A pre-concentration system for ultra-low grade iron ore

Abstract

The utility model relates to a kind of ultra-low grade iron ore preselection system, including raw ore bin, jaw crusher, medium crushing line, shaping screening line.Rod bar vibrating feeder is set in the discharge port of raw ore bin, and the material under the screen of rod bar vibrating feeder is transported to primary magnetic separation line, and the material on the screen enters jaw crusher, and first conveyor is arranged in the discharge port of jaw crusher, and medium crushing line is arranged below the discharge port of first conveyor, and the material on the screen of shaping screening line is used as final crushed stone product.The ultra-low grade iron ore preselection system provided by the utility model is used to preselect iron ore with total iron content of 10-15%, shaping screening line is introduced in the preselection system to obtain material with particle size of 10-22mm, secondary magnetic separation line is introduced downstream of shaping screening line to obtain 0-3.5mm machine-made sand, so that the ore quantity of ultra-low grade iron ore entering grinding and iron ore selection operation after preselection is only 40-50% of raw ore, and the final selection grade is increased to more than 20%.

Description

Technical Field

[0001] This utility model belongs to the field of ferrous metal beneficiation, specifically relating to a pre-selection system for ultra-low grade iron ore. Background Technology

[0002] There are two main traditional iron ore pre-selection processes. One is to use magnetic drum dry separation to remove waste after medium and fine crushing. However, this method has poor pre-selection and waste removal effect and can hardly improve the iron ore grade before entering the mill. Therefore, it is not suitable for ultra-low grade iron ore. The second method is to use high-pressure roller mill to crush the raw ore to within 0-6mm and then use wet magnetic separation to remove waste. This method has a relatively coarse particle size and insufficient liberation. The pre-selection effect is generally poor. Moreover, the magnetic separation tailings after pre-selection need to be further processed to produce manufactured sand. At the same time, the high pressure extrusion of the ore may cause micro-cracks inside the particles, affecting the quality of manufactured sand. Utility Model Content

[0003] The purpose of this invention is to provide a pre-selection system for ultra-low grade iron ore to overcome the above-mentioned technical defects.

[0004] To solve the above-mentioned technical problems, this utility model provides a pre-selection system for ultra-low grade iron ore, comprising: Raw ore bins; A bar vibrating feeder is installed at the discharge port of the raw ore bin. It is used to receive ultra-low grade iron ore from the raw ore bin. The undersize material of the bar vibrating feeder is conveyed to the primary magnetic separation line, and the oversize material enters the jaw crusher. A jaw crusher, wherein a first conveyor is arranged at the discharge port of the jaw crusher; The intermediate crushing line is arranged below the discharge port of the first conveyor; A shaping and screening line is arranged at the discharge port of the intermediate crushing line. The oversize material of the shaping and screening line is used as the final crushed stone product, and the undersize material of the shaping and screening line is conveyed to the secondary magnetic separation line. The discharge port of the secondary magnetic separation line is equipped with a machine-made sand product stockpile.

[0005] According to an ultra-low grade iron ore pre-selection system, the primary magnetic separation line includes: The soil removal circular vibrating screen has a second conveyor at the undersize material outlet of the bar vibrating feeder, and the soil removal circular vibrating screen is located below the discharge port of the second conveyor. A dry magnetic separator is installed at the undersize material outlet of the soil removal circular vibrating screen; The spoil disposal area is used to receive non-magnetic materials from the dry magnetic separator after magnetic separation.

[0006] According to an ultra-low grade iron ore pre-selection system, the medium-crushing line includes: The medium-sized cone crusher has its discharge port of the jaw crusher, the oversize material outlet of the soil removal circular vibrating screen, and the magnetic material outlet of the dry magnetic separator after magnetic separation all connected to the first conveyor. The discharge port of the first conveyor is equipped with the medium-sized cone crusher. Fine cone crusher; The banana screen has a double-layer screen, namely an upper screen and a lower screen. The material on the upper screen falls into the fine crushing cone crusher, and the material on the lower screen and the material under the screen both fall into the shaping and screening line. The third conveyor carries the materials from both the medium and fine cone crushers to the banana screen.

[0007] According to an ultra-low grade iron ore pre-selection system, the shaping and screening line includes: A vertical shaft impact crusher receives oversize material from the lower screen of the banana screen; The finished product circular vibrating screen is arranged at the discharge port of the vertical shaft impact crusher; The fourth conveyor is used to receive the undersize material from the lower screen of the banana screen and the undersize material from the finished circular vibrating screen, and the oversize material from the finished circular vibrating screen is conveyed to the crushed stone finished product stockpile.

[0008] According to an ultra-low grade iron ore pre-selection system, the secondary magnetic separation line includes: The rod mill buffer chamber is used to receive material from the discharge port of the fourth conveyor; A rod mill is located at the discharge port of the rod mill buffer chamber; A permanent magnet drum magnetic separator is arranged at the discharge port of the rod mill. The permanent magnet drum magnetic separator magnetically separates the material from the rod mill into magnetic minerals and non-magnetic minerals, wherein the magnetic minerals enter the grinding and iron beneficiation operation. A sand washing machine is used to receive the non-magnetic minerals after magnetic separation from the permanent magnet drum separator.

[0009] According to an ultra-low grade iron ore pre-selection system, the ultra-low grade iron ore refers to iron ore with a total iron content of 10-15%. The bar spacing of the bar vibrating feeder is 80mm. Material larger than 80mm screened out falls into the jaw crusher, while material smaller than 80mm screened out is conveyed to the soil removal circular vibrating screen via the second conveyor.

[0010] According to an ultra-low grade iron ore pre-selection system, the screen aperture of the soil removal circular vibrating screen is 10mm. The material smaller than 10mm screened out falls into the dry magnetic separator, and the material larger than 10mm screened out is conveyed to the medium crushing cone crusher by the first conveyor.

[0011] According to an ultra-low grade iron ore pre-selection system, the upper screen of the banana screen has a mesh size of 22mm, and the lower screen has a mesh size of 10mm. The material larger than 22mm falls into the fine crushing cone crusher, the material between 10 and 22mm falls into the vertical shaft impact crusher, and the material smaller than 10mm is conveyed to the rod mill buffer bin by the fourth conveyor.

[0012] According to an ultra-low grade iron ore pre-selection system, the screen aperture of the finished circular vibrating screen is 10mm. The material smaller than 10mm screened out is transported to the rod mill buffer chamber by the fourth conveyor, and the material of 10-22mm screened out is transported to the crushed stone finished product stockpile.

[0013] According to an ultra-low grade iron ore pre-selection system, the grinding discharge particle size of the rod mill is 0-3.5 mm; The outlet of the integrated sand washing machine is equipped with a finished manufactured sand storage shed; The manufactured sand finished product storage shed is used to receive 0-3.5mm manufactured sand finished products from the integrated sand washing machine.

[0014] This invention provides a pre-selection system for ultra-low grade iron ore, which is used for the pre-selection of iron ore with a total iron content of 10-15%. A shaping screening line is introduced into the pre-selection system to obtain materials with a particle size of 10-22mm. A secondary magnetic separation line is introduced downstream of the shaping screening line to obtain manufactured sand of 0-3.5mm. This makes the amount of ultra-low grade iron ore entering the grinding and iron beneficiation operation after pre-selection only 40-50% of the original ore, and the final grade of the beneficiated ore is increased to more than 20%.

[0015] To make the above-mentioned contents of this utility model more obvious and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of an ultra-low grade iron ore pre-selection system.

[0017] Explanation of reference numerals in the attached figures: 1. Bar vibrating feeder; 2. Jaw crusher; 3. Circular vibrating screen for soil removal; 4. Dry magnetic separator; 5. Spoil disposal area; 6. Medium cone crusher; 7. Fine cone crusher; 8. Banana screen; 9. Vertical shaft impact crusher; 10. Finished product circular vibrating screen; 11. Rod mill buffer silo; 12. Rod mill; 13. Permanent magnet drum magnetic separator; 14. Integrated sand washing machine; 151. First conveyor; 152. Second conveyor; 153. Third conveyor; 154. Fourth conveyor. Detailed Implementation

[0018] The following specific embodiments illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification.

[0019] It should be noted that in this utility model, the upper, lower, left, and right in the figure are regarded as the upper, lower, left, and right of the ultra-low grade iron ore pre-selection system described in this specification.

[0020] Exemplary embodiments of the present invention are now described with reference to the accompanying drawings. However, the present invention may be embodied in many different forms and is not limited to the embodiments described herein. These embodiments are provided to fully and completely disclose the present invention and to fully convey its scope to those skilled in the art. The terminology used in the exemplary embodiments shown in the drawings is not intended to limit the present invention. In the drawings, the same units / elements are referred to by the same reference numerals.

[0021] Unless otherwise stated, the terms used herein (including technical terms) have their common meaning as understood by one of ordinary skill in the art. Furthermore, it is understood that terms defined in commonly used dictionaries should be understood to have a meaning consistent with the context of their relevant field, and not to be interpreted as having an idealized or overly formal meaning.

[0022] This embodiment relates to an ultra-low grade iron ore pre-selection system. Please refer to [link / reference]. Figure 1 It includes the raw ore bin, bar vibrating feeder 1, jaw crusher 2, intermediate crushing line, and shaping and screening line.

[0023] Specifically, ultra-low-grade iron ore is transported from the mine to the raw ore bin of the concentrator (i.e., the raw ore bin of the concentrator, also known as the beneficiation plant). A bar vibrating feeder 1 is installed at the discharge port of the raw ore bin to receive the ultra-low-grade iron ore from the raw ore bin. The undersize material from the bar vibrating feeder 1 is conveyed to the primary magnetic separation line, while the oversize material enters the jaw crusher 2. Ultra-low-grade iron ore refers to iron ore with a total iron content of 10-15%.

[0024] The primary magnetic separation line includes a soil-removing circular vibrating screen 3, a dry magnetic separator 4, and a spoil disposal area 5. A second conveyor 152 is installed at the undersize outlet of the bar vibrating feeder 1. Below the outlet of the second conveyor 152 is the soil-removing circular vibrating screen 3. The dry magnetic separator 4 is located at the undersize outlet of the soil-removing circular vibrating screen 3. The spoil disposal area 5 is used to receive non-magnetic materials from the dry magnetic separator 4 after magnetic separation.

[0025] In some embodiments, the bar spacing of the bar vibrating feeder 1 is 80mm. The material larger than 80mm screened out falls into the jaw crusher 2 for coarse crushing, while the material smaller than 80mm screened out is conveyed to the soil removal circular vibrating screen 3 by the second conveyor 152.

[0026] In some embodiments, the screen aperture of the circular vibrating screen 3 is 10mm. The material smaller than 10mm that is screened out falls into the dry magnetic separator 4 for the first magnetic separation. The non-magnetic material after the first magnetic separation is discharged into the spoil disposal room 5 as waste soil, and the material larger than 10mm that is screened out is conveyed to the first conveyor 151.

[0027] A first conveyor 151 is arranged at the discharge port of the jaw crusher 2. The intermediate crushing line is arranged below the discharge port of the first conveyor 151. The shaping and screening line is arranged at the discharge port of the intermediate crushing line. The oversize material of the shaping and screening line is used as the final crushed stone product. The undersize material of the shaping and screening line is conveyed to the secondary magnetic separation line. The discharge port of the secondary magnetic separation line is equipped with a machine sand finished product stockpile.

[0028] Please continue reading. Figure 1 The medium crushing line includes a medium crushing cone crusher 6, a fine crushing cone crusher 7, a banana screen 8, and a third conveyor 153.

[0029] The discharge port of jaw crusher 2, the oversize material outlet of the soil removal circular vibrating screen 3, and the magnetic material outlet of the dry magnetic separator 4 after magnetic separation are all connected to the first conveyor 151. The discharge port of the first conveyor 151 is equipped with a medium crushing cone crusher 6. The materials from the medium crushing cone crusher 6 and the fine crushing cone crusher 7 fall into the third conveyor 153, which conveys the materials to the banana screen 8.

[0030] In some embodiments, the screen aperture of the soil removal circular vibrating screen 3 is 10mm. The material smaller than 10mm screened out falls into the dry magnetic separator 4 for the first magnetic separation. The non-magnetic material after the first magnetic separation is discharged into the spoil disposal room 5 as waste soil. The material larger than 10mm screened out is conveyed to the medium crushing cone crusher 6 through the first conveyor 151.

[0031] The banana screen 8 has a double-layer screen, namely an upper screen and a lower screen. The material on the upper screen falls into the fine crushing cone crusher 7, while the material on the lower screen and the material under the screen both fall into the shaping screening line.

[0032] The shaping and screening line includes a vertical shaft impact crusher 9, a finished product circular vibrating screen 10, and a fourth conveyor 154.

[0033] The vertical shaft impact crusher 9 is used to receive the oversize material from the lower screen of the banana screen 8.

[0034] The finished circular vibrating screen 10 is arranged at the discharge port of the vertical shaft impact crusher 9.

[0035] The fourth conveyor 154 is used to receive the undersize material from the lower screen of the banana screen 8 and the undersize material from the finished circular vibrating screen 10. The oversize material of the finished circular vibrating screen 10 is conveyed to the crushed stone finished product stockpile.

[0036] The secondary magnetic separation line includes a rod mill buffer chamber 11, a rod mill 12, a permanent magnet drum magnetic separator 13, and a sand washing integrated machine 14.

[0037] The rod mill buffer chamber 11 is used to receive material from the discharge port of the fourth conveyor 154.

[0038] The rod mill 12 is located at the discharge port of the rod mill buffer chamber 11.

[0039] The permanent magnet drum separator 13 is arranged at the discharge port of the rod mill 12. The permanent magnet drum separator 13 magnetically separates the material from the rod mill 12 into magnetic minerals and non-magnetic minerals, among which the magnetic minerals enter the grinding and iron beneficiation operation.

[0040] The integrated sand washing machine 14 is used to receive non-magnetic minerals from the permanent magnet drum separator 13 after magnetic separation.

[0041] In some embodiments, the material entering the intermediate crushing cone crusher 6 is crushed and then screened by the banana screen 8. The upper screen mesh of the banana screen 8 has a mesh size of 22mm and the lower screen mesh has a mesh size of 10mm. The material larger than 22mm falls into the fine crushing cone crusher 7, and the material between 10 and 22mm falls into the vertical shaft impact crusher 9 for shaping. The material smaller than 10mm is conveyed to the rod mill buffer chamber 11 by the fourth conveyor 154.

[0042] In some embodiments, the material shaped by the vertical shaft impact crusher 9 enters the finished product circular vibrating screen 10 for screening. The screen mesh size of the finished product circular vibrating screen 10 is 10mm. The material smaller than 10mm screened out is conveyed to the rod mill buffer chamber 11 by the fourth conveyor 154, and the material of 10-22mm screened out is conveyed to the finished stone stockpile shed.

[0043] After medium crushing, fine crushing, and shaping screening, the 10-22mm particles produced in the ultra-low grade iron ore pre-selection system are sold directly as high-quality "crushed stone products." This is no longer a simple "waste disposal," but rather a transformation of waste rock into a commodity, creating additional economic income.

[0044] The material entering the rod mill buffer chamber 11 is fed into the rod mill 12 for rod milling and sand making. After the grinding discharge particle size is controlled to 0-3.5mm (meaning less than or equal to 3.5mm), it enters the permanent magnet drum magnetic separator 13 for pre-selection. The non-magnetic minerals after magnetic separation are used for sand making; the magnetic minerals (TFe grade > 20%) are used for iron grinding.

[0045] In some embodiments, the grinding discharge particle size of the rod mill 12 is 0-3.5 mm, and the outlet of the integrated sand washing machine 14 is equipped with a finished manufactured sand shed, which is used to receive the 0-3.5 mm finished manufactured sand from the integrated sand washing machine 14. That is, after non-magnetic minerals enter the integrated sand washing machine 14 for sand washing, high-quality 0-3.5 mm manufactured sand is obtained.

[0046] The ultra-low grade iron ore pre-selection system feeds materials smaller than 10mm (which would traditionally become tailings or difficult-to-handle waste) through a rod mill 12 for light grinding and dissociation, followed by magnetic separation. The non-magnetic minerals after magnetic separation are directly processed into high-quality manufactured sand of 0-3.5mm through a sand washing machine 14. This not only completely solves the environmental problem of tailings disposal, but also produces high-value-added building materials, achieving truly "tailings-free" or "tailings-reduced" processing.

[0047] Unlike traditional high-pressure roller milling processes, the ultra-low grade iron ore pre-selection system adopts a crushing method of "cone crusher + vertical shaft impact crusher". In particular, the "stone-on-stone" or "stone-on-iron" principle of the vertical shaft impact crusher 9 (shaping machine) can produce high-quality manufactured sand with rounded particle shape and reasonable gradation, avoiding the negative impact of internal micro-cracks that may be generated by high-pressure roller milling on the compressive strength and durability of manufactured sand.

[0048] This invention provides a pre-selection system for ultra-low-grade iron ore, used for pre-selecting iron ore with a total iron content of 10-15%. A shaping screening line is introduced into the pre-selection system to obtain material with a particle size of 10-22 mm. A secondary magnetic separation line is introduced downstream of the shaping screening line to obtain manufactured sand of 0-3.5 mm. This means that after pre-selection, the amount of ultra-low-grade iron ore entering the grinding and iron beneficiation process is only 40-50% of the original ore, while the final grade of the ore is increased to over 20%. In other words, through pre-selection, a large amount of waste rock in ultra-low-grade iron ore is discarded, reducing the amount of ore requiring subsequent processing by about half (only 40-50% of the original). This not only significantly reduces the processing burden but also enriches the ore grade, increasing it from ultra-low to over 20%.

[0049] Those skilled in the art will understand that the above embodiments are specific examples of implementing the present invention, and in practical applications, various changes can be made to them in form and detail without departing from the spirit and scope of the present invention.

Claims

1. A pre-selection system for ultra-low-grade iron ore, characterized in that, include: Raw ore bins; A bar vibrating feeder (1) is installed at the discharge port of the raw ore bin. It is used to receive ultra-low grade iron ore from the raw ore bin. The undersize material of the bar vibrating feeder (1) is conveyed to the primary magnetic separation line, and the oversize material enters the jaw crusher (2). Jaw crusher (2), with a first conveyor (151) arranged at the discharge port of the jaw crusher (2); The intermediate crushing line is arranged below the discharge port of the first conveyor (151); A shaping and screening line is arranged at the discharge port of the intermediate crushing line. The oversize material of the shaping and screening line is used as the final crushed stone product, and the undersize material of the shaping and screening line is conveyed to the secondary magnetic separation line. The discharge port of the secondary magnetic separation line is equipped with a machine-made sand product stockpile.

2. The ultra-low grade iron ore pre-selection system according to claim 1, characterized in that, The primary magnetic separation line includes: The soil removal circular vibrating screen (3) has a second conveyor (152) at the undersize material outlet of the bar vibrating feeder (1), and the soil removal circular vibrating screen (3) is located below the discharge port of the second conveyor (152). A dry magnetic separator (4) is arranged at the undersize material outlet of the soil removal circular vibrating screen (3); The spoil disposal area (5) is used to receive non-magnetic materials from the dry magnetic separator (4) after magnetic separation.

3. The ultra-low grade iron ore pre-selection system according to claim 2, characterized in that, The medium-fragmented line includes: The medium crushing cone crusher (6), the discharge port of the jaw crusher (2), the oversize material outlet of the soil removal circular vibrating screen (3), and the magnetic material outlet of the dry magnetic separator (4) after magnetic separation are all connected to the first conveyor (151), and the discharge port of the first conveyor (151) is provided with the medium crushing cone crusher (6). Fine cone crusher (7); The banana screen (8) has a double screen, namely an upper screen and a lower screen. The material on the upper screen falls into the fine crushing cone crusher (7), and the material on the lower screen and the material under the screen both fall into the shaping screening line. The third conveyor (153) carries the materials from the medium crushing cone crusher (6) and the fine crushing cone crusher (7) to the banana screen (8).

4. The ultra-low grade iron ore pre-selection system according to claim 3, characterized in that, The shaping and screening line includes: The vertical shaft impact crusher (9) receives the oversize material from the lower screen of the banana screen (8); The finished product circular vibrating screen (10) is arranged at the discharge port of the vertical shaft impact crusher (9); The fourth conveyor (154) is used to receive the undersize material from the lower screen of the banana screen (8) and the undersize material from the finished circular vibrating screen (10), and the oversize material of the finished circular vibrating screen (10) is conveyed to the crushed stone finished product stockpile.

5. The ultra-low grade iron ore pre-selection system according to claim 4, characterized in that, The secondary magnetic separation line includes: The rod mill buffer chamber (11) is used to receive material from the discharge port of the fourth conveyor (154); A rod mill (12) is installed at the discharge port of the rod mill buffer chamber (11); A permanent magnet drum magnetic separator (13) is arranged at the discharge port of the rod mill (12). The permanent magnet drum magnetic separator (13) magnetically separates the material from the rod mill (12) into magnetic minerals and non-magnetic minerals, wherein the magnetic minerals enter the grinding and iron beneficiation operation. A sand washing machine (14) is used to receive the non-magnetic minerals after magnetic separation from the permanent magnet drum separator (13).

6. The ultra-low grade iron ore pre-selection system according to claim 2, characterized in that, The ultra-low grade iron ore refers to iron ore with a total iron content of 10-15%. The bar spacing of the bar vibrating feeder (1) is 80mm. The material larger than 80mm screened out falls into the jaw crusher (2), and the material smaller than 80mm screened out is conveyed to the soil removal circular vibrating screen (3) through the second conveyor (152).

7. The ultra-low grade iron ore pre-selection system according to claim 5, characterized in that, The screen aperture of the soil removal circular vibrating screen (3) is 10mm. The material smaller than 10mm that is screened out falls into the dry magnetic separator (4), and the material larger than 10mm that is screened out is transported to the medium crushing cone crusher (6) through the first conveyor (151).

8. The ultra-low grade iron ore pre-selection system according to claim 7, characterized in that, The upper screen of the banana screen (8) has a mesh size of 22mm and the lower screen has a mesh size of 10mm. The material larger than 22mm falls into the fine crushing cone crusher (7), the material between 10 and 22mm falls into the vertical shaft impact crusher (9), and the material smaller than 10mm is conveyed to the rod mill buffer chamber (11) by the fourth conveyor (154).

9. The ultra-low grade iron ore pre-selection system according to claim 8, characterized in that, The finished circular vibrating screen (10) has a screen aperture of 10mm. The material smaller than 10mm screened out is transported to the rod mill buffer chamber (11) by the fourth conveyor (154), and the material of 10-22mm screened out is transported to the crushed stone finished product stockpile.

10. The ultra-low grade iron ore pre-selection system according to claim 5 or 8, characterized in that, The grinding discharge particle size of the rod mill (12) is 0-3.5 mm; The outlet of the integrated sand washing machine (14) is equipped with a finished manufactured sand storage shed; The manufactured sand finished product stacking shed is used to receive 0-3.5mm manufactured sand finished products from the sand washing machine (14).

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