Electromagnetic classificator for producing iron ore concentrate from coarse-grained iron ore and use method of electromagnetic classificator

Abstract

The invention provides an electromagnetic classificator for producing iron ore concentrate from coarse-grained iron ore and a using method of the electromagnetic classificator. The electromagnetic classificator is sequentially divided into a rapid tailing discharging area, a coarse-grained separation area, a fine-grained separation area and a concentration dehydration area from top to bottom and comprises an ore feeding device, an upper coil, a lower coil, an inner cylinder, a flushing device and a concentration cone. The feeding device is positioned at the uppermost part of the equipment and comprises an upper feeding device and a lower feeding device; the inner cylinder is of a cylinder structure with a thin upper part and a thick lower part; the upper coil is sleeved outside the coarse grain sorting area of the inner column body, and the lower coil is sleeved outside the fine grain sorting area of the inner column body; the flushing device is of an upper-layer water supply structure and a lower-layer water supply structure which correspond to the coarse grain separation area and the fine grain separation area respectively. The concentration cone is positioned at the lowermost part to form a concentration dehydration area. Through the quick tail discharging area, the coarse grain separation area, the fine grain separation area and the concentration and dehydration area, and in cooperation with the upper and lower ore feeding devices, the layered coil, the inner column with the specific structure and the flushing device, concentration operation can be directly conducted on whole-fraction coarse grain iron ore after coarse grinding.

Description

Technical Field

[0001] This invention relates to the field of iron ore beneficiation equipment technology, and in particular to an electromagnetic beneficiator for producing iron concentrate from coarse iron ore and its usage method. Background Technology

[0002] Currently, most mineral processing plants employ a staged grinding and separation process. This process involves coarse grinding (stage 1), fine grinding (stage 2), and even ultrafine grinding (vertical mill), followed by magnetic separation and waste removal after grinding, to achieve gradual liberation and separation of ores with different dissemination characteristics. After the iron ore particles have achieved a certain degree of individual liberation, the final stage of the mineral processing generally uses an electromagnetic washing and cleaning machine to produce qualified iron concentrate. In other words, the iron concentrate produced by the iron ore processing plant must go through all the grinding operations in the plant. This mineral processing process has significant drawbacks: each grinding stage generates newly formed qualified particle sizes that have been fully liberated. For example, in the coarse grinding stage (around 50% of -200 mesh), there are already a large number of newly formed qualified particle sizes. These particle sizes have the mineral liberation conditions to directly produce some iron concentrate. However, in the current process, these newly formed qualified particle sizes will re-enter the next grinding stage, which will not only cause over-grinding and affect the separation effect, but also increase grinding energy consumption.

[0003] Furthermore, the grain size distribution of iron ore in my country is uneven, specifically manifested in significant differences in particle size between iron minerals and gangue minerals, with an irregular distribution. Taking the Anshan-type iron ore as an example, the magnetite grain size ranges from a few millimeters to a few micrometers, with coarse and fine particles mixed together. This unevenness poses many challenges to the development and utilization of iron ore. If traditional grinding and beneficiation processes are used, the finer grains may be under-ground, resulting in incomplete liberation of iron minerals and affecting the grade, while the coarser grains may be over-ground, affecting beneficiation indicators.

[0004] While coarse and fine classification techniques (cyclones / fine screens) combined with electromagnetic panning and beneficiation after coarse grinding can produce some qualified fine-grained iron concentrate directly, the target minerals in this classification-benefit process are still fully liberated fine-grained minerals (overflow from the cyclone or undersize minerals from the high-frequency screen). For coarse-grained iron ore of all sizes, it is still impossible to directly produce iron concentrate; it needs to enter the next grinding process until the predetermined particle size is reached. Furthermore, this classification-benefit process is relatively complex, requires multiple pieces of equipment, and is rarely used in iron ore beneficiation plants. However, after coarse grinding, most of the fine-grained and some coarse-grained minerals in the iron ore have already achieved individual liberation, providing a mineralogical basis for directly producing some qualified iron concentrate. However, the existing electromagnetic washing and beneficiation technology for producing iron concentrate is designed for fine-grained iron ore (95% of which is -200 mesh, or even 95% of which is -325 mesh). It cannot be used for beneficiation of coarse-grained iron ore of all sizes. As a result, in the current iron beneficiation process, all iron concentrate products are the result of two or even three grinding operations. This not only increases the energy consumption of grinding, but also causes over-grinding of iron ore, affecting the iron ore beneficiation operation.

[0005] To address the aforementioned problems, this invention provides an electromagnetic concentrator for producing iron concentrate from coarse-grained iron ore and its operating method. This concentrator can directly perform concentrating operations on all coarse-grained iron ore after coarse grinding (approximately 50% of which is -200 mesh), separating fully liberated coarse and fine-grained iron concentrate to produce qualified iron concentrate. This not only reduces grinding energy consumption and avoids over-grinding of iron ore, but also improves beneficiation efficiency, providing a new solution for the efficient development and utilization of iron ore resources. Summary of the Invention

[0006] The purpose of this invention is to provide an electromagnetic beneficiator for producing iron concentrate from coarse iron ore and its usage method, so as to realize the beneficiation operation of coarse iron ore of all sizes after coarse grinding, directly produce qualified iron concentrate, thereby reducing grinding energy consumption, avoiding the problem of over-grinding of iron ore, and improving beneficiation efficiency.

[0007] According to one objective of the present invention, the present invention provides an electromagnetic separator for producing iron concentrate from coarse iron ore, which is divided into a rapid tailings discharge zone, a coarse particle separation zone, a fine particle separation zone and a concentration and dewatering zone from top to bottom. Its structure includes a feeding device, an upper coil, a lower coil, an inner column, a flushing device and a concentration cone. The inner column has a column structure that is thinner at the top and thicker at the bottom; the upper coil is sleeved outside the coarse particle sorting area of ​​the inner column, and the lower coil is sleeved outside the fine particle sorting area of ​​the inner column. The flushing device has a two-layer water supply structure, corresponding to the coarse particle sorting zone and the fine particle sorting zone respectively; the concentration cone is located at the bottom and constitutes the concentration and dehydration zone. The feeding device is located at the top of the equipment and includes an upper feeding device and a lower feeding device. The upper feeding device includes an upper cover, a material equalization pipe, a material equalization cone, a vent pipe, an upper feeding cylinder, an upper cylinder flange, and a feeding pipe. The upper part of the material equalization pipe is directly opposite to the feeding pipe but not connected, and the lower part is seamlessly fixed to the upper part of the material equalization cone. Several coarse outlets are opened in the circumferential direction on the lower side wall of the material equalization pipe. The vent pipe connects the internal space of the material equalization cone with the external space of the upper feeding cylinder. The lower feeding device includes a lower cylinder flange, a support plate, an observation port, a coarse feed pipe, a fine feed pipe, a ore gathering cone, a ore separating cone, a coarse outlet fixing plate, and a coarse outlet adjusting plate. The upper end of the coarse feed pipe is connected to the upper feeding device, and the lower end is horizontally aligned with the lower edge of the second upper coil of the coarse separation zone from top to bottom. Several layers of coarse ore outlets are evenly distributed in the lower circumferential direction, and each layer of outlets is staggered. The upper edge of the coarse ore outlet is aligned with the upper edge of the uppermost coil of the coarse separation zone. The upper end of the fine feed pipe is inserted into the ore gathering cone, and the lower end of the fine feed pipe is provided with a ore gathering cone and a ore separating cone. The gap between the ore gathering cone and the ore separating cone is the fine particle feed outlet. The feeding position is aligned with the first lower coil of the fine separation zone from top to bottom. The coarse feed nozzle fixing plate and the coarse feed nozzle adjusting plate constitute a particle size adjustment device. Both the coarse feed nozzle fixing plate and the coarse feed nozzle adjusting plate have several identical holes. The coarse feed nozzle adjusting plate can rotate freely around the fine feed pipe. By controlling the size of the overlapping area of ​​the coarse feed nozzles, the size of the coarse feed nozzle can be adjusted. The upper part of the coarse feed nozzle fixing plate is provided with a fixing rod. The coarse feed pipe and the fine feed pipe are concentric and are seamlessly connected to the bottom plate of the coarse pipe as a whole. In order to ensure smooth feeding, the spatial position of the coarse feed nozzle fixing plate in the electromagnetic separator is required to be at least 50mm higher than the uppermost edge of the inner column. The flushing device includes an upper water distribution cone, an upper water distribution pipe, a lower water distribution cone, a lower water distribution pipe, an upper water inlet, a lower water inlet, an upper water distribution cone fixing plate, a lower water distribution cone baffle, a lower water distribution cone fixing plate, and a lower water outlet pipe; the upper water distribution cone is horizontal with the upper coil at the bottom of the coarse particle separation zone and is located between the coarse particle feed pipe and the inner column; the lower water distribution cone is horizontal with the lower coil at the bottom of the fine particle separation zone and is close to the inner wall of the inner column; the upper water distribution cone is conical at both the top and bottom, and the lower water distribution cone is provided with a lower water distribution cone baffle near the cylinder wall.

[0008] Furthermore, the inner diameter of the uniform feed pipe is 1.2 to 1.5 times the inner diameter of the feed pipe, and the total cross-sectional area of ​​the coarse feed outlet is 1 / 5 to 1 / 3 of the total cross-sectional area of ​​the feed pipe; the upper cover has ventilation holes.

[0009] Furthermore, the upper end of the fine-grained feed pipe is more than 200mm higher than the lower edge of the uniform feed cone, and three observation ports are evenly distributed on the outside of the coarse-grained feed pipe, with the lower edge of the observation port flush with the upper edge of the coarse feed pipe fixing plate.

[0010] Furthermore, a handle is provided on the outer edge of the adjusting plate, and the handle is positioned directly opposite the observation port.

[0011] Furthermore, the diameter d1 of the upper column and the diameter d2 of the lower column of the inner column satisfy d1≈(0.7~0.8)*d2, and the height H3 of the upper column is 1 / 10 of the height H1 of the lower column.

[0012] Furthermore, the coarse particle sorting zone and the fine particle sorting zone each occupy half of the inner column sorting zone; the center distance between adjacent coils is (0.15~0.25)*d2, wherein the center distance between coils in the coarse particle sorting zone is 0.25*d2, and the center distance between coils in the fine particle sorting zone is 0.15*d2; the cross-sectional dimensions of the upper coil and the lower coil both satisfy a=2b, where a is the coil height and b is the coil width; the number of upper coils is 1.5~2 times the number of lower coils, and the number of turns of the upper coil is 1 / 3~1 / 2 of the number of turns of the lower coil.

[0013] Furthermore, the height of the concentration cone is 0.5 times the height of the inner column sorting zone.

[0014] Furthermore, the coarse feed outlet at the lower end of the uniform feed pipe is evenly distributed along the circumferential direction; the ore separating cone is used to achieve uniform feeding of ore around the circumference within the sorting space, and the ore gathering cone is used to isolate the water outlet position to prevent the loss of fine ore particles.

[0015] According to another objective of the present invention, the present invention provides a method for using the electromagnetic separator for producing iron concentrate from coarse iron ore, comprising the following steps: S1. Slurry Classification and Zonal Feeding: The slurry is classified into coarse and fine particles through the feeding device: part of the coarse particles settle through the coarse outlet of the uniform feed pipe, and the other part of the slurry overflows to the uniform feed cone; After the flow rate of the settled coarse particles is controlled by the coarse particle regulating device, they are discharged into the coarse particle sorting area through the coarse particle feed pipe in layers. Fine particles in the overflow slurry are evenly distributed to the fine particle separation zone through the annular gap at the lower end of the fine particle feed pipe; S2, Zoned Magnetic Field Sorting: Coarse-grained sorting zone processing: This zone has a large number of coils but few turns. Coarse particles in the coarse-grained sorting zone are affected by the wide-spacing, low-intensity intermittent magnetic field generated by the upper coils. When energized, the magnetic particles agglomerate and sink; when de-energized, the magnetic particles disperse. The water flow from the flushing device can wash away gangue and lean intergrowth into the tailings. The coarse-grained feed point is located at the top of the sorting zone, making it easy for them to be washed into the tailings. The coarse-grained concentrate needs to undergo combined sorting in both the coarse-grained and fine-grained sorting zones to become the final concentrate. The long sorting time and long water flow flushing time for coarse-grained minerals increase the probability of coarse-grained gangue and intergrowth becoming tailings, which is beneficial to improving the grade of the coarse-grained concentrate. Fine particle separation zone: This zone has fewer coils but more turns. Fine particles are subjected to a narrow-spacing, high-intensity intermittent magnetic field generated by the lower coils, achieving fine dispersion and agglomeration separation. The fine particle feed point is located in the middle of the separation zone (between the coarse and fine particle separation zones). Fine particle concentrate only needs to be separated in the fine particle separation zone to become concentrate, but fine particle tailings still need to be scavenged and recovered by the magnetic field in the coarse particle separation zone. This solves the problem of fine particle magnetic materials easily being lost to the tailings, achieving both fine particle concentrate and tailings separation. S3, Independent water flow control: In the coarse particle sorting zone, water is distributed radially by an upper water distribution cone, and the water flows from bottom to top to wash the particles. In the fine-particle sorting zone, water is distributed centripetally and directionally by a baffled lower water distribution cone to achieve uniform dispersion of magnetic minerals and prevent particles from agglomerating towards the cylinder wall. S4. Tailings and concentrate separation: After passing through the rapid tailings discharge zone, the scoured gangue is discharged through the overflow trough; After sorting, the concentrate is concentrated in the concentration and dehydration zone, and after reaching a certain concentration, it is continuously discharged through the concentrate valve.

[0016] Furthermore, the coarse-feeding outlet adjustment device changes the overlap of the openings by rotating the coarse-feeding outlet adjustment plate, and dynamically controls the ratio of coarse / fine particles to feed; the total cross-sectional area of ​​the coarse-feeding outlet of the uniform feed pipe is 1 / 5 to 1 / 3 of the total cross-sectional area of ​​the feed pipe, so as to realize the natural sedimentation and classification of coarse particles.

[0017] This invention's technical solution, by setting up a rapid tailings discharge zone, a coarse particle separation zone, a fine particle separation zone, and a concentration and dewatering zone, combined with upper and lower feeding devices, layered coils, a specially structured internal column, and a flushing device, can directly concentrate all coarse and fine iron ore particles after coarse grinding, producing qualified iron concentrate. This reduces the amount of ore fed into the fine grinding mill, lowers grinding energy consumption, avoids over-grinding, shortens part of the iron concentrate production process, reduces equipment investment and land occupation, and can also increase output by coarsening the ore to a finer degree, thereby improving beneficiation efficiency and economic benefits. Attached Figure Description

[0018] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the structure of an embodiment of the present invention; Figure 2 This is a schematic diagram of the ore feeding device in an embodiment of the present invention; Figure 3 This is a cross-sectional view of the ore feeding device AA in an embodiment of the present invention; Figure 4 This is a schematic diagram of the structure of the cover in an embodiment of the present invention; Figure 5 This is a schematic diagram of the material distribution tube according to an embodiment of the present invention; Figure 6 This is a schematic diagram of the coarse and fine ore feeding principle according to an embodiment of the present invention; Figure 7 This is a schematic diagram of the ore feeding device according to an embodiment of the present invention; Figure 8 This is a top view of the ore feeding device according to an embodiment of the present invention; Figure 9 This is a cross-sectional view of the ore feeding device BB according to an embodiment of the present invention; Figure 10 This is a schematic diagram illustrating the principle of the adjusting device for adjusting the size of the undercut in an embodiment of the present invention; Figure 11 This is a schematic diagram of the structure of the countersunk nozzle fixing plate according to an embodiment of the present invention; Figure 12 This is a schematic diagram of the structure of the adjusting plate for roughing out in an embodiment of the present invention; Figure 13 This is a schematic diagram of the internal column structure in an embodiment of the present invention; Figure 14 This is a schematic diagram of the coil structure according to an embodiment of the present invention; Figure 15 This is a schematic diagram of the flushing device according to an embodiment of the present invention; Figure 16 This is a top view of the flushing device according to an embodiment of the present invention; Figure 17 This is a partial structural diagram of the water outlet on the flushing device according to an embodiment of the present invention; Figure 18 This is a partial structural diagram of the lower water outlet of the flushing device according to an embodiment of the present invention; In the diagram: 1. Upper feeder; 2. Lower feeder; 3. Overflow trough; 4. Upper pressure gauge; 5. Inner cylinder; 6. Upper coil; 7. Middle pressure gauge; 8. Lower coil; 9. Outer cover; 10. Flushing device; 11. Lower pressure gauge; 12. Concentrating cone; 13. Concentrate valve; 1-1. Top cover; 1-2. Flooding pipe; 1-3. Flooding cone; 1-4. Ventilation pipe; 1-5. Upper feed cylinder; 1-6. Upper cylinder flange; 1-7. Feed pipe; 2-1. Lower flange; 2-2. Support plate; 2-3. Observation port; 2-4. Coarse feed pipe; 2-5. Fine feed pipe; 2-6. Gathering cone; 2-7. Dividing cone; 2-8-1. Lower coarse feed pipe fixing plate; 2-8-2. Lower coarse feed pipe adjusting plate; 2-9. Coarse pipe bottom plate; 10-1. Upper water distribution cone; 10-2. Upper water distribution pipe; 10-3. Lower water distribution cone; 10-4. Lower water distribution pipe; 10-5. Upper water inlet; 10-6. Lower water inlet; 10-7. Upper water distribution cone fixing plate; 10-8. Lower water distribution cone baffle; 10-9. Lower water distribution cone fixing plate; 10-10. Lower water outlet pipe. Detailed Implementation

[0020] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0022] 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 indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified. Furthermore, the terms "installed," "connected," and "linked" should be interpreted broadly; for example, they may refer to a fixed connection, a detachable connection, or an integral connection; they may refer to a mechanical connection or an electrical connection; they may refer to a direct connection or an indirect connection through an intermediate medium; and they may refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0023] Example 1 like Figures 1-18 As shown, an electromagnetic separator for producing iron concentrate from coarse iron ore is divided into a rapid tailings discharge zone, a coarse particle separation zone, a fine particle separation zone, and a concentration and dewatering zone from top to bottom according to different functions. Its main structure includes a feeding device, an upper coil 6, a lower coil 8, an inner column 5, a flushing device 10, and a concentration cone 12.

[0024] The inner column 5 provides sorting space and overflow space for the present invention. It has an overall column structure that is thinner at the top and thicker at the bottom, with a conical transition between the thinner and thicker sections.

[0025] The coil is threaded from top to bottom around the outside of the inner cylinder 5, providing a magnetic field environment for the sorting space. There are two types of coils: an upper coil 6 and a lower coil 8. The upper coil 6 is located in the coarse particle sorting area, and the lower coil 8 is located in the fine particle sorting area.

[0026] The flushing device 10 consists of a two-layer water supply structure. The upper water distribution cone 10-1 at the upper outlet is horizontal with the upper coil 6 at the bottom of the coarse particle separation zone, and its spatial position is between the coarse feed pipe and the inner column 5. The lower water distribution cone 10-3 at the lower outlet is horizontal with the lower coil 8 at the bottom of the fine particle separation zone, and its spatial position is close to the inner wall of the inner column 5. The concentration cone 12 is located at the bottom, forming the concentration and dewatering zone. The feeding device is located at the top of the coarse electromagnetic separator and includes two sub-components: the upper feeding device 1 and the lower feeding device 2, which are connected as a whole by a flange.

[0027] Specifically, such as Figure 2 and Figure 3 As shown, the upper feeding device 1 includes an upper cover 1-1, a material equalization pipe 1-2, a material equalization cone 1-3, a vent pipe 1-4, an upper feeding cylinder 1-5, an upper cylinder flange 1-6, and a feeding pipe 1-7.

[0028] The upper part of the uniform material distribution pipe 1-2 is directly opposite to the feed pipe 1-7 but is not connected to the feed pipe 1-7. Its lower part is seamlessly fixed to the upper part of the uniform material distribution cone 1-3. Several coarse sedimentation outlets are opened in the circumferential direction on the lower side wall of the uniform material distribution pipe 1-2. The coarse sedimentation outlets are the outlets at the lower end of the uniform material distribution pipe used for the initial settling of coarse particles.

[0029] Specifically, such as Figures 7-10 As shown, the lower feeding device 2 includes components such as a lower cylinder flange 2-1, a support plate 2-2, an observation port 2-3, a coarse feed pipe 2-4, a fine feed pipe 2-5, a ore gathering cone 2-6, a ore separating cone 2-7, a coarse feed inlet fixing plate 2-8-1, and a coarse feed inlet adjusting plate 2-8-2. The coarse feed inlet fixing plate and the adjusting plate cooperate to form the coarse feed inlet, which is an adjustable opening used to control the flow rate of coarse particles.

[0030] The upper end of the coarse feed pipe 2-4 is connected to the upper feed device 1 via a flange, specifically, it is connected to the upper flange 1-6 via the lower cylinder flange 2-1. The lower end is horizontally aligned with the lower edge of the second coil from top to bottom in the coarse particle selection zone. Several outlets are evenly distributed in layers along the lower circumference of the coarse feed pipe 2-4, with the upper edge of the uppermost outlet aligned with the upper edge of the uppermost coil. To ensure uniform circumferential ore discharge, the outlets in each layer are staggered.

[0031] The coarse particle feed pipe 2-4 and the fine particle feed pipe 2-5 are concentric and are seamlessly connected as a whole by the coarse opening fixing plate 2-8-1 and the coarse pipe bottom plate 2-9.

[0032] The coarse feed nozzle fixing plate 2-8-1 and the coarse feed nozzle adjusting plate 2-8-2 constitute a particle size adjustment device. Both plates have several identical holes. A handle is located on the outer edge of the adjusting plate 2-8-2, positioned opposite the observation hole 2-3. A hand can be inserted into the observation hole to move the handle, allowing the adjusting plate 2-8-2 to rotate freely around the fine feed pipe 2-5. The output ratio of the coarse and fine feed pipes is adjusted by changing the cross-sectional area of ​​the coarse feed nozzle. A fixing rod is installed on the upper part of the fixing plate 2-8-1, which is fixed after the adjusting plate 2-8-2 reaches the appropriate position. To ensure smooth feeding of the coarse particles, the fixing plate 2-8-1 is at least 50mm higher than the uppermost edge of the inner column.

[0033] The upper end of the fine particle feed pipe 2-5 is inserted into the uniform cone 1-3 of the upper feed device 1, and is at least 200mm above the lower edge of the uniform cone 1-3. The lower end of the fine particle feed pipe 2-5 is equipped with a gathering cone 2-6 and a separating cone 2-7. The gathering cone 2-6 isolates the outlet of the upper feed water to prevent the loss of fine particles due to the impact of the upper feed water flow. The separating cone 2-7 ensures uniform feeding around the perimeter of the separation space. The gap between the gathering cone and the separating cone is the fine particle feed outlet, and its feeding position is flush with the first lower coil from top to bottom in the fine particle separation zone.

[0034] The main structure of the flushing device 10 includes an upper water distribution cone 10-1, an upper water distribution pipe 10-2, a lower water distribution cone 10-3, a lower water distribution pipe 10-4, an upper water inlet 10-5, a lower water inlet 10-6, an upper water distribution cone fixing plate 10-7, a lower water distribution cone baffle 10-8, a lower water distribution cone fixing plate 10-9, and a lower water outlet pipe 10-10.

[0035] The upper water distribution cone 10-1 is connected to the outlet of the upper water supply pipe through the upper water distribution cone fixing plate 10-7. Both the upper and lower parts are conical. The lower cone can make the water flow at the outlet of the upper water supply pipe spray in all directions, increasing the radiation area of ​​the water flow, while the upper cone can prevent mineral accumulation.

[0036] The structure of the lower water distribution cone 10-3 is basically the same as that of the upper water distribution cone. The difference is that a lower water distribution cone baffle 10-8 is set on the side near the cylinder wall, so that the water flow does not spray towards the cylinder wall, but only towards the column sorting space.

[0037] The synergistic effect of this embodiment is as follows: Grading and sorting process Coarse particle path: The slurry passes through the coarse feed pipe 1-2, the coarse feed pipe 2-4, and the coarse particle separation zone. In the coarse particle separation zone, due to the combined effects of the magnetic field and water flow, the movement path of the coarse particles is divided into two paths. The coarse concentrate path is: coarse particle separation zone → fine particle separation zone → concentration and dewatering zone → concentrate valve discharge; the coarse tailings path is: coarse particle separation zone → rapid tailings discharge zone → overflow trough discharge.

[0038] Fine particle path: The slurry overflows through the uniform feed pipe, passes through uniform feed cones 1-3, fine particle feed pipes 2-5, and then enters the fine particle separation zone. In the fine particle separation zone, due to the combined effects of the magnetic field and water flow, the movement path of the fine particles is divided into two paths. The fine particle concentrate path is: fine particle separation zone → concentration and dewatering zone → concentrate valve discharge; the fine particle tailings path is: fine particle separation zone → coarse particle separation zone → rapid tailings discharge zone → overflow trough discharge.

[0039] Magnetic field-water flow coordination During the energizing stage: the coil generates a magnetic field that causes the magnetic particles to agglomerate and sink. The water flow impacts the magnetic agglomerates, causing them to continuously disperse and rearrange. During the power outage phase: the magnetic aggregates disperse, and the upward water flow (flushing device 10) flushes the gangue to the overflow tank 3 for discharge; Gradient design: The low-field-strength upward water flow in the coarse-grained zone enhances the discharge of coarse particles that are non-magnetic or weakly magnetic; the high-field-strength directional water flow in the fine-grained zone inhibits the upward flotation and washing of fine-grained concentrate into the tailings, and enhances the uniform dispersion of magnetic particles in the cross-section of the separator, thus preventing the formation of large particle agglomeration.

[0040] Dynamic adjustment system The coarse / fine flow ratio can be manually / automatically adjusted using the coarse-to-fine adjustment plate 2-8-2. The three pressure gauges interlock control the opening degree of the discharge valve, the size of the flushing water flow, the magnitude of the coil current, and the coil logic energizing sequence.

[0041] This invention enables direct separation of coarse particles: it breaks through the limitation of traditional electromagnetic washing machines that are only suitable for fine particles (-200 mesh > 95%), and enables the production of qualified iron concentrate after coarse grinding (e.g., -200 mesh accounts for about 50%). This invention can achieve a dual reduction in energy consumption: it avoids the re-grinding of already fully dissociated coarse and fine iron concentrate particles, preventing over-grinding, while simultaneously improving the grinding efficiency of the mill, reducing the power consumption per ton of ore, and lowering the enterprise's production costs.

[0042] This invention can reduce the amount of equipment used in the iron ore beneficiation process: it can reduce the amount of grading equipment such as hydrocyclones and high-frequency vibrating screens in the traditional iron beneficiation process, and at the same time significantly reduce the amount of drum magnetic separators used in stage grinding operations.

[0043] The present invention features an adjustable feed coarse-to-fine ratio design, which can adjust the amount of coarse sand by controlling the overlap area between the coarse sand settling fixing plate and the coarse sand settling adjusting plate.

[0044] The present invention features a uniform circumferential feeding design: the feed pipe is directly opposite the uniform feed pipe, and the uniform feed pipe has a coarse particle settling opening at the bottom, which can solve the problem of coarse particle deposition and achieve uniform circumferential feeding of coarse particles.

[0045] The method of using the electromagnetic separator for producing iron concentrate from coarse iron ore according to the present invention includes the following steps: S1. Slurry Classification and Zonal Feeding: The slurry is classified into coarse and fine particles through the feeding device: part of the coarse particles settle through the coarse outlet of the uniform feed pipe, and the other part of the slurry overflows to the uniform feed cone; After the flow rate of the settled coarse particles is controlled by the coarse particle regulating device, they are discharged into the coarse particle sorting zone through the coarse particle feed pipe in layers. The coarse particle regulating device changes the overlap of the openings by rotating the coarse particle regulating plate, and dynamically controls the coarse / fine particle feed ratio. The total cross-sectional area of ​​the coarse particle outlet of the uniform material pipe is 1 / 5 to 1 / 3 of the total cross-sectional area of ​​the feed pipe, so as to realize the natural sedimentation and classification of coarse particles. Fine particles in the overflow slurry are evenly distributed to the fine particle separation zone through the annular gap at the lower end of the fine particle feed pipe; S2, Zoned Magnetic Field Sorting: Coarse-grained sorting zone processing: This zone has a large number of coils but few turns. Coarse particles in the coarse-grained sorting zone are affected by the wide-spacing, low-intensity intermittent magnetic field generated by the upper coils. When energized, the magnetic particles agglomerate and sink; when de-energized, the water flow from the flushing device washes away the gangue. The coarse-grained feed point is located at the top of the sorting zone, making it easy for them to be washed into the tailings. The coarse-grained concentrate needs to undergo combined sorting in both the coarse-grained and fine-grained sorting zones to become the final concentrate. The long sorting time and water flow washing time for coarse-grained minerals increase the probability of coarse-grained gangue and intergrowths becoming tailings, which is beneficial for improving the grade of the coarse-grained concentrate.

[0046] Fine-particle separation zone: This zone has fewer coils but more turns. Fine particles are subjected to a narrow-spacing, high-intensity intermittent magnetic field generated by the lower coils, achieving fine dispersion and agglomeration separation. The fine-particle feed point is located in the middle of the separation zone (between the coarse-particle separation zone and the fine-particle separation zone). Fine-particle concentrate only needs to be separated in the fine-particle separation zone to become concentrate. However, fine-particle tailings still need to be scavenged and recovered by the magnetic field in the coarse-particle separation zone. This solves the problem of fine-particle magnetic materials easily being lost to the tailings, achieving both fine-particle concentrate and tailings separation.

[0047] S3, Independent water flow control: In the coarse particle sorting zone, water is distributed radially by an upper water distribution cone, and the water flows from bottom to top to wash the particles. In the fine-particle sorting zone, water is distributed centripetally by a baffled lower water distribution cone to achieve uniform dispersion of magnetic minerals and prevent particles from agglomerating towards the cylinder wall.

[0048] S4. Tailings and concentrate separation: After passing through the rapid tailings discharge zone, the scoured gangue is discharged through the overflow trough; After sorting, the concentrate is concentrated in the concentration and dehydration zone, and after reaching a certain concentration, it is continuously discharged through the concentrate valve.

[0049] Example 2 like Figures 1-18 As shown, the structure of this embodiment is basically the same as that of Embodiment 1. The structure and function of the electromagnetic separator for producing iron concentrate from coarse iron ore in this embodiment are described as follows: This electromagnetic separator is used to produce iron concentrate from coarse iron ore. It is divided into a rapid tailings discharge zone, a coarse particle separation zone, a fine particle separation zone, and a concentration and dewatering zone from top to bottom. The main structure includes: a feeding device, an upper coil 6, a lower coil 8, an inner column 5, a flushing device 10, a concentration cone 12, and monitoring auxiliary components.

[0050] I. Structure and Function of Core Components (1) Feeding device Located at the top of the equipment, it consists of an upper feeding device 1 and a lower feeding device 2 connected by flanges.

[0051] like Figures 2-3 As shown, the upper feeding device includes an upper cover 1-1, a material leveling pipe 1-2, a material leveling cone 1-3, a vent pipe 1-4, an upper feeding cylinder 1-5, an upper cylinder flange 1-6, and a feeding pipe 1-7. Details of each component are as follows: The top cover 1-1 has a vent at the top and is a sealed cover plate. Its function is to maintain the air pressure balance inside and outside the coarse ore feed pipe and prevent the slurry from flowing poorly due to air resistance.

[0052] The uniform feed pipe 1-2 has an inner diameter designed to be 1.2 to 1.5 times the inner diameter of the feed pipe 1-7. Several coarse feed outlets are opened along the circumference of its lower side wall, with the total cross-sectional area of ​​these outlets being approximately 1 / 5 to 1 / 3 of the total cross-sectional area of ​​the feed pipe. During feeding, all ore is first fed into the uniform feed pipe 1-2 through the feed pipe 1-7. A small portion of the particles that sink to the bottom are discharged through the coarse feed outlets of the uniform feed pipe 1-2, while the majority of the remaining particles overflow out through the circumference of the uniform feed pipe 1-2.

[0053] The slurry distribution cones 1-3 are cone-shaped structures with a seamless connection at the top to the distribution pipe. Their function is to guide the slurry to diffuse evenly and prevent uneven separation caused by eccentric flow.

[0054] Ventilation pipes 1-4 connect the interior of the uniform feed cone to the exterior of the upper feed cylinder. Their function is to balance the air pressure inside and outside the fine particle feed pipe, preventing blockage caused by vacuum suction.

[0055] Upper feed cylinders 1-5 are cylindrical containers connected to the external ore supply system via flanges at the top. Their function is to contain and stabilize the ore slurry flow, transitioning it to the lower feed device.

[0056] Upper cylinder flange 1-6, annular flange. Its function is to seal and connect with the lower cylinder flange 2-1 of the lower feed device to form an integral structure.

[0057] Ore supply pipes 1-7 are straight pipes with inlets connected to the external ore supply system. Their function is to serve as the core channel for raw ore input.

[0058] like Figure 7-10 As shown, the lower feeding device 2 includes a lower cylinder flange 2-1, a support plate 2-2, an observation port 2-3, a coarse feed pipe 2-4, a fine feed pipe 2-5, a ore gathering cone 2-6, a ore separating cone 2-7, a coarse feed nozzle fixing plate 2-8-1, a coarse feed nozzle adjusting plate 2-8-2, and a coarse pipe bottom plate 2-9, etc. Details of each component are as follows: Lower cylinder flange 2-1, annular flange. Its function is to securely connect with upper cylinder flange 1-6 to ensure the overall sealing of the feeding device.

[0059] Support plate 2-2, an annular steel plate welded to the outer wall of the coarse feed pipe. Its function is to fix the observation port 2-3 and the coarse feed pipe adjustment mechanism.

[0060] Observation ports 2-3 and three flange-type windows are evenly distributed on the outside of the coarse feed pipe, with their lower edges flush with the upper edge of the settling port fixing plate 2-8-1. Their function is to visually monitor the status of the settling port and to open it for cleaning accumulated ore.

[0061] The coarse-grained feed pipe 2-4, serving as the outer layer of the concentric sleeve, has staggered ore outlets arranged in layers along the circumference at its lower part. The upper edge of the uppermost ore outlet is flush with the upper edge of the uppermost coil. Its function is to transport coarse-grained slurry to the coarse-grained sorting zone and achieve uniform ore distribution in the circumference.

[0062] The fine-particle feed pipe 2-5 serves as the inner layer of the concentric sleeve, with its upper end inserted into the ore-leveling cone (more than 200mm above the lower edge of the ore-leveling cone), and its lower end equipped with an ore-gathering cone 2-6 and a ore-separating cone 2-7. Its function is to precisely deliver the fine-particle slurry to the fine-particle separation zone, with its outlet position flush with the first lower coil.

[0063] Ore-collecting cones 2-6 have an inverted cone shape. Their function is to isolate the upper-level flushing water flow and prevent fine-particle ore from being washed away.

[0064] Separating cones 2-7 have a conical structure and form an annular gap with the collecting cone. Their function is to achieve a uniform distribution of fine-grained slurry around the perimeter within the separation space.

[0065] The coarse-particle fixing plate 2-8-1 has several through holes and a fixing rod at the top. Its overall height is more than 50mm higher than the top edge of the inner column. Its function is to work with the adjusting plate to control the proportion of coarse particles discharged and to provide mechanical support.

[0066] The coarse feed adjustment plate 2-8-2 has the same through hole as the fixed plate, and a handle is set on the outer edge (directly opposite the observation port). Its function is to dynamically control the coarse / fine feed ratio by adjusting the overlap of the hole position through rotation.

[0067] Coarse-grained bottom plate 2-9, annular bottom plate. Its function is to seamlessly connect the coarse-grained feed pipe and the fine-grained feed pipe into an integral structure.

[0068] (2) Inner column 5 and outer protective cover 9 The inner column 5 has a column structure that is thinner at the top and thicker at the bottom (the upper diameter d1≈0.7~0.8*d2, the upper height H3 is 1 / 10 of the lower height H1, and there is a cone in the middle for transition), which provides a sorting space. The upper thin column accelerates the overflow and tailings discharge, while the lower thick column prolongs the sorting time, increases the uniformity of magnetic particle dispersion, and improves the concentrate grade.

[0069] An outer protective cover 9 is provided on the outside of the inner column 5. The outer protective cover 9 protects the internal coils and reduces the impact of the external environment (such as dust, debris, slurry, collisions, etc.) on the critical internal components. It also provides a certain degree of protection and isolation, ensuring the stability and safety of the equipment operation. The outer protective cover 9 acts as a sealed shell to enclose the inner column and coils. Its functions are to prevent dust, slurry, and impacts, protect the core components, maintain a stable sorting environment, and protect personnel's electrical safety.

[0070] (3) Coils (upper coil 6 and lower coil 8) In this embodiment, the coarse particle sorting zone and the fine particle sorting zone each occupy half of the sorting zone of the inner column 5. The center distance between adjacent coils is (0.15~0.25)*d2. Preferably, for the coils in the coarse particle sorting zone, the center distance between coils is 0.25*d2, and for the coils in the fine particle sorting zone, the center distance between coils is 0.15*d2. The cross-sectional dimensions of the upper coil 6 and the lower coil 8 both conform to a=2b (a is the coil height, b is the coil width). To ensure a better sorting effect, the number of upper coils 6 is 1.5 to 2 times the number of lower coils 8, and the number of turns of the upper coil 6 is 1 / 3 to 1 / 2 of the number of turns of the lower coil 8.

[0071] In this embodiment, the upper coil 6 is mounted outside the coarse particle sorting area, with a cross-sectional dimension satisfying height a = 2 * width b. Its number is 1.5 to 2 times that of the lower coil, and its number of turns is 1 / 3 to 1 / 2 of the lower coil. Its function is to generate a wide-spacing (center distance 0.25 * d²) intermittent magnetic field to capture coarse particles and form magnetic agglomerates.

[0072] In this embodiment, the lower coil 8 is mounted outside the fine particle sorting area, with a cross-sectional dimension satisfying a=2b and a center distance of 0.15*d2. Its function is to generate a narrow-spacing, high-intensity intermittent magnetic field to achieve fine particle "dispersion-agglomeration" sorting.

[0073] (4) Flushing device 10 The water supply structure consists of two layers, upper and lower. Includes upper water distribution cone 10-1, upper water distribution pipe 10-2, lower water distribution cone 10-3, lower water distribution pipe 10-4, upper water inlet 10-5, lower water inlet 10-6, upper water distribution cone fixing plate 10-7, lower water distribution cone baffle 10-8, lower water distribution cone fixing plate 10-9, and lower water outlet pipe 10-10: Upper structure: The upper water distribution cone 10-1 (double cone shape, connected to the upper water distribution pipe through a fixed plate) is horizontal with the upper coil at the bottom of the coarse particle separation zone, located between the coarse feed pipe and the inner column, and distributes water radially to the coarse particle separation zone (the lower cone surface expands the coverage area, and the upper cone surface prevents mineral accumulation); the upper water distribution pipe 10-2 transports the upper flushing water, and the upper water inlet 10-5 connects to the external water source.

[0074] Lower structure: The lower water distribution cone 10-3 (with a baffle 10-8 on one side, close to the inner wall of the inner column) is horizontal with the lowest coil of the fine particle sorting zone, and sprays water directionally into the fine particle sorting zone (the baffle constrains the water flow to spray inward to prevent fine particles from sticking to the wall); the lower water distribution pipe 10-4 delivers the lower flushing water, and the lower water inlet 10-6 connects to the external water source.

[0075] Other: The upper / lower water distribution cone fixing plate fixes the water distribution cone, and the lower water outlet pipe 10-10 discharges the overflow water from the concentration zone.

[0076] Specifically, in this embodiment, the structure and function of each component of the flushing device 10 are summarized as follows: Upper water distribution cone 10-1: A double-conical structure, connected to the upper water distribution pipe via an upper water distribution cone fixing plate 10-7. Its function is to radially distribute water to the coarse particle sorting area, with the lower cone surface allowing the water flow to cover a large area of ​​the sorting area.

[0077] Upper water distribution pipe 10-2: A ring-shaped pipe connected to the upper water inlet 10-5. Its function is to deliver flushing water from the upper layer.

[0078] Lower water-distributing cone 10-3: A baffle 10-8 is installed on one side, close to the inner wall of the inner column. Its function is to separate water for fine particles, and the baffle forces the water flow to spray inward to prevent fine particles from sticking to the wall.

[0079] Lower water distribution pipe 10-4: A ring-shaped pipe connected to the lower water inlet 10-6. Its function is to deliver flushing water to the lower level.

[0080] Upper water inlet 10-5: Connects to an external water source. Its function is to serve as the flushing inlet for the coarse particle sorting zone.

[0081] Lower inlet 10-6: Connects to an external water source. Its function is as the flushing inlet for the fine particle sorting zone.

[0082] Upper water distribution cone fixing plate 10-7: welded to the end of the upper water distribution pipe. Its function is to fix the upper water distribution cone and ensure the stability of the water spray direction.

[0083] Lower water distribution cone baffle 10-8: An arc-shaped steel plate is welded to the side of the lower water distribution cone cylinder wall. Its function is to constrain the water flow to only be directed towards the center of the sorting space.

[0084] Lower water distribution cone fixing plate 10-9: welded to the end of the lower water distribution pipe. Its function is to fix the lower water distribution cone and baffle assembly.

[0085] Bottom drain pipe 10-10: Bottom drain pipe. Its function is to drain the overflow water from the concentration zone.

[0086] (5) Concentration and Dehydration Zone The height of the concentration cone 12 in the concentration and dehydration zone is half the height of the sorting zone of the inner column 5, i.e., 0.5*H1. To ensure a better concentration effect, the nominal diameter of the cone bottom connecting pipe is selected from five models: DN65, DN80, DN100, DN125 and DN150, depending on the diameter d2 of the inner column 5.

[0087] Among them, d2≤1500mm, DN65 is preferred; 1500mm<d2≤2000mm, DN80 is preferred; 2000<d2≤2200mm, DN100 is preferred; 2200<d2≤2500mm, DN125 is preferred; 2500<d2≤3000mm, DN150 is preferred.

[0088] In this embodiment, the concentrator cone 12 has a cone angle of 60°~70° and a height that is 0.5 times the height (H1) of the inner column sorting zone. Its function is to accelerate the sedimentation and concentration of the concentrate by gravity, thereby increasing the discharge concentration.

[0089] Concentrate valve 13 is a pneumatic / electric valve located at the bottom of the cone. During operation, the valve is normally open. The valve opening can be controlled by an external PLC program, and its function is to maintain a stable concentrate concentration by controlling the valve opening.

[0090] II. In this embodiment, the electromagnetic separator for producing iron concentrate from coarse-grained iron ore is further equipped with monitoring and auxiliary components, specifically including: Overflow trough 3: An annular trough located at the top of the inner column. Its function is to collect tailings slurry and discharge it from the equipment.

[0091] Upper pressure gauge 4: Installed above the inner cylinder. Its function is to monitor the pressure in the overflow area and optimize the coil energizing current parameters.

[0092] Medium pressure gauge 7: Installed between the coarse and fine particle separation zones. Its function is to monitor the slurry concentration in the coarse separation space and optimize the flushing water flow parameters.

[0093] Downward pressure gauge 11: Installed on the upper part of the concentration cone. Its function is to provide feedback on the concentration status of the concentrate and to link the concentrate valve to prevent clogging.

[0094] III. Synergistic Mechanism Grading and sorting process Coarse particle path: The slurry passes through the coarse feed pipes 1-2 and 2-4 before reaching the coarse particle separation zone. In the coarse particle separation zone, due to the combined effects of the magnetic field and water flow, the movement path of the coarse particles is divided into two paths. The coarse concentrate path is: coarse particle separation zone → fine particle separation zone → concentration and dewatering zone → concentrate valve discharge; the coarse tailings path is: coarse particle separation zone → rapid tailings discharge zone → overflow trough discharge.

[0095] Fine particle path: The slurry overflows through the uniform feed pipe, passes through uniform feed cones 1-3, and then through fine particle feed pipes 2-5 before reaching the fine particle separation zone. In the fine particle separation zone, due to the combined effects of the magnetic field and water flow, the movement path of the fine particles is divided into two paths. The fine particle concentrate path is: fine particle separation zone → concentration and dewatering zone → concentrate valve discharge; the fine particle tailings path is: fine particle separation zone → coarse particle separation zone → rapid tailings discharge zone → overflow trough discharge.

[0096] Magnetic field-water flow coordination During the energizing stage: the coil generates a magnetic field that causes the magnetic particles to agglomerate and sink. The water flow impacts the magnetic agglomerates, causing them to continuously disperse and rearrange. During the power outage phase: the magnetic aggregates disperse, and the water flushing from bottom to top washes the gangue into the overflow tank for discharge; Gradient design: Low field strength and wide flow in the coarse-grained region prevent over-agglomeration, while high field strength and directional flow in the fine-grained region suppress tailing.

[0097] Dynamic adjustment system The coarse and fine flow ratio can be manually / automatically adjusted using the 2-8-2 coarse-to-fine flow adjustment plate. Three pressure gauges are interlocked to control water flow pressure and ore discharge frequency.

[0098] The method of using the electromagnetic separator for producing iron concentrate from coarse iron ore according to the present invention includes the following steps: S1. Slurry Classification and Zonal Feeding: The slurry is classified into coarse and fine particles through the feeding device: a small portion of coarse particles settle through the coarse outlet of the uniform feed pipe, while most of the slurry overflows into the uniform feed cone. After the flow rate of the settled coarse particles is controlled by the coarse particle regulating device, they are discharged into the coarse particle sorting zone through the coarse particle feed pipe in layers. The coarse particle regulating device changes the overlap of the openings by rotating the coarse particle regulating plate, and dynamically controls the coarse / fine particle feed ratio. The total cross-sectional area of ​​the coarse particle outlet of the uniform material pipe is 1 / 5 to 1 / 3 of the total cross-sectional area of ​​the feed pipe, so as to realize the natural sedimentation and classification of coarse particles. Fine particles in the overflow slurry are evenly distributed to the fine particle sorting zone through the fine particle feed pipe (lower annular gap); S2, Zoned Magnetic Field Sorting: Coarse-grained sorting zone processing: This zone has a large number of coils but few turns. Coarse particles in the coarse-grained sorting zone are affected by the wide-spacing, low-intensity intermittent magnetic field generated by the upper coils. When energized, the magnetic particles agglomerate and sink; when de-energized, the water flow from the flushing device washes away the gangue. The coarse-grained feed point is located at the top of the sorting zone, making it easy for them to be washed into the tailings. The coarse-grained concentrate needs to undergo combined sorting in both the coarse-grained and fine-grained sorting zones to become the final concentrate. The long sorting time and water flow washing time for coarse-grained minerals increase the probability of coarse-grained gangue and intergrowths becoming tailings, which is beneficial for improving the grade of the coarse-grained concentrate.

[0099] Fine-particle separation zone: This zone has fewer coils but more turns. Fine particles are subjected to a narrow-spacing, high-intensity intermittent magnetic field generated by the lower coils, achieving fine dispersion and agglomeration separation. The fine-particle feed point is located in the middle of the separation zone (between the coarse-particle separation zone and the fine-particle separation zone). Fine-particle concentrate only needs to be separated in the fine-particle separation zone to become concentrate. However, fine-particle tailings still need to be scavenged and recovered by the magnetic field in the coarse-particle separation zone. This solves the problem of fine-particle magnetic materials easily being lost to the tailings, achieving both fine-particle concentrate and tailings separation.

[0100] S3, Independent water flow control: In the coarse particle sorting zone, water is distributed radially by an upper water distribution cone, and the water flows from bottom to top to wash the particles. In the fine-particle sorting zone, water is distributed centripetally and directionally by a baffled lower water distribution cone to achieve uniform dispersion of magnetic minerals and prevent particles from agglomerating towards the cylinder wall. S4. Tailings and concentrate separation: After passing through the rapid tailings discharge zone, the scoured gangue is discharged through the overflow trough; After sorting, the concentrate is concentrated in the concentration and dehydration zone, and after reaching a certain concentration, it is continuously discharged through the concentrate valve.

[0101] IV. Equipment Advantages Direct separation of coarse particles: Breaking through the limitation of traditional electromagnetic washing machines that are only suitable for separating fine-grained iron ore (-200 mesh > 95%), it enables the production of qualified iron concentrate after coarse grinding (e.g., -200 mesh accounts for about 50%).

[0102] Energy consumption is reduced in two ways: avoiding the re-grinding of fully dissociated coarse and fine iron concentrate, preventing over-grinding, improving the grinding efficiency of the mill, reducing the power consumption per ton of ore, and reducing the production cost of enterprises.

[0103] Reduced equipment usage: It can reduce the amount of grading equipment such as hydrocyclones and high-frequency vibrating screens in the traditional iron ore beneficiation process, and at the same time significantly reduce the amount of drum magnetic separators used in stage grinding operations.

[0104] Uniform feeding and distribution of ore: The combination of the coarse inlet of the uniform feed pipe, the coarse inlet of the coarse particle feed pipe, and the coarse inlet fixing plate achieves uniform feeding and distribution of coarse particles; the overflow of the uniform feed pipe, the overflow of the fine particle feed pipe, the ore distribution cone, and the water distribution cone directional injection solve the problem of uniform feeding of fine particles and uniform dispersion of magnetic fine particles in the fine particle selection area.

[0105] This invention relates to an electromagnetic separator for producing iron concentrate from coarse-grained iron ore. It can directly perform beneficiation on coarse and fine-grained iron ore after coarse grinding, producing qualified iron concentrate. This invention not only reduces grinding energy consumption and avoids over-grinding of iron ore, but also improves beneficiation efficiency. When used after coarse grinding, this invention enables the direct production of iron concentrate from coarse-grained iron ore, reducing regrinding by approximately 40%–50%, optimizing the grinding environment in fine grinding, reducing grinding energy consumption, and saving economic costs. Because some iron concentrate is produced in advance during coarse grinding, the subsequent grinding and beneficiation volume is significantly reduced, shortening the iron concentrate production process and reducing the number of magnetic separation and classification equipment used before and after fine grinding, thus reducing floor space and equipment investment. When used after fine grinding, this invention can further increase the fineness of the coarse grinding, increase the feed rate, increase the iron ore output, improve economic efficiency, and simultaneously reduce energy consumption per ton of ore.

[0106] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An electromagnetic separator for producing iron concentrate from coarse-grained iron ore, characterized in that, From top to bottom, it is divided into a rapid tailings discharge zone, a coarse particle separation zone, a fine particle separation zone, and a concentration and dewatering zone. Its structure includes a feeding device, an upper coil, a lower coil, an inner column, a flushing device, and a concentration cone. The feeding device is located at the top of the equipment and includes an upper feeding device and a lower feeding device. The upper feeding device includes an upper cover, a material equalization pipe, a material equalization cone, a vent pipe, an upper feeding cylinder, an upper cylinder flange, and a feeding pipe. The upper part of the material equalization pipe is directly opposite to the feeding pipe but not connected, and the lower part is seamlessly fixed to the upper part of the material equalization cone. Several coarse outlets are opened in the circumferential direction on the lower side wall of the material equalization pipe. The vent pipe connects the internal space of the material equalization cone with the external space of the upper feeding cylinder. The lower feeding device includes a lower cylinder flange, a support plate, an observation port, a coarse feed pipe, a fine feed pipe, a ore gathering cone, a ore separating cone, a coarse outlet fixing plate, and a coarse outlet adjusting plate. The upper end of the coarse feed pipe is connected to the upper feeding device, and the lower end is horizontally aligned with the lower edge of the second upper coil of the coarse separation zone from top to bottom. Several layers of coarse ore outlets are evenly distributed in the lower circumferential direction, and each layer of outlets is staggered. The upper edge of the coarse ore outlet is aligned with the upper edge of the uppermost coil of the coarse separation zone. The upper end of the fine feed pipe is inserted into the ore gathering cone, and the lower end of the fine feed pipe is provided with a ore gathering cone and a ore separating cone. The gap between the ore gathering cone and the ore separating cone is the fine particle feed outlet. The feeding position is aligned with the first lower coil of the fine separation zone from top to bottom. The coarse feed nozzle fixing plate and the coarse feed nozzle adjusting plate constitute a particle size adjustment device. Both the coarse feed nozzle fixing plate and the coarse feed nozzle adjusting plate have several identical holes. The coarse feed nozzle adjusting plate can rotate freely around the fine feed pipe. By controlling the size of the overlapping area of ​​the coarse feed nozzles, the size of the coarse feed nozzle can be adjusted. The upper part of the coarse feed nozzle fixing plate is provided with a fixing rod. The coarse feed pipe and the fine feed pipe are concentric and are seamlessly connected to the coarse pipe bottom plate as a whole. The spatial position of the coarse feed nozzle fixing plate in the electromagnetic separator is more than 50mm higher than the uppermost edge of the inner column. The inner column has a column structure that is thinner at the top and thicker at the bottom; the upper coil is sleeved outside the coarse particle sorting area of ​​the inner column, and the lower coil is sleeved outside the fine particle sorting area of ​​the inner column. The flushing device has a two-layer water supply structure, corresponding to the coarse particle sorting zone and the fine particle sorting zone respectively; the concentration cone is located at the bottom and constitutes the concentration and dehydration zone. The flushing device includes an upper water distribution cone, an upper water distribution pipe, a lower water distribution cone, a lower water distribution pipe, an upper water inlet, a lower water inlet, an upper water distribution cone fixing plate, a lower water distribution cone baffle, a lower water distribution cone fixing plate, and a lower water outlet pipe; the upper water distribution cone is horizontal with the upper coil at the bottom of the coarse particle separation zone and is located between the coarse particle feed pipe and the inner column; the lower water distribution cone is horizontal with the lower coil at the bottom of the fine particle separation zone and is close to the inner wall of the inner column; the upper water distribution cone is conical at both the top and bottom, and the lower water distribution cone is provided with a lower water distribution cone baffle near the cylinder wall.

2. The electromagnetic separator for producing iron concentrate from coarse-grained iron ore according to claim 1, characterized in that, The inner diameter of the uniform feed pipe is 1.2 to 1.5 times the inner diameter of the feed pipe, and the total cross-sectional area of ​​the coarse feed outlet is 1 / 5 to 1 / 3 of the total cross-sectional area of ​​the feed pipe; the upper cover has ventilation holes.

3. The electromagnetic separator for producing iron concentrate from coarse-grained iron ore according to claim 1, characterized in that, The upper end of the fine-grained feed pipe is more than 200mm higher than the lower edge of the uniform feed cone. Three observation ports are evenly distributed on the outside of the coarse-grained feed pipe, and the lower edge of the observation port is flush with the upper edge of the coarse feed pipe fixing plate.

4. The electromagnetic separator for producing iron concentrate from coarse-grained iron ore according to claim 1, characterized in that, The outer edge of the adjusting plate is provided with a handle, and the handle is positioned directly opposite the observation port.

5. The electromagnetic separator for producing iron concentrate from coarse-grained iron ore according to claim 1, characterized in that, The diameter d1 of the upper column of the inner column is 0.7 to 0.8 times the diameter d2 of the lower column, and the height H3 of the upper column is 1 / 10 of the height H1 of the lower column.

6. The electromagnetic separator for producing iron concentrate from coarse-grained iron ore according to claim 1, characterized in that, The coarse particle sorting zone and the fine particle sorting zone each occupy half of the inner column sorting zone; the center distance between adjacent coils is (0.15~0.25)*d2, wherein the center distance between coils in the coarse particle sorting zone is 0.25*d2, and the center distance between coils in the fine particle sorting zone is 0.15*d2; the cross-sectional dimensions of the upper coil and the lower coil both satisfy a=2b, where a is the coil height and b is the coil width; the number of upper coils is 1.5~2 times the number of lower coils, and the number of turns of the upper coil is 1 / 3~1 / 2 of the number of turns of the lower coil.

7. The electromagnetic separator for producing iron concentrate from coarse-grained iron ore according to claim 1, characterized in that, The height of the concentration cone is 0.5 times the height of the inner column sorting zone.

8. The electromagnetic concentrator for producing iron concentrate from coarse-grained iron ore according to claim 1, characterized in that, The coarse feed outlet at the lower end of the uniform feed pipe is evenly distributed along the circumference; the ore separating cone is used to achieve uniform feeding of ore around the circumference in the sorting space; and the ore gathering cone is used to isolate the water outlet position to prevent the loss of fine ore particles.

9. The method of using the electromagnetic concentrator for producing iron concentrate from coarse-grained iron ore according to any one of claims 1-8, characterized in that, Includes the following steps: S1. Pulp Classification and Zonal Feeding: The slurry is classified into coarse and fine particles through the feeding device: part of the coarse particles settle through the coarse outlet of the uniform feed pipe, and the other part of the slurry overflows to the uniform feed cone; After the flow rate of the settled coarse particles is controlled by the coarse particle regulating device, they are discharged into the coarse particle sorting area through the coarse particle feed pipe in layers. Fine particles in the overflow slurry are evenly distributed to the fine particle separation zone through the annular gap at the lower end of the fine particle feed pipe; S2, Zoned Magnetic Field Sorting: Coarse-grained sorting zone processing: This zone has a large number of coils but few turns. Magnetic coarse particles in the coarse-grained sorting zone are affected by the wide-spacing, low-intensity intermittent magnetic field generated by the upper coil. When energized, the magnetic particles agglomerate and sink; when de-energized, the magnetic particles disperse. The water flow from the flushing device washes away gangue and lean intergrowth into the tailings. The coarse-grained feed point is located at the top of the sorting zone, making it easy for them to be washed into the tailings. The coarse-grained concentrate becomes the final concentrate after joint sorting in the coarse-grained and fine-grained sorting zones. The long sorting time and long water flow flushing time for coarse-grained minerals increase the probability of coarse-grained gangue and intergrowth becoming tailings, which is beneficial to improving the grade of coarse-grained concentrate. Fine particle separation zone processing: This zone has fewer coils but more turns. Fine particles are subjected to a narrow-spacing, high-intensity intermittent magnetic field generated by the lower coil in the fine particle separation zone, achieving fine dispersion-agglomeration separation. The fine particle feed point is located in the middle of the separation zone, between the coarse particle separation zone and the fine particle separation zone. Fine particle concentrate only needs to be separated in the fine particle separation zone to become concentrate. However, fine particle tailings still need to be scavenged and recovered by the magnetic field of the coarse particle separation zone to solve the problem that fine particle magnetic materials are easily lost to the tailings. This achieves both fine particle concentrate and tailings separation. S3, Independent water flow control: In the coarse particle sorting zone, water is distributed radially by an upper water distribution cone, and the water flows from bottom to top to wash the particles. In the fine-particle sorting zone, water is distributed centripetally and directionally by a baffled lower water distribution cone to achieve uniform dispersion of magnetic minerals and prevent particles from agglomerating towards the cylinder wall. S4. Tailings and concentrate separation: After passing through the rapid tailings discharge zone, the scoured gangue is discharged through the overflow trough; After sorting, the concentrate is concentrated in the concentration and dehydration zone, and after reaching a certain concentration, it is continuously discharged through the concentrate valve.

10. The method of using the electromagnetic concentrator for producing iron concentrate from coarse-grained iron ore according to claim 9, characterized in that, The coarse and fine particle feeding ratio is dynamically controlled by changing the overlap of the openings by rotating the coarse and fine particle adjusting plate. The total cross-sectional area of ​​the coarse and fine particle outlet of the uniform feed pipe is 1 / 5 to 1 / 3 of the total cross-sectional area of ​​the feed pipe, so as to realize the natural sedimentation and classification of coarse particles.

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