A method for recovering an extremely poor vanadium-titanium magnetite

Abstract

The application discloses a recovery method of extremely poor vanadium-titanium magnetite, which comprises the following steps: raw ore crushing, ZCLA pre-concentration and tailing throwing, grinding, SHP strong magnetic separation, table re-concentration, dry magnetic separation, electric separation and fine concentration, and qualified titanium concentrate production. The method reduces the processing capacity and cost of the grinding process, throws a large amount of low-grade tailings through pre-concentration technology, improves the titanium element grade of the grinding ore, reduces the processing load of subsequent strong magnetic separation and other processes, and reduces the equipment investment and operation cost. The combined process of dry magnetic separation and electric separation is adopted in the fine concentration process, the TiO2 grade of the titanium concentrate is improved, the product quality is improved, the influence of the process on the environment is reduced, and the green recovery of the extremely poor vanadium-titanium magnetite resources is realized.

Description

Technical Field

[0001] This invention relates to the field of mineral resource processing and utilization technology, specifically to a method for recovering extremely low-grade vanadium-titanium magnetite. Background Technology

[0002] Extremely low-grade vanadium-titanium magnetite has long faced problems of low recovery efficiency and high costs due to its low titanium content and difficulty in resource utilization. Currently, the industry mainly uses the following two typical processes for the recovery and processing of this type of mineral resource: The first typical process is "direct grinding after crushing the raw ore + high-intensity magnetic separation + gravity separation + dry magnetic separation for finer treatment". The core problem with this process is that it does not perform effective pre-selection and enrichment of the raw ore, directly sending all the raw ore into the ball mill process, resulting in extremely low grade of ore entering the mill, high load on the grinding equipment, and high grinding costs. At the same time, its fine treatment relies solely on the single process of dry magnetic separation, resulting in a low grade of TiO2 in the final titanium concentrate, and the large amount of ore entering the high-intensity magnetic separation process significantly increases equipment investment and subsequent operating costs.

[0003] The second typical process is "direct grinding of raw ore after crushing + gravity concentration + flotation for further cleaning". This process also fails to solve the drawbacks of direct grinding of raw ore, as all raw ore is directly fed into the mill, resulting in high grinding costs. Although spiral sluices and shaking tables are used for gravity concentration followed by flotation for further cleaning, the flotation process consumes a large amount of reagents (such as sulfuric acid and butyl xanthate), which not only increases reagent costs but also has a significant impact on the surrounding ecological environment. In addition, the final product, titanium concentrate, has a TiO2 grade of only 39.69%, which is far from meeting the demand for high-quality titanium resources.

[0004] Neither of the two existing typical processes mentioned above has designed a pre-treatment stage specifically for the "poor" characteristics of extremely poor vanadium-titanium magnetite, resulting in high load and cost in subsequent processes, and difficulty in balancing product quality and environmental protection, which seriously restricts the efficient and green utilization of extremely poor vanadium-titanium magnetite resources. Summary of the Invention

[0005] The technical problem to be solved by this invention is to address the technical defects of existing extremely low vanadium-titanium magnetite recovery processes, such as high grinding costs, low feed grade, heavy load on subsequent processes, low product grade, and significant environmental pollution from flotation processes. This invention provides a method for recovering extremely low vanadium-titanium magnetite that is easy to operate, has high recovery efficiency, and is environmentally friendly.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: A method for recovering extremely low vanadium-titanium magnetite includes the following steps: Step S1, Raw ore crushing: The mined extremely low vanadium-titanium magnetite raw ore is fed into the crushing equipment for multi-stage crushing; Step S2, ZCLA pre-selection and tailings disposal: The crushed raw ore is fed into the ZCLA pre-selection equipment to accurately separate high-grade rough concentrate and low-grade tailings; Step S3, Grinding: The high-grade ore material pre-selected by ZCLA is fed into a ball mill for grinding. Step S4, SHP high-intensity magnetic separation: The slurry after grinding is fed into an SHP high-intensity magnetic separator for preliminary magnetic enrichment, so as to initially separate titanium rough concentrate and magnetic tailings. Step S5, Shaking table gravity separation: Feed the SHP high-intensity magnetic separation rough concentrate into a shaking table for further enrichment; Step S6, Dry magnetic separation: The crude titanium concentrate after shaking table gravity separation is sent to a dry magnetic separator for magnetic enrichment, further separating the crude titanium concentrate and magnetic tailings. Step S7, Electrostatic Concentration: The titanium rough concentrate obtained by dry magnetic separation is sent to an electrostatic separator for further purification to remove gangue minerals from the titanium rough concentrate, and finally obtain high-quality qualified titanium concentrate.

[0007] As a further improvement of the present invention, in step S1, the particle size of the crushed raw ore is 1 mm to 20 mm.

[0008] As a further improvement of the present invention, in step S2, the ZCLA preselects a 6mm elliptical dielectric rod, a magnetic field strength of 0.6T to 0.9T, a cleaning water pressure of 1.0MPa to 2.0MPa, and a slope of 8° to 13°.

[0009] As a further improvement of the present invention, in step S3, the grinding is carried out in two stages, wherein the fineness of the first stage grinding is controlled at 50% to 60% of -200 mesh, and the fineness of the second stage grinding is controlled at 90% or more of -200 mesh.

[0010] As a further improvement of the present invention, in step S4, the SHP strong magnetic separation process includes: weak magnetic separation → first-stage strong magnetic separation → second-stage weak magnetic separation → second-stage strong magnetic separation.

[0011] As a further improvement of the present invention, in step S4, the magnetic field strength of the weak magnetic separation is 0.13T to 0.15T, the magnetic field strength of the first-stage strong magnetic separation is 1.0T to 1.2T, the magnetic field strength of the second-stage weak magnetic separation is 0.14T to 0.16T, and the magnetic field strength of the second-stage strong magnetic separation is 0.8T to 1.0T; during the magnetic separation process, the rinsing water pressure is controlled at 2.0 to 3.0 MPa, and the rotation speed of the SHP strong magnetic separator is 2 rpm to 4 rpm.

[0012] As a further improvement of the present invention, in step S5, the shaking table re-selection includes shaking table coarse selection and shaking table sweeping selection; wherein, the stroke of the coarse selection is 16 mm to 28 mm, the number of strokes is 260 rpm to 290 rpm, and the slope is 2.5° to 4.5°, and the stroke of the sweeping selection is less than 10 mm, the number of strokes is more than 300 rpm, and the slope is 1° to 2°.

[0013] As a further improvement of the present invention, in step S6, the dry magnetic separation process includes: a first stage of weak magnetic separation → a second stage of strong magnetic separation → a third stage of strong magnetic separation.

[0014] As a further improvement of the present invention, in step S6, the magnetic field strength of the first stage of weak magnetic separation is 0.14T to 0.16T, and the rotation speed of the dry magnetic separator is 40rpm to 60rpm; the magnetic field strength of the second stage of strong magnetic separation is 0.5T to 0.7T, and the rotation speed of the dry magnetic separator is 20rpm to 40rpm; the magnetic field strength of the third stage of strong magnetic separation is 0.6T to 1.0T, and the rotation speed of the dry magnetic separator is 20rpm to 40rpm.

[0015] As a further improvement of the present invention, in step S7, the voltage of the electric separator is 2.8 kV to 3.8 kV, and the rotation speed of the electric separator is controlled to be 60 rpm to 200 rpm.

[0016] Compared with existing technologies, the method for recovering extremely low-grade vanadium-titanium magnetite of the present invention, through the processing steps of "raw ore crushing → ZCLA pre-selection and tailings disposal → grinding → SHP high-intensity magnetic separation → shaking table gravity separation → dry magnetic separation → electrostatic separation and cleaning → production of qualified titanium concentrate", has the following significant advantages: Grinding costs are significantly reduced: The ZCLA pre-selection process can remove 20% to 60% of low-grade tailings, reducing the grinding volume by more than half, significantly increasing the TiO2 grade of the feed material, improving grinding efficiency by more than 30%, and reducing the overall grinding cost by 40% to 50%.

[0017] Product quality has been significantly improved: the final titanium concentrate TiO2 grade reached 45.73%, which is 3 percentage points higher than the first typical process (42.77%) and 6 percentage points higher than the second typical process (39.69%), far exceeding the existing technology level, and well meeting the raw material requirements of high-end titanium products.

[0018] Reduced equipment investment and operating costs: Due to the reduced processing capacity of subsequent grinding, magnetic separation and other processes, the required equipment specifications are smaller, and the initial equipment investment is reduced by 25% to 30%; at the same time, the simplification of processes reduces operating energy consumption by more than 20%, significantly reducing production and operating costs.

[0019] Improved environmental friendliness: The fine selection process does not use flotation, avoiding the use of large amounts of chemical reagents such as sulfuric acid and butyl xanthate, reducing the pollution of soil and water bodies by reagent residues, and reducing wastewater discharge by more than 60%, which meets the requirements for green mine construction.

[0020] Improved resource utilization: The precise sorting of ZCLA pre-selection technology enables the efficient recovery of extremely poor vanadium-titanium magnetite resources that were originally difficult to utilize, increasing the recovery rate of ilmenite minerals to over 85%, which is 10% to 15% higher than existing processes, thus maximizing resource utilization. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the process for recovering extremely poor vanadium-titanium magnetite in a specific embodiment of the present invention; Figure 2 This is a schematic diagram of the process for recovering extremely poor vanadium-titanium magnetite in Comparative Example 1. Figure 3 This is a schematic diagram of the process for recovering extremely poor vanadium-titanium magnetite in Comparative Example 2. Figure 4 This is a schematic diagram of the flotation process for vanadium-titanium magnetite in Comparative Example 2. Detailed Implementation

[0022] The present invention will be further described below with reference to the accompanying drawings and specific preferred embodiments, but this does not limit the scope of protection of the present invention.

[0023] In the description of this invention, it should be understood that the terms "side", "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0024] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more unless otherwise explicitly specified.

[0025] Example 1 like Figure 1As shown, the method for recovering extremely low vanadium-titanium magnetite of the present invention includes the following steps: Step S1, Raw Ore Crushing: The mined extremely low vanadium-titanium magnetite raw ore is fed into a jaw crusher or cone crusher for multi-stage crushing; the particle size of the raw ore is controlled between 1 mm and 20 mm to meet the feeding requirements of the subsequent ZCLA pre-selection process, providing a particle size basis for the efficient pre-selection tailings disposal.

[0026] Step S2, ZCLA Pre-selection and Tailings Disposal: The crushed raw ore is fed into the ZCLA pre-selection equipment. The ZCLA pre-selection uses a 6mm elliptical media bar, a magnetic field strength of 0.7T, a washing water pressure of 1.5MPa, and a slope of 10° to accurately separate 43.46% high-grade rough concentrate and 56.54% low-grade tailings.

[0027] Utilizing the high-efficiency separation characteristics of ZCLA technology, high-grade mineral particles and low-grade tailings can be accurately separated. Qualified tailings with a yield of 20% to 60% and a TiO2 grade of only 0.5% to 1.9% can be discarded, while only 40% to 80% of the high-grade ore is retained for subsequent grinding processes, significantly reducing the grinding load.

[0028] Step S3, Grinding: The high-grade ore pre-selected by ZCLA is fed into a ball mill for grinding. Grinding is carried out in two stages. The fineness of the first stage grinding is controlled at -200 mesh 65%, and the fineness of the second stage grinding is controlled at -200 mesh 92%. Both stages of grinding require pre-screening processes; other requirements are not specified.

[0029] By applying ZCLA pre-selection technology to the pre-treatment stage of extremely low-grade vanadium-titanium magnetite, efficient tailings removal is used to improve the grade of the feed ore and reduce the throughput, thus solving the core drawback of direct grinding of raw ore in existing processes. Because the feed ore grade is significantly higher than in existing processes, grinding efficiency is improved, while the grinding throughput is reduced by 20%–60%, resulting in a substantial reduction in grinding costs. The particle size control of the post-grinding slurry meets the particle size requirements of subsequent separation processes.

[0030] Step S4, SHP high-intensity magnetic separation: The slurry after grinding is fed into an SHP high-intensity magnetic separator for preliminary enrichment, so as to initially separate titanium rough concentrate and magnetic tailings; wherein the TiO2 grade of titanium rough concentrate can be increased to 10% to 20%.

[0031] The SHP high-intensity magnetic separation process specifically includes: weak magnetic separation → first-stage strong magnetic separation → second-stage weak magnetic separation → second-stage strong magnetic separation. The magnetic field strength of the weak magnetic separation is 0.14T, the first-stage strong magnetic separation is 1.0T, the second-stage weak magnetic separation is 0.15T, and the third-stage strong magnetic separation is 0.8T. During the magnetic separation process, the washing water pressure is controlled between 2.0 and 3.0 MPa, and the rotation speed of the SHP high-intensity magnetic separator is 4 rpm. Weak magnetic separation yields 5.57% iron concentrate and 37.89% tailings. The tailings undergo a first-stage strong magnetic separation. The first-stage strong magnetic separation yields 24.16% tailings. The 13.73% iron concentrate obtained from the first-stage strong magnetic separation is further ground and then subjected to a second-stage weak magnetic separation, yielding 0.03% secondary iron ore concentrate. The combined results of the second-stage weak magnetic separation and the weak magnetic separation yield a total of 5.60% mixed iron concentrate. The 13.70% tailings obtained from the second-stage weak magnetic separation are then subjected to a second-stage strong magnetic separation. The 5.25% iron concentrate obtained from the second-stage strong magnetic separation is fed into a shaking table for further enrichment, yielding 8.45% tailings. The total yield of magnetic tailings after SHP magnetic separation is 32.61%. Staged grinding and magnetic separation reduces the loss of ilmenite due to excessive grinding and improves the recovery rate of ilmenite.

[0032] Step S5, Shaking Table Gravity Separation: The SHP high-intensity magnetic separation rough concentrate is fed into a shaking table for further enrichment. Shaking table gravity separation includes shaking table roughing and shaking table scavenging; the roughing stroke is 24 mm, the stroke rate is 280 rpm, and the slope is 3.0°; the scavenging stroke is less than 10 mm, the stroke rate is above 300 rpm, and the slope is 1.5°. The final titanium rough concentrate yield is 0.47%, and the TiO2 grade in the titanium rough concentrate is increased by 20%–30%. Shaking table gravity separation specifically includes two processes: shaking table roughing and shaking table scavenging. Shaking table roughing can quickly separate valuable minerals from gangue in the ore, significantly improving the concentrate grade, and can process large quantities of ore in a short time. Shaking table scavenging further processes the roughed ore to recover residual valuable minerals and improve the overall recovery rate.

[0033] Step S6, Dry Magnetic Separation: The crude titanium concentrate after shaking table gravity separation is fed into a dry magnetic separator for magnetic enrichment, further separating the titanium crude concentrate and magnetic tailings. By accurately separating magnetic minerals with different specific magnetic susceptibility, the final ilmenite product is obtained, and the TiO2 grade of the titanium crude concentrate can be increased to 35%–40%.

[0034] The dry magnetic separation process specifically includes: a first-stage weak magnetic separation → a second-stage strong magnetic separation → a third-stage strong magnetic separation. The magnetic field strength of the first-stage weak magnetic separation is 0.15T, and the rotation speed of the dry magnetic separator is 50 rpm; the magnetic field strength of the second-stage strong magnetic separation is 0.6T, and the rotation speed of the dry magnetic separator is 37 rpm; the magnetic field strength of the third-stage strong magnetic separation is 0.6T, and the rotation speed of the dry magnetic separator is 38.5 rpm. The tailings obtained from the first-stage magnetic separation continue to undergo the second-stage magnetic separation, the middlings obtained from the second-stage magnetic separation continue to undergo the third-stage magnetic separation, and the middlings obtained from the third-stage magnetic separation continue to undergo electrostatic separation.

[0035] Step S7, Electrostatic Concentration: The titanium rough concentrate obtained from dry magnetic separation is fed into an electrostatic separator for further purification. The separator operates at 3.2kV ​​and rotates at 80rpm. Utilizing the differences in conductivity among different minerals, gangue minerals are further removed from the titanium rough concentrate, ultimately yielding high-quality, qualified titanium concentrate. By employing a combined purification process of "dry magnetic separation + electrostatic separation," the single magnetic separation or flotation process in existing technologies is replaced, significantly improving the grade of titanium concentrate without causing environmental pollution.

[0036] In this embodiment, an integrated process of "pre-selection-grinding-joint beneficiation" was constructed, with reasonable matching of parameters for each process, achieving a synergistic improvement in resource recovery efficiency, product quality, and environmental friendliness. Specifically, ZCLA pre-selection technology was used to remove qualified tailings with a yield of 56.54% and a TiO2 grade of 1.19%, significantly reducing the amount of subsequent grinding and increasing the grade of the feed material. The beneficiation process employed "dry magnetic separation and electrostatic separation" to ultimately obtain qualified titanium concentrate with a yield of 0.27% and a TiO2 grade of 45.73%.

[0037] Comparative Example 1 like Figure 2 As shown, the direct grinding process after crushing the raw ore resulted in a ball mill feed grade of only 1.678%, with 93.98% of the raw ore being fed into the mill, leading to very high grinding costs. In the beneficiation process, only dry magnetic separation was used, ultimately yielding a titanium concentrate with a yield of 0.39% and a TiO2 grade of 42.77%, a decrease of 3 percentage points compared to Example 1. Furthermore, the amount of ore entering the high-intensity magnetic separation process was significantly greater than in Example 1, resulting in significantly higher investment and operating costs.

[0038] Comparative Example 2 Similar to Comparative Example 1, the direct grinding process after crushing the raw ore was adopted. The ball mill feed grade was only 1.678%, and the feed volume was 93.98% of the raw ore, resulting in very high grinding costs. For example... Figure 3 and Figure 4As shown, the ground raw material was directly enriched by gravity separation using spiral sluices and shaking tables. The enriched gravity-separated rough titanium concentrate was then further refined by flotation, ultimately yielding a titanium concentrate with a yield of 0.29% and a TiO2 grade of 39.69%, a decrease of 6 percentage points compared to Example 1. Furthermore, flotation requires the use of large quantities of reagents such as sulfuric acid, butyl xanthate, and sodium fluorosilicate, which has a significant environmental impact and does not align with the concept of green and environmentally friendly development.

[0039] Table 1. Quality Indicators of the Entire Process Experiment in Comparative Example 2

[0040] Table 2. Quality Indicators of Flotation Process Number in Comparative Example 2

[0041] The above description is merely a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A method for recovering extremely low-grade vanadium-titanium magnetite, characterized in that, Includes the following steps: Step S1, Raw ore crushing: The mined extremely low vanadium-titanium magnetite raw ore is fed into the crushing equipment for multi-stage crushing; Step S2, ZCLA pre-selection and tailings disposal: The crushed raw ore is fed into the ZCLA pre-selection equipment to accurately separate high-grade rough concentrate and low-grade tailings; Step S3, Grinding: The high-grade ore material pre-selected by ZCLA is fed into a ball mill for grinding. Step S4, SHP high-intensity magnetic separation: The slurry after grinding is fed into an SHP high-intensity magnetic separator for preliminary magnetic enrichment, so as to initially separate titanium rough concentrate and magnetic tailings. Step S5, Shaking table gravity separation: Feed the SHP high-intensity magnetic separation rough concentrate into a shaking table for further enrichment; Step S6, Dry magnetic separation: The crude titanium concentrate after shaking table gravity separation is sent to a dry magnetic separator for magnetic enrichment, further separating the crude titanium concentrate and magnetic tailings. Step S7, Electrostatic Concentration: The titanium rough concentrate obtained by dry magnetic separation is sent to an electrostatic separator for further purification to remove gangue minerals from the titanium rough concentrate, and finally obtain high-quality qualified titanium concentrate.

2. The method for recovering extremely low-grade vanadium-titanium magnetite according to claim 1, characterized in that, In step S1, the particle size of the crushed raw ore is 1 mm to 20 mm.

3. The method for recovering extremely low-grade vanadium-titanium magnetite according to claim 1, characterized in that, In step S2, ZCLA pre-selects a 6mm elliptical dielectric rod, a magnetic field strength of 0.6T to 0.9T, a cleaning water pressure of 1.0MPa to 2.0MPa, and a slope of 8° to 13°.

4. The method for recovering extremely low-grade vanadium-titanium magnetite according to claim 1, characterized in that, In step S3, the grinding is carried out in two stages. The fineness of the first stage grinding is controlled at 50% to 60% of -200 mesh, and the fineness of the second stage grinding is controlled at more than 90% of -200 mesh.

5. The method for recovering extremely low-grade vanadium-titanium magnetite according to any one of claims 1 to 4, characterized in that, In step S4, the SHP strong magnetic separation process includes: weak magnetic separation → first-stage strong magnetic separation → second-stage weak magnetic separation → second-stage strong magnetic separation.

6. The method for recovering extremely low-grade vanadium-titanium magnetite according to claim 5, characterized in that, In step S4, the magnetic field strength of the weak magnetic separation is 0.13T to 0.15T, the magnetic field strength of the first-stage strong magnetic separation is 1.0T to 1.2T, the magnetic field strength of the second-stage weak magnetic separation is 0.14T to 0.16T, and the magnetic field strength of the second-stage strong magnetic separation is 0.8T to 1.0T. During the magnetic separation process, the rinsing water pressure is controlled at 2.0 to 3.0 MPa, and the rotation speed of the SHP strong magnetic separator is 2 rpm to 4 rpm.

7. The method for recovering extremely low-grade vanadium-titanium magnetite according to any one of claims 1 to 4, characterized in that, In step S5, the shaking table gravity separation includes shaking table coarse separation and shaking table sweeping separation; wherein, the stroke of the coarse separation is 16 mm to 28 mm, the number of strokes is 260 rpm to 290 rpm, and the slope is 2.5° to 4.5°, and the stroke of the sweeping separation is less than 10 mm, the number of strokes is more than 300 rpm, and the slope is 1° to 2°.

8. The method for recovering extremely low-grade vanadium-titanium magnetite according to any one of claims 1 to 4, characterized in that, In step S6, the dry magnetic separation process includes: a first stage of weak magnetic separation → a second stage of strong magnetic separation → a third stage of strong magnetic separation.

9. The method for recovering extremely low-grade vanadium-titanium magnetite according to claim 8, characterized in that, In step S6, the magnetic field strength of the first stage of weak magnetic separation is 0.14T to 0.16T, and the rotation speed of the dry magnetic separator is 40rpm to 60rpm; the magnetic field strength of the second stage of strong magnetic separation is 0.5T to 0.7T, and the rotation speed of the dry magnetic separator is 20rpm to 40rpm; the magnetic field strength of the third stage of strong magnetic separation is 0.6T to 1.0T, and the rotation speed of the dry magnetic separator is 20rpm to 40rpm.

10. The method for recovering extremely low-grade vanadium-titanium magnetite according to any one of claims 1 to 4, characterized in that, In step S7, the voltage of the electrostatic separator is 2.8 kV to 3.8 kV, and the rotation speed of the electrostatic separator is controlled to be 60 rpm to 200 rpm.

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