Magnetism and hematite mixed iron ore beneficiation method for improving metal recovery rate and reducing impurities
Through classification and multi-stage magnetic separation process, combined with magnetic separators and washing equipment with different magnetic field strengths, the problems of low metal recovery rate and high impurity content in magnetic and hematite mixed iron ore were solved, and high-grade, high-yield and low-cost production of iron ore concentrate was achieved.
Patent Information
- Application Number
- CN202511074128.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-01
- Publication Date
- 2025-09-19
AI Technical Summary
Existing technologies are difficult to effectively improve the metal recovery rate and reduce the impurity content of mixed magnetic and hematite ores, resulting in low iron concentrate yield, low metal recovery rate and high cost.
The process of classification, weak magnetic separation, strong magnetic separation, shaking table gravity separation and washing is adopted, and weak magnetic separators and strong magnetic separators with different magnetic field strengths are combined to process magnetic and hematite mixed iron ore in sections to improve the grinding fineness. The gangue and poor intergrowth are processed by washing machines and tailings salvage machines to ensure the iron ore recovery rate.
The grade and yield of iron ore concentrate are improved, the silicon content is reduced, the resource utilization rate is expanded, and the production cost is reduced.
Smart Images
Figure CN120662439A_ABST
Abstract
Description
Technical Field
[0001] The invention provides a method for beneficiating mixed magnetic and hematite ores with the purpose of improving metal recovery and reducing impurities, belonging to the technical field of beneficiation. Background Art
[0002] With the continuous depletion of high-quality domestic iron ore resources, more and more mining companies are facing the technical challenge of beneficiating low-grade, high-impurity, and difficult-to-be-beneficiated iron ores. The difficulty in beneficiating mixed magnetite and hematite ores is particularly prominent. In some acidic ores containing mixed magnetite and hematite, the dissemination of magnetite and hematite varies. There are crystals of multiple minerals connected together, some fine-grained hematite crystals embedded in the gangue as a dense body, quartz grains cemented by iron, and fine-grained iron inclusions in feldspar and other gangue mineral crystals. These mineral characteristics lead to the difficulty of beneficiating mixed magnetite and hematite ores, making it even more difficult to obtain a low-silicon, high-iron concentrate with a high recovery rate. The applicant, Yuxi Dahongshan Mining Company's affiliated ore dressing plant, uses a combined separation process of semi-autogenous grinding - two-stage ball milling - weak magnetic separation - strong magnetic separation - shaking table to beneficiate mixed magnetic and hematite ores. The grinding fineness is: the minerals with a fineness of -325 mesh account for about 65%, the total concentrate iron grade is 64%, the SiO2 content is 6.8%, and the yield is only about 36%. Moreover, when a large amount of hematite is used as secondary concentrate, it cannot be incorporated into the final iron concentrate and sent to the blast furnace for smelting due to its excessively high silicon content, resulting in problems such as low iron concentrate yield, low metal recovery rate, and high cost.
[0003] Therefore, a mineral processing technology is developed to treat magnetic and hematite mixed minerals, which can effectively improve the metal recovery rate of magnetic and hematite mixed iron concentrate and reduce the silicon content of iron concentrate, so as to improve the economic benefits of the enterprise and the resource recovery rate. Summary of the Invention
[0004] In order to solve the problems of low iron concentrate yield, low metal recovery rate, high cost and high silicon content in the existing magnetic and hematite mixed ore, the present invention provides a magnetic and hematite mixed iron ore beneficiation method which improves metal recovery rate and reduces impurities.
[0005] The present invention is accomplished by the following technical solutions: a method for beneficiating mixed magnetic and hematite ores with improved metal recovery and reduced impurities, comprising the following steps: (1) Mixed ore classification: the coarsely crushed magnetic and hematite mixed ore is sent to the first cyclone for classification, and the classification produces coarse-grained ore and fine-grained ore. The coarse-grained ore is sent to the ball mill for grinding and then returned to the first cyclone for further classification; (2) The fine-particle ore is subjected to a first-stage weak magnetic separation, and the fine-particle ore of step (1) is sent to a first-stage weak magnetic separator for a first-stage weak magnetic separation to obtain a first-stage weak magnetic separation iron ore and a first-stage weak magnetic separation tailings; (3) The first-stage weak magnetic separation iron ore is classified and subjected to second-stage weak magnetic separation. The first-stage weak magnetic separation iron ore of step (2) is sent to the second cyclone for classification to obtain coarse-grained first-stage weak magnetic separation iron ore and fine-grained first-stage weak magnetic separation iron ore. The coarse-grained first-stage weak magnetic separation iron ore is sent to the mill for grinding and then returned to the second cyclone for further classification; the fine-grained first-stage weak magnetic separation iron ore is sent to the second-stage weak magnetic separator for second-stage weak magnetic separation to obtain second-stage weak magnetic separation iron ore and second-stage weak magnetic separation tailings; (4) Screening and strong magnetic separation of the first-stage weak magnetic separation tailings. The first-stage weak magnetic separation tailings of step (2) are sent to a cylindrical screen for screening. The material on the screen is sent to the second cyclone for classification. The material under the screen is sent to a first-stage strong magnetic separator for a first-stage strong magnetic separation to obtain a first-stage strong magnetic separation iron ore and a first-stage strong magnetic separation tailings. The first-stage strong magnetic separation tailings are sent to the tailings field. (5) The second stage weak magnetic separation iron ore is upgraded and washed. The second stage weak magnetic separation iron ore of step (3) is sent to the washing machine for upgrading and washing to obtain concentrate and washed tailings. The concentrate is sent to the concentrate bin. The washed tailings are sent to the tailings salvage machine for processing to obtain salvaged concentrate and salvaged tailings. The salvaged concentrate is returned to the second cyclone for further classification. The salvaged tailings and the second stage weak magnetic separation tailings of step (3) are sent to the concentration tank for concentration to obtain concentrated minerals and the first water. (6) The first stage of strong magnetic separation iron ore is subjected to shaking table gravity separation, and the first stage of strong magnetic separation iron ore in step (4) is sent to the shaking table for gravity separation to obtain valuable ore and shaking table tailings, and the valuable ore is sent to the inclined plate concentrator for concentration to obtain concentrated ore and second water, and the concentrated concentrate is sent to the concentrate bin, and the second water is mixed with the first water in step (5) as circulating water; (7) The concentrated minerals are subjected to high-intensity magnetic separation. The concentrated minerals from step (5) are sent to a three-stage high-intensity magnetic separator for high-intensity magnetic separation to obtain secondary concentrates and tailings, which are sent to the secondary concentrate bin and tailings field respectively; (8) The shaking table tailings are subjected to a second-stage strong magnetic separation. The shaking table tailings of step (6) are sent to a second-stage strong magnetic separator for strong magnetic separation to obtain second-stage strong magnetic separation iron ore and second-stage strong magnetic separation iron tailings. The second-stage strong magnetic separation iron ore is sent to the secondary concentrate bin, and the second-stage strong magnetic separation tailings are sent to the tailings field.
[0006] Furthermore, the fineness of the fine particle ore in step (2) is: -200 mesh ore particles ≥ 77%, and is prepared into a slurry with a concentration of ≤ 45%.
[0007] Furthermore, the mill in step (3) is set as a ball mill or a vertical mill, and the slurry fineness is ≥92% for -200 mesh ore particles and ≥74% for -325 mesh ore particles.
[0008] Furthermore, the magnetic field strength of the weak magnetic separator in step (2) is 180-220 mT; Furthermore, the magnetic field strength of the second-stage weak magnetic separator in step (3) is 180 mT; The magnetic field intensity decreases successively through the first and second stage weak magnetic separation, which is beneficial to improving the concentrate grade.
[0009] Furthermore, the magnetic field strength of the high-intensity magnetic separator in step (4) is 1.0 to 1.2 T; Furthermore, the magnetic field strength of the second-stage high-intensity magnetic separator in step (8) is 0.8 to 1.3 T; Furthermore, the magnetic field strength of the three-stage high-intensity magnetic separator in step (7) is 0.8 to 1.3 T; The concentrate recovery rate can be increased as much as possible through the first and second stage strong magnetic separation; while the third stage strong magnetic separation ensures the grade of the third stage strong magnetic concentrate, it is beneficial to use the shaking table to process the first stage strong magnetic separation iron ore, further reduce the loss of iron minerals, and ensure the iron ore recovery rate.
[0010] Furthermore, the magnetic field strength of the tailings salvage machine in step (5) is 280 mT to ensure the tailings recovery effect.
[0011] The present invention has the following advantages and effects: The above-mentioned scheme changes the process from separate grinding and separation to combined grinding and separation. By utilizing the characteristics of magnetite and hematite mixed ore, such as different interpenetrating particle sizes of different mineral components, interlinked crystals, and the dissemination of some fine grains in the hematite into the gangue, the iron ore recovery rate is maximized. The first-stage high-intensity magnetic separation concentrate is recovered in advance through a shaking table gravity separation, and then concentrated and incorporated into the concentrate. The problems of low dissociation degree of weak magnetic separation feed monomers, insufficient combined grinding capacity, and over-grinding of gravity separation feed are simultaneously solved. The fineness of the three-stage grinding is increased to over 92% of -200 mesh ore particles and over 74% of -325 mesh ore particles, thereby improving the concentrate grade, reducing the silicon content, expanding resource utilization, and reducing costs. By replacing the three-stage low-intensity magnetic separator with an elutriator and a tailings salvage machine, gangue and poor interpenetrating materials are removed, increasing the concentrate iron grade by over 2.5 percentage points and reducing the concentrate SiO2 content by 1.8 percentage points. BRIEF DESCRIPTION OF THE DRAWINGS
[0012] Figure 1 It is a process flow chart of the present invention. DETAILED DESCRIPTION
[0013] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.
[0014] All the equipment in the present invention are conventional mineral processing equipment.
[0015] The parameters of the elutriator used in the embodiment are as follows: the background magnetic field strength of the constant magnetic field is 20-30 mT, the background magnetic field strength of the circulating magnetic field is 20-30 mT, and the rising water flow rate is 0.017-0.019 m / s.
[0016] The parameters of the shaking table used in the embodiment are: 300-360 r / m of stroke and 11-16 mm of stroke. Example 1
[0017] The present invention provides a method for beneficiating mixed magnetic and hematite ores with improved metal recovery and reduced impurities, comprising the following steps: (1) The mixed ore of magnetic and hematite is sent to a two-stage cone crusher, a high-pressure roller mill and a sieve closed-circuit mill to be crushed to 3 mm, and a coarse-ground product of the mixed ore of magnetic and hematite is obtained with a total iron grade of 35.5%, a SiO2 content of 29.9% and a magnetic iron occupancy rate of 50.02%. The coarse-ground product of the mixed ore of magnetic and hematite is then sent to a first cyclone for classification to obtain coarse-grained ore and fine-grained ore. The coarse-grained ore is sent to a ball mill to be ground to a mineral particle size of -200 mesh accounting for 77%, and then returned to the first cyclone for further classification; (2) feeding the fine particle ore of step (1) into a semi-countercurrent drum-type one-stage weak magnetic separator with a magnetic field strength of 180 mT for one-stage weak magnetic separation to obtain one-stage weak magnetic separation iron ore with a grade of 60.2% and one-stage weak magnetic separation tailings; (3) The first stage weak magnetic separation iron ore of step (2) is sent to the second cyclone for classification, and the classification obtains coarse-grained first stage weak magnetic separation iron ore and fine-grained first stage weak magnetic separation iron ore. The coarse-grained first stage weak magnetic separation iron ore is ground by a mill to a mineral particle size of -200 mesh accounting for 92% and a mineral particle size of -325 mesh accounting for 74%, and then returned to the second cyclone for further classification; the fine-grained first stage weak magnetic separation iron ore is sent to a second stage weak magnetic separator with a magnetic field strength of 180mT for second stage weak magnetic separation to obtain second stage weak magnetic separation iron ore and second stage weak magnetic separation tailings; (4) The first stage weak magnetic separation tailings in step (2) are sent to a cylindrical screen for screening, the screened material is returned to the second cyclone for classification, and the screened material is sent to a vertical ring pulsating high gradient first stage strong magnetic separator with a magnetic field strength of 1.0T for first stage strong magnetic separation to obtain a first stage strong magnetic separation iron ore with an iron grade of 35% and a concentration of 14% and a first stage strong magnetic separation tailings, and the first stage strong magnetic separation tailings are sent to the tailings yard; (5) The iron ore from the second stage weak magnetic separation of step (3) is sent to a washing machine with a constant magnetic field background magnetic field strength of 20 mt, a circulating magnetic field background magnetic field strength of 20 mt, and an ascending water flow rate of 0.017 m / s for upgrading and washing, and a concentrate with an iron grade of 67.5% and a SiO2 content of 4.52% and washing tailings are obtained. The concentrate is sent to a concentrate bin, and the washing tailings are sent to a tailings salvage machine with a magnetic field strength of 280 mT for treatment to obtain a salvaged concentrate with an iron grade of 15% and salvaged tailings. The salvaged concentrate is returned to the second cyclone for further classification, and the salvaged tailings are sent to a concentration tank together with the tailings from the second stage weak magnetic separation of step (3) for concentration to obtain concentrated minerals and the first water; (6) The iron ore from the first stage of intense magnetic separation in step (4) is fed into a shaking table with a stroke of 300 r / min and a stroke of 11 mm for gravity separation to obtain valuable ore with an iron grade of 57.5% and a SiO2 content of 7.2% and shaking table tailings. The valuable ore is fed into an inclined plate concentrator for concentration to obtain concentrated concentrate and a second water. The concentrated concentrate is fed into a concentrate bin, and the second water is mixed with the first water from step (5) as circulating water; (7) The concentrated ore from step (5) is sent to a three-stage high-intensity magnetic separator with a magnetic field strength of 0.8 T for high-intensity magnetic separation to obtain secondary concentrate and tailings, which are sent to the secondary concentrate bin and tailings field respectively; (8) The shaking table tailings of step (6) are sent to a vertical ring pulsating high gradient two-stage strong magnetic separator with a magnetic field strength of 0.8T for strong magnetic separation to obtain two-stage strong magnetic separation iron ore with an iron grade of 30% and two-stage strong magnetic separation iron tailings. The two-stage strong magnetic separation iron ore is sent to the secondary concentrate bin, and the two-stage strong magnetic separation tailings are sent to the tailings yard.
[0018] In this Example 1, a total concentrate with an iron grade of 65.8% and a SiO2 content of 4.9% was finally obtained, with a yield of 40%. At the same time, a secondary concentrate with an iron grade of 31% and a SiO2 content of 28.2% was also obtained, with a yield of 13%, which effectively improved the iron concentrate yield and iron grade, while reducing the SiO2 content of the iron concentrate. Example 2
[0019] The present invention provides a method for beneficiating mixed magnetic and hematite ores with improved metal recovery and reduced impurities, comprising the following steps: (1) The mixed ore of magnetic and hematite is sent to a two-stage cone crusher, a high-pressure roller mill and a sieve closed-circuit mill to be crushed to 3 mm, and a coarse-ground product of the mixed ore of magnetic and hematite is obtained with a total iron grade of 35.9%, a SiO2 content of 29.6% and a magnetic iron occupancy rate of 50.18%. The coarse-ground product of the mixed ore of magnetic and hematite is then sent to a first cyclone for classification to obtain coarse-grained ore and fine-grained ore. The coarse-grained ore is sent to a ball mill to be ground to a mineral particle size of -200 mesh accounting for 80%, and then returned to the first cyclone for further classification; (2) feeding the fine particle ore of step (1) into a semi-countercurrent drum-type one-stage weak magnetic separator with a magnetic field strength of 220 mT for one-stage weak magnetic separation to obtain one-stage weak magnetic separation iron ore with a grade of 60.66% and one-stage weak magnetic separation tailings; (3) The first stage weak magnetic separation iron ore of step (2) is fed into the second cyclone for classification, and the classification obtains coarse-grained first stage weak magnetic separation iron ore and fine-grained first stage weak magnetic separation iron ore. The coarse-grained first stage weak magnetic separation iron ore is ground by a mill to a mineral particle size of -200 mesh accounting for 93% and a mineral particle size of -325 mesh accounting for 76%, and then returned to the second cyclone for further classification; the fine-grained first stage weak magnetic separation iron ore is fed into a second stage weak magnetic separator with a magnetic field strength of 200 mT for second stage weak magnetic separation, and obtains second stage weak magnetic separation iron ore and second stage weak magnetic separation tailings; (4) The first stage weak magnetic separation tailings in step (2) are sent to a cylindrical screen for screening, the screened material is returned to the second cyclone for classification, and the screened material is sent to a vertical ring pulsating high gradient first stage strong magnetic separator with a magnetic field strength of 1.18T for first stage strong magnetic separation, to obtain a first stage strong magnetic separation iron ore with an iron grade of 36% and a concentration of 17% and a first stage strong magnetic separation tailings, and the first stage strong magnetic separation tailings are sent to the tailings yard; (5) The iron ore from the second stage weak magnetic separation of step (3) is sent to a washing machine with a constant magnetic field background magnetic field strength of 30 mt, a circulating magnetic field background magnetic field strength of 30 mt, and an ascending water flow rate of 0.019 m / s for upgrading and washing, and a concentrate with an iron grade of 67.3% and a SiO2 content of 4.44% and washing tailings are obtained. The concentrate is sent to a concentrate bin, and the washing tailings are sent to a tailings salvage machine with a magnetic field strength of 280 mT for processing to obtain a salvaged concentrate with an iron grade of 16% and salvaged tailings. The salvaged concentrate is returned to the second cyclone for further classification, and the salvaged tailings are sent to a concentration tank together with the tailings from the second stage weak magnetic separation of step (3) for concentration to obtain concentrated minerals and the first water; (6) The iron ore from the first stage of intense magnetic separation in step (4) is fed into a shaking table with a stroke of 360 r / min and a stroke of 16 mm for re-selection to obtain valuable ore with an iron grade of 57.02% and a SiO2 content of 7.11% and shaking table tailings. The valuable ore is fed into an inclined plate concentrator for concentration to obtain concentrated concentrate and a second water. The concentrated concentrate is fed into a concentrate bin, and the second water is mixed with the first water from step (5) as circulating water; (7) The concentrated ore from step (5) is sent to a three-stage high-intensity magnetic separator with a magnetic field strength of 1.3T for high-intensity magnetic separation to obtain secondary concentrate and tailings, which are sent to the secondary concentrate bin and tailings field respectively; (8) The shaking table tailings of step (6) are sent to a vertical ring pulsating high gradient two-stage strong magnetic separator with a magnetic field strength of 1.3T for strong magnetic separation to obtain two-stage strong magnetic separation iron ore with an iron grade of 31% and two-stage strong magnetic separation iron tailings. The two-stage strong magnetic separation iron ore is sent to the secondary concentrate bin, and the two-stage strong magnetic separation tailings are sent to the tailings yard.
[0020] In this Example 2, a total concentrate with an iron grade of 65.67% and a SiO2 content of 4.8% was finally obtained, with a yield of 42%. A secondary concentrate with an iron grade of 32% and a SiO2 content of 27.8% was also obtained, with a yield of 14%, which effectively improved the iron concentrate yield and iron grade while reducing the SiO2 content of the iron concentrate.
[0021] Throughout this specification, references to terms such as "one embodiment," "example," or "specific example" indicate that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.
[0022] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the foregoing embodiments. The foregoing embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.
Claims
1. A method for beneficiating mixed magnetic and hematite ores with improved metal recovery and reduced impurities, characterized in that The following steps are involved: (1) Mixed ore classification: the coarsely crushed magnetic and hematite mixed ore is sent to the first cyclone for classification, and the classification produces coarse-grained ore and fine-grained ore. The coarse-grained ore is sent to the ball mill for grinding and then returned to the first cyclone for further classification; (2) The fine-particle ore is subjected to a first-stage weak magnetic separation, and the fine-particle ore of step (1) is sent to a first-stage weak magnetic separator for a first-stage weak magnetic separation to obtain a first-stage weak magnetic separation iron ore and a first-stage weak magnetic separation tailings; (3) The first-stage weak magnetic separation iron ore is classified and subjected to second-stage weak magnetic separation. The first-stage weak magnetic separation iron ore of step (2) is sent to the second cyclone for classification to obtain coarse-grained first-stage weak magnetic separation iron ore and fine-grained first-stage weak magnetic separation iron ore. The coarse-grained first-stage weak magnetic separation iron ore is sent to the mill for grinding and then returned to the second cyclone for further classification; the fine-grained first-stage weak magnetic separation iron ore is sent to the second-stage weak magnetic separator for second-stage weak magnetic separation to obtain second-stage weak magnetic separation iron ore and second-stage weak magnetic separation tailings; (4) Screening and strong magnetic separation of the first-stage weak magnetic separation tailings. The first-stage weak magnetic separation tailings of step (2) are sent to a cylindrical screen for screening. The material on the screen is sent to the second cyclone for classification. The material under the screen is sent to a first-stage strong magnetic separator for a first-stage strong magnetic separation to obtain a first-stage strong magnetic separation iron ore and a first-stage strong magnetic separation tailings. The first-stage strong magnetic separation tailings are sent to the tailings field. (5) The second stage weak magnetic separation iron ore is upgraded and washed. The second stage weak magnetic separation iron ore of step (3) is sent to the washing machine for upgrading and washing to obtain concentrate and washed tailings. The concentrate is sent to the concentrate bin. The washed tailings are sent to the tailings salvage machine for processing to obtain salvaged concentrate and salvaged tailings. The salvaged concentrate is returned to the second cyclone for further classification. The salvaged tailings and the second stage weak magnetic separation tailings of step (3) are sent to the concentration tank for concentration to obtain concentrated minerals and the first water. (6) The first stage of strong magnetic separation iron ore is subjected to shaking table gravity separation, and the first stage of strong magnetic separation iron ore in step (4) is sent to the shaking table for gravity separation to obtain valuable ore and shaking table tailings, and the valuable ore is sent to the inclined plate concentrator for concentration to obtain concentrated ore and second water, and the concentrated concentrate is sent to the concentrate bin, and the second water is mixed with the first water in step (5) as circulating water; (7) The concentrated minerals are subjected to high-intensity magnetic separation. The concentrated minerals from step (5) are sent to a three-stage high-intensity magnetic separator for high-intensity magnetic separation to obtain secondary concentrates and tailings, which are sent to the secondary concentrate bin and tailings field respectively; (8) The shaking table tailings are subjected to a second-stage strong magnetic separation. The shaking table tailings of step (6) are sent to a second-stage strong magnetic separator for strong magnetic separation to obtain second-stage strong magnetic separation iron ore and second-stage strong magnetic separation iron tailings. The second-stage strong magnetic separation iron ore is sent to the secondary concentrate bin, and the second-stage strong magnetic separation tailings are sent to the tailings field.
2. The method for beneficiating mixed magnetic and hematite ores with improved metal recovery and reduced impurities according to claim 1, characterized in that The fineness of the fine particle ore in step (2) is: -200 mesh ore particles ≥ 77%, and is prepared into a slurry with a concentration of ≤ 45%.
3. The method for beneficiating mixed magnetic and hematite ores with improved metal recovery and reduced impurities according to claim 1, characterized in that The mill in step (3) is set as a ball mill or a vertical mill, and the slurry fineness is ≥92% for -200 mesh ore particles and ≥74% for -325 mesh ore particles.
4. The method for beneficiating mixed magnetic and hematite ores with improved metal recovery and reduced impurities according to claim 1, characterized in that The magnetic field strength of the first-stage weak magnetic separator in step (2) is 180-220 mT; the magnetic field strength of the second-stage weak magnetic separator in step (3) is 180 mT; the magnetic field strength decreases successively through the first and second-stage weak magnetic separations, which is beneficial to improving the concentrate grade.
5. The method for beneficiating mixed magnetic and hematite ores with improved metal recovery and reduced impurities according to claim 1, characterized in that The magnetic field strength of the high-intensity magnetic separator in step (4) is 1.0 to 1.2 T; The magnetic field strength of the second-stage high-intensity magnetic separator in step (8) is 0.8 to 1.3 T; the magnetic field strength of the third-stage high-intensity magnetic separator in step (7) is 0.8 to 1.3 T; the concentrate recovery rate is increased as much as possible by the first-stage high-intensity magnetic separation and the second-stage high-intensity magnetic separation; the third-stage high-intensity magnetic separation is used to ensure the grade of the third-stage high-intensity magnetic concentrate while facilitating the use of a shaking table to process the first-stage high-intensity magnetic separation iron ore, further reducing the loss of iron ore and ensuring the iron ore recovery rate.
6. The method for beneficiating mixed magnetic and hematite ores with improved metal recovery and reduced impurities according to claim 1, characterized in that In step (5), the magnetic field strength of the tailings salvage machine is 280 mT to ensure the tailings recovery effect.