Efficient dry-type mineral separation system for magnetic ores and process method of efficient dry-type mineral separation system

Abstract

The invention provides a high-efficiency dry-type mineral separation system for magnetic ores and a process method of the high-efficiency dry-type mineral separation system. The mineral separation system comprises a dry grinding pre-separation process and a dry type fine separation process, in the dry grinding pre-separation process, materials obtained after ore grinding are fed into a magnetic separation pre-separation device through a first-section crushing and grinding device, three kinds of materials with different magnetisms are separated out and comprise rough concentrate, rough middling and rough tailings, the rough tailings are thrown away, and the rough middling and the rough tailings are separated out; rough middlings are returned to the first-section crushing and grinding device to continue grinding, rough concentrate is fed into a second magnetic separation and concentration device, finished iron powder and middlings are magnetically screened out through the second magnetic separation and concentration device, and the middlings enter the dry type concentration technological process. And the middlings are subjected to second-stage ore grinding, the materials obtained after ore grinding are fed into a second magnetic separation and concentration device, three kinds of materials with different magnetisms are separated out, and the three kinds of materials are 6 finished product iron powder, fine middlings and fine tailings correspondingly, and the fine middlings are returned to the second-stage crushing and grinding device for continuous ore grinding. According to the efficient dry-type mineral separation system for the magnetic ores and the process method of the efficient dry-type mineral separation system, the ores are rapidly crushed, and therefore magnetic separation mineral separation is conducted while the large granularity of the ores is guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of magnetic mineral beneficiation, and more particularly, to a high-efficiency dry magnetic mineral beneficiation system and its process method. Background Art

[0002] China is rich in mineral resources, but there are many lean ores and few rich ores. The dissemination size of magnetic minerals is extremely uneven, ranging from a few microns to a few millimeters, and the same problem exists in the same ore body of the same mine, which brings great difficulties to the beneficiation operation. In order to achieve the process requirements for the liberation of magnetic minerals, the current beneficiation process inevitably uses the minimum dissemination size as the standard for grinding, resulting in over-grinding of some minerals. Since most minerals are difficult to beneficiate and have a low grade, and multiple particle size classifications, grindings, and magnetic separations are required, the beneficiation process flow of general beneficiation plants is long and cumbersome, with high one-time investment and maintenance costs. Moreover, there are many unreasonable aspects in the traditional process, resulting in too high beneficiation costs. The high-grade concentrates obtained by dry magnetic separation in the existing magnetic ore separation systems are all powdered finished ore products. The obtained finished product has a fine particle size, and the beneficiation energy consumption is also relatively large. In actual external sales, the competitiveness of the finished product is relatively weak.

[0003] In addition, with the improvement of the national environmental protection system, the traditional beneficiation process relying on water as the medium faces many problems, such as insufficient tailings reservoir capacity, tailings reservoir safety management, water resource depletion, groundwater pollution, etc. Therefore, there is an urgent need to fundamentally improve the traditional wet process system to obtain a new type of all-dry high-efficiency dry magnetic mineral beneficiation system that can not only meet the technical index requirements but also improve the grinding and separation efficiency, simplify the process, reduce the management difficulty, reduce the investment capital, and reduce the production cost. Summary of the Invention

[0004] In view of this, the present invention provides a high-efficiency dry magnetic mineral beneficiation system and its process method, aiming to provide a high-efficiency dry magnetic mineral beneficiation system and its process method that can quickly crush ore and perform magnetic separation beneficiation while ensuring a relatively large particle size of the ore.

[0005] A high-efficiency dry magnetic mineral beneficiation system and its process method include the following processes:

[0006] Preferably, in step one: the iron ore raw material is input into a primary crushing and grinding device, and the crushed iron ore raw material is fed into a magnetic pre-selection device.

[0007] Preferably, in step two: the magnetic pre-selection device separates the iron ore raw material into rough concentrates, rough middlings, and rough tailings according to the magnetic strength generated by the magnetic ore after crushing.

[0008] Preferably, step three: the rough middlings are conveyed back to the first-stage crushing and grinding device to continue crushing the ore. The crushed rough middlings are fed into the magnetic pre-selection device to separate out rough concentrates, rough middlings, and rough tailings. The obtained rough middlings repeat this step.

[0009] Preferably, step four: the rough concentrates are fed into the first magnetic separation and concentration device. The first magnetic separation and concentration device screens out finished iron ore particles with a content of more than 60% and middlings with a content of less than 60% according to the magnetic strength.

[0010] Preferably, the above steps are the dry grinding and pre-selection process steps.

[0011] Preferably, step five: the middlings are input into the second-stage crushing and grinding device. The crushed middlings are fed into the second magnetic separation and concentration device.

[0012] Preferably, step six: the second magnetic separation and concentration device separates the middlings into finished iron ore particles with a content of more than 60%, fine middlings with a content of less than 60%, and fine tailings according to the magnetic strength generated by the magnetic ore after the middlings are crushed.

[0013] Preferably, step seven: the fine middlings are input back into the second-stage crushing and grinding device to continue crushing. The crushed fine middlings are fed into the second magnetic separation and concentration device to separate out finished iron ore particles, fine middlings, and fine tailings. The obtained fine middlings repeat this step.

[0014] Preferably, the above steps are the dry grinding and concentration process steps.

[0015] Preferably, in the dry grinding and pre-selection process, when the product yield of the finished iron ore particles with a content of more than 60% is lower than the set yield threshold of the system, the rough concentrates are not fed into the second magnetic separation and concentration device to produce middlings, and the rough concentrates are directly fed into the second-stage crushing and grinding device of the dry grinding and concentration process steps.

[0016] Preferably, the thickness of the ore crushed by the first-stage crushing and grinding device for the iron ore raw material and the rough middlings generated therefrom is 0 - 10 mm.

[0017] Preferably, the thickness of the ore crushed by the second-stage crushing and grinding device for the middlings and the fine middlings generated therefrom is 0 - 1 mm.

[0018] Preferably, the crushing structures in the first-stage crushing and grinding device (1) and the second-stage crushing and grinding device (4) are the same.

[0019] Preferably, the crushing structure includes an internal crushing component, an external slag collection component, and a driving component.

[0020] Preferably, the internal crushing component includes an inner barrel and grinding columns.

[0021] Preferably, the inner barrel is arranged at the driving end of the driving component. The inner barrel rotates through the driving component. A number of grinding columns are arranged on the inner wall of the inner barrel, and the distance between adjacent grinding columns is less than 10 mm.

[0022] Preferably, the surface of the grinding column is a rough structure.

[0023] Preferably, the external slag collecting assembly includes an outer barrel, sieve holes, and a blowing assembly.

[0024] Preferably, the outer barrel is coaxially sleeved outside the inner barrel, and there is a gap space between the outer barrel and the inner barrel, which is the slag collecting space. The outer barrel and the inner barrel are connected by ribs.

[0025] Preferably, a number of sieve holes penetrate through the wall of the inner barrel, and at least one sieve hole is located between adjacent grinding columns. The sieve holes communicate the inside of the inner barrel with the slag collecting space.

[0026] Preferably, a blowing assembly is arranged in the slag collecting space, and the blowing direction of the blowing assembly is along the length direction of the outer barrel.

[0027] Preferably, the magnetic separation structures in the magnetic separation preselection device, the first magnetic separation concentration device, and the second magnetic separation concentration device are the same.

[0028] Preferably, the magnetic separation structure includes a feeding port, a first permanent magnetic drum, a material box, a scraper, a second permanent magnetic drum, and a supporting box body.

[0029] Preferably, the feeding port is arranged above the first permanent magnetic drum. The first permanent magnetic drum is connected to a rotating assembly. A material box for containing coarse tailings or fine tailings is arranged on one side of the rotating direction of the first permanent magnetic drum. A scraper is arranged on one side below the first permanent magnetic drum, and one end of the scraper is in sliding contact with the surface of the first permanent magnetic drum.

[0030] Preferably, a second permanent magnetic drum is arranged below the contact end of the first permanent magnetic drum and the scraper. A material box for containing coarse middlings or middlings or fine middlings is arranged on one side of the rotating direction of the second permanent magnetic drum.

[0031] Preferably, a scraper is also arranged on one side below the second permanent magnetic drum, and one end of the scraper is in sliding contact with the surface of the second permanent magnetic drum. A material box for containing coarse concentrate or iron ore particles is arranged below the contact end.

[0032] Preferably, the feeding port, the first permanent magnetic drum, the material box, the scraper, and the second permanent magnetic drum are all arranged on the supporting box body.

[0033] The technical solution of the present application has at least the following advantages and beneficial effects:

[0034] The present invention uses a magnetic classification dry separator in combination with a dry grinding mill. The materials are classified not according to the conventional process particle size but according to the magnetism of the materials, eliminating the particle size screening and classification process, simplifying the ore dressing process flow, reducing the types and quantities of equipment in the process, and reducing the manual maintenance cost of the entire ore dressing plant.

[0035] The magnetic classification technology provided by the present invention classifies minerals according to their magnetism. Compared with conventional particle size screening and classification, the particle sizes of its products (concentrate, middlings, and tailings) become larger and coarser. In this technical solution, the dry mill only selectively grinds the materials that need to be ground, rather than grinding all of them. As long as the required grade is achieved, the materials directly enter the concentrate, tailings, or middlings products regardless of their particle sizes, reducing the useless work of the mill and greatly lowering its grinding cost. Generally speaking, it is "selective grinding", reducing the phenomenon of over-grinding.

[0036] The present invention uses the direct discharge of the dry mill into a magnetic classification dry separator for waste rejection and magnetic classification. The same equipment simultaneously completes the two functions of waste rejection and classification. Only the intermediate magnetic products are returned to the mill for continuous grinding. The process is extremely short, and the mill directly faces the dry separator, which can achieve the purpose of timely grinding and timely waste rejection. There will be no situation where the mill grinds a large amount of waste rock, and the phenomenon of over-grinding of materials is also reduced, lowering its ore dressing cost.

[0037] The ore dressing system proposed by the present invention realizes all-dry magnetic ore dressing, saving water resources. Moreover, the particle size of its tailings product becomes coarser, and the products in powder form are greatly reduced, with less dust emission. The tailings are easy to handle and can be used for mine backfilling without the situation of soil subsidence, meeting the current environmental protection requirements.

[0038] The present invention sets up a stacking magnetic separation process to magnetically separate the crushed ore into two or more types of ore, including slightly magnetic ore, weakly magnetic ore, and strongly magnetic ore (i.e., concentrate, middlings, and tailings), thus more conveniently crushing different magnetic ores. By changing the magnetic property through the crushing size, it avoids excessive ore accumulation in the same process step and reduces the ore dressing efficiency. Brief Description of the Drawings

[0039] By reading the detailed description of the preferred embodiments below, various other advantages and benefits will become clear to those of ordinary skill in the art. The drawings are only for the purpose of showing the preferred embodiments and are not considered to be a limitation of the present invention. In the drawings:

[0040] Figure 1 is the flow chart of the ore dressing system provided by the embodiment of the present invention Figure 1 ;

[0041] Figure 2 is the flow chart of the ore dressing system provided by the embodiment of the present invention Figure 2 ;

[0042] Figure 3 is the structural schematic diagram of the crushing structure provided by the embodiment of the present invention;

[0043] Figure 4 is the sectional structural schematic diagram of the crushing structure provided by the embodiment of the present invention;

[0044] Figure 5 A schematic cross-sectional view of another angle of the crushing structure provided by the embodiment of the present invention;

[0045] Figure 6 A schematic structural view of the magnetic separation structure provided by the embodiment of the present invention;

[0046] Figure 7 A schematic cross-sectional view of a vertical roller mill provided by the prior art.

[0047] Schematic diagram: 1 - primary crushing and grinding device, 101 - outer barrel, 102 - inner barrel, 103 - grinding column, 104 - sieve holes, 105 - blowing assembly, 106 - support seat, 107 - gear ring, 108 - gear, 109 - motor, 11 - grinding roller, 12 - grinding disc, 13 - transmission arm, 2 - magnetic separation preselection device, 201 - feeding port, 202 - first permanent magnetic drum, 203 - feed box, 204 - scraper, 205 - second permanent magnetic drum, 206 - support box body, 207 - high-pressure air pipe, 3 - first magnetic separation concentration device, 4 - secondary crushing and grinding device, 5 - second magnetic separation concentration device, 6 - iron ore raw material, 601 - coarse tailings, 602 - coarse concentrate, 603 - coarse middlings, 604 - middlings, 605 - iron ore particles, 606 - fine tailings, 607 - fine middlings. Specific embodiments

[0048] Hereinafter, exemplary embodiments of the present disclosure will be described in more detail with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided so that the present disclosure can be more thoroughly understood and the scope of the present disclosure can be completely conveyed to those skilled in the art. It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other. Hereinafter, the present invention will be described in detail with reference to the drawings and in conjunction with the embodiments.

[0049] Method embodiments:

[0050] Please refer to Figure 1 - Figure 2 The present invention provides a high-efficiency dry beneficiation system for magnetic ore and its process method.

[0051] The dry grinding and preselection process steps are as follows;

[0052] Step 1: The iron ore material first passes through the primary crushing and grinding device 1 to crush the iron ore raw material 6 with different particle sizes, generating iron ore raw material 6 fragments with different diameters. The magnetic ore content inside the iron ore raw material 6 with different diameters is different, and the generated magnetism is also different.

[0053] Among them, the thickness of the ore preliminarily crushed by the first-stage crushing and grinding device 1 of the iron ore raw material 6 is 0-10 mm, which are ore particles with relatively large particle sizes. The iron ore raw material 6 with large particle sizes is directly subjected to classification magnetic separation after discharging from the first-stage crushing and grinding device 1, and the large non-magnetic waste rocks are promptly discarded, reducing the grinding power consumption of the waste rocks and the work done by the mill.

[0054] Step 2: Feed the ground iron ore raw material 6 into the magnetic separation pre-selection device 2, and screen the iron ore raw material 6 according to the magnetic properties of the material itself, so as to screen the iron ore raw material 6 into three different magnetic ore materials, namely, rough concentrate 602, rough middlings 603, and rough tailings 601.

[0055] Step 3: Among them, the particle sizes of the three ore materials are relatively large. The rough tailings 601 have weak magnetism and cannot be used continuously, so they are discarded; the rough middlings 603 have low magnetism and are returned to the first-stage crushing and grinding device 1 to continue the crushing work, further reducing their particle sizes and changing their magnetism. The rough concentrate 602 has strong magnetism and is fed into the magnetic separation and cleaning device two 3 for magnetic separation.

[0056] Among them, the thickness of the ore returned from the rough middlings 603 to the first-stage crushing and grinding device 1 for crushing is also 0-10 mm.

[0057] Among them, the rough tailings 601 have weak magnetism and a very low content of magnetic minerals inside, making it difficult to be separated by magnetic separation. They belong to waste materials and need to be transported outside the system after being screened out; while the rough concentrate 602 is the iron ore raw material 6 that meets the magnetic requirements and can be further screened; the rough middlings 603 have low magnetism and do not meet the magnetic detection standards temporarily. They need to be returned to the first-stage crushing and grinding device 1 to continue crushing, so that the rough middlings 603 are crushed into smaller particle sizes, reducing the weight and increasing the magnetism, so that they can be attracted by magnetism and continue to be screened, and thus are magnetically separated into rough concentrate 602 subsequently.

[0058] It should be noted that when the ore is subjected to magnetic separation, the magnetic separation and cleaning devices all use the magnetic attraction force of the magnetic force on the ore to resist the gravity of the ore itself, so as to magnetically separate and adsorb the ore to achieve magnetic separation; therefore, even if the particle sizes of the magnetically separated ore are different, the magnetic separation process requires the magnetic force of the ore itself to be greater than the gravity (that is, the proportion of the weight of the magnetic minerals in the weight of the ore itself). Therefore, the magnetic separation classification of the ore is only related to the content of magnetic minerals in the ore and has nothing to do with the ore particle size.

[0059] Step 4: The rough concentrate 602 is fed into the first magnetic separation and beneficiation device 3. The first magnetic separation and beneficiation device 3 screens the rough concentrate 602 into two products through magnetism, namely, the finished iron ore particles 605 with a content above 60% and the middlings 604 with a content below 60%. Among them, the iron content in the finished iron ore particles 605 with a content above 60% has reached the salable standard, so they are stockpiled, while the middlings 604 with a content below 60% still do not meet the standard, so they enter the next stage of the dry beneficiation process flow.

[0060] Preferably, by setting the first magnetic separation and beneficiation device 3 in the dry pre-selection process flow, the high-content finished iron ore particles 605 that have met the sales requirements in the pre-selection process can be directly magnetically separated, reducing the beneficiation steps. Moreover, by magnetically separating the finished iron ore particles 605 in advance, excessive waste rock can be reduced from entering the dry beneficiation process, reducing the magnetic separation amount of the second-stage ore crushing, reducing the ore screening pressure in the subsequent dry beneficiation process flow, and avoiding the situation of ore particle backlog in some processes, thereby improving the screening efficiency of the entire beneficiation system and reducing the beneficiation cost.

[0061] Please refer to Figure 2 , in the actual beneficiation process, because the specific iron content of the ore raw materials input into the system cannot be determined, if the product yield of the finished iron ore particles 605 with a content above 60% in the ore particles of the rough concentrate 602 is too low, the rough concentrate 602 is directly fed into the second-stage crushing and grinding device 4 in the dry beneficiation process flow. At this time, the rough concentrate 602 is equivalent to the middlings 604.

[0062] The steps of the dry grinding and beneficiation process are as follows;

[0063] Step 5: The middlings 604 or the rough concentrate 602 output from the dry grinding pre-selection process enters the second-stage crushing and grinding device 4 for more detailed crushing of the middlings 604 or the rough concentrate 602 with different particle sizes.

[0064] Preferably, the working principle of the second-stage crushing and grinding device 4 here is still the same as that of the first-stage crushing and grinding device 1, crushing the ore particles and increasing the magnetism.

[0065] The thickness of the ore crushed by the second-stage crushing and grinding device 4 for the middlings 604 or the rough concentrate 602 here is 0 - 1 mm. In the steps of the dry grinding and beneficiation process, the second-stage crushing and grinding device does not grind the ore into powder, but semi-grinds it into a form with powder and particles. Therefore, the particle size range of the generated middlings 604 or the rough concentrate 602 is larger and coarser, reducing the useless work of the mill.

[0066] Step 6: Feed the middlings 604 or rough concentrate 602 after grinding into the second magnetic separation and concentration device 5. The second magnetic separation and concentration device 5 further separates three different magnetism ore materials according to the magnetic size, namely finished iron ore particles 605 with a content above 60%, fine middlings 607, and fine tailings 606.

[0067] Step 7: Among them, the fine tailings 606 are discarded, the fine middlings 607 are returned to the secondary crushing and grinding device 4 for further crushing, and the finished iron ore particles 605 with a content above 60% are stockpiled for sale.

[0068] Preferably, the fine tailings 606 are ore waste materials with extremely low magnetism separated from the middlings 604 or rough concentrate 602 during the grinding process. After screening them out, they are transported outside the system; the second magnetic separation and concentration device 5 will magnetically screen out the finished iron ore particles 605 with a content above 60% for direct sale; and those with a content below 60% are fine middlings 607. Since the iron content still does not meet the standard and cannot be used for sale, they need to be input into the secondary crushing and grinding device 4 again for further crushing until they are magnetically screened by the second magnetic separation and concentration device 5 into finished iron ore particles 605 with a content above 60%.

[0069] Among them, the thickness of the ore crushed by the secondary crushing and grinding device 4 for the fine middlings 604 is 0 - 1 mm.

[0070] In this embodiment, a high-efficiency dry beneficiation system for magnetic ore is provided with a primary crushing and grinding device 11 and a secondary crushing and grinding device 44, and the crushing structures in the primary crushing and grinding device 11 and the secondary crushing and grinding device 44 are the same.

[0071] It should be noted that the crushing structure can also be set as an existing vertical roller mill or dry ball mill; however, in order to more conveniently control the thickness of the magnetic ore crushing and avoid excessive powdered finished ore during the crushing process of the magnetic ore, a new type of crushing structure is adopted in this embodiment.

[0072] Please refer to Figure 7 , in the prior art, the vertical roller mill includes a grinding roll 11, a grinding disc 12, and a transmission arm 13; the grinding disc 12 is arranged at the upper end of the grinding disc 12, and the grinding disc 12 is rotated by a driving component. The rotation of the grinding disc 12 drives the grinding roll 11 to rotate passively along their respective centers. The grinding disc 12 is a concave grinding disc, and the grinding roll 11 is a tire type, and at least 2 are evenly arranged along the circumference of the grinding disc.

[0073] When the magnetic ore material falls from the top feed port to the center position of the grinding disc 12, the grinding disc 12 rotates, driving the material to spread from the center position of the grinding disc 12 to the surrounding, and then a stable material layer is formed on the surface of the grinding disc 12; the grinding roll 11 is connected to the transmission arm 13, and the transmission arm 13 drives the grinding roll 11 to press on the material layer above the grinding disc 12, applying an adjustable pressure to the material layer; so that the magnetic materials on the material layer are squeezed, crushed, and ground into different particle sizes.

[0074] As the material continuously enters the grinding disc 12, a phenomenon of material squeezing material and material grinding material is formed, and it can fall from the peripheral edge of the grinding disc 12 into the sand discharge port and be discharged.

[0075] Please refer to Figure 3 - Figure 5 , in this embodiment, the novel crushing structure includes an internal crushing component, an external slag collection component, and a driving component. The internal crushing component crushes the ore, the external slag collection component collects the stone residues and powders generated after crushing, and the driving component drives the internal crushing component to perform the crushing work.

[0076] Furthermore, the internal crushing component includes an inner barrel 102 and grinding columns 103; the driving component includes a support seat 106, a toothed ring 107, a gear 108, and a motor 109.

[0077] Specifically, both ends of the inner barrel 102 are rotatably arranged on the support seat 106. The two ends of the inner barrel 102 are respectively provided with a feed port and a discharge port. A toothed ring 107 is fixedly arranged along the outer edge of one end of the inner barrel 102. The toothed ring 107 is meshed and connected with the gear 108. The gear 108 is coaxially fixed on the driving shaft of the motor 109, and the motor 109 is fixed on the support seat 106. When the motor 109 is started, it will drive the inner barrel 102 to rotate.

[0078] A number of grinding columns 103 are arranged on the inner wall of the inner barrel 102. When the ore raw material is conveyed into the inner barrel, the inner barrel 102 rotates, and a number of grinding columns 103 inside it will collide with the surface of the ore raw material. The small-area columnar collision ends of the grinding columns 103 will perform a number of small-area collisions on the ore surface, causing the ore raw material to quickly break and separating the ore raw material into ore raw material particles of different diameters. The ore raw material particles of different diameters have different magnetisms due to the different contents of magnetic ores inside them, thus facilitating the magnetic separation process.

[0079] The surface of the grinding column 103 is a rough structure, and the distance between adjacent grinding columns 103 is less than 10 mm. Some magnetic ores may be mixed in the small stone blocks crushed by the grinding columns 103. Therefore, these small stone blocks will fall between adjacent grinding columns 103 and continue to be ground between the grinding columns 103, slowly grinding off the stones and exposing the magnetic ores in the small stone blocks, and continuing the subsequent magnetic separation, thereby increasing the qualified finished product quantity after ore dressing.

[0080] Furthermore, the external slag collection component includes an outer barrel 101, sieve holes 104, and a blowing component 105.

[0081] Specifically, the outer barrel 101 is coaxially sleeved outside the inner barrel 102. There is a gap space between the outer barrel 101 and the inner barrel 102, which is the slag collection space. The outer barrel 101 and the inner barrel 102 are connected by reinforcing ribs. A number of sieve holes 104 penetrate through the wall of the inner barrel 102, and at least one sieve hole 104 is located between adjacent grinding columns 103. The sieve holes 104 communicate the inside of the inner barrel 102 with the slag collection space.

[0082] When the inner barrel performs the crushing work, the fine stones generated after crushing will leak to the sieve holes 104 and enter the slag collection space, while the larger stones will be polished between the grinding columns 103, and the powdered stones after polishing will also be screened out by the sieve holes 104.

[0083] A blowing component 105 is fixedly arranged in the slag collection space. The blowing direction of the blowing component 105 is along the length direction of the outer barrel 101. The blowing component 105 is set as a fan and its driving part, and the driving part drives the fan to rotate and blow.

[0084] Please refer to Figure 6 , in this embodiment, a high-efficiency dry magnetic separation system for magnetic ore is provided with a magnetic pre-selection device 2, a first magnetic separation and concentration device 3, and a second magnetic separation and concentration device 5. The magnetic separation structures in the magnetic pre-selection device 2, the first magnetic separation and concentration device 3, and the second magnetic separation and concentration device 5 are the same.

[0085] The magnetic separation structure includes a feeding port 201, a first permanent magnet drum 202, a material box 203, a scraper 204, a second permanent magnet drum 205, a support box body 206, and a high-pressure air pipe 207.

[0086] The feeding port 201 is fixed on the top of the support box body 206 and is arranged above the first permanent magnet drum 202. The first permanent magnet drum 202 is connected to a rotating component, and the rotating component is fixed on the support box body 206 to drive the first permanent magnet drum 202 to rotate clockwise.

[0087] A material box 203 for containing coarse tailings 601 or fine tailings 606 is correspondingly arranged right below the first permanent magnet drum 202. The material box 203 is fixed on the support box body 206. When the ore is fed from the feeding port 201 onto the surface of the first permanent magnet drum 202, the magnetic ore will be adsorbed, while the waste materials with extremely low magnetism will be sent into the corresponding material box 203 right below by the first permanent magnet drum 202 rotating clockwise for collection.

[0088] A scraper 204 is provided at the lower left of the first permanent magnetic drum 202. The scraper 204 is fixed on the support box body 206. The scraping end of the scraper 204 is in sliding contact with the surface of the first permanent magnetic drum 202. Below the contact position between the first permanent magnetic drum 202 and the scraping end of the scraper 204, a second permanent magnetic drum 205 is provided. The first permanent magnetic drum 202 is connected to a corresponding rotating assembly. The rotating assembly is fixed on the support box body 206 and drives the second permanent magnetic drum 205 to rotate clockwise. A feed box 203 for containing coarse medium ore 603 or medium ore 604 or fine medium ore 607 is correspondingly provided at the lower right of the second permanent magnetic drum 205. The feed box 203 is fixed on the support box body 206.

[0089] The ore magnetically adsorbed by the first permanent magnetic drum 202 will be scraped off by the scraper 204 and fall onto the surface of the right side of the second permanent magnetic drum 205. The magnetic attraction of the second permanent magnetic drum 205 is weaker than that of the first permanent magnetic drum 202, so that some ores with lower magnetism cannot be adsorbed by the second permanent magnetic drum 205 and are thus collected into the corresponding feed box 203 at the lower right of the second permanent magnetic drum 205.

[0090] The ores with stronger magnetism will still be adsorbed by the second permanent magnetic drum 205. A scraper 204 is also fixedly provided at the lower left of the second permanent magnetic drum 205. The scraping end 123 of the scraper 204 is in sliding contact with the surface of the second permanent magnetic drum 205. A feed box 203 for containing rough concentrate 602 or iron ore particles 605 is correspondingly provided at the lower left of the contact end. The scraper 204 here will scrape off the ores with stronger magnetism and fall into the corresponding feed box 203 at the lower left of the second permanent magnetic drum 205.

[0091] The three feed boxes store ores of different qualities respectively, which is convenient for subsequent different crushing or magnetic separation processes.

[0092] Among them, both the first permanent magnetic drum 202 and the second permanent magnetic drum 205 include a non-metallic drum skin and permanent magnetic blocks. The permanent magnetic blocks are coated with a layer of non-metallic drum skin on the outside, so that the magnetic ores are adsorbed on the smooth non-metallic drum skin, which is convenient for being quickly scraped off by the scraper 204.

[0093] In addition, a high-pressure air pipe 207 is fixedly provided inside the support box body 206. The high-pressure air pipe 207 is connected to a high-pressure air blower fixed outside the support box body 206 to suck dust under negative pressure inside the feed box 203, and the negative pressure air direction is tangent to the permanent magnetic drum.

[0094] Since the crushed ore entering the interior of the support box body 206 through the feed inlet 201 is doped with some powder, and some of the powder is difficult to fall into the feed box 203 below the right of the permanent magnetic drum 1 202 due to some ore adsorbed on the permanent magnetic drum 1 202, and thus is scraped off at the contact position between the scraper 204 and the permanent magnetic drum 1 202 and is taken into the corresponding feed box 203 below the right of the permanent magnetic drum 2 205, resulting in the classified ore being doped with powder impurities and affecting the quality. Therefore, the non-magnetic powder at the contact position between the scraper 204 and the permanent magnetic drum 1 202 is sucked away by the negative pressure of the high-pressure air pipe 207 to ensure the quality of the separated different ores.

[0095] The above is the preferred implementation mode of the present invention. Those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention also intends to include these modifications and variations.

Claims

1. An efficient dry magnetic ore dressing system and its process method, characterized in that, It includes the following processes: Step 1: The iron ore raw material (6) is input into a primary grinding device (1), and the crushed iron ore raw material (6) is fed into a magnetic pre-selection device (2); Step 2: The magnetic pre-selection device (2) separates the iron ore raw material (6) into a rough concentrate (602), a rough middling (603), and a rough tailing (601) according to the magnetic strength generated by the magnetic ore after crushing; Step 3: Among them, the rough middling (603) is transported back to the primary grinding device to continue crushing the ore. The crushed rough middling (603) is fed into the magnetic pre-selection device (2) to separate the rough concentrate (602), the rough middling (603), and the rough tailing (601). The obtained rough middling (603) repeats this step; Step 4: Among them, the rough concentrate (602) is fed into the first magnetic cleaning device (3), and the first magnetic cleaning device (3) screens out finished iron ore particles (605) with a content of more than 60% and middlings (604) with a content of less than 60% through magnetic strength; The above steps are the dry grinding pre-selection process steps; Step 5: The middlings (604) are input into the secondary grinding device (4), and the crushed middlings (604) are fed into the second magnetic cleaning device (5); Step 6: The second magnetic cleaning device (5) separates the middlings (604) into finished iron ore particles (605) with a content of more than 60%, fine middlings (607) with a content of less than 60%, and fine tailings (606) according to the magnetic strength generated by the magnetic ore after crushing; Step 7: The fine middlings (607) are input back into the secondary grinding device (4) to continue crushing. The crushed fine middlings (607) are fed into the second magnetic cleaning device (5) to separate the finished iron ore particles (605), the fine middlings (607), and the fine tailings (606). The obtained fine middlings (607) repeat this step; The above steps are the dry grinding cleaning process steps.

2. The high-efficiency dry magnetic ore dressing process method according to claim 1, characterized in that, In the dry grinding pre-selection process, when the product yield of the finished iron ore particles (605) with a content of more than 60% is lower than the yield threshold set by the system, the rough concentrate (602) is not input into the first magnetic cleaning device (3) to produce middlings (604), and the rough concentrate (602) is directly input into the secondary grinding device (4) in the dry grinding cleaning process steps.

3. The high-efficiency dry magnetic ore dressing process method according to claim 1, characterized in that, The thickness of the ore crushed by the primary grinding device (1) for the iron ore raw material (6) and the rough middlings (603) it produces is 0 - 10 mm.

4. The high-efficiency dry magnetic ore dressing process method according to claim 1, characterized in that, The thickness of the ore crushed by the secondary grinding device (4) for the middlings (604) and the fine middlings (607) it produces is 0 - 1 mm.

5. The high-efficiency dry magnetic ore dressing system according to claim 1, wherein, The crushing structures in the primary grinding device (1) and the secondary grinding device (4) are the same; The crushing structure includes an internal crushing component, an external slag collection component, and a driving component.

6. The high-efficiency dry magnetic ore dressing system according to claim 5, wherein, The internal crushing component includes an inner barrel (102) and grinding columns (103); The inner barrel (102) is arranged at the driving end of the driving component. The inner barrel (102) rotates through the driving component. A number of grinding columns (103) are arranged on the inner wall of the inner barrel (102), and the distance between adjacent grinding columns (103) is less than 10 mm; The surface of the grinding column (103) is a rough structure.

7. The high-efficiency dry magnetic ore dressing system according to claim 5, wherein, The external slag collection component includes an outer barrel (101), a sieve hole (104) and a blowing component (105); The outer barrel (101) is coaxially sleeved outside the inner barrel (102). There is a gap space between the outer barrel (101) and the inner barrel (102), which is the slag collection space. The outer barrel (101) and the inner barrel (102) are connected by ribs. A number of sieve holes (104) penetrate through the wall of the inner barrel (102). At least one sieve hole (104) is located between adjacent grinding columns (103). The sieve holes (104) communicate the inside of the inner barrel (102) with the slag collection space. A blowing component (105) is arranged in the slag collection space. The blowing direction of the blowing component (105) is along the length direction of the outer barrel (101).

8. The high-efficiency dry magnetic ore dressing system according to claim 1, wherein, The magnetic separation structures in the magnetic separation preselection device (2), the first magnetic separation concentration device (3) and the second magnetic separation concentration device (5) are the same. The magnetic separation structure includes a feeding port (201), a first permanent magnet drum (202), a feed box (203), a scraper (204), a second permanent magnet drum (205), and a support box body (206). The feeding port (201) is arranged above the first permanent magnet drum (202). The first permanent magnet drum (202) is connected to a rotating component. A feed box (203) for containing coarse tailings (601) or fine tailings (606) is arranged on one side of the rotating direction of the first permanent magnet drum (202). A scraper (204) is arranged on the lower side of the first permanent magnet drum (202). One end of the scraper (204) is in sliding contact with the surface of the first permanent magnet drum (202). A second permanent magnet drum (205) is arranged below the contact end of the first permanent magnet drum (202) and the scraper (204). A feed box (203) for containing coarse middlings (603) or middlings (604) or fine middlings (607) is arranged on one side of the rotating direction of the second permanent magnet drum (205). A scraper (204) is also arranged on the lower side of the second permanent magnet drum (205). One end of the scraper (204) is in sliding contact with the surface of the second permanent magnet drum (205). A feed box (203) for containing coarse concentrate (602) or iron ore particles (605) is arranged below the contact end. The feeding port (201), the first permanent magnet drum (202), the feed box (203), the scraper (204), and the second permanent magnet drum (205) are all arranged on the support box body (206).

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