cobalt leaching residue. The dried cobalt leaching residue is separated and enriched by weak magnetic separation to obtain iron ore concentrate.

[0007] Wherein, the ferrous sulfate heptahydrate of the sulphur-cobalt concentrate in step S1 is industrial grade ferrous sulfate heptahydrate with a purity of 98%; Specifically, in step S1, the mass ratio of the cobalt sulfide concentrate to the ferrous sulfate heptahydrate is 10:1-1.5; Specifically, the microwave drying power of the microwave drying material in step S1 is 1500-4000 W, the heating temperature is 100-300° C., and the dehydration conversion time is 15-60 min; Specifically, the sulfide-cobalt concentrate is obtained by sulfur concentration and enrichment of iron ore, wherein Fe is 40% to 50%, S is 30% to 35%, and Co is 0.25% to 2.0%.

[0008] Specifically, the temperature of the first stage calcination in step S2 is controlled at 500-600°C and the calcination is continued for 1-1.5 hours; the temperature of the second stage calcination is controlled at 600-750°C and the calcination is continued for 1-1.5 hours; Specifically, in step S2, the removal rate of the second-stage boiling cobalt calcine reaches 85% to 90%, and the activation rate of cobalt and nickel reaches 70% to 85%; Specifically, the jigging conditions in step S3 are as follows: the maximum eccentric stroke is less than 40 mm, the jigging frequency is 30 to 90 times / min, and the magnetic separation condition is 0.1 to 0.8 T; Specifically, the jigging conditions in step S3 also include a bed thickness of 50 to 70 mm; Specifically, the pressure leaching process temperature in step S4 is 150-180° C., the oxygen pressure leaching time is 2.5-4.0 hours, and the oxygen partial pressure is 1.0-2.0 MPa; the enriched cobalt concentrate is ball-milled to a particle size of 200-325 mesh, and the initial pH value is controlled at 3.0-7.0.

[0009] Specifically, the reaction equation for the reaction of cobalt and iron in the sulfur-cobalt concentrate with oxygen under high temperature and high pressure in step S4 is: The above reaction can generate soluble sulfate.

[0010] The beneficial technical effects brought about by adopting this technical solution are: 1. Significantly improve the recovery rate of valuable elements such as cobalt, iron, and sulfur: Through precise raw material pretreatment, two-stage boiling furnace roasting and desulfurization, and fine-tuning of each subsequent link of pressure leaching and separation, the total recovery rate of cobalt can be increased by 25% to 35% compared with traditional processes, and the concentration of sulfur-cobalt concentrate acid flue gas can be increased by 4% to 7%.

[0011] 2. The iron ore concentrate made from the cobalt-leached slag after tempering, drying and magnetic separation has a stable iron content of 60% or above, successfully turning waste into treasure and putting it on the market as high-quality iron ore concentrate, avoiding the environmental problems caused by waste slag storage and generating additional sales revenue for the company every year.

[0012] 3. The entire process is highly clean: During the entire process, physical methods (such as microwave drying, jigging gravity separation, magnetic separation, etc.) are combined with green chemical methods (such as closed boiling roasting and closed pressure leaching) as much as possible, which reduces the use of highly corrosive and highly toxic chemical reagents and reduces the chemical and environmental risks in the production process. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is the process flow chart of this application. DETAILED DESCRIPTION

[0014] The following specific examples are used to further illustrate the content of this application.

[0015] The following is a further detailed description of the present invention in conjunction with specific preferred embodiments, and the specific implementation of this application should not be considered to be limited to these descriptions. For those skilled in the art to which this application belongs, several simple deductions or substitutions can be made without departing from the concept of this application, and all of these should be considered to fall within the scope of protection of this application.

[0016] Example 1 (1) Raw materials: The sulfur-enriched cobalt concentrate from an iron mine in Panzhihua was analyzed by ICP-AES (detection accuracy <0.05%), and the S content was 32%, the Co content was 0.7%, and the particle size distribution was more than 60% at -200 mesh. Industrial grade ferrous sulfate heptahydrate with a purity of 98% was selected, and its particle size of -100 mesh accounted for 85%.

[0017] (2) Process: ① Blending: Take 1kg of sulphur cobalt concentrate and blend it with 120g of ferrous sulfate heptahydrate. Ensure that the mixing uniformity deviation is controlled within ±3%.

[0018] ② Microwave Drying: The mixed material is fed into a microwave drying device. The microwave generator is turned on, and the microwave power is precisely set to 2500 W. Under microwave radiation, the material temperature rapidly rises from room temperature to 200°C within 30 minutes, achieving efficient dehydration. The material is cooled to room temperature within 15 minutes, resulting in a microwave-dried powder with a moisture content of 5%.

[0019] ③ Second-stage fluidized bed roasting: The microwave-dried powder is fed into a second-stage fluidized bed furnace. During the first stage, the roasting temperature is precisely controlled at 550°C, with a temperature fluctuation range of ±10°C. Oxygen-enriched air is evenly pumped into the furnace at a flow rate of 6 m³ / h. The roasting lasts for one hour, initially removing some sulfur from the material and making it looser. In the second stage, the temperature is rapidly raised to 620°C, with temperature fluctuations similarly controlled within ±10°C. The oxygen-enriched air flow rate is increased to 10 m³ / h. After 2 hours of roasting, the sulfur removal rate reaches 90.5%, the cobalt activation rate reaches 84.3%, and the roasted product has a uniform color.

[0020] ④ Cobalt roasted sand beneficiation and enrichment: The high-temperature cobalt roasted sand discharged from the boiling furnace is sent to the combined beneficiation area of ​​jig gravity separation and weak magnetic separation. In the jig gravity separation stage, a jig is used, and the jig frequency is adjusted to 40 times / minute. At the same time, the maximum eccentric stroke is strictly controlled at 20 mm. Based on the difference in mineral density, the heavier cobalt and nickel minerals are enriched at the bottom of the pulsating water flow, and the lighter gangue minerals are discharged with the water flow. After preliminary separation, the material is immediately fed into a weak magnetic separator. The magnetic field strength of the magnetic separator is precisely set to 0.1 T, which enriches the cobalt and nickel grade in the cobalt roasted sand from the initial 0.8% to 0.92%, resulting in high-quality cobalt concentrate.

[0021] ⑤ Pressure leaching of cobalt concentrate to separate iron and cobalt: The enriched cobalt-nickel concentrate is carefully placed in a high-pressure reactor with high-precision pressure control and temperature control functions. The temperature is maintained at 160°C. During oxygen pressure leaching, the oxygen partial pressure is controlled at 1.5 MPa and the duration is 3 hours. Under this condition, 99.2% of the cobalt enters the solution, the leachate appears clear and light blue, and the cobalt concentration reaches 0.52 g / L, which meets the requirements of subsequent cobalt metallurgical wet extraction; the cobalt slag is leached with a cobalt grade of 0.13% and an iron grade of 60.4%.

[0022] ⑥ Cobalt leaching slag conditioning, drying, and magnetic separation: The cobalt leaching slag after pressure leaching contains a large amount of water. It is first tempered and dried using vacuum rotary evaporation and drying equipment. This reduces the moisture content of the slag from the initial 35% to 8%, effectively preventing oxidation and agglomeration of the iron minerals. The tempered and dried slag enters a magnetic separator with a magnetic field strength of 0.8 T. The drum speed of the magnetic separator is optimized to 80 rpm. Due to the magnetic difference between iron minerals and other residual impurities, the iron minerals are efficiently enriched. Testing shows that the iron content reaches 63%, meeting the quality requirements of iron concentrate in the ironmaking industry.

[0023] Example 2 (1) Raw materials: The sulfur-enriched cobalt concentrate from an iron mine in Xichang was analyzed by ICP-AES (detection accuracy <0.05%), and the S content was 30%, the Co content was 0.5%, and the particle size distribution was more than 70% at -200 mesh. Industrial grade ferrous sulfate heptahydrate with a purity of 98% was selected, and its particle size of -50 mesh accounted for 70%.

[0024] (2) Process: ① Blending: Take 10 kg of sulphur-cobalt concentrate and mix it with 1 kg of ferrous sulfate heptahydrate per ton of sulphur-cobalt concentrate. Ensure that the mixing uniformity deviation is controlled within ±3%.

[0025] ② Microwave Drying: The mixed material is fed into a microwave drying device. The microwave generator is turned on, and the microwave power is precisely set to 2000W. Under microwave radiation, the material temperature rapidly rises from room temperature to 120°C within 30 minutes, achieving efficient dehydration. The material is cooled to room temperature within 20 minutes, resulting in a microwave-dried powder with a moisture content of 6%.

[0026] ③ Second-stage fluidized bed roasting: The microwave-dried powder is fed into a second-stage fluidized bed furnace. During the first stage, the roasting temperature is precisely controlled at 500°C, with a temperature fluctuation range of ±10°C. Oxygen-enriched air is evenly pumped into the furnace at a flow rate of 5 m³ / h. The roasting process lasts for one hour, initially removing some sulfur from the material and making it looser. In the second stage, the temperature is rapidly raised to 700°C, with temperature fluctuations similarly controlled within ±10°C. The oxygen-enriched air flow rate is increased to 10 m³ / h. After 1.5 hours of roasting, the sulfur removal rate reaches 88%, the cobalt activation rate reaches 75%, and the roasted product has a uniform color.

[0027] ④ Cobalt roasted sand beneficiation and enrichment: The high-temperature cobalt-containing roasted sand discharged from the boiling furnace is sent to the combined beneficiation area of ​​jig-gravity separation and weak magnetic separation. In the jig-gravity separation stage, a jig is used, with the jig frequency adjusted to 60 times / minute and the maximum eccentric stroke strictly controlled at 30 mm. Based on the difference in mineral density, the heavier cobalt and nickel minerals are enriched at the bottom of the pulsating water flow, while the lighter gangue minerals are discharged with the water flow. After preliminary separation, the material is immediately fed into a weak magnetic separator with a magnetic field strength precisely set to 0.2 T, which enriches the cobalt and nickel grade in the cobalt roasted sand from the initial 0.68% to 0.81%, resulting in a high-quality cobalt concentrate.

[0028] ⑤ Pressure leaching of cobalt concentrate to separate iron and cobalt: The enriched cobalt-nickel concentrate is carefully placed in a high-pressure reactor with high-precision pressure control and temperature control functions. The temperature is maintained at 170°C. During oxygen pressure leaching, the oxygen partial pressure is controlled at 1.4 MPa and the duration is 2.5 hours. Under this condition, 99.1% of the cobalt enters the solution, the leachate appears clear and light blue, and the cobalt concentration reaches 0.28g / L, which meets the requirements of subsequent cobalt metallurgical wet extraction; the cobalt slag is leached with a cobalt grade of 0.17% and an iron grade of 60.8%.

[0029] ⑥ Cobalt leaching slag conditioning, drying, and magnetic separation: The cobalt leaching slag after pressure leaching contains a large amount of water. It is first tempered and dried using vacuum rotary evaporation and drying equipment. This reduces the moisture content of the cobalt leaching slag from an initial 20.5% to 9.3%, effectively preventing oxidation and agglomeration of the iron minerals. The tempered and dried cobalt leaching slag enters a magnetic separator with a magnetic field strength of 0.3 T. The drum speed of the magnetic separator is optimized to 40 rpm. Due to the magnetic difference between iron minerals and other residual impurities, the iron minerals are efficiently enriched. Testing shows that the iron content reaches 62.1%, meeting the iron concentrate quality requirements of the iron ore industry.

[0030] Example 3 (1) Raw materials: The sulfur-enriched cobalt concentrate from an iron mine in Chengde was obtained. After analysis by ICP-AES (detection accuracy < 0.05%), the S content was measured to be 30.5%, the Co content was 1.2%, and the particle size distribution was more than 75% of -200 mesh. Industrial grade ferrous sulfate heptahydrate with a purity of 98% was selected, and its particle size of -200 mesh accounted for 70%.

[0031] (2) Process: ① Blending: Take 1 kg of sulfide-cobalt concentrate and mix it with 100 g of ferrous sulfate heptahydrate per ton of sulfide-cobalt concentrate. Ensure that the mixing uniformity deviation is controlled within ±5%.

[0032] ② Microwave Drying: The mixed material is fed into a microwave drying device. The microwave generator is turned on, and the microwave power is precisely set to 3700 W. Under microwave radiation, the material temperature rapidly rises from room temperature to 150°C within 12 minutes, achieving efficient dehydration. The material is cooled to room temperature within 20 minutes, resulting in a microwave-dried powder with a moisture content of 7%.

[0033] ③ Second-stage fluidized bed roasting: The microwave-dried powder is fed into a second-stage fluidized bed furnace. During the first stage of roasting, the roasting temperature is precisely controlled at 500°C, with a temperature fluctuation range of ±10°C. Oxygen-enriched air is evenly introduced into the furnace at a flow rate of 3 m³ / h. Roasting lasts for one hour, initially removing some sulfur from the material and making it looser. In the second stage, the temperature is rapidly raised to 620°C, with temperature fluctuations similarly controlled within ±10°C. The oxygen-enriched air flow rate is increased to 3 m³ / h. After roasting for 2.0 hours, the sulfur removal rate reaches 92%, the cobalt activation rate reaches 79%, and the roasted product has a uniform color.

[0034] ④ Cobalt roasted sand beneficiation and enrichment: The cobalt roasted sand discharged from the boiling furnace is sent to the combined beneficiation area of ​​jig gravity separation and weak magnetic separation. In the jig gravity separation stage, a jig is used, with the jig frequency adjusted to 55 times / minute and the maximum eccentric stroke strictly controlled at 40 mm. Based on the difference in mineral density, the heavier cobalt and nickel minerals are enriched at the bottom of the pulsating water flow, while the lighter gangue minerals are discharged with the water flow. After preliminary separation, the material is immediately fed into a weak magnetic separator with a magnetic field strength precisely set to 0.15 T, which enriches the cobalt grade in the cobalt roasted sand from the initial 1.17% to 1.47%, resulting in a high-quality cobalt concentrate.

[0035] ⑤ Pressure leaching of cobalt concentrate to separate iron and cobalt: The enriched cobalt-nickel concentrate is carefully placed in a high-pressure reactor with high-precision pressure control and temperature control functions. The temperature is maintained at 170°C. During oxygen pressure leaching, the oxygen partial pressure is controlled at 1.6 MPa and the duration is 3.5 hours. Under this condition, 99.5% of the cobalt enters the solution, the leachate appears clear and light blue, and the cobalt concentration reaches 0.52g / L, which meets the requirements of subsequent cobalt metallurgical wet extraction; the cobalt slag is leached with a cobalt grade of 0.15% and an iron grade of 60.8%.

[0036] ⑥ Cobalt leaching slag conditioning, drying, and magnetic separation: The cobalt leaching slag after pressure leaching contains a large amount of water. It is first tempered and dried using vacuum rotary evaporation and drying equipment. This reduces the moisture content of the slag from an initial 23% to 7%, effectively preventing oxidation and agglomeration of the iron minerals. The conditioned and dried slag then enters a magnetic separator with a magnetic field strength of 0.3 T. The drum speed of the separator is optimized to 60 rpm. Due to the magnetic difference between iron minerals and other residual impurities, the iron minerals are efficiently enriched. Testing shows an iron content of 62.4%, meeting the iron concentrate quality requirements of the iron ore industry.

[0037] Through the above multiple examples, it is fully verified that sulfur-cobalt concentrates of different regions and qualities can achieve efficient conversion of sulfur, cobalt and iron elements according to this process, and produce high-grade sulfur, cobalt and iron-related mineral products, achieving balance and optimization in resource utilization, environmental protection, economic benefits and other aspects.

[0038] Comparative Example 1 The raw materials are the same as those in Example 2. In terms of process, except that step ① “blending” is not performed, the remaining steps are the same as those in Example 2.

[0039] The results showed that after the third step of the second stage of boiling roasting, the sulfur removal rate reached 85.17% and the cobalt activation rate was 83.15%; after the fourth step of cobalt roasting sand beneficiation and enrichment, the cobalt grade in the cobalt roasting sand was enriched from the initial 0.72% to 0.87%; during the fifth step of pressure leaching of cobalt concentrate to separate iron and cobalt, 96.3% of the cobalt entered the solution, the leachate appeared cobalt blue, and the cobalt concentration reached 0.30 g / L; the cobalt grade of the leached cobalt slag was 0.05% and the iron grade was 54.6%; in the sixth step of the leached cobalt slag, the iron content reached 57.3% after tempering, drying and magnetic separation, which is slightly lower than the quality requirement of iron concentrate in the ironmaking industry.

[0040] By comparing Example 2 with Comparative Example 1, it is found that without the treatment of adding ferrous sulfate heptahydrate, the cobalt grade and iron grade in the cobalt leaching slag are much lower than those in Example 2 of the present application, and the iron content of the refined iron powder is also lower, indicating that the present application can improve the cobalt grade and the iron content in the iron concentrate by adding ferrous sulfate heptahydrate before treating the sulfide cobalt concentrate. The present application not only achieves the comprehensive utilization of ferrous sulfate and sulfide cobalt concentrate, but also effectively improves the cobalt grade and the quality of the iron concentrate.

[0041] Comparative Example 2 The raw materials are the same as those in Example 2. The process is the same as that in Example 2 except that step ③ "two-stage fluidized bed roasting" is not performed and "oxidative roasting" is performed instead. The remaining steps are the same as those in Example 2.

[0042] The results showed that after the third step of oxidative roasting, the sulfur removal rate reached 72.15% and the cobalt activation rate was 65.02%; after the fourth step of cobalt roasting beneficiation and enrichment, the cobalt grade in the cobalt roasting was enriched from the initial 0.57% to 0.72%; during the fifth step of pressure leaching of cobalt concentrate to separate iron and cobalt, 97.5% of the cobalt entered the solution, the leachate appeared cobalt blue, and the cobalt concentration reached 0.26 g / L; the cobalt grade of the leached cobalt slag was 0.13% and the iron grade was 56.2%; and the iron content of the leached cobalt slag reached 60.7% after tempering, drying and magnetic separation in the sixth step, which met the quality requirements of iron concentrate in the ironmaking industry.

[0043] By analyzing Example 2 and Comparative Example 2, it was found that by replacing "two-stage fluidized bed roasting" with "oxidative roasting", the cobalt grade and iron grade in the cobalt leaching slag of Comparative Example 2 were lower than those in Example 2, and the iron content in the iron concentrate was also lower than that in Example 2 of the present application, indicating that the present application can save energy while also promoting the improvement of cobalt grade and yield and the improvement of iron concentrate quality.

[0044] The above description is merely a preferred embodiment of the present application. It should be understood that the present application is not limited to the form disclosed herein and should not be construed as excluding other embodiments. Instead, the present application can be used in various other combinations, modifications, and environments and can be modified within the scope of the concept described herein through the above teachings or techniques or knowledge in related fields. Modifications and variations made by those skilled in the art that do not depart from the spirit and scope of the present application should be protected by the claims appended hereto.

Claims

1. A method for comprehensive utilization of sulphur-cobalt concentrate, characterized in that: The following steps are involved: S1: mixing the sulfide cobalt concentrate and ferrous sulfate heptahydrate, and then performing microwave drying to obtain a microwave-dried powder; S2: Second stage boiling roasting desulfurization: the microwave dried powder is put into the boiling furnace for second stage roasting, wherein The process comprises the following steps: first stage roasting and second stage roasting to obtain two-stage boiling cobalt roasted sand; S3: Cobalt roasted sand beneficiation and enrichment: After the second-stage boiling furnace roasting and desulfurization are completed, the second-stage boiling cobalt roasted sand is immediately subjected to a combined beneficiation of jigging gravity separation and weak magnetic separation to obtain enriched cobalt concentrate; S4: Separation of iron and cobalt from cobalt concentrate by pressure leaching: The enriched cobalt concentrate is ball-milled into a slurry and then put into a pressure leaching process to obtain cobalt leaching residue; S5: Tempering, drying and magnetic separation of cobalt leaching residue: The cobalt leaching residue is dehydrated and screened, and then a neutralizing agent is added to obtain tempered cobalt leaching residue. The tempered cobalt leaching residue is dried to obtain dried cobalt leaching residue. The dried cobalt leaching residue is separated and enriched by weak magnetic separation to obtain iron ore concentrate.

2. The method according to claim 1, wherein: The mass ratio of the cobalt sulfide concentrate to the ferrous sulfate heptahydrate in step S1 is 10:1-1.

5.

3. The method according to claim 1, wherein: The sulfide-cobalt concentrate in step S1 is a sulfide-cobalt concentrate obtained by sulfur concentration of iron ore, wherein Fe is 40% to 50%, S is 30% to 35%, and Co is 0.25% to 2.0%.

4. The method according to claim 1, wherein: The microwave drying in step S1 has a microwave power of 1500-4000 W, a heating temperature of 100-300° C., and a time of 15-60 min.

5. The method according to claim 1, wherein: In step S2, the temperature of the first stage calcination is controlled at 500-600°C, and the calcination is continued for 1-1.5 h; the temperature of the second stage calcination is controlled at 600-750°C, and the calcination is continued for 1-1.5 h.

6. The method according to claim 1, wherein: The conditions for the jig reselection in step S3 are as follows: the maximum eccentric stroke is less than 40 mm, the jig frequency is 30 to 90 times / min, the magnetic separation condition is 0.1 to 0.8 T, and the bed thickness is 50 to 70 mm.

7. The method according to claim 1, wherein: The pressure leaching process temperature in step S4 is 150-180°C, the oxygen pressure leaching time is 2.5-4.0 h, and the oxygen partial pressure is 1.0-2.0 MPa.

8. The method according to claim 1, wherein: The enriched cobalt concentrate in step S4 is ball-milled to a slurry grinding particle size of 200-325 mesh, and the initial pH value is controlled at 3.0-7.

0.

9. The method according to claim 1, wherein: The dehydration in step S5 is to reduce the water content of the cobalt leaching residue to 7.0% to 9.3%; the magnetic field strength of the weak magnetic separation in step S5 is 0.3 to 0.8 T.

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